# A n a l y s i s o f V e n t i l a t i o n D a t a f r o m t h e U

. S

. E n v i r o n m e n t a l P r o t e c t i o n A g e n c y B u i l d i n g A s s e s s m e n t S u r v e y a n d E v a l u a t i o n ( B A S E ) S t u d y

A n d r e w P e r s i l y J o s h G o r f a i n 

# N I S T I R 7 1 4 5

- R E V I S E D

# N I S T I R 7 1 4 5

- R E V I S E D

N o v e m b e r 2 0 0 8 ( r e p l a c e s v e r s i o n p u b l i s h e d i n D e c e m b e r 2 0 0 4 )

U

. S

. D e p a r t m e n t o f C o m m e r c e

C a r l o s M

. G u t i e r r e z , S e c r e t a r y
N a t i o n a l I n s t i t u t e o f S t a n d a r d s a n d T e c h n o l o g y P a t r i c k G a l l a g h e r , A c t i n g D i r e c t o r 

# A n a l y s i s o f V e n t i l a t i o n D a t a f r o m t h e U

. S

. E n v i r o n m e n t a l P r o t e c t i o n A g e n c y B u i l d i n g A s s e s s m e n t S u r v e y a n d E v a l u a t i o n ( B A S E ) S t u d y

A n d r e w P e r s i l y B u i l d i n g a n d F i r e R e s e a r c h L a b o r a t o r y J o s h G o r f a i n B u i l d i n g a n d F i r e R e s e a r c h L a b o r a t o r y

P r e p a r e d f o r : U

. S

. E n v i r o n m e n t a l P r o t e c t i o n A g e n c y W a s h i n g t o n , D C

### ii

### iii ABSTRACT The U.S. Environmental Protection Agency (EPA) Building Assessment Survey and Evaluation (BASE) study included a range of measurements in 100 randomly selected U.S. office b uildings for the purpose of characterizing the existing building stock with respect to determinants of indoor air quality and occupant perceptions of indoor environments. One aspect of the evaluation was the characterization of the ventilation sy stems serv ing the study spaces and selected measurements of ventilation performance. This report presents an analy sis of these data with a focus on supply and outdoor airflows, including comparisons of the measured data with design values and the outdoor air require ments in ASHRAE Standard 62

- 2001. The results indicate that, as expected based on thermal load considerations, the average value of the design and measured supply airflow are both about 5 L/s• m 2 

### (1 cfm/ft 2 

### ). The measured outdoor air ventilation is higher t han might be expected, with a mean value of 49 L/s (105 cfm) per person based on volumetric airflow measurements at the air handlers and measured occupant densities. These outdoor air ventilation values are high on average relative to the minimum outdoor a ir requirements in Standard 62 due to the high outdoor air fractions (relative to minimum) and the actual occupancy being on average 80 % of the design occupancy . Nevertheless, about 17 % of the ventilation measurements are still below the 10 L/s (20 cfm) per person requirement in Standard 62. Under conditions of minimum outdoor air intake and accounting for the lower
occupancy levels, the mean ventilation rate is roughly 11 L/s (22 cfm) per person and about one

half of the values are below the per person r equirement in Standard 62. In addition, this report contains a number of suggested modifications to the protocol used in these assessments for consideration in future studies.

This report is a revision of the original report on these data published in 200 4. This revision reflects some additional analy ses of the data, which results in some changes to the numerical values reported, but not to the overall conclusions. The additional analy ses are discussed in Appendix F of this report, which was published as a NIST Letter Report in October 2008. All values in this revised report that have changed relative to the original report are noted in bold font. Those tables and figures have been updated are also noted in bold font in the lists of tables and figures page vii and viii respectively

.

Key words: carbon dioxide, design, measurement, mechanical ventilation, office buildings, ventilation

### iv

### v TABLE OF CONTENTS

Abstract iii

List of Tables vi List of Figures vii

1. INTRODUCTION AND BACKGROUND 1 1.1 EPA BASE Study 1

1.2 Objectives of Ventilation Analy sis 3

2. METHODOLOGY 3 2.1 Buildings, Study Spaces and Air Handling Sy stems 3
2.2 Measured Data 4 2.3 Timing of Building Evaluations 6

3. RESULTS 8 3.1 Building and Study Space Information 8 3.2 Ventilation Sy stem Design Parameters 9 3.3 Exhaust Sy stem Design and Building Airflow Balance 16 3.4 Measured Occupant Density 17 3.5 Ventilation Sy stem Performance Measurements 18 3.5.1 Supply Airflow 18
3.5.2 Outdoor Air Fraction 20
3.5.3 Outdoor Air Ventilation 26
3.5.4 Outdoor Airflows from Peak Carbon Dioxide 29 3.5.5 Supply Diffuser Airflows 33
3.5.6 Exhaust Airflows 33

4. DISCUSSION 34 4.1 Summary of Conclusions 34 4.2 Comparison with European Audit Project 35
4.3 Recommendations for Ventilation Assessment Protocols 36

5. AC KNOW LEDGEMENTS 37

6. REFERENCES 38 Appendix A: BASE Variables Used in Analy sis 40 Appendix B: Sy stem Design Information 42 Appendix C: Volumetric Airflow Data Issues 49 Appendix D: Measured Data for Air Handlers 51 Appendix E: Measured Data for Study Space s 72 Appendix F: Reanaly sis of BASE Ventilation Data 93

### viv i i 

### LIST OF TABLES 1. HVAC performance parameters 2 2. Building information 8 3. Study space information 9 4. Ventilation sy stem ty pes 10

5. Outdoor air intake control 10 6. Sy stem design values 11

7. S y stem design outliers 12 8. Outdoor air requirements based on Standard 62 addendum n 13 9. Reported frequencies of selected sy stem maintenance activities 14 10. Summary of exhaust sy stem design values 16 11. Net design airflow analy sis 17 12. Summary of me asured occupant density 17 13. Summary of measured supply airflows 19 14. Summary of measured outdoor air fraction 21 15. Summary of measured outdoor air ventilation

–volumetric 27 16. Summary of measured outdoor air ventilation

–CO 2 

### ratio 28

17. Outdoor air ventilation adjusted for occupancy and outdoor air fraction 29 18. Summary of measured outdoor air ventilation

–Peak CO 2 

### 30 19. Outdoor air ventilation for naturally ventilated spaces 32 20. Summary of measured supply airflows at diffusers 33v i i i 

### LIST OF FIGURES 1. Frequency distribution of measurement based on month 7 2. Frequency distribution of measurement based on outdoor temperature 7 3. Design supply airflow capacity versus y ear built 14 4. Design minimum outdoor air intake versus y ear built 15

5. Design occupant density versus y ear built 15 6. Ratio of measured to design supply airflow versus outdoor temperature 19 7. Measured study space supply airflow versus outdoor temperature 20 8. Volumetric outdoor air fraction versus outdoor temperature 22 9. Outdoor air fraction for an idealized economizer cy cle 22 10. Measured air change rates versus outdoor air temperature (Persily et al. 1992) 23

11. Return minus outdoor air CO 2 

### concentration versus time of day 24

12. Outdoor air fraction based on CO 2 

### ve rsus volumetric 25 13. Ratio of measured to design outdoor airflow versus outdoor temperature 26 14. Outdoor air ventilation, CO 2 

### ratio versus volumetric 28 15. Outdoor air ventilation, CO 2 

### peak versus volumetric 31i x1 

### 1. INTRODUCTION AND BACKGROUND

Build ing ventilation is a primary determinant of indoor air quality (IAQ) in buildings as it impacts indoor contaminant concentrations and occupant comfort. However, relatively few measurements of office building ventilation performance have been conducted, and those data that exist generally have not employ ed consistent measurement methods and have not involved representative collections of buildings. As discussed below, the EPA Building Assessment Survey and Evaluation (BASE) study was conducted to assess IAQ, including ventilation, in a large number of randomly selected office buildings throughout the U.S. using a standardized protocol. Ventilation performance assessment was a key part of the survey , and this report presents an analy sis of the ventilation data collected during the study . The building evaluations were conducted by EPA contractors, and the analy sis presented in this report is based on the ventilation data collected by the contractors.

1.1 EPA BASE Study The EPA BASE study was originally conceived to address the IAQ data gap in public and commercial office buildings. As described in the protocol for the study (EPA 2003), the primary goal of the study was to define the status of the existing building stock with respect to determinants of IAQ and occ upant perceptions. The study was also intended to provide data that would form the basis for future building studies, as well as provide guidance on building design, construction, operation, and maintenance. EPA assembled a steering committee to support th e design, planning, and implementation of the effort in the following areas: study design; building and heating, ventilating, and air conditioning (HVAC) characteristics; human response and questionnaires; environmental measurements; diagnostics and mitiga tion; and program integration. A protocol was then developed that incorporated the three major study areas: comfort and environmental measurements; building and HVAC characterization; and an occupant questionnaire. W hile certain aspects of the entire build ing were characterized, one or more representative sampling spaces (referred to in this report as study spaces ) in each building were more intensively characterized due to cost and time limitations. Ultimately the data from the study will reside in a publi cly accessible database, and it is expected that the data will be used for a number of applications, such as: developing distributions of IAQ, building and HVAC characteristics; developing new hy potheses regarding, for example, the causes of occupant
sy mpt oms; establishing standardized protocols for IAQ studies; examining the relationship of
sy mptoms to building characteristics; and, developing guidance on building design, construction, operation, and maintenance. Buildings included in the sample were not i ntended to be IAQ complaint buildings, although some complaint buildings may have been included. However, buildings that had been highly publicized by the media for their IAQ problems were excluded. The building sampling strategy randomized the sample to t he extent possible, limited by the success in gaining access to buildings. Over the five

- y ear period from 1994 to 1998, 100 buildings were studied as part of the BASE program. Each building was studied for a one

- week period, generally in either the summer or winter, during which the various measurements were conducted. On W ednesday s and Thursday s of that week, HVAC sy stem performance measurements were made at the same time that environmental measurements were made in the occupied space. These HVAC performan ce measurements were generally made at approximately 9:30 a.m. and 2:30 p.m. on each day . The HVAC performance measurements are described briefly in Table 1, which also contains the number of the data form from the BASE protocol.2 P a r a m e t e r M o n i t o r i n g a p p r o a c h F o r m N u m b e r * S u p p l y a n d r e c i r c u l a t i o n

a i r f l o w D u c t t r a v e r s e f o r e a c h a i r h a n d l i n g u n i t ( A H U ) s e r v i n g

s t u d y s p a c e u s i n g p i t o t t u b e o r h o t

- w i r e a n e m o m e t e r

. E

- 1

P e r c e n t o u t d o o r a i r i n t a k e C a l c u l a t i o n f r o m c a r b o n d i o x i d e ( C O 2 ) c o n c e n t r a t i o n

m e a s u r e d i n o u t d o o r a i r a n d t h e s u p p l y a n d r e t u r n a i r o f

e a c h A H U s e r v i n g t h e s t u d y s p a c e

. E

- 1

O u t d o o r a i r i n t a k e F o r e a c h A H U s e r v i n g t h e s t u d y s p a c e , d u c t t r a v e r s e i n t h e o u t d o o r a i r i n t a k e d u c t

. I f n o t p o s s i b l e , e s t i m a t e f r o m d i f f e r e n c e b e t w e e n s u p p l y a n d r e c i r c u l a t i o n a i r f l o w

. E

- 1

S u p p l y a i r t e m p e r a t u r e a n d

r e l a t i v e h u m i d i t y M e a s u r e m e n t i n s u p p l y a i r d u c t f o r e a c h A H U s e r v i n g

s t u d y s p a c e

. E

- 1

E x h a u s t f a n o p e r a t i o n O b s e r v a t i o n b y t e c h n i c i a n m o r n i n g s a n d a f t e r n o o n s o f

m o n i t o r i n g d a y s E

- 3

E x h a u s t f a n a i r f l o w M e a s u r e m e n t o f a i r f l o w r a t e s o f a l l e x h a u s t f a n s s e r v i n g t h e s t u d y s p a c e u s i n g f l o w c a p t u r e h o o d o r d u c t t r a v e r s e ;

m e a s u r e m e n t o f i n d i v i d u a l e x h a u s t g r i l l e s w i t h i n t h e

s t u d y a r e a ; o n e t i m e m e a s u r e m e n t

. E

- 4

L o c a l v e n t i l a t i o n p e r f o r m a n c e

– s u p p l y

a i r f l o w M e a s u r e m e n t o f a i r f l o w f r o m a l l s u p p l y d i f f u s e r s s e r v i n g t h e s t u d y s p a c e ( p r e f e r r e d ) u s i n g f l o w c a p t u r e h o o d ;

m e a s u r e a m i n i m u m o f 5 0 % o f t h e s u p p l y d i f f u s e r s

s e r v i n g t h e s t u d y s p a c e

. E

- 2

O u t d o o r a i r v e n t i l a t i o n r a t e

– c o n t i n u o u s C O 2 E s t i m a t i o n o f v e n t i l a t i o n f r o m c o n t i n u o u s C O 2
c o n c e n t r a t i o n a t t h r e e l o c a t i o n s i n s t u d y s p a c e ; o n l y

m e t h o d u s e d i n n a t u r a l l y v e n t i l a t e d b u i l d i n g s E

- 5

* F o r m n u m b e r f o r d a t a c o l l e c t i o n i n B A S E p r o t o c o l

. 

### Table 1 HV AC performance parameters
The study areas in each building were sele cted based on the following criteria (EPA 2003):

• Number of occupants: 25 occupants who work for 20 or more hours per week and are available to complete the questionnaire, but preferably 50 to 60 such occupants.

• Served by no more than two air

- handling units , but preferably just one.

• A maximum of three floors, but preferably just one.

• Preferably floor area not to exceed 1900 m 2 

### (20 000 ft 2 

### ) There have been previous analy ses of the building and HVAC data, as well as some papers describing the BASE study in mor e general terms (Brightman et al. 1996, W omble et al. 1995 and 1996). Ludwig et al. (2002) present an analy sis of the ventilation data, including a comparison with the outdoor air requirements in ASHRAE Standard 62

- 1999 (ASHRAE 1999). They conclude that ve ntilation rates based on indoor CO 2 

### levels have lower uncertainties than the rates based on the other methods considered and that most of the measured values are higher than the requirements in Standard 62. However, the uncertainties considered are based o nly on instrumentation specifications and do not consider other sources of error. In particular, the uncertainties of the ventilation estimates using indoor CO 2 

### are based on only the concentration measurements and not on validity of the assumptions inheren t in the mass balance methodology used to make these estimates. Also, their analy sis did not investigate ventilation sy stem design values and did not address other ventilation performance parameters of interest, such as supply airflows. Apte et al. (2000) and Erdman et al. (2002) examine associations between sick building
sy ndrome sy mptoms and indoor

- outdoor CO 2 

### concentration differences as surrogates for per person ventilation rates.3 

### 1.2 Objectives of V entilation Analy sis The purpose of the analy sis presen ted in this report is to produce information on ventilation
sy stem design and performance for the 100 BASE office buildings. W hile there have been some studies of ventilation in office buildings (Persily 1989, Persily and Dols 1991, Persily at al. 1992), n one have been associated with such thorough characterizations of indoor environmental conditions and occupant sy mptoms nor have they been applied to a representative set of buildings. Therefore, the BASE data provide a unique opportunity to obtain importan t information about U.S. office buildings including ventilation sy stem design values, measured ventilation performance, and the relationship of these measurement results to design values and to requirements in standards. W hile the following sections descri be the specific parameters that are considered, the focus of this analy sis is primarily on supply airflows and outdoor air ventilation. It is envisioned that the results of this analy sis will be used to investigate relationships of ventilation to IAQ perfo rmance parameters and to occupant sy mptoms. In addition to providing design and measured ventilation data, this study was performed to evaluate the BASE protocol with respect to its ability to obtain reliable ventilation performance data and to recommend m odifications to the protocol for use in future studies.

2. METHODOLOGY The data analy sis involved calculations of various parameters using the data obtained by the EPA contractor, most of which is described in the results section. The overall analy sis appr oach is summarized in this section, along with a more detailed discussion of some specific parameters such as the outdoor air fraction of an air handler. The analy sis focused primarily on the study spaces and the ventilation sy stems serving these spaces in terms of both design and measured performance. As noted earlier, the study spaces were portions of buildings, or in some cases whole buildings, that were the subject of the BASE study test protocol. In this study , ventilation design and performance is ass essed primarily in terms of supply airflow and outdoor air intake, along with exhaust airflows to a lesser degree. In addition, occupancy levels are examined. All of the analy sis performed by NIST employ s data that were provided by EPA, much of which had a lready been processed by their contractors. For example, the data from duct traverses had already been converted into volumetric airflows. NIST did not use the raw data from the field to verify the processing done by the contractor, as the protocol and dat a processing already had significant quality control checks. The BASE variables used in the NIST analy sis, as well as those obtained from the contractor’s analy sis, are identified in Appendix A. The analy sis results are presented in the form of the followi ng summary statistics for the variables of interest: mean, standard deviation, median, the 10 t h 

### , 25 t h 

### , 75 t h 

### and 90 t h 

### percentile values, and the minimum and maximum values.

2.1 Buildings, Study Spaces and Air Handling Sy stems The data analy sis focused first on the buildings involved in the BASE study and the study spaces in the buildings. Basic information was analy zed to characterize the age and size of the buildings as well as the size and occupancy of the study spaces. The air handling sy stems serving the study spaces were examined in terms of the ty pes of sy stem, means of outdoor air intake control, and
sy stem design specifications. The latter includes supply , return and minimum outdoor airflow capacity and design occupant density . The sy stem design airfl ows were obtained as part of the BASE protocol, when available, from sy stem specifications and other design documentation. The primary outcomes of these analy ses are the supply airflow capacity per unit floor area, expressed4 

### as L/s• m 2 

### (cfm/ft 2 

### ), and the mi nimum outdoor air intake in L/s• person (cfm/person). These design parameters are then examined as a function of building age to determine if any trends over time are evident. In addition, the design capacities of the exhaust ventilation sy stems are examine d, including their contribution to the net airflow balance of the building.

2.2 Measured Data The analy sis of the measured data focused on the following ventilation performance parameters: supply airflow, outdoor air fraction, outdoor air ventilation, and exhaust airflow. An uncertainty analy sis is performed for all the calculated parameters based on propagation of the uncertainty estimates for each of the measured quantities, i.e., 30 % for the measured outdoor air intake and recirculation airflow, 10 % fo r the supply airflows, and 90 mg/m 3 

### (50 ppm(v)) for the CO 2 

### concentrations. The uncertainties of the airflows are estimates from an analy sis by the EPA contractor who performed the tests (EHE 2001a). The actual uncertainties may very well be larger, or per haps smaller, than these estimates; however, there is insufficient information available to develop better estimates of the measurement uncertainties. The value for the CO 2 

### monitors is based on the instrumentation specifications in the study protocol.

Occ upant Density As part of the BASE protocol, the number of occupants in each study space was counted twice a day for at least two day s during the test week. These data are analy zed to determine the occupant density of each space in units of number per 100 m 2 

### (1000 ft 2 

### ). These values are compared with the design occupancy based on the number of workstations in each study space and with the occupant density values in ASHRAE Standard 62

- 2001 (ASHRAE 2001a) and in addendum n to that standard (ASHRAE 2003). Suppl y Airflow The measured supply airflows for the individual air handlers are first compared with the design values. The ratios of measured to design are then evaluated as a function of sy stem ty pe and outdoor air temperature. The supply airflows for the air handlers were combined to determine the total supply airflow to each study space. The supply airflow to each study space was based on the percentage of the air handler airflow serving the study space, which is a variable determined in the ventilation sy ste m evaluation. The survey protocol did not provide an uncertainty estimate for these percentages. For the purposes of this analy sis, the uncertainty is assumed to equal 10 % of the value except in cases where 100 % of the air is delivered to the study space . In those cases the uncertainty is assumed to be zero. The study space supply airflows are normalized by floor area served and examined as a function of outdoor air temperature.

Outdoor Air Fraction A key ventilation performance parameter assessed in the study is the outdoor air fraction F o 

### , i.e., the ratio of the outdoor air intake to the supply airflow. It is of interest as a performance parameter itself and as a means of determining the outdoor air intake through multiplication by the supply airflow. Th e outdoor air fraction was determined in two way s, dividing the measured outdoor airflow by the measured supply airflow and through the measurement of CO 2 

### concentrations in the outdoor, supply and recirculation airstreams. The former determination is refer red to as a volumetric value, while the latter is referred to as the CO 2 

### ratio value.

The volumetric outdoor air fraction was determined for each air handler measurement based on whichever of the expressions in Equations (1a), (1b) and (1c) apply . In Equat ion (1a), F o 

### volumetric is determined by the measured outdoor air intake divided by the supply airflow. In5 

### cases where the outdoor air intake was not measured directly but the supply and recirculation flows were measured, F o 

### - volumetric was determined using Equation (1b). Finally , in cases where the supply airflow was not measured, F o 

### - volumetric was determined using Equation (1c) based on the sum of the outdoor and recirculation airflows. Mathematically , these three means of determining the volumetric intake fraction are expressed as follows:

F o 

### = Q O 

### /Q S 

### (1a)

F o 

### = (Q S


### –Q R 

### )/Q S 

### (1b)

F o 

### = Q O 

### /(Q O 

### + Q R 

### ) (1c)

where F o 

### is the outdoor air fraction and Q O 

### , Q S 

### and Q R 

### are the outdoor, supply and recirculation airflows respectively . The value of F o 

### with the minimum un certainty was identified and is referred to as the best volumetric value of F o 

### . For some air handlers, the value of F o 

### could be determined using more than one of these expressions. For a small number of cases in which only Equation (1b) could be used, the value of Q S 

### was less than Q R 

### , resulting in a negative value. In those cases, the outdoor air fraction and Q O 

### were both set to zero, but the large uncertainty values were carried through the analy sis.

Values of F o 

### were also determined based on measured CO 2 

### concentrations in the outdoor, supply and recirculation airstreams using Equation (2),

F o 

### = (C R 

### –C S 

### ) / (C R 

### –C O 

### ) (2)

where C R 

### , C S 

### and C O 

### are the CO 2 

### concentrations in the supply , recirculation and outdoor airstreams respectively

. Outdoor Air Ventilation Outdoor air intake is determined for individual air handlers using whichever of the following approaches was possible:

• Direct measurements of the volumetric airflow in the outdoor air intake duct using standard air speed traverse approaches.

• The differenc e between direct measurements of the supply and recirculation volumetric airflows.

• The outdoor air fraction based on CO 2 

### (see Equation (2)) multiplied by the supply airflow. The measured outdoor airflows for the individual air handlers are compared with th e design values for minimum outdoor air for the sy stems where such a design value exists. The ratios of the measured to design values are evaluated as a function of sy stem ty pe and outdoor air temperature. Based on the measurements at the individual air ha ndlers, the outdoor air ventilation in each study space is calculated. These calculations employ the value of the percentage of the air from each handler that is provided to the study space. As noted above, the protocol does not provide an uncertainty esti mate for these values, and the uncertainty is assumed to equal 10 % except when the value is 100 %. The outdoor air ventilation in the study space is also estimated based on the CO 2 

### concentrations measured with the fixed monitors used in the study . A numbe r of such monitors were deploy ed in each study space, which recorded the CO 2 

### concentration (and other variables) every 5 min over several day s. The CO 2 

### concentrations were averaged across the study space and the peak value identified. In some cases both a morning and an afternoon peak were identified, if the concentration pattern indicated two distinct peaks. In other cases, only a single peak was determined for the day . The peak concentration minus the corresponding outdoor concentration6 

### is then used to es timate the outdoor airflow per person assuming that the CO 2 

### concentration is at equilibrium and assuming a CO 2 

### generation rate per person of 0.0052 L/s (0.011 cfm). This method is based on a single

- zone mass balance of CO 2 

### in the study space and therefore is valid only when the concentration is indeed at steady

- state, the concentration is uniform throughout the space, airflows from adjoining spaces can be ignored, and the outdoor concentration, ventilation rate and generation rate are all constant (Persily 1997). Since the validity of these assumptions was not investigated as part of this study (except that the outdoor concentration was monitored), the validity of the results obtained with this method are subject to question. Supply Diffuser and Exhaust Airf lows The BASE protocol included one measurement of the supply airflow at the accessible supply air diffusers and the exhaust airflow at exhaust grilles located in the study space. In the case of the supply diffusers, the total supply airflow to the study s pace is compared with the value based on the measurements at the air handler(s). The measured exhaust airflows are compared with the corresponding design values.

2.3 Timing of Building Evaluations As noted earlier, the goal in the BASE study was to conduct the measurements during the winter and summer when the sy stems were more likely to be operating at minimum outdoor air conditions and to increase the likelihood that the sy stem operation would not vary over the test week. Figure 1 is a plot of the measure ment dates by month of the y ear. Note the large number of measurements made during the month of March. However, the month does not necessarily indicate the percentage of outdoor air intake; the outdoor air temperature is a better predictor. Figure 2 shows the distribution of the measurements based on the outdoor air temperature at which the ventilation measurements were made. If one assumes that minimum outdoor air intake occurs for air temperatures below 5 °C (41 °F) and above 20 °C (68 °F), then 339 of th e 548 measurement events (or 62 %), with the outdoor temperature recorded, would correspond to minimum outdoor air intake. Of course, the percent of outdoor air intake as a function of outdoor temperature depends on the individual sy stem, and some sy stems were 100 % outdoor air
sy stems. But based on temperature alone, about one

- third of the tests might be expected to be at other than minimum outdoor air intake. The issue of percent outdoor air intake, including the temperature dependence, is discussed again when the outdoor air fraction and outdoor air ventilation measurements are presented.7 

### Figure 1 Frequency distribution of measurements based on month

Figure 2 Frequency distribution of measurements based on outdoor temperature 0 25 50 75 100 125-15 to -10 °C(5 to 14 °F)-10 to -5 °C(14 to 23 °F)-5 to 0 °C(23 to 32 °F)0 to 5 °C(32 to 41 °F)5 to 10 °C(41 to 50 °F)10 to 15 °C(50 to 59 °F)15 to 20 °C(59 to 68 °F)20 to 25 °C(68 to 77 °F)25 to 30 °C(77 to 86 °F)30 to 35 °C(86 to 95 °F)> 35 °C(> 95 °F)

Outdoor temperature rangeNumber of measurements 0 20 40 60 80 100 120

January February March April May June July August September October November December

MonthNumber of Measuremments8 

### 3. RESULTS

This secti on presents the results of the ventilation analy sis performed on the BASE building data. These results include information on the buildings and study spaces, sy stem design parameters, and measured values of occupant density , supply airflow, outdoor air fra ction, outdoor air ventilation and exhaust airflow.

3.1 Building and Study Space Information As noted earlier, 100 buildings were involved in the BASE study . These buildings were randomly selected as described in W omble et al. (1995), and were located thro ughout the United States. Table 1 presents a summary of the characteristics of the buildings. The y ears of construction range from 1850 to 1996, with a mean of 1961, though most of them have been renovated at some point. The total number of stories, below and above grade, range from 1 to 61, with a mean of 10 stories. The gross floor area of the buildings range from about 1700 m 2 

### (18 000 ft 2 

### ) to 134 200 m 2 

### (1 445 000 ft 2 

### ), with a mean of 24 800 m 2 

### (266 000 ft 2 

### ). The occupied floor areas, which exclude atria , vacant office space, hallway s, stair and elevator shafts, mechanical rooms and core areas, range from 600 m 2 

### (6000 ft 2 

### ) to 98 500 m 2 

### (1 060 000 ft 2 

### ), with a mean of 16 400 m 2 

### (177 000 ft 2 

### ). Of the 100 buildings, 97 have mechanical ventilation
sy stems whi le three employ predominantly natural ventilation, i.e., buildings NYBS06, ORIS02 and W AIA01. (These building codes are used in the BASE study to identify each building, with the first two letters indicating the state in which they are located.) Ninety

- nin e of the buildings are air

- conditioned (building W AIA01 being the exception), and all are heated.

Y e a r o f

c o n s t r u c t i o n N u m b e r o f

s t o r i e s G r o s s f l o o r a r e a

m 2 ( f t 2 ) O c c u p i e d f l o o r a r e a

m 2 ( f t 2 )

M e a n 1 9 6 1 1 0 2 4 8 0 0 ( 2 6 6 0 0 0 ) 1 6 4 0 0 ( 1 7 7 0 0 0 )
S t d

. D e v

. 3 1 1 1 2 7 9 0 0 ( 3 0 0 0 0 0 ) 1 8 5 0 0 ( 1 9 9 0 0 0 )
M i n i m u m 1 8 5 0 1 1 7 0 0 ( 1 8 0 0 0 ) 6 0 0 ( 6 0 0 0 )
1 0 t h p e r c e n t i l e 1 9 0 6 3 3 7 0 0 ( 4 0 0 0 0 ) 2 3 0 0 ( 2 5 0 0 0 )
2 5 t h p e r c e n t i l e 1 9 5 3 4 7 4 0 0 ( 8 0 0 0 0 ) 5 1 0 0 ( 5 5 0 0 0 )
M e d i a n 1 9 7 2 6 1 4 0 0 0 ( 1 5 1 0 0 0 ) 8 5 0 0 ( 9 1 0 0 0 )
7 5 t h p e r c e n t i l e 1 9 8 3 1 2 2 7 9 0 0 ( 3 0 0 0 0 0 ) 2 1 3 0 0 ( 2 2 9 0 0 0 )
9 0 t h p e r c e n t i l e 1 9 8 8 2 2 6 5 1 0 0 ( 7 0 1 0 0 0 ) 3 5 9 0 0 ( 3 8 6 0 0 0 )
M a x i m u m 1 9 9 6 6 1 1 3 4 2 0 0 ( 1 4 4 5 0 0 0 ) 9 8 5 0 0 ( 1 0 6 0 0 0 0 ) 

### Table 2 Building information

It is interesting to compare the BASE buildings to those included in the 1995 U. S. Department of Energy Commercial Building Energy Consumption Survey or CBECS (DOE 1998). CBECS is a national survey of commercial buildings that is conducted quadrennially with a target population of all commercial buildings in the United States with mor e than 100 m 2 

### (1000 ft 2 

### ) of floor area. The median age of the CBECS buildings corresponds to a y ear of construction of 1972, which is identical to the BASE value. The mean floor area of the 1995 CBECS office buildings is 1400 m 2 

### (14 900 ft 2 

### ), which is much less than the BASE buildings. However, as noted earlier, the BASE buildings were selected such that the study space had at least 25 occupants and preferably 50 or 60 occupants. The mean number of workers in the CBECS office buildings is 38.4 and 74 % of t he office buildings have less than 20 occupants. Therefore the difference in the floor areas between CBECS and BASE is not surprising. Of the 705 000 CBECS office buildings, all but 1000 are heated and 98 % are cooled, consistent with the BASE buildings. A9 

### previous analy sis of the BASE buildings relative to the CBECS data notes that the BASE buildings are most representative of office buildings with more than 50 occupants, which constitute roughly 11 % of the office building stock but about 73 % of the U.S. office building occupants (EHE 2001b). The 100 study spaces within the buildings were selected based on the criteria described above, and some of their characteristics are summarized in Table 3. The occupied floor areas range from 430 m 2 

### (4600 ft 2 

### ) to 644 0 m 2 

### (69 300 ft 2 

### ), with a mean of 1540 m 2 

### (16 600 ft 2 

### ). The mean number of workstations is 72, which corresponds to 5.3 workstations per 100 m 2 

### of floor area (4.9 per 1000 ft 2 

### ). The number of workstations in this table is the sum of the number of private, partitioned and open

- space workstations that were counted as part of the study space characterization. The study space characterization also y ielded a value for the design floor area per workstation (variable name B1DESW S). Computing the number of workstat ions per floor area based on B1DESW S y ields similar values to those obtained based on the number of workstations as presented in the table, but not identical. The number of workstation density in the table is below the default value of 7 per 100 m 2 

### (1000 f t 2 

### ) in ASHRAE Standard 62

- 2001, but close to the default value of 5 per 100 m 2 

### (1000 ft 2 

### ) for office space in addendum n to the standard (ASHRAE 2003). For the 97 study spaces with mechanical ventilation, the mean number of supply air diffusers is 106 and the mean floor area per diffuser of 18.4 m 2 

### (198 ft 2 

### ).

O c c u p i e d f l o o r

a r e a , m 2 ( f t 2 ) N u m b e r o f

w o r k s t a t i o n s W o r k s t a t i o n s p e r 1 0 0 m 2

( 1 0 0 0 f t 2 ) N u m b e r o f

s u p p l y a i r d i f f u s e r s F l o o r a r e a p e r d i f f u s e r m 2 ( f t 2 ) # o f v a l u e s 1 0 0 1 0 0 1 0 0 9 7 9 7
M e a n 1 5 4 0 ( 1 6 6 0 0 ) 7 2 5

. 3 ( 4

. 9 ) 1 0 6 1 8

. 4 ( 1 9 8 )
S t d

. D e v

. 7 4 0 ( 8 0 0 0 ) 1 9 2

. 0 ( 1

. 9 ) 5 3 1 6

. 1 ( 1 7 4 )
M i n i m u m 4 3 0 ( 4 6 0 0 ) 3 9 1

. 0 ( 0

. 9 ) 6 5

. 3 ( 5 7 )
1 0 t h p e r c e n t i l e 8 8 0 ( 9 5 0 0 ) 5 0 3

. 0 ( 2

. 8 ) 4 7 8

. 4 ( 9 1 )
2 5 t h p e r c e n t i l e 1 1 3 0 ( 1 2 1 0 0 ) 5 8 4

. 0 ( 3

. 7 ) 7 3 1 0

. 9 ( 1 1 8 )
M e d i a n 1 4 3 0 ( 1 5 4 0 0 ) 6 8 4

. 8 ( 4

. 5 ) 9 8 1 5

. 1 ( 1 6 3 )
7 5 t h p e r c e n t i l e 1 7 8 0 ( 1 9 2 0 0 ) 8 8 6

. 3 ( 5

. 8 ) 1 3 2 1 9

. 8 ( 2 1 3 )
9 0 t h p e r c e n t i l e 2 2 5 0 ( 2 4 2 0 0 ) 1 0 0 7

. 6 ( 7

. 1 ) 1 6 8 2 6

. 9 ( 2 9 0 )
M a x i m u m 6 4 4 0 ( 6 9 3 0 0 ) 1 1 8 1 2

. 5 ( 1 1

. 6 ) 2 8 1 1 4 0

. 0 ( 1 5 0 7 ) 

### Table 3 Study space information

3.2 V entilation Sy s tem Design Parameters The study spaces in the 97 mechanically ventilated buildings are served by a total of 141 mechanical ventilation sy stems. Of these sy stems, 50 are constant air volume (CV) and 91 are variable air volume (VAV). CV sy stems provide a co nstant amount of supply air, while vary ing the supply air temperature to meet the heating and cooling loads of the space. VAV sy stems maintain a constant supply air temperature and vary the supply airflow to meet the loads. The
sy stem ty pes are summarized in Table 4 based on the sy stem classification and letter codes in the BASE protocol. In addition to the sy stem ty pes in Table 4, other design features related to outdoor air intake control were collected for the ventilation sy stems. Table 5 presents this i nformation for the mechanically ventilated buildings, including the number with sy stems that employ temperature (dry

- bulb) or enthalpy economizer cy cles. Twenty

- one buildings have dedicated outdoor air fans,1 0 

### with 11 of those also conditioning the air. Five buildings have 100 % outdoor air sy stems, and 88 have fixed minimum outdoor air intake dampers. A small number have the outdoor air intake controlled using airflow monitoring, supply /return fan tracking or building pressure.

C o n s t a n t v o l u m e ( C V ) N u m b e r

o f s y s t e m s V a r i a b l e a i r v o l u m e ( V A V ) N u m b e r

o f s y s t e m s A S i n g l e d u c t
, s i n g l e z o n e 1 3 D S i n g l e d u c t 3 7 B S i n g l e d u c t
, m u l t i p l e z o n e r e h e a t 8 E S i n g l e d u c t
, r e h e a t 1 7 J D u a l d u c t 2 F S i n g l e d u c t
, i n d u c t i o n 7 K D u a l d u c t
, r e h e a t 7 G S i n g l e d u c t
, f a n p o w e r e d

, c o n s t a n t f a n 8

N M u l t i z o n e 1 7 H S i n g l e d u c t
, f a n p o w e r e d

, i n t e r m i t t e n t f a n 1 8

O B l o w

- t h r o u g h b y p a s s 3 L D u a l d u c t
, s i n g l e f a n 3 M D u a l d u c t
, d u a l f a n 1 T O T A L C V 5 0 T O T A L V A V 9 1 

### Table 4 V entilation Sy stem Ty pes

O u t d o o r a i r i n t a k e c o n t r o l N u m b e r o f b u i l d i n g s E c o n o m i z e r c y c l e ( t e m p e r a t u r e c o n t r o l ) 5 0
E c o n o m i z e r c y c l e ( e n t h a l p y c o n t r o l ) 2 1
D e d i c a t e d o u t d o o r a i r f a n , c o n d i t i o n e d 1 1
D e d i c a t e d o u t d o o r a i r f a n , u n c o n d i t i o n e d 1 0
1 0 0 % o u t d o o r a i r 5
F i x e d m i n i m u m o u t d o o r a i r d a m p e r 8 8
O u t d o o r a i r i n t a k e c o n t r o l l e d v i a m o n i t o r i n g 2
O u t d o o r a i r i n t a k e c o n t r o l l e d v i a s u p p l y / r e t u r n f a n t r a c k i n g 5
O u t d o o r a i r i n t a k e c o n t r o l l e d b y b u i l d i n g p r e s s u r e 4


### Table 5 Outdoor air intak e control The availability of design information varies among the sy stems, how ever the information that does exist was analy zed and the results are summarized in Table 6. (Detailed design information for all the sy stems is provided in Appendix B.) Table 6 presents the floor area served by the
sy stems, the design supply airflow capac ity normalized by floor area served (for all sy stems as well as for CV and VAV sy stems separately ), the ratio of design supply to return airflows, the design minimum outdoor air intake per person and per unit floor area, the ratio of the design minimum out door air intake to the design supply air capacity , and the occupant density . The occupant density is based on the number of occupants served by the air handler, which was obtained during the survey s from a building walkthrough or from the building manageme nt. (During the study space survey s, the actual number of occupants was counted and those results are presented later in this report.) W hen calculating the supply airflow capacities, the minimum outdoor air intake, and the occupant densities, some values w ere not in the expected range. These values include supply airflows greater than 15 L/s• m 2 

### (3 cfm/ft 2 

### ), minimum outdoor air intake greater than 33 L/s (70 cfm) per person or 5 L/s• m 2 

### (1 cfm/ft 2 

### ), and occupant densities greater than 12 per 100 m 2 

### (1000 ft 2 

### ) . Values outside these ranges are included in the statistics in Table 6, and the outliers themselves are identified in Table 7. As seen in Table 6, for the 134 air handling sy stems with design data, the mean value of the design supply airflow normalized by floor area served is 5.86 L/s•m 2 

### (1.15 cfm/ft 2 

### ) , which is1 1 

### close to the expected value of 5 L/s• m 2 

### (1 cfm/ ft 2 

### ) based on ty pical cooling loads and supply air temperatures in office buildings. The median value is even closer to the expected supply airflow

r ate, and the mean is slightly higher for CV sy stems and lower for VAV sy stems. The ratio of the design supply airflow to the design return airflow could be determined for 41 of the sy stems, and the mean value is 1.14. This value is consistent with the comm on design intent to provide more supply than return air to a space to achieve positive pressurization and to ensure that toilet and other exhaust sy stems are able to function properly

. D e s i g n s u p p l y a i r f l o w c a p a c i t y L / s • m 2 ( c f m / f t 2 ) F l o o r a r e a s e r v e d

m 2 ( f t 2 ) A l l s y s t e m s C V V A V S u p p l y / R e t u r n # o f v a l u e s 1 4 1 1 3 4 4 7 8 7 4 1
M e a n 3 1 0 0 ( 3 3 3 0 0 ) 5

. 8 6 ( 1

. 1 5 ) 7

. 0 1 ( 1

. 3 8 ) 5

. 2 5 ( 1

. 0 3 ) 1

. 1 4
S t d

. D e v

. 4 2 3 0 ( 4 5 6 0 0 ) 3

. 5 7 ( 0

. 7 0 ) 5

. 3 3 ( 1

. 0 5 ) 1

. 8 5 ( 0

. 3 6 ) 0

. 2 2
M i n i m u m 1 1 0 ( 1 2 0 0 ) 1

. 1 3 ( 0

. 2 2 ) 1

. 1 3 ( 0

. 2 2 ) 1

. 6 7 ( 0

. 3 3 ) 0

. 2 0
1 0 t h p e r c e n t i l e 5 4 0 ( 5 8 0 0 ) 2

. 9 0 ( 0

. 5 7 ) 2

. 7 4 ( 0

. 5 4 ) 3

. 2 6 ( 0

. 6 4 ) 1

. 0 0
2 5 t h p e r c e n t i l e 9 9 0 ( 1 0 7 0 0 ) 4

. 1 5 ( 0

. 8 2 ) 4

. 1 9 ( 0

. 8 3 ) 4

. 1 5 ( 0

. 8 2 ) 1

. 0 7
M e d i a n 1 6 4 0 ( 1 7 6 0 0 ) 5

. 2 1 ( 1

. 0 3 ) 5

. 6 3 ( 1

. 1 1 ) 4

. 9 9 ( 0

. 9 8 ) 1

. 1 1
7 5 t h p e r c e n t i l e 3 4 4 0 ( 3 7 0 0 0 ) 6

. 7 8 ( 1

. 3 3 ) 7

. 8 3 ( 1

. 5 4 ) 6

. 1 7 ( 1

. 2 2 ) 1

. 2 5
9 0 t h p e r c e n t i l e 7 6 2 0 ( 8 2 1 0 0 ) 8

. 4 5 ( 1

. 6 6 ) 1 1

. 2 1 ( 2

. 2 1 ) 7

. 5 6 ( 1

. 4 9 ) 1

. 2 8
M a x i m u m 3 3 7 8 0 ( 3 6 3 6 0 0 ) 3 0

. 1 8 ( 5

. 9 4 ) 3 0

. 1 8 ( 5

. 9 4 ) 1 2

. 4 7 ( 2

. 4 5 ) 1

. 8 5

D e s i g n m i n i m u m o u t d o o r a i r i n t a k e L / s ( c f m ) p e r p e r s o n L / s • m 2 ( c f m / f t 2 ) M i n i m u m O A / S u p p l y O c c u p a n t d e n s i t y # / 1 0 0 m 2 ( 1 0 0 0 f t 2 )

# o f v a l u e s 7 4 7 6 7 6 1 3 7
M e a n 1 8

. 4 ( 3 9

. 0 ) 0

. 9 4 ( 0

. 1 8 ) 0

. 1 9 5

. 3 ( 4

. 9 )
S t d

. D e v

. 1 3

. 7 ( 2 9

. 0 ) 1

. 0 6 ( 0

. 2 1 ) 0

. 2 2 6

. 5 ( 6

. 1 )
M i n i m u m 1

. 3 ( 2

. 9 ) 0

. 1 7 ( 0

. 0 3 ) 0

. 0 6 0

. 9 ( 0

. 8 )
1 0 t h p e r c e n t i l e 7

. 5 ( 1 6

. 0 ) 0

. 3 1 ( 0

. 0 6 ) 0

. 0 8 2

. 2 ( 2

. 0 )
2 5 t h p e r c e n t i l e 1 0

. 6 ( 2 2

. 4 ) 0

. 4 2 ( 0

. 0 8 ) 0

. 1 0 2

. 9 ( 2

. 7 )
M e d i a n 1 5

. 2 ( 3 2

. 1 ) 0

. 6 0 ( 0

. 1 2 ) 0

. 1 2 3

. 9 ( 3

. 7 )
7 5 t h p e r c e n t i l e 2 3

. 6 ( 5 0

. 0 ) 0

. 9 2 ( 0

. 1 8 ) 0

. 1 5 5

. 9 ( 5

. 4 )
9 0 t h p e r c e n t i l e 2 9

. 7 ( 6 3

. 0 ) 1

. 8 2 ( 0

. 3 6 ) 0

. 3 1 8

. 0 ( 7

. 4 )
M a x i m u m 9 8

. 3 ( 2 0 8

. 2 ) 6

. 6 7 ( 1

. 3 1 ) 1

. 0 0 6 5

. 1 ( 6 0

. 5 ) 

### Table 6 Sy stem design values The mean value of the design minimum outdoor air intake per person is 18.4 L/s (39.0 cfm), and the median is 15.2 L/s (32.1 cfm). These values are above the minimum outdoor air requirement for office spa ce in ASHRAE Standard 62

- 2001 (ASHRAE 2001) of 10 L/s (20 cfm) per person. The design outdoor air intake in Table 6 is based on the number of workstations, since the number of occupants used in the design is not available. However, dividing the design mini mum outdoor airflow by the number of occupants based on the occupant density in ASHRAE Standard 62

- 2001 (7 people per 100 m 2 

### (1000 ft 2 

### )) instead of the actual number of workstations y ields a mean per person outdoor air intake of 13.1 L/s (25.8 cfm) and a m edian of 8.5 L/s (16.7 cfm), which are closer to the ASHRAE requirement. Note that design the minimum outdoor air intake is available for only 76 of the 141 sy stems. Also, these sy stems were designed at various times, and therefore it is not clear what sta ndard or code requirements the sy stems were used in the design. The table also provides the design minimum outdoor air intake on a floor area basis.1 2 

### Finally , the mean ratio of the minimum outdoor air intake to supply airflow capacity is 0.18 and the median value is 0.12, consistent with expected values of 10 % to 20 %. The mean value of the design occupant density in Table 6 is 5.3 people per 100 m 2 

### (4.9 per 1000 ft 2 

### ) , while the median value is 3.9 per 100 m 2 

### (3.7 per 1000 ft 2 

### ). As noted earlier when discu ssing the study spaces, these values for the individual air handlers are below the default value of 7 per 100 m 2 

### (1000 ft 2 

### ) in ASHRAE Standard 62

- 2001, but close to the default value of 5 per 100 m 2 

### (1000 ft 2 

### ) for office space in addendum n to the standard (ASHRAE 2003).

S y s t e m * I s s u e C o m m e n t s A Z H W 1 0 ( 2 o f 2 ) H i g h s u p p l y c a p a c i t y , 2 4 L / s • m 2 ( 4

. 7 c f m / f t 2 ) S y s t e m ( 1 ) a t 8 L / s • m 2 ( 1

. 5 c f m / f t 2 )

L A G W 0 5 ( 1 o f 2 ) H i g h s u p p l y c a p a c i t y , 1 8 L / s • m 2 ( 3

. 6 c f m / f t 2 ) S y s t e m ( 2 ) a t 4 L / s • m 2 ( 0

. 7 c f m / f t 2 ) ;

o c c u p a n t d e n s i t y 5 t i m e s t h a t o f s y s t e m ( 2 ) ; f l o o r a r e a c o u l d b e l o w M O C S 0 1 ( 1 o f 1 ) H i g h s u p p l y c a p a c i t y , 2 7 L / s • m 2 ( 5

. 3 c f m / f t 2 ) P A B S 0 4 ( 2 o f 2 ) H i g h s u p p l y c a p a c i t y , 2 5 L / s • m 2 ( 5

. 9 c f m / f t 2 ) S y s t e m ( 1 ) a t 4 L / s • m 2 ( 0

. 8 c f m / f t 2 )

C A E W 0 9 ( 1 o f 1 ) H i g h m i n i m u m o u t d o o r a i r 5 3 L / s ( 1 1 3 c f m ) p e r p e r s o n , M i n i m u m o u t d o o r a i r b a s e d o n s u p p l y a n d

r e t u r n c a p a c i t i e s C A J S 2 1 ( 2 o f 2 ) H i g h m i n i m u m o u t d o o r a i r , 9 8 L / s ( 2 0 8 c f m ) p e r p e r s o n 1 0 0 % o u t d o o r a i r s y s t e m ; S y s t e m ( 1 ) a t 2 9 L / s ( 6 1 c f m ) p e r p e r s o n M D D S 0 1 ( 1 o f 1 ) H i g h m i n i m u m o u t d o o r a i r , 5 1 L / s ( 1 0 9 c f m ) p e r p e r s o n N C D W 0 3 ( 2 o f 5 ) H i g h m i n i m u m o u t d o o r a i r , 3 8 L / s ( 8 0 c f m ) p e r p e r s o n O t h e r 4 s y s t e m s f r o m 9 L / s ( 2 0 c f m ) p e r p e r s o n t o 1 6 L / s ( 3 3 c f m ) p e r p e r s o n ;

s y s t e m ( 2 ) o c c u p a n t d e n s i t y a b o u t 2 5 % o f

o t h e r 4 s y s t e m s

. N E C W 0 2 ( 1 o f 1 ) H i g h m i n i m u m o u t d o o r a i r , 3 8 L / s ( 8 0 c f m ) p e r p e r s o n H i g h o c c u p a n t d e n s i t y , 1 6 o c c u p a n t s p e r 1 0 0 m 2 ( 1 0 0 0 f t 2 ) T N F S 1 0 ( 1 o f 1 ) H i g h m i n i m u m o u t d o o r a i r , 3 4 L / s ( 7 2 c f m ) p e r p e r s o n L o w o c c u p a n t d e n s i t y , 1

. 1 o c c u p a n t s p e r 1 0 0 m 2 ( 1 0 0 0 f t 2 ) C A J W 2 5 ( 1 o f 1 ) H i g h o c c u p a n t d e n s i t y , 6 1

o c c u p a n t s p e r 1 0 0 m 2 ( 1 0 0 0 f t 2 ) S u p p l y a i r f l o w 2 4 L / s • m 2 ( 2

. 5 c f m / f t 2 ) ; f l o o r a r e a c o u l d b e l o w M O C S 0 1 ( 1 o f 1 ) H i g h o c c u p a n t d e n s i t y , 2 4

o c c u p a n t s p e r 1 0 0 m 2 ( 1 0 0 0 f t 2 ) N E C W 0 2 ( 1 o f 1 ) H i g h o c c u p a n t d e n s i t y , 1 6

o c c u p a n t s p e r 1 0 0 m 2 ( 1 0 0 0 f t 2 ) S D B W 0 2 ( 1 o f 1 ) H i g h o c c u p a n t d e n s i t y , 3 8

o c c u p a n t s p e r 1 0 0 m 2 ( 1 0 0 0 f t 2 ) L o w m i n i m u m o u t d o o r a i r 1 L / s ( 3 c f m ) p e r p e r s o n , c o n s i s t e n t w i t h h i g h o c c u p a n t d e n s i t y v a l u e T N D S 0 5 ( 1 o f 2 ) H i g h o c c u p a n t d e n s i t y , j u s t o v e r 1 2 o c c u p a n t s p e r 1 0 0 m 2 ( 1 0 0 0 f t 2 ) S y s t e m ( 2 ) l i s t s n o o c c u p a n t s



### * Values in parentheses refers to air handler number relative to total number of air handlers, e.g.

(2 of 2) means second of two air handlers serving the study space. Table 7 Sy stem design outli ers +

+ 

### The text in the table noted with a strikethrough corresponds to two occurrences that are no longer outliers given the mod ifications to the data described earlier.1 3 

### The ventilation requirements in ASHRAE Standard 62

- 2001 were recently revised by addendum n to the standard (ASHRAE 2003). In the new procedure, the number of occupants is multiplied by an outdoor air requirement in units of L/s (cfm) per person and t he product is added to the floor area multiplied by a separate requirement in units of L/s• m 2 

### (cfm/ft 2 

### ). For office space these values are 2.5 L/s (5 cfm) per person and 0.3 L/s• m 2 

### (0.06 cfm/ft 2 

### ). This method was used to determine the per person ventilatio n requirements of the study spaces based on the number of workstations and the floor area. Table 8 presents the results. Note that the mean outdoor air requirement is slightly lower than the 10 L/s (20 cfm) per person requirement in Standard 62

- 2001, but t he variation about the mean highlights the intended impact of occupant density

.

S t u d y s p a c e o u t d o o r a i r r e q u i r e m e n t L / s ( c f m ) p e r p e r s o n M e a n 9

. 0 ( 1 9

. 1 )
S t d

. D e v

. 3

. 3 ( 6

. 9 )
M i n i m u m 4

. 8 ( 1 0

. 2 )
1 0 t h p e r c e n t i l e 6

. 5 ( 1 3

. 7 )
2 5 t h p e r c e n t i l e 7

. 2 ( 1 5

. 3 )
M e d i a n 8

. 7 ( 1 8

. 3 )
7 5 t h p e r c e n t i l e 1 0

. 0 ( 2 1

. 1 )
9 0 t h p e r c e n t i l e 1 2

. 1 ( 2 5

. 7 )
M a x i m u m 3 3

. 5 ( 7 1

. 0 ) 

### Table 8 Study space outdoor air requirements based on Standard 62 addendum n

The sy stem design values were examined to determine if there was a dependence on the y ear that the building was built. Figures 3 through 5 show the design supply airflow capacity , the design minimum outdoor air intake, and the occupant density , respectively , as a function of the y ear built. No clear trends are evident for any of these par ameters, though there is a suggestion of lower supply airflows and occupant densities in newer buildings. Figures 3 and 4 show that more of the recent buildings employ VAV than CV sy stems, and that these VAV sy stems tend to have lower supply capacities as seen in Table 6. The supply air capacity was also examined as a function of the climate in which the building is located, as expressed by the number of heating and cooling degree day s, but no relationship was evident. The BASE protocol also obtained infor mation on the frequency of a number of sy stem maintenance activities. Table 9 summarizes the frequency of some inspection and maintenance activities that might impact ventilation airflows. Note that these frequencies are listed as the number of buildings, not the number of air handlers. Some of the less common frequencies, such as bi

- weekly , are not included in the table. Also, not all of the buildings reported the inspection and maintenance items listed in the table. The air handler inspections appear to o ccur fairly often, but there is no information on the extent of these inspections. The other four activities are reported to occur much less often, particularly ductwork inspections and sy stem testing, adjusting and balancing. The ratios of the measured ai rflows to design values were evaluated with respect to these frequencies, but no trends were evident.1 4 F r e q u e n c y A i r h a n d l e r i n s p e c t i o n D u c t w o r k i n s p e c t i o n C o n t r o l s i n s p e c t i o n C o n t r o l s

r e c a l i b r a t i o n T e s t i n g , a d j u s t i n g & b a l a n c i n g N u m b e r o f b u i l d i n g s D a i l y 1 4 0 1 4 0 0
W e e k l y 5 0 2 0 0
M o n t h l y 2 3 1 4 4 0 Q u a r t e r l y 2 9 2 1 2 3 0
S e m i

- a n n u a l l y 6 1 1 1 7 0
A n n u a l l y 3 4 1 4 1 0 3
A s n e e d e d 4 3 2 2 8 5 8 5 2
N o n e 0 5 9 1 2 1 5 4 3 

### Table 9 Reported frequencies of selected sy stem maintenance activities

Figure 3 D esign supply airflow capacity versus y ear built1 5 

### Figure 4 Design minimum outdoor air intak e versus y ear built

Figure 5 Design occupant density versus y ear built 0 10 20 30 40 50 60 70 80

1840 1860 1880 1900 1920 1940 1960 1980 2000

Year builtMinimum outdoor air, cfm/person

0 5 10 15 20 25 30 35Minimum outdoor air, L/s•person CV
VAV1 6 

### 3.3 Exhaust Sy stem Design and Building Airflow Balance

In addition to the air handlers d iscussed in the last section, the 159 exhaust ventilation sy stems serving the study spaces were also considered in an attempt to examine the net design airflow into or out of the buildings. Table 10 presents a summary of the design information for the exha ust sy stems, which are predominantly toilet exhausts but also include kitchen exhaust, building relief and other fans. Design airflows are available for only 129 of the exhaust fans. Note that the individual airflows cover a wide range, with the maximum de sign airflow 500 times the minimum. The third column presents the design airflow normalized by floor area for the 126 sy stems for which the floor area served is available. (For toilet exhausts, the floor area is that of the toilet room.) W hile the variatio n in this normalized value is still large, it is less than for the airflows. The last column presents the normalized design airflows for only the toilet exhausts, which exhibit a smaller standard deviation than for all the exhaust fans.

A l l e x h a u s t s y s t e m s T o i l e t e x h a u s t s o n l y L / s ( c f m ) L / s • m 2 ( c f m / f t 2 ) L / s • m 2 ( c f m / f t 2 )
# o f v a l u e s 1 2 9 1 2 6 8 8
M e a n 2 3 1 0 ( 4 8 8 0 ) 1 4

. 9 ( 2

. 9 4 ) 1 4

. 3 ( 2

. 8 1 )
S t a n d a r d d e v i a t i o n 3 2 9 0 ( 6 9 6 0 ) 2 1

. 8 ( 4

. 2 8 ) 1 3

. 2 ( 2

. 5 9 )
M i n i m u m 4 0 ( 9 0 ) 0

. 6 ( 0

. 1 3 ) 0

. 7 ( 0

. 1 4 )
1 0 t h p e r c e n t i l e 1 8 0 ( 3 9 0 ) 4

. 2 ( 0

. 8 3 ) 6

. 2 ( 1

. 2 3 )
2 5 t h p e r c e n t i l e 4 0 0 ( 8 5 0 ) 6

. 8 ( 1

. 3 4 ) 7

. 5 ( 1

. 4 7 )
M e d i a n 9 5 0 ( 2 0 2 0 ) 9

. 6 ( 1

. 8 9 ) 1 0

. 1 ( 1

. 9 9 )
7 5 t h p e r c e n t i l e 2 6 1 0 ( 5 5 3 0 ) 1 5

. 0 ( 2

. 9 6 ) 1 6

. 0 ( 3

. 1 5 )
9 0 t h p e r c e n t i l e 4 9 9 0 ( 1 0 5 7 0 ) 2 3

. 0 ( 4

. 5 2 ) 2 2

. 9 ( 4

. 5 1 )
M a x i m u m 2 1 2 5 0 ( 4 5 0 3 0 ) 1 8 9

. 0 ( 3 7

. 1 9 ) 9 1

. 3 ( 1 7

. 9 8 ) 

### Table 10 Summary of exhaust sy stem design values

In addition to the exhaust fan design values, the net design airflow into, or out of, the buildings was also considered. The issue of interest is whether and to what extent these building s are designed for positive pressurization, which is the ty pical design intent motivated by infiltration control, moisture transport through building envelopes and proper functioning of building exhaust fans. W hile the mean ratio of the supply to return de sign airflows for the study space air handlers in Table 6 is greater than one, this ratio does not include exhaust airflows and therefore does not describe the design airflow balance. In the BASE protocol, design values were obtained for air handler supply , return and outdoor airflows and for the exhaust fans serving the study spaces. These design values do not allow the determination of the net airflow for the building when there are other air handlers and exhaust fans. Therefore, a design airflow analy sis for the whole building could only be performed for the six study spaces that correspond to an entire building. Table 11 presents the relevant design values for these buildings and the results of the net airflow analy sis.

W ith only six buildings, and a lac k of design data in some cases, the net building airflow can be calculated for only a small number of cases. The sixth column of Table 11 contains the design supply airflow minus the design return and exhaust airflows for the three buildings for which it

c ould be calculated. This quantity describes the net airflow into the conditioned space of the building. For buildings CAEW 09 and CAJS22, the values are positive and equal to 0.05 L/s• m 2 

### (0.23 cfm/ft 2 

### ) and 0.17 L/s• m 2 

### (0.85 cfm/ft 2 

### ) respectively . In buildin g SDBW 01 the value is1 7 

### negative but very small,

- 0.01 L/s• m 2 

### (

- 0.05 cfm/ft 2 

### ), which is very close to a balance between the airstreams. The last column presents the balance between the air entering and leaving the building, i.e., the design minimum outdoor a ir intake minus the exhaust. Only four values can be determined, with three positive and one slightly negative. The three positive values, for buildings CAES09, CAJS22 and SDBW 01 respectively , are 0.05 L/s• m 2 

### (0.23 cfm/ft 2 

### ), 0.01 L/s• m 2 

### (0.03 cfm/ft 2 

### ) and 0.01 L/s• m 2 

### (0.05 cfm/ft 2 

### ). The negative value is so close to zero that it indicates a balance between the minimum intake and exhaust airflows.

D e s i g n a i r f l o w s , L / s ( c f m ) N e t d e s i g n a i r f l o w , L / s ( c f m )

B u i l d i n g S u p p l y R e t u r n M i n i m u m

o u t d o o r a i r E x h a u s t S u p . – r e t

.

– e x h

. M i n O A

– E x h

.

A Z H S 0 4 1 1 1 5 0 ( 2 3 6 1 0 ) N o v a l u e N o v a l u e 8 3 3 0 ( 1 7 6 4 0 ) - - - -
C A E W 0 9 3 8 7 3 0 ( 8 2 0 5 0 ) 3 0 7 0 0 ( 6 5 0 4 0 ) 8 0 3 0 ( 1 7 0 1 0 ) 6 0 0 ( 1 2 8 0 ) 7 4 3 0 ( 1 5 7 3 0 ) 7 4 3 0 ( 1 5 7 3 0 ) C A J S 2 2 8 9 7 0 ( 1 9 0 1 0 ) N o v a l u e 1 0 4 0 ( 2 2 0 0 ) 7 8 0 ( 1 6 5 0 ) 8 1 9 0 ( 1 7 3 6 0 ) 2 6 0 ( 5 5 0 ) S D B W 0 1 9 9 2 0 ( 2 1 0 1 0 ) 9 5 9 0 ( 2 0 3 1 0 ) 1 5 0 0 ( 3 1 7 0 ) 9 2 0 ( 1 9 5 0 ) - 5 9 0 (

- 1 2 5 0 ) 5 8 0 ( 1 2 2 0 ) T N F S 0 8 8 6 4 0 ( 1 8 3 1 0 ) N o v a l u e 5 9 0 ( 1 2 5 0 ) 6 0 0 ( 1 2 6 0 ) - - - 1 0 (

- 1 0 ) T X F S 0 2 1 7 0 0 0 ( 3 6 0 2 0 ) N o v a l u e N o v a l u e N o v a l u e

- - - - 

### Table 11 Net design airflow analy sis

3.4 Meas ured Occupant Density The actual number of occupants was counted at least four times in each study space. Table 12 summarizes these observations. These data show that on average the actual occupancy is about 80 % of the design occupancy as defined by the n umber of work stations, corresponding to a mean occupant density of 4.0 people per 100 m 2 

### (3.7 per 1000 ft 2 

### ). The occupant density data were also analy zed for only those times when the ventilation parameters were measured, ty pically on W ednesday and Thursd ay of the test week. There were 388 such values, but the
summary statistics are essentially identical to those seen in Table 11.

M e a s u r e d o c c u p a n t d e n s i t y , # / 1 0 0 m 2 ( # / 1 0 0 0 f t 2 ) M e a s u r e d d e n s i t y / N u m b e r

o f w o r k s t a t i o n s # o f v a l u e s 8 2 4 8 2 4
M e a n 4

. 0 ( 3

. 7 ) 0

. 7 8
S t a n d a r d d e v i a t i o n 1

. 7 ( 1

. 6 ) 0

. 2 4
M i n i m u m 0

. 9 ( 0

. 9 ) 0

. 2 4
1 0 t h p e r c e n t i l e 2

. 3 ( 2

. 2 ) 0

. 5 7
2 5 t h p e r c e n t i l e 2

. 8 ( 2

. 6 ) 0

. 6 5
M e d i a n 3

. 6 ( 3

. 3 ) 0

. 7 6
7 5 t h p e r c e n t i l e 5

. 0 ( 4

. 6 ) 0

. 8 7
9 0 t h p e r c e n t i l e 6

. 3 ( 5

. 9 ) 0

. 9 8
M a x i m u m 1 1

. 1 ( 1 0

. 3 ) 3

. 1 3



### Table 12 Su mmary of measured occupant density1 8 

### 3.5 V entilation Sy stem Performance Measurements This section presents the ventilation sy stem performance measurement results for the air handlers serving the study spaces and for the study spaces themselves. There were 5 62 ventilation measurement events, that is, the total number of times that some or all of the ventilation measurements were made on the study space air handlers. These measurements cover 97 of the 100 BASE buildings, excluding the three naturally ventilate d buildings. Appendix C lists a number of cases where measurement issues associated with the volumetric airflow measurements were identified, along with any adjustments that were made to account for these issues. The measurements are presented in Appendix D for the air handlers and Appendix E for the study spaces. Each measured value in these appendices is presented with an uncertainty estimate associated with the value. The naturally ventilated buildings are discussed in conjunction with the outdoor air ve ntilation estimated using peak CO 2 

### concentrations in section 3.5.4.

3.5.1 Supply Airflow Of the 562 measurement events, 495 included measurements of the sy stem supply airflow. In some cases, the supply airflow is estimated by adding the outdoor air intak e and the recirculation airflow, resulting in a total of 536 measured supply airflow values. As noted earlier, the uncertainty associated with the supply airflow measurements was estimated to equal 10 %. W hen the supply airflow is based on the sum of the o utdoor and recirculation airflows, the uncertainty in the supply airflow is about 25 %, based on a 30 % uncertainty in the outdoor airflow and 10 % in the recirculation flow. The measured supply airflows are compared with the design supply capacities in th e 512 cases where a design value exists. The mean value of the ratio of the measured supply airflow to the design value is 0.83. The mean is 0.72 for the VAV sy stems and 1.07 for the CV sy stems. The VAV sy stems are e xpected to have a lower ratio of measure d to design, since these sy stems modulate the supply airflow in response to internal loads. Figure 6 is a plot of the measured to design ratio against outdoor temperature. Note that for the VAV sy stems, the ratio decreases for outdoor temperatures below ab out 15 °C (59 °F), presumably due to the lower cooling loads at these temperatures. The CV data points exhibit little dependence on outdoor temperature. Four CV points have a ratio of about 4.5, which all correspond to the single air handler serving study space CAJS03. This air handler has the lowest design value of supply airflow capacity per unit floor area, and it is possible that the design value is in error or out of date. The mean ratio of measured to design for CV sy stems is reduced from 1.07 to 0.98 without these four values. The supply airflows for the air handlers were combined to determine the supply airflow to each study space. These supply airflows were then divided by the study space floor area (B1AREA), and the results are summarized in Table 13 and plotted versus outdoor air temperature in Figure 7. Both the table and the figure distinguish between VAV and CV sy stems. The values of the study space supply airflow per unit floor area range from 0.88 L/s•m 2 

### (0.17 cfm/ft 2 

### ) to 21.11 L/s• m 2 

### (4.15 cf m/ft 2 

### ). The mean value for all the sy stems is 5.12 L/s•m 2 

### (1.01 cfm/ft 2 

### ) ; the mean uncertainty is 16 % of the measured value, and the maximum is 31 %. As expected, the VAV sy stems have lower supply airflows than the CV sy stems, and the dependence on outdoo r temperature is similar to that seen in Figure 6. Note that the high points in Figure 7 do not correspond to the high points in Figure 6. The eight points in Figure 7 greater than 15 L/s• m 2 

### (3 cfm/ft 2 

### ) correspond to cases with high design supply airflows (CAES17 and LAGW 05).1 9 

### Figure 6 Ratio of measured to design supply airflow versus outdoor temperature

S u p p l y a i r f l o w / F l o o r a r e a L / s • m 2 ( c f m / f t 2 ) A l l s y s t e m s V A V C V
# o f v a l u e s 3 8 4 2 8 9 9 5
M e a n 5

. 1 2 ( 1

. 0 1 ) 4

. 5 5 ( 0

. 9 0 ) 6

. 8 6 ( 1

. 3 5 ) S t d

. D e v

. 3

. 0 2 ( 0

. 5 9 ) 2

. 6 2 ( 0

. 5 2 ) 3

. 4 6 ( 0

. 6 8 )
M i n i m u m 0

. 8 8 ( 0

. 1 7 ) 0

. 8 8 ( 0

. 1 7 ) 1

. 8 0 ( 0

. 3 5 )
1 0 t h p e r c e n t i l e 2

. 1 6 ( 0

. 4 3 ) 2

. 1 2 ( 0

. 4 2 ) 2

. 2 5 ( 0

. 4 4 )
2 5 t h p e r c e n t i l e 2

. 9 9 ( 0

. 5 9 ) 2

. 8 9 ( 0

. 5 7 ) 4

. 8 2 ( 0

. 9 5 )
M e d i a n 4

. 6 9 ( 0

. 9 2 ) 4

. 3 0 ( 0

. 8 5 ) 5

. 7 2 ( 1

. 1 3 )
7 5 t h p e r c e n t i l e 6

. 2 5 ( 1

. 2 3 ) 5

. 6 9 ( 1

. 1 2 ) 9

. 0 4 ( 1

. 7 8 )
9 0 t h p e r c e n t i l e 8

. 4 7 ( 1

. 6 7 ) 7

. 1 9 ( 1

. 4 1 ) 1 1

. 3 4 ( 2

. 2 3 )
M a x i m u m 2 1

. 1 1 ( 4

. 1 5 ) 2 1

. 1 1 ( 4

. 1 5 ) 1 6

. 2 4 ( 3

. 2 0 ) 

### Table 13 Summary of measured supply airflows 0 1 2 3 4 5

-20 -10 0 10 20 30 40 0 20 40 60 80 100

VAV
CVMeasured supply airflow/Design supply airflow Outdoor temperature (°F)

Outdoor temperature (°C)2 0 

### Figure 7 Measured study space supply airflow versus outdoor temperature

3.5.2 Outdoor A ir Fraction The outdoor air fraction (i.e., the outdoor air intake divided by the supply airflow) was determined in two way s, dividing the measured outdoor airflow by the measured supply airflow and second through the measurement of CO 2 

### concentrations in t he outdoor, supply and recirculation airstreams. The former determination is referred to as the volumetric value, while the latter is referred to as the CO 2 

### ratio value. The volumetric outdoor air fraction was determined for each air handler test based on whichever of the expressions in Equations (1a), (1b) and (1c), described in section 2.2, apply . For some air handlers, the value of F o 

### could be determined using more than one of the expressions. Of the 562 air handler test events, there were 350 values of F o 

### based on Q O 

### divided by Q S 

### (Equation 1a), 125 based on (Q S 

### minus Q R 

### ) divided by Q S 

### (Equation 1b) and 57 based on Q O 

### divided by (Q O 

### plus Q R 

### ) (Equation 1c). As noted earlier, in some cases when Equation (1b) was applied, the value of Q R 

### was greater than Q S 

### , but the difference was never significantly different from zero. In those cases, the outdoor airflow and outdoor air fraction are both set equal to zero. For each determination of the outdoor air fraction, the uncertainty is calculated based on the uncert ainties in Q O 

### , Q S 

### and Q R 

### . W hen F o 

### can be determined using more than one of these expressions, the value of F o 

### with the lowest uncertainty is identified and referred to as the best volumetric value of F o 

### . The outdoor air fraction was also determined using C O 2 

### concentrations measured in the outdoor, supply and recirculation airstreams using Equation (2).

Table 14 summarizes the measured outdoor air fractions for both the volumetric and CO 2 

### methods. Some of the volumetric values are greater than 100 %, which d oes not make phy sical sense. However, in all of these cases but one, the uncertainty around the value includes 100 % outdoor air. That single value is not included in Table 14 or the subsequent analy sis, but it is included in Appendix D. The mean volumetri c outdoor air fraction is 0.38 , and the mean CO 22 1 

### value is 0.31. The mean uncertainty in the volumetric outdoor air fraction is 0.16, while the maximum uncertainty is 0.44. The uncertainties in the CO 2 

### - based values tend to be larger, with a mean uncertainty of 0.60 (roughly twice the mean outdoor air fraction) and several values as high as 2 to 4 in units of outdoor air fraction.

B e s t v o l u m e t r i c C a r b o n d i o x i d e # o f v a l u e s 5 0 9 5 2 0
M e a n 0

. 3 8 0

. 3 1
S t a n d a r d d e v i a t i o n 0

. 3 5 0

. 2 7
M i n i m u m 0

. 0 0 0

. 0 0
1 0 t h p e r c e n t i l e 0

. 0 4 0

. 0 3
2 5 t h p e r c e n t i l e 0

. 1 0 0

. 1 1
M e d i a n 0

. 2 2 0

. 2 3
7 5 t h p e r c e n t i l e 0

. 5 9 0

. 4 4
9 0 t h p e r c e n t i l e 1

. 0 0 0

. 7 5
M a x i m u m 1

. 5 2 1

. 2 0



### Table 14 Summary of measured outdoor air fraction

Figure 8 is a plot of the outdoor air fraction against outdoor air tempe rature, with sy stems having economizer cy cles distinguished from those that do not. Note that most of the low outdoor air intake values, i.e., outdoor air fractions below about 0.25, correspond to temperatures greater than 20 °C (68 °F). As expected, sy ste ms with economizer cy cles tend to have higher outdoor air fractions at milder temperatures than sy stems without economizers; the non

- economizer sy stems also tend to operate more consistently at lower outdoor air fractions. However, there are some exception s to this general dependence, which could be due to a variety of causes such as the temperature and humidity sensors used to control the economizers being out of calibration. The dependence of outdoor air fraction on outdoor temperature leads one to expect that minimum outdoor air intake conditions are more likely to exist at these warmer temperatures than under colder conditions, which has implications for planning field evaluations of ventilation sy stem performance. Figure 9 is a plot of the outdoor air fraction against outdoor temperature for an idealized economizer cy cle. It shows that such a sy stem operates at minimum outdoor air at cold and hot temperatures, less than 0 °C (32 °F) and greater than 20 °C (68 °F), though these particular values are only examples. In between these two temperatures, the sy stem uses outdoor air to cool the building, with a lower outdoor air fraction as the temperature gets colder. Figure 10 is a plot of whole building air change rates measured with the tracer gas decay meth od plotted against outdoor air temperature from a previous study (Persily et al. 1992). These data clearly exhibit the pattern seen in Figure 9. W hile the data in Figure 8 suggest the same pattern and are consistent with expected variations due to economiz er operation, note that the actual data include ty pically four points for each building generally over a narrow temperature range and not all the buildings have economizer cy cles.2 2 0.0 0.2 0.4 0.6 0.8 1.0 1.2

-20 -10 0 10 20 30 40 0 20 40 60 80 100Outdoor air fraction Outdoor temperature (°F)

Outdoor temperature (°C) 

### Figure 8 V olumetric outdoor air fraction versus outdoor temperature

Fi gure 9 Outdoor air fraction for an idealized economizer cy cle 0.00 0.25 0.50 0.75 1.00 1.25 1.50

-20 -10 0 10 20 30 40 0 20 40 60 80 100

Economizer cycle No economizer cycle Outdoor temperature (°F)

Outdoor temperature (°C)Outdoor air fraction - volumetric2 3 

### Figure 10 Measured air change rates versus outdoor air temperature (Persily et al. 1992)

As noted earlier, the uncertainties in the CO 2 

### - based outdoor air fractions tend to be larger than the u ncertainties in the volumetric values. The CO 2 

### uncertainties are based on the concentration measurement uncertainty of 90 mg/m 3 

### (50 ppm(v)). The larger uncertainties in the CO 2 

### values occur due to the magnitude of the concentration measurement uncertainty relative to the concentration differences in Equation 2. The difference between C R 

### and C O 

### , relative to the concentration measurement uncertainty , is the primary determinant of the uncertainty in F o 

### . Figure 11 is a plot of the CO 2 

### concentration difference between the recirculation and outdoor airstream versus time of day at which the concentration measurements began. The average concentration difference is 391 mg/m 3 

### (217 ppm(v)), with a mean difference for measurements before noon of 418 mg/m 3 

### (232 ppm(v)) and an afternoon mean of 369 mg/m 3 

### (205 ppm(v)). Given that the concentration measurement uncertainty of 90 mg/m 3 

### (50 ppm(v)) is equal to 25 % of the mean concentration difference, it is not surprising that the values of F o 

### based on CO 2 

### are so imprecise. In making these measurements, the same CO 2 

### monitor was used to measure the concentration in the three airstreams over a relatively short period of time. Therefore, it is reasonable to expect that the uncertainty is lower for the differential CO 2 

### concentrat ions in Equation 2 than for the absolute concentrations. The uncertainties in the CO 2 

### outdoor air fractions were recalculated using an uncertainty of 90 mg/m 3 

### (50 ppm(v)) for the differential concentrations. The mean uncertainty was reduced from 0.60 to 0. 42, and the median value of the uncertainty decreased from 0.43 to 0.31. It is not possible to estimate the actual uncertainty in the differential concentrations after the fact, though it is likely to be less than for the absolute concentrations. Nonethele ss, the form of the equation used to determine F o 

### from CO 2 

### concentrations makes it advantageous to perform the uncertainty calculations based on the uncertainty in the differential concentration and also implies that one can tolerate some zero drift in the CO 2 

### monitor without a large degradation in accuracy

. 0.0 0.5 1.0 1.5 2.0 2.5 3.0

-20 -10 0 10 20 30 40 0 20 40 60 80 100Air change rate (h-1) Outdoor temperature (°F)

Outdoor temperature (°C)2 4 

### Figure 11 Return minus outdoor air CO 2 

### concentration versus time of day

Figure 12 is a plot of F o 

### based on CO 2 

### versus the volumetric value. This comparison shows that despite the high level of uncer tainty in the CO 2 

### values, they are generally consistent with those based on volumetric airflows. The line in the plot corresponds to perfect agreement between the two parameters and is not a curve fit to the data. A linear regression of the CO 2 

### to the volu metric values y ields a slope of 0.61 and an r

- squared of 0.58. 0 100 200 300 400 500 600 700 800

8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00

Start Time of MeasurementCR- CO(ppm(v))

0 200 400 600 800 1000 1200 1400CR- CO(mg/m3)2 5 

### Figure 12 Outdoor air fraction based on CO 2 

### versus volumetric 0.00 0.25 0.50 0.75 1.00 1.25

0.00 0.25 0.50 0.75 1.00 1.25

Outdoor air fraction - VolumetricOutdoor air fraction - CO2ratio2 6 

### 3.5.3 Outdoor Air Ventilation
Of the 562 measurement events, 510 included traverse measurements, or estimates based on the d ifference between the supply and recirculation airflow, of the sy stem outdoor air intake. The measured outdoor airflows are compared with the design minimum outdoor air intakes for the 274 cases where such a design value exists. Figure 13 is a plot of the ratio of the measured outdoor air intake to the design intake versus outdoor air temperature, with a distinction between
sy stems with economizer cy cles and those without. The mean ratio of the measured to design outdoor airflow is 1.93, including one case where the measured value is about 30 times larger than the design minimum. The mean is 2.28 for the economizer sy stems and 1.37 for non

economizer sy stems. Economizer sy stems are expected to have a higher ratio of measured to design, since they increase th e outdoor air intake for free cooling and the design value is a minimum. Note the existence of many points with a ratio of measured to design below 1.0, which would not exist if the sy stems were operating as intended.

Figure 13 Ratio of measured to desig n outdoor airflow versus outdoor temperature

As described in section 2.2, outdoor air ventilation rates in the study spaces were calculated based on the measurements for the individual air handlers and the percentage of air from each handler provided to th e study space. Table 15 summarizes the measured outdoor air ventilation to the study spaces. The second column presents these values on a per person basis using the actual number of occupants during each measurement. The mean value is 49 L/s (105 cfm) per person, which is high relative to the 10 L/s (20 cfm) per person value specified in many current building codes (based on ASHRAE Standard 62

- 2001). The mean uncertainty in the per person rates is about 40 % of the mean value. Of these per person values, 17 % are below 10 L/s (20 cfm) per person and 9 % are below 5 L/s (10 cfm). Per person rates below 10 L/s (20 cfm) were seen in 22 of the 97 mechanically ventilated buildings, while rates below 5 L/s (10 cfm) were seen in 13 of the buildings. The table also presents the outdoor air ventilation in L/s• m 2 

### (cfm/ft 2 

### ) 0 2 4 6 8 10

-20 -10 0 10 20 30 40 0 20 40 60 80 100

Economizer cycle No economizer cycleMeasured/design minimum outdoor air intake Outdoor temperature (°F)

Outdoor temperature (°C)2 7 

### of floor area and air changes per hour. There are two less cases of ventilation per person because of two events without measured values of occupancy

.

P e r p e r s o n L / s ( c f m ) p e r p e r s o n P e r u n i t f l o o r a r e a L / s • m 2 ( c f m / f t 2 ) A i r c h a n g e s p e r h o u r , h - 1

# o f v a l u e s 3 6 7 3 6 9 3 6 9
M e a n 4 9 ( 1 0 5 ) 1

. 8 7 ( 0

. 3 7 ) 1

. 8 3
S t d

. D e v

. 5 4 ( 1 1 4 ) 2

. 0 8 ( 0

. 4 1 ) 2

. 0 7
M i n i m u m 0 ( 0 ) 0 ( 0 ) 0

. 0 0
1 0 t h p e r c e n t i l e 6 ( 1 3 ) 0

. 2 4 ( 0

. 0 5 ) 0

. 2 2
2 5 t h p e r c e n t i l e 1 3 ( 2 7 ) 0

. 5 0 ( 0

. 1 0 ) 0

. 4 7
M e d i a n 3 0 ( 6 3 ) 1

. 0 3 ( 0

. 2 0 ) 0

. 9 8
7 5 t h p e r c e n t i l e 6 6 ( 1 4 0 ) 2

. 3 0 ( 0

. 4 5 ) 2

. 4 6
9 0 t h p e r c e n t i l e 1 1 6 ( 2 4 5 ) 4

. 6 4 ( 0

. 9 1 ) 4

. 4 6
M a x i m u m 3 1 0 ( 6 5 7 ) 1 2

. 3 1 ( 2

. 4 2 ) 1 3

. 2 3 

### Table 15 Summary of Measured Outdoor Air V entilation

–V olumetric

Given the noted prevalence of minim um outdoor air intake conditions at higher outdoor air temperatures, the per person ventilation values were separated into those with outdoor temperatures below and above 20 °C (68 ° F). The mean value below 20 °C (68 °F) is 60 L/s ( 126 cfm) per person, and the mean for temperatures greater than or equal to that value is 38 L/s (81 cfm) per person. The per person outdoor air rates were also analy zed to identify those for which the outdoor air fraction was below 20 %, presuming that those values correspond to operation under minimum outdoor air intake. Of the 367 values of outdoor air per person, 148 correspond to less than 20 % outdoor air. (These minimum conditions are seen in 42 of the 97 mechanically ventilated buildings.) The mean of these values is 13.7 L/s (28.9 cfm) per person based on the measured number of occupants, and the median is 11.7 L/s (24.7 cfm). Normalizing these minimum outdoor airflows by the number of workstations, rather than the measured number of o ccupants, y ields a mean of 10.5 L/s (2 2.2 cfm) per person and a median of 9.4 L/s (20.0 cfm). Of these 148 values corresponding to minimum outdoor air, 41 % are below the per person requirement in Standard 62

- 2001 based on the measured number of occupants and 50 % are below that requirement ba sed on the number of workstations. In other words, under minimum outdoor air intake, about one

- half of the measured outdoor air intake rates are below the requirements in ASHRAE Standard 62

- 2001 based on the expected occupancy levels in the space. Similarl y , about 20 % of these minimum values are below 5 L/s (10 cfm) per measured occupant and about 25 % are below 5 L/s (10 cfm) per workstation.

Outdoor air ventilation was also determined from the CO 2 

### - based outdoor air fraction multiplied by the measured sup ply airflow. The values for the air handlers are then combined to determine the outdoor airflow per person for the study spaces, and the results are summarized in Table 16. Due to the large uncertainties in the CO 2 

### outdoor air fraction, the mean uncertaint y in the study space outdoor airflow is also quite large, 8 5 L/s ( 179 cfm) per person . Nevertheless, the mean values of the volumetric and CO 2 

### - ratio outdoor ventilation airflow per person are remarkably similar, 49 L/s (105 cfm) and 44 L/s ( 9 4 cfm) respect ively . Figure 14 is a plot of the CO 2 

### - ratio ventilation to the volumetric values. W hile there is significant scatter about the line of perfect agreement, and a tendency for the CO 2 

### - ratio values to be lower at the highest per person2 8 

### ventilation, the two det erminations are consistent o n average. A linear regression of CO 2 

### - ratio to the volumetric ventilation y ields a slope of 0. 80 and an r

- squared of 0. 64

.

O u t d o o r a i r p e r p e r s o n , L / s ( c f m ) # o f v a l u e s 3 5 6 M e a n 4 4 ( 9 4 ) S t d

. D e v

. 4 7 ( 1 0 1 ) M i n i m u m 0 ( 0 ) 1 0 t h p e r c e n t i l e 5 ( 1 1 ) 2 5 t h p e r c e n t i l e 1 2 ( 2 6 ) M e d i a n 3 1 ( 6 5 ) 7 5 t h p e r c e n t i l e 5 9 ( 1 2 5 ) 9 0 t h p e r c e n t i l e 9 6 ( 2 0 3 ) M a x i m u m 3 3 9 ( 7 1 7 ) 

### Table 16 Summary of Measured Outdoor Air V entilation

–CO 2 

### Ratio

Figure 14 Outdoor air ventilation, CO 2 

### - ratio versus vol umetric

As noted, the measured per person outdoor air ventilation values are high relative to the outdoor air requirement in ASHRAE Standard 62

- 2001. These values are higher than might be expected for two primary reasons; the occupant density is below desi gn and the outdoor air fraction is frequently not at minimum, generally due to economizer operation. As noted earlier, the mean measured occupant density is about 3.5 persons per 100 m 2 

### (3.2 per 1000 ft 2 

### ), corresponding to about 80 % of the number of works tations and about half of the default occupant density in Standard 62

- 2001. In addition, the mean outdoor air fraction is about 0.40. If each outdoor air2 9 

### measurement is adjusted to the design occupant density (number of workstations) and to minimum outdoor air intake, then the per person ventilation values are more consistent with expectations. Table 17 presents these adjustments, with the measured outdoor air ventilation per person from Table 15 in the second column. The next column presents the outdoor ai r ventilation normalized by the number of workstations in the space rather than the measured occupancy

, which reduces the mean ventilation rate to 36 L/s (76 cfm) per person. In the last two columns, the values are adjusted to an outdoor air fraction of 0. 15. This adjustment involves dividing the outdoor air ventilation rate by the actual outdoor air fraction and then multiply ing the result by 0.15, unless the actual fraction is already 0.15 or less. In the latter cases, the ventilation rate is not adjusted . The 15 % value is used as a ty pical value of the minimum outdoor air fraction. (Note from Table 6 that the mean value of the design minimum outdoor air fraction was 1 9 %

, and the median was 12 %.) The values in the fourth column are based on the number o f workstations in the study space, while the values in the last column use the default occupant density for office space in Standard 62

- 2001, i.e., 7 people per 100 m 2 

### (1000 ft 2 

### ). As discussed earlier, the design value for occupant density is not available for the study spaces. However, if one uses the default value in Standard 62

- 2001 for office space, as in the last column of Table 17, the mean per person ventilation rate are very close to the requirement in the standard.

A d j u s t e d t o 1 5 % o u t d o o r a i r M e a s u r e d ( T a b l e 1 5 ) A d j u s t e d t o #

o f w o r k s t a t i o n s # o f w o r k s t a t i o n s S t a n d a r d 6 2 d e f a u l t

o c c u p a n t d e n s i t y L / s ( c f m ) p e r p e r s o n M e a n 4 9 ( 1 0 5 ) 3 6 ( 7 6 ) 1 2 ( 2 6 ) 8 ( 1 8 )
S t d

. D e v

. 5 4 ( 1 1 4 ) 3 7 ( 7 9 ) 8 ( 1 7 ) 6 ( 1 3 )
M i n i m u m 0 ( 0 ) 0 ( 0 ) 0 ( 0 ) 0 ( 0 )
1 0 t h p e r c e n t i l e 6 ( 1 3 ) 5 ( 1 0 ) 4 ( 9 ) 3 ( 5 )
2 5 t h p e r c e n t i l e 1 3 ( 2 7 ) 1 0 ( 2 2 ) 7 ( 1 4 ) 5 ( 1 0 )
M e d i a n 3 0 ( 6 3 ) 2 1 ( 4 5 ) 1 1 ( 2 3 ) 7 ( 1 5 )
7 5 t h p e r c e n t i l e 6 6 ( 1 4 0 ) 5 2 ( 1 1 0 ) 1 6 ( 3 4 ) 1 1 ( 2 3 )
9 0 t h p e r c e n t i l e 1 1 6 ( 2 4 5 ) 8 7 ( 1 8 4 ) 2 1 ( 4 4 ) 1 6 ( 3 4 )
M a x i m u m 3 1 0 ( 6 5 7 ) 2 1 0 ( 4 4 4 ) 4 7 ( 1 0 0 ) 4 2 ( 8 9 ) 

### Table 17 Outdoor air ventilation adjusted for occupancy and outdoor air fraction

3.5.4 Outdoor Airflows from Peak Carbon Dioxide Indoor carbon dioxide concentrations were also used to estimate outdoor air ventilation, using a steady

- state, single

- zone mass balance analy sis to relate the indoor CO 2 

### concentration to the per person outdoor air ventilation as discussed in Section 2.2. As noted, a critical assumption behind the approach is that the indoor CO 2 

### concentration is indeed at steady state. It is also assumes constant outdoor concentration, ventilation and occupancy , as well as a uniform indoor CO 2 

### concentration. Note that this approach provides the only means to estimate the outdoor air ventilation in the three naturally ventilated buildings. As described earlier, peak CO 2 

### concentrations were used to estimate outdoor ventilation per person for all 100 study spaces. These estimates are based on averaging the CO 2 

### concentrations among the fixed monitors in each space on a 10 min basis, and then id entify ing the maximum value of this average for the morning and afternoon of each day . The per person ventilation rates based on these estimates are summarized in Table 18. The second column contains all the values of the per person outdoor airflow determi ned from the peak CO 2 

### data. The third column contains3 0 

### only those values obtained on the “test day s,” i.e., those day s (ty pically W ednesday and Thursday of the study week) during which the other ventilation measurements were made. The last column reproduces the summary statistics for the volumetric measurements from Table 15. The mean uncertainty in the peak CO 2 

### ventilation rates is 10 L/s ( 22 cfm) per person , which is about one

- half the mean uncertainty for the volumetric rates. Also, note that the peak CO 2 

### values are significantly lower than those obtained from the volumetric measurements. This trend is contrary to what one might expect, as the outdoor airflows determined using the peak CO 2 

### method include both ventilation sy stem outdoor air intake and outdo or air infiltration due to envelope leakage, while the volumetric results include only the former. Figure 15 is a plot of the per person outdoor air ventilation determined from the peak CO 2 

### concentrations versus the corresponding volumetric values. The sol id line corresponds to perfect agreement. Note that above roughly 25 L/s (50 cfm) per person, almost all of the CO 2 

### - based values are lower than the volumetric airflows.

O u t d o o r a i r v e n t i l a t i o n , L / s ( c f m ) p e r p e r s o n

A l l p e a k C O 2 d a t a P e a k C O 2 d a t a o n

“ t e s t d a y s ” V o l u m e t r i c r e s u l t s f r o m T a b l e 1 5
# o f v a l u e s 5 4 8 3 5 3 3 6 7
M e a n 2 0 ( 4 3 ) 2 1 ( 4 5 ) 4 9 ( 1 0 5 )
S t d

. D e v

. 1 4 ( 3 1 ) 1 7 ( 3 5 ) 5 4 ( 1 1 4 )
M i n i m u m 6 ( 1 3 ) 6 ( 1 3 ) 0 ( 0 )
1 0 t h p e r c e n t i l e 1 0 ( 2 0 ) 1 0 ( 2 1 ) 6 ( 1 3 )
2 5 t h p e r c e n t i l e 1 2 ( 2 6 ) 1 3 ( 2 7 ) 1 3 ( 2 7 )
M e d i a n 1 8 ( 3 7 ) 1 8 ( 3 8 ) 3 0 ( 6 3 )
7 5 t h p e r c e n t i l e 2 4 ( 5 0 ) 2 5 ( 5 3 ) 6 6 ( 1 4 0 )
9 0 t h p e r c e n t i l e 3 2 ( 6 8 ) 3 3 ( 7 1 ) 1 1 6 ( 2 4 5 )
M a x i m u m 2 1 3 ( 4 5 2 ) 2 1 3 ( 4 5 2 ) 3 1 0 ( 6 5 7 ) 

### Table 18 Summary of Measured Outdoor Air V entilation

–Peak CO 2


### The reason that the peak CO 2 

### values tend to be lower than expected has been investigated, but no explanation has y et been verified. Considering the methodology behind the peak CO 2 

### analy sis, one might suspect the lack of steady

- state CO 2 

### concentrations could be impacting the agreement between the two v alues. However, steady state is more likely to occur at the higher ventilation rates due to the shorter sy stem time constants, resulting in better agreement at higher rates, which is contrary to what is seen in Figure 15. Another potential explanation is t he existence of significant CO 2 

### concentration gradients within the study spaces, as well as between them and adjoining spaces, given that the single

- zone analy sis method assumes a uniform concentration within the zone and neglects interzone transfer of CO 2 

### . W hile it is certainly possible that the CO 2 

### concentrations were different in adjoining zones, one would expect the impact to be positive in some cases and negative in others. However, the differences in the data tend to all be in one direction. The level of agreement was examined in those study spaces that corresponded to an entire building, for which concentration differences in adjoining spaces are not an issue, and the peak CO 2 

### and volumetric ventilation rates were not observed to agree any better. Not e that the fixed CO 2 

### monitors in the study spaces were placed at a height of 1.1 m (43 in.) above the floor and at locations representative of workstation lay out and work activities, i.e., locations in hallway s and passageway s were intentionally avoided (E PA 2003). Given these guidelines on location, it is possible that the measured CO 2 

### concentrations are higher than the study

- space3 1 

### average. If the measured CO 2 

### concentration is indeed higher than the true space average, then the calculated ventilation rates would be low relative to their actual value. Also, it is reasonable to expect that the lack of uniformity would be more pronounced at higher outdoor air ventilation with less recirculation of return air, leading to the observed increase in errors. However , it is not possible to verify the magnitude of the concentration nonuniformity in these spaces based on the available data, and therefore it cannot be confirmed whether this is necessarily a valid explanation for the observed differences. The peak CO 2 

### con centrations were examined with the issue of nonuniformity in mind, and it was determined that the actual average concentration in the study space would have to be 360 mg/m 3 

### to 720 mg/m 3 

### (200 ppm(v) to 400 ppm(v)) lower than that measured by the fixed monit ors to explain the observed differences.

Figure 15 Outdoor air ventilation, CO 2 

### peak versus volumetric

The peak CO 2 

### analy sis provides the only means for estimating ventilation rates in the three naturally ventilated buildings. Table 19 presents the estim ated outdoor air ventilation rates for each of the three study spaces for each time period it was estimated, generally once in the morning and once in the afternoon. These values are presented first as per person values, based only on the difference betwee n the peak CO 2 

### concentration and the outdoor concentration, along with an estimate of the uncertainty in each value. The last column presents these values in air changes per hour, based on the study space volume and the measured occupancy . The first study space, NYBS06, has high per person ventilation rates, especially in units of air changes per hour, but also high uncertainties. Since high ventilation values correspond to low differences between the peak CO 2 

### concentration and the outdoor concentration, hi gher uncertainties alway s exist at higher ventilation rates. It is not clear why the ventilation rates in this building are so high, but it does have operable windows, 50 % of which were reported to be open during the measurements. In addition, the buildin g has toilet exhausts with design flow rates per floor area on the high end of the buildings. However, the measured exhaust flows during the test week were zero. The3 2 

### afternoon reading on the third day for NYBS06 has a much lower ventilation rate than the o ther times. There were no outdoor concentration readings available for building ORIS02, and a value of 670 mg/m 3 

### (373 ppm(v)) was assumed. W hile peak CO 2 

### analy sis allows the estimation of ventilation in the naturally ventilated buildings, the comparison wi th the volumetric values in the mechanically ventilated buildings does raise questions regarding their validity

.

S t u d y

s p a c e D a t e T i m e o f d a y O u t d o o r a i r

v e n t i l a t i o n p e r p e r s o n U n c e r t a i n t y i n o u t d o o r a i r

p e r p e r s o n O u t d o o r a i r

v e n t i l a t i o n U n c e r t a i n t y i n

o u t d o o r a i r

v e n t i l a t i o n A M o r P M L / s ( c f m ) h - 1

N Y B S 0 6 6 / 1 6 / 9 8 A M 4 0

. 3 ( 8 5

. 4 ) 1 7

. 8 ( 3 8

. 0 ) 3 3

. 4 1 6

. 3
6 / 1 6 / 9 8 P M 2 7

. 8 ( 5 8

. 9 ) 8

. 8 ( 1 8

. 6 ) 2 8

. 5 1 2

. 4
6 / 1 7 / 9 8 A M 4 2

. 6 ( 9 0

. 2 ) 2 0

. 0 ( 4 2

. 3 ) 4 0

. 2 2 0

. 9
6 / 1 7 / 9 8 P M 3 3

. 3 ( 7 0

. 6 ) 1 2

. 4 ( 2 6

. 3 ) 4 0

. 3 1 8

. 1
6 / 1 8 / 9 8 A M 4 4

. 2 ( 9 3

. 6 ) 2 1

. 5 ( 4 5

. 5 ) 4 6

. 1 2 2

. 9
6 / 1 8 / 9 8 P M 1 9

. 6 ( 4 1

. 5 ) 4

. 6 ( 9

. 7 ) 7

. 8 4

. 5
O R I S 0 2 8 / 3 0 / 9 4 A M 2 6

. 1 ( 5 5

. 4 ) 8

. 0 ( 1 7

. 0 ) 0

. 5 0

. 2
8 / 3 0 / 9 4 P M 2 5

. 9 ( 5 4

. 9 ) 7

. 9 ( 1 6

. 7 ) 0

. 4 0

. 2
8 / 3 1 / 9 4 A M 2 9

. 5 ( 6 2

. 5 ) 1 0

. 1 ( 2 1

. 4 ) 0

. 5 0

. 2
8 / 3 1 / 9 4 P M 2 8

. 0 ( 5 9

. 3 ) 9

. 2 ( 1 9

. 4 ) 0

. 6 0

. 3
9 / 1 / 9 4 A M 4 5

. 2 ( 9 5

. 7 ) 2 3

. 1 ( 4 9

. 0 ) 1

. 0 0

. 5
9 / 1 / 9 4 P M 2 8

. 3 ( 6 0

. 0 ) 9

. 4 ( 1 9

. 8 ) 0

. 5 0

. 2
W A I W 0 1 2 / 2 5 / 9 7 A M 8

. 4 ( 1 7

. 9 ) 1

. 2 ( 2

. 5 ) 0

. 5 0

. 1
2 / 2 5 / 9 7 P M 7

. 4 ( 1 5

. 7 ) 1

. 0 ( 2

. 0 ) 0

. 4 0

. 1
2 / 2 6 / 9 7 A M 1 2

. 6 ( 2 6

. 8 ) 2

. 2 ( 4

. 6 ) 0

. 4 0

. 1
2 / 2 6 / 9 7 P M 7

. 4 ( 1 5

. 6 ) 1

. 0 ( 2

. 0 ) 0

. 4 0

. 1
2 / 2 7 / 9 7 A M 8

. 8 ( 1 8

. 7 ) 1

. 2 ( 2

. 6 ) 0

. 5 0

. 1



### Table 19 Outdoor air ventilation for naturally ventilated spaces3 3 

### 3.5.5 Supply Diffuser Airflows The BASE protocol calls for airflow to be measured at the individual supply diffusers serving the study sp ace one time during the test week. Diffuser measurements were made in 88 of the 97 mechanically ventilated buildings, and Table 20 presents the results of those measurements. The second column contains the number of diffusers in these 88 study spaces, whil e the third column summarizes the fraction of those diffusers for which the supply airflow was measured. The total supply airflow, normalized by study space floor area, is presented in the fourth column. This value is adjusted to account for less than 100 % of the diffusers being measured by assuming the supply airflow per diffuser at the unmeasured diffusers is the same as at the mean of the measured value. The last column is the total (adjusted) supply airflow in the fourth column divided by the supply a irflow determined at the air handlers, as discussed in section 3.3.1. On average, the total supply airflow at the diffusers is only 73 % of the value measured at the air handlers. This lack of agreement is a function of the large measurement uncertainties in both values, plus the possibility of supply duct leakage. However, the existence and magnitude of such leakage was not assessed as part of this study , and these data do not serve as a reliable measure of duct leakage.

# o f d i f f u s e r s F r a c t i o n o f d i f f u s e r s

m e a s u r e d T o t a l d i f f u s e r f l o w , a d j u s t e d L / s • m 2 ( c f m / f t 2 ) T o t a l d i f f u s e r f l o w / S t u d y s p a c e s u p p l y

a i r f l o w a t a i r h a n d l e r s M e a n 9 3 0

. 9 4 3

. 4 0 ( 0

. 6 7 ) 0

. 7 3
S t d

. D e v

. 4 2 0

. 0 9 1

. 6 6 ( 0

. 3 3 ) 0

. 3 6
M i n i m u m 1 3 0

. 5 7 0

. 3 0 ( 0

. 0 6 ) 0

. 1 6
1 0 t h p e r c e n t i l e 3 9 0

. 8 6 1

. 3 1 ( 0

. 2 6 ) 0

. 3 6
2 5 t h p e r c e n t i l e 7 1 0

. 9 1 2

. 2 8 ( 0

. 4 5 ) 0

. 4 8
M e d i a n 9 3 0

. 9 7 3

. 2 7 ( 0

. 6 4 ) 0

. 6 7
7 5 t h p e r c e n t i l e 1 0 7 1

. 0 0 4

. 2 3 ( 0

. 8 3 ) 0

. 8 3
9 0 t h p e r c e n t i l e 1 4 6 1

. 0 0 5

. 2 5 ( 1

. 0 3 ) 1

. 2 2
M a x i m u m 2 5 8 1

. 0 0 9

. 6 6 ( 1

. 9 0 ) 1

. 9 6 

### Table 20 Summary of measured supply airflows at diffusers

3.5.6 Exhaust Airflows Airflows for the exhaust fans serving each study space were measured one time during the test week. Measured airflows were obtained for 56 of the 159 exhaust fans serving the study spaces. Of these values, design airflows a re only available for 41 of the fans. Neglecting the seven cases where the measured exhaust airflow is zero, the average ratio of the measured exhaust airflow to the design value is 0.57. The median value is 0.47 and the standard deviation is 0.34; the 10 and 90 percentile values are 0.21 and 0.99 respectively

.3 4 

### 4. DISCUSSION 4.1 Summary of Results

The ventilation

- related information collected as part of the BASE study provides a unique characterization of ventilation sy stem design and performance in U.S. office buildings. No such database of randomly selected office buildings existed prior to this effort, making the results of the survey that much more significant. W hile the office buildings studied tend to be larger and with higher occupancy than the ave rage U.S. office building, the results obtained are quite revealing. In terms of design, the data show the relative prevalence of different sy stem ty pes and different approaches to outdoor air control, as described in Tables 4 and 5. Of the 141 ventilation
sy stems considered, 50 are constant volume and the rest are VAV. In almost 75 % of the study spaces the sy stems employ economizer control to provide “free cooling” when the outdoor weather is appropriate. Twenty

- one of the spaces have dedicated outdoor ai r fans, and five have 100 % outdoor air sy stems. As expected based on thermal load considerations, but never previously verified, the average value of the supply air capacity is about 5 L/s• m 2 

### (1 cfm/ft 2 

### ). Other sy stem design parameters of interest have th e following mean values: ratio of supply airflow capacity to return airflow capacity , 1.14; design minimum outdoor air per person (workstation), 18 L/s (39 cfm); and, ratio of design minimum outdoor air intake to supply air capacity

, 19 % . The per person d esign minimum outdoor air intake, based on the number of workstations, is significantly higher than the requirement in ASHRAE Standard 62

- 2001 of 10 L/s (20 cfm) per person. However, if the per person design value is instead calculated using the default oc cupant density in the ASHRAE standard, the mean value of the minimum outdoor air intake per person is 13 L/s (26 cfm) and the median is roughly 9 L/s (17 cfm). However, as noted, the design occupancy used to determine the design minimum outdoor air intake is not available for the sy stems studied. The BASE study also provides valuable information on occupant density in office buildings. The mean number of workstations per 100 m 2 

### (1000 ft 2 

### ) is about 5, as compared with the default value in Standard 62

- 2001 of 7. However, the recent revision of that standard via addendum n (ASHRAE 2003) reduces the default value to 5, which appears to be a reasonable change given the results of this study . The measured occupant density in the spaces is lower still, with a mean value of 4.0 people/100 m 2 

### (3.7 people /1000 ft 2 

### ), corresponding to about 80 % of the workstations being occupied. The ventilation measurements indicate how the sy stems operate relative to their design and also provide performance parameters that can be u sed to analy ze other data collected in the BASE study , for example contaminant concentrations and prevalence of occupant sy mptoms. The mean measured supply airflow for the 97 mechanically ventilated study spaces is very close to the mean design value, i.e. , 5 L/s• m 2 

### (1 cfm/ft 2 

### ). As might be expected, these supply values are relatively independent of outdoor air temperature for the constant volume sy stems but tend to increase for warmer temperatures in the VAV sy stems. The measured outdoor air fraction, i.e.

, the ratio of the outdoor air intake to the supply airflow, has a mean value of about 0.40. For buildings with economizer controls, the outdoor air fraction tends to be lowest for warmer temperatures and increases at milder temperatures. However, with onl y 4 measurements per
sy stem, generally under similar weather conditions, the noted dependence mixes the results for
many buildings, and the temperature dependence cannot be examined in detail for any single building. Outdoor air ventilation rates tend to b e higher than might be expected, with a mean value of 49 L/s (105 cfm) per person based on the number of occupants and 36 L/s (76 cfm) per person based on the number of workstations in the space. Still, seventeen percent of these3 5 

### measured values (per occup ant) are below the 10 L/s (20 cfm) per person requirement in ASHRAE Standard 62

- 2001, and these lower rates occur in 22 of the 97 mechanically ventilated buildings. W hile these values are high on average relative to the minimum outdoor air requirements in Standard 62, the high outdoor air fractions and the low occupancy relative to the actual number of workstations (and to the default occupancy value in the standard) explains most of the higher values. Adjusting the measured outdoor air ventilation rates to minimum outdoor air conditions and to the occupant density in Standard 62 reduces the mean to 9 L/s (19 cfm) per person. Considering only those values that correspond to minimum outdoor air intake, the mean ventilation rate is 14 L/s (29 cfm) per person. Adjusting these minimum values for the number of workstations rather than the measured occupancy levels y ields a mean of 11 L/s (22 cfm) per person, with one

- half of these minimum values being below the requirement in ASHRAE Standard 62

- 2001. In other word s, under minimum outdoor air intake, about one

- half of the measured outdoor air intake rates are below the requirements in ASHRAE Standard 62

- 2001 based on the expected occupant levels in the space, and about one

- quarter of the rates are below 5 L/s (10 cf m) per person, i.e., one

- half of the ASHRAE requirement.

The outdoor air ventilation rates calculated from the CO 2 

### - based outdoor air fraction (determined from airstream CO 2 

### concentrations) multiplied by the volumetric supply airflow rate are generally cons istent with the outdoor air rates from volumetric airflow measurements in the air handlers. However, the CO 2 

### ratio ventilation rates have much larger uncertainties due to the larger uncertainties in the CO 2 

### - based outdoor air fractions. Outdoor air ventilat ion rates determined from steady

- state analy sis of peak CO 2 

### concentrations in the space are consistently lower than the volumetric outdoor air rates. A number of explanations have been explored, but the reason for this discrepancy has not been identified. Therefore, questions exist as to the reliability of the peak

- CO 2 

### ventilation rates.

4.2 Comparison with European Audit Project During the time of the BASE study , a similar research effort was conducted in Europe. The European Audit Project involved measu rements of building characteristics, environmental conditions and ventilation performance, as well as the administration of occupant questionnaires, in 56 buildings in eleven European countries (Bluy ssen et al. 1995 and 1996). Ventilation performance was m easured in nine of the countries using a range of different techniques, e.g., tracer gas decay in a single room, constant concentration tracer gas, and subtraction of exhaust from supply airflows determined using velocity traverses. The final report (Bluy s sen et al., 1995) contains one value of supply airflow, infiltration and outdoor airflow per unit floor area for each building in which they were measured. The results are also presented in the form of cumulative frequency distributions for outdoor and sup ply airflow in units of L/s

- m 2 

### and air changes per hour. The median value of the supply airflow is roughly 2.2 L/s

- m 2 

### (0.43 cfm/ft 2 

### ), which is about one

- half of the median for the BASE buildings. The median outdoor airflow in the European Audit buildings is about 1.7 L/s

- m 2 

### (0.33 cfm/ft 2 

### ), which is somewhat higher than the median for the BASE buildings of 1.1 L/s

- m 2 

### (0.22 cfm/ft 2 

### ). In units of air changes per hour, the medians are roughly 2.1 h - 1 

### and 1.0 h - 1 

### for the European and BASE buildings respective ly . Given the uniqueness of these two datasets, a more detailed comparison of the ventilation results would be worth pursuing.3 6 

### 4.3 Recommendations for V entilation Assessment In addition to analy zing the ventilation

- related data collected as part of the BASE study , another objective of this effort was to examine the procedures used to collect these data and recommend changes to the protocol for potential consideration in future studies. In terms of the design information, it would have been helpful to col lect sufficient design data to perform an airflow balance on each building and each study space. The existing protocol includes the collection of design specifications for only the supply , return and exhaust fans that serve the study space. These data only allow the calculation of the net design airflow into and out of the building when the study space is a whole building. It would have been desirable to collect design data for all fans serving the building, including supply and return fan capacities, minim um outdoor air values, and exhaust fan capacities. Given the interest in net airflow balances for whole buildings, particularly in the context of infiltration and moisture control, such data would be of great interest.

The determination of the outdoor air fraction from CO 2 

### concentrations in the supply , return and outdoor airstreams was associated with large measurement uncertainties due to the uncertainty in the concentration measurement itself and the low concentration differentials that exist under

some c onditions. These large uncertainties limited the usefulness of multiply ing these outdoor air fractions by sy stem supply airflows as a means of determining outdoor air intake. Nevertheless, this approach still has value based on the relative simplicity of m easuring CO 2 

### concentrations and on the fact that some outdoor air intakes are configured such that a velocity traverse is impractical. The CO 2 

### approach to determining outdoor air fraction could be improved by using a more accurate concentration monitor, em ploy ing the uncertainty in the differential concentration rather than absolute concentration (when a single monitor is used), and making the concentration measurements after the indoor concentration has increased to the maximum degree expected based on the occupancy schedule. Despite these large uncertainties, the outdoor air fractions determined from CO 2 

### concentrations agree on average with the volumetric outdoor air fractions. Outdoor air ventilation measurements are performed for a number of reasons, but often to determine the minimum outdoor airflow for a sy stem. Based on the measurements in this study

, it is evident that one is more likely to encounter conditions of minimum intake at warmer outdoor air temperatures, perhaps 25 °C (77 °F) and above. Mini mum intake is less likely to be encountered at colder temperatures based on the data presented here. Since the dependence of outdoor air fraction on temperature is building specific, it is important to obtain a sense of this dependency when study ing a buil ding if one aims to determine outdoor airflow under conditions of minimum intake. Outdoor air ventilation was also estimated based on peak CO 2 

### concentrations, using a single

zone steady

- state mass balance analy sis of each study space. The values determine d tended to be lower than those based on volumetric airflow measurements at the air handlers, and the reason for this difference is not evident. In fact, one would expect these values to be higher since they include envelope infiltration in addition to out door air intake. One potential explanation is that the concentrations measured in the space were elevated due to the influence of high CO 2 

### levels from occupant exhalations. The CO 2 

### data collected in the BASE study should be examined further to understand t his discrepancy and potentially determine way s to improve this approach to estimate building ventilation. In addition, the reliability of the estimates of the generation rates of CO 2 

### from occupants and of the occupant activity or met levels used in making these estimates merits evaluation if this approach is going to be more widely used. Current guidance on estimating ventilation rates based on peak CO 2 

### levels (ASTM 1998) may then need to be updated based on the results of this evaluation.3 7 

### In addition to th ese potential modifications of the BASE protocol, there are other ventilation performance parameters of interest that could be added to such evaluations. One such addition is the determination of envelope airtightness using fan pressurization testing. The importance of building leakage on energy consumption and indoor air quality has been discussed elsewhere and the available airtightness data is quite limited (Persily 1998). In addition, building survey protocols could also be extended to include tracer ga s measurements of infiltration rates, both with the ventilation sy stems on and off. These rates are again of interest due to their influence on
energy and indoor air quality , and the number of office buildings in which they have been measured is indeed sma ll. The challenges in making reliable measurements of outdoor air intake rates is evident from this study . Some of the problems include limited access to sy stem components, ductwork configurations that do not provide appropriate traverse planes, and accur acy limitations inherent in duct traverses. Alternative approaches to determining outdoor air intake at air handlers are being investigated and ideally will be more reliable and convenient for field application. One challenge in this respect is the lack of a primary standard for use in evaluating the accuracy of these various approaches. Finally , the BASE ventilation assessment has provided a unique dataset for U.S. office buildings, but the study was focused intentionally on larger buildings. As noted in t he discussion of the CBECS data, most U.S. office buildings are much smaller than those included in the BASE study . Based on both indoor air quality and energy considerations, there is a need to conduct a similar study in smaller office buildings. In addit ion to the obvious difference of size, smaller buildings tend to different sy stem ty pes that larger buildings and different approaches to design and operation.

5. ACKNOWLEDGEMENTS This effort was supported by the U.S. Environmental Protection Agency under Interagency Agreement No. DW

- 13

- 93936601

- 0. The authors express their appreciation to Gregory Brunner, Laureen Burton, John Girman, Robert Thompson and Susan W omble at EPA and Steven Emmerich and Jonathan Kruft at NIST for their support and assistance in t his work. The many useful comments of Terry Brennan and W illiam Fisk are also acknowledged.3 8 

### 6. REFERENCES Apte, MG, W J Fisk and JM Daisey . 2000. Associations Between Indoor CO 2 

### Concentrations and Sick Building Sy ndrome Sy mptoms in US Office Buildings: An Analy sis of the 1994

- 1996 BASE Study Data. Indoor Air, 10 (4): 246

- 257.

ASHRAE. 1999. ANSI/ASHRAE Standard 62

- 1999, Ventilation for Acceptable Indoor Air Quality . American Society of Heating, Refrigerating and Air

- Conditioning Engineers.

ASHRAE. 2001a. ANS I/ASHRAE Standard 62

- 2001, Ventilation for Acceptable Indoor Air Quality . American Society of Heating, Refrigerating and Air

- Conditioning Engineers. ASHRAE. 2001b. ASHRAE Handbook of Fundamentals. American Society of Heating, Refrigerating, and Air Conditi oning Engineers.

ASHRAE. 2003. Addendum n to ASHRAE Standard 62

- 2001. www.ashrae.org.

ASTM. 1998. D6245

- 98, Standard Guide for Using Indoor Carbon Dioxide Concentrations to Evaluate Indoor Air Quality and Ventilation. American Society for Testing and Mater ials. Bluy ssen, PM, EO Fernandes, PO Fanger, L Groes, G Clausen, CA Roulet, CA Bernhard, O Valbjorn. 1995. European Audit Project to Optimize Indoor Air Quality and Energy Consumption in Office Buildings, Final Report. The Commission of the European Commun ities. Bluy ssen, PM, EO Fernandes, L Groes, G Clausen, PO Fanger, O Valbjorn, CA Bernhard, CA Roulet. 1996. European Indoor Air Quality Audit Project in 56 Office Buildings. Indoor Air 6: 221

- 238. Brightman, HS, SE W omble, EL Ronca and JR Girman. 1996. Bas eline Information on Indoor Air Quality in Large Buildings (BASE ' 95). Proceedings of 7th International Conference on Indoor Air Quality and Climate, Nagoy a, 3:1033

- 1038. DOE. 1998. A Look at Commercial Buildings in 1995: Characteristics, Energy Consumptio n, and Energy Expenditures. DOE/EIA

- 0625(95). U.S. Department of Energy , Energy Information Administration. EHE. 2000. Building Assessment Survey and Evaluation (BASE) Study Database Description and Variable List, Environmental Health & Engineering, Inc. R eport #11868 to U.S. Environmental Protection Agency

. EHE. 2001a. The Evaluation of Ventilation Performance Measurements Conducted During the Building Assessment Survey Evaluation Study , Environmental Health & Engineering, Inc. Report to U.S. Environmental Protection Agency

. EHE. 2001b. Summary and Analy sis Report of the BASE Study Building Selection Process, Environmental Health & Engineering, Inc. Report to U.S. Environmental Protection Agency

. EPA. 2003. A Standardized EPA Protocol for Characterizing Ind oor Air Quality in Large Office Buildings. U.S. Environmental Protection Agency

. Erdmann, CA, KC Steiner and MG Apte. 2002. Indoor Carbon Dioxide Concentrations and Sick Building Sy ndrome Sy mptoms in the BASE Study Revisited: Analy ses of the 100 Building D ataset. 9th International Conference on Indoor Air Quality and Climate, Monterey , 3: 443

- 448. Ludwig, JF, BJ Baker and JF McCarthy . 2002. Analy sis of Ventilation Rates for the BASE Study : Assessment of Measurement Uncertainty and Comparison with ASHRAE 62

- 1999. Proceedings of Indoor Air 2002. Volume 5: 388

- 393.3 9 

### Persily , AK. 1989. Ventilation Rates in Office Buildings. Proceedings of IAQ ' 89 The Human Equation: Health and Comfort, San Diego: 128

- 136. Persily , AK and W S Dols. 1991. Field Measurements of Venti lation and Ventilation Effectiveness in an Office/Library Building. Indoor Air 3: 229

- 246. Persily , AK, W S Dols and SJ Nabinger. 1992. Environmental Evaluation of the Federal Records Center in Overland Missouri. National Institute of Standards and Technolo gy , NISTIR 4883. Persily , AK. 1997. Evaluating Building IAQ and Ventilation with Indoor Carbon Dioxide. ASHRAE Transactions 103(2): 193

- 204. Persily , A. 1998. My ths About Building Envelopes. ASHRAE Journal 41(3): 39

- 47.

W omble, SE, JR Girman, EL Ronca, R A xelrad, HS Brightman and JF McCarthy . 1995. Developing Baseline Information on Buildings and Indoor Air Quality (BASE ' 94): Part I

- Study Design, Building Selection, and Building Description. Proceedings of Healthy Buildings

' 95, Milan, 3: 1305

- 1310.

W omb le, SE, EL Ronca, JR Girman and HS Brightman. 1996. Developing Baseline Information on Buildings and Indoor Air Quality (BASE ' 95). Proceedings of ASHRAE IAQ 96. Paths to Better Building Environments, Baltimore: 109

- 117.4 0 

### Appendix A: BASE V ariables Used in Analy sis

This appendix lists the variables used in the analy sis presented in this report. The variable names referenced in the BASE protocol are as listed in the BASE Study Database Description and Variable List (EHE 2000) and from the initial processing of the field data by the EPA contractor.

Building Variables EVENT: Building identifier A1YEAR: Year built A1YEAR2: Year of last building addition A1AREA: Building occupied floor area A1AREA2: Building gross floor area A1BELOW : Building stories below grad e A1ABOVE: Building stories above grade A1VENTIL: Building has mechanical or natural ventilation? A1COOLIN: Building has air conditioning sy stem, y es or no? A1HEATIN: Building has air heating sy stem, y es or no?

Sy stem Variables SYSTEM: Sy stem number C1TYP E: Central air handling and distribution sy stem ty pe code, A through P as described in Appendix B C1RETFAN: Return fan, y es or no? C1TS#PCT: Percent of sy stem capacity serving the study space, by air handler #. C5CONPOS: Dedicated outdoor air intake fan, o utdoor air conditioned C5UNPOS: Dedicated outdoor air intake fan, outdoor air unconditioned C5UNSUC1: Outdoor air drawn into sy stem by supply fan suction through distinct intake duct C5UNSUC2: Outdoor air drawn directly into air handler by supply fan sucti on with no duct C5CONST1: 100% outdoor air sy stem C5CONST2: Sy stem has temperature

- based economizer C5CONST3: Sy stem has fixed minimum outdoor air intake C5CONST4: Sy stem has enthalpy

- based economizer C5CONST5: Sy stem controls outdoor air intake based on b uilding pressure C5MINOU1: Minimum outdoor air intake controlled by fixed damper C5MINOU2: Minimum outdoor air intake controlled by airflow monitoring C5MINOU3: Minimum outdoor air intake controlled by fan tracking C7ARAT1: Design supply air capacity of sy stem C7ARAT2: Design minimum outdoor air intake for sy stem C7AAREA: Floor area served by sy stem C7AOCCU: Number of occupants served by air handler C7ARETFA: Sy stem has a return fan? C7ARET1: Design return air capacity C7ARET2: Floor area served by return

Study Space Variables EVENT: Building identifier TSDESC: Floors and spaces constituting study space B1AREA: Study space occupied floor area B1AREA2: Study space gross floor area4 1 

### B1AH#PCT: Percentage of study space air supply by air handler number # B1CEIL IN: Study space ceiling height B1PLENUM: Study space plenum height B1PRIV: Number of private workstations in study space B1PART: Number of workstations in study space located in partitioned areas B1OPEN: Number of workstations in study space located in ope n office areas B1DESW S: Floor area per workstation B1SUPPLY: Number of supply vents in the study space B1OCC_#A and B1OCC_#B: Measured test space occupancy , with # indicating measurement event (Monday is 1, Tuesday is 2, ...); A indicates morning measurement and B indicates afternoon

Supply diffuser measurements D3ADATE: Date of measurement D3ARAT#: Measured supply diffuser airflow, # indicated which diffuser

Exhaust measurements C7BAREA: Floor area served by exhaust fan C7BRATE: Design exhaust airflow rate C7BLOCAT; Location of exhaust fan D2DATE: Date of measurement D2FLOW : Measured airflow rate of exhaust fan

W eather DATE: Date of measurement TIME: Time of measurement TEMP: Outdoor air temperature

Continuous carbon dioxide measurements using fixed moni tors CO2: Measured carbon dioxide concentration. DATE: Date of measurement EVENT: Building identifier SITEID: Sample site identifier TIME: Time of measurement

Variables provided with data analy sis by EPA contractor These apply to ventilation sy stem airflo w and carbon dioxide concentration measurements. Several are directly from the BASE variable list, but others (primarily volumetric airflow rates) are derived from BASE variables. Building/study space number Date of measurement Period of measurement, AM or PM Supply airflow rate, for each date and period Outdoor airflow rate, for each date and period Recirculation airflow rate, for each date and period Supply air carbon dioxide concentration, for each date and period Outdoor air carbon dioxide concentration , for each date and period Recirculation air carbon dioxide concentration, for each date and period4 2 

### Appendix B: Sy stem Design Information

This appendix presents the following design information for the air handlers serving the study
spaces:

Sy stem ID Sy stem ty pe from list below: A Single Duct, Constant Volume, Single Zone B Single Duct, Constant Volume, Multiple Zone Reheat C Single Duct, Constant Volume, Multiple Zone By pass D Single Duct, Variable Air Volume E Single Duct, Variable Air Volume, Reheat F Single Duct, Variable Air Volume, Induction G Single Duct, Variable Air Volume, Fan Powered, Constant Fan H Single Duct, Variable Air Volume, Fan Powered, Intermittent Fan I Single Duct, Variable Air Volume, Dual Conduit J Dual Duct, Constant Volume K Dua l Duct, Constant Volume, Reheat L Dual Duct, Variable Air Volume, Single Fan M Dual Duct, Variable Air Volume, Dual Fan N Multizone, Constant Volume O Constant Volume, Blow

- Through By pass P Texas Multizone, or Three

- Deck Multizone Design supply airflow ca pacity Floor area served by sy stem Design supply airflow capacity per unit floor area Design minimum outdoor air intake Design minimum outdoor air intake per unit floor area Number of occupants served by air handler Design minimum outdoor air intake per pe rson Ratio of design minimum outdoor air intake to design supply airflow capacity Occupant density per unit floor area Design return airflow capacity Ratio of design supply airflow capacity to design return airflow

Changes in the table relative to the ori ginal 2004 report are highlighted in y ellow

.4 3 L/s cfm m 2 ft 2 L/s-m 2 cfm/ft 2 L/s cfm ARFW01(01) N 5195 11006 890 9584 5.83 1.15 ARFW01(02) N 5195 11006 890 9584 5.83 1.15 ARFW02(01) E 10638 22538 3642 39201 2.92 0.57 708 1501 ARFW02(02) E 9011 19091 1529 16457 5.89 1.16 590 1251 ARFW03(01) H 4865 10306 729 7846 6.67 1.31 ARFW03(02) H 4510 9555 502 5404 8.98 1.77 AZHS02(01) E 7835 16600 1085 11680 7.22 1.42 AZHS02(02) E 7084 15009 855 9206 8.28 1.63 AZHS04(01) E 9540 20212 1731 18630 5.51 1.08 AZHS04(02) A 1606 3402 189 2033 8.50 1.67 AZHW10(01) N 9446 20012 1227 13203 7.70 1.52 AZHW10(02) N 7557 16010 317 3408 23.86 4.70 AZHW11(01) N 19364 41024 2599 27972 7.45 1.47 AZHW12(01) G 7455 15795 3732 40169 2.00 0.39 1077 2281 AZHW12(02) G 7462 15809 3202 34462 2.33 0.46 1077 2281 CAES17(01) K 11713 24814 1458 15696 8.03 1.58 1757 3722 CAEW07(01) K 17475 37022 3289 35398 5.31 1.05 CAEW001) E 38727 82048 6438 69295 6.01 1.18 8029 17010 CAJS01(01) A 2090 22499 CAJS01(02) A 711 7650 CAJS01(03) A 711 7650 CAJS02(01) J 14169 30018 1260 13561 11.24 2.21 2834 6004 CAJS03(01) B 9295 19692 8242 88721 1.13 0.22 1394 2954 CAJS21(01) K 6718 14233 924 9950 7.27 1.43 1429 3027 CAJS21(02) K 4520 9576 831 8944 5.44 1.07 4520 9576 CAJS222(01) E 8973 19011 1901 20466 4.72 0.93 1039 2201 CAJS23(01) J 8312 17610 1044 11237 7.96 1.57 945 2001 CAJW18(01) D 8218 17410 1646 17719 4.99 0.98 CAJW18(02) L 572 6154 CAJW19(01) K 16199 34320 2650 28521 6.11 1.20 CAJW20(01) F 75566 160094 13889 149499 5.44 1.07 13224 28016 CAJW24(01) E 28337 60035 3790 40800 7.47 1.47 CAJW25(01) F 14742 31233 1183 12730 12.46 2.45 CAJW26(01) F 38539 81648 7153 77000 5.39 1.06 COAS02(01) D 19248 40779 3439 37018 5.60 1.10 COAS04(01) D 47229 100059 5086 54750 9.28 1.83 4723 10006 COAS06(01) F 9134 19352 1427 15363 6.40 1.26 850 1801 FLDW07(02) N 7745 16410 2076 22350 3.73 0.73 1495 3167 FLDW08(01) H 11160 23643 1636 17608 6.82 1.34 1086 2301 FLDW10(01) H 5904 12507 1556 16750 3.79 0.75 520 1101 FLGS01(01) E 10211 21633 1878 20220 5.43 1.07 1417 3002 FLGS04(01) N 6707 14208 989 10650 6.78 1.33 708 1501 FLGS04(02) N 6707 14208 989 10650 6.78 1.33 708 1501 FLGS11(01) H 5564 11787 1486 16000 3.74 0.74 331 700 FLGS11(02) H 5564 11787 1486 16000 3.74 0.74 331 700 FLGS12(01) N 11557 24484 1033 11119 11.19 2.20 1747 3702 GADS01(01) E 10296 21813 2392 25748 4.30 0.85 1015 2151 GADS02(01) E 6990 14809 1686 18145 4.15 0.82 945 2001 GADS02(02) E 6990 14809 1686 18145 4.15 0.82 945 2001 GADS03(01) A 9583 20303 2187 23538 4.38 0.86 Design supply airflow capacity Design minimum outdoor air intake Floor area served by system Design supply capacity
per unit floor area System

type System ID4 44 54 6 L/s-m 2 cfm/ft 2 cfm L/s /1000 ft 2 /100 m 2 L/s cfm ARFW01(01) 46 4.8 5.2 ARFW01(02) 46 4.8 5.2 ARFW02(01) 0.19 0.04 60 25.0 11.8 0.07 1.5 1.6 ARFW02(02) 0.39 0.08 50 25.0 11.8 0.07 3.0 3.3 ARFW03(01) 44 5.6 6.0 ARFW03(02) 32 5.9 6.4 AZHS02(01) 42 3.6 3.9 AZHS02(02) 33 3.6 3.9 6707 14208 1.06 AZHS04(01) 68 3.7 3.9 AZHS04(02) 12 5.9 6.4 AZHW10(01) 35 2.7 2.9 AZHW10(02) 19 5.6 6.0 AZHW11(01) 113 4.0 4.3 AZHW12(01) 0.29 0.06 94 24.3 11.5 0.14 2.3 2.5 AZHW12(02) 0.34 0.07 45 50.7 23.9 0.14 1.3 1.4 CAES17(01) 1.20 0.24 70 53.2 25.1 0.15 4.5 4.8 CAEW07(01) 95 2.7 2.9 12752 27016 1.37 CAEW001) 1.25 0.25 150 113.4 53.5 0.21 2.2 2.3 30699 65038 1.26 CAJS01(01) 52 2.3 2.5 CAJS01(02) 30 3.9 4.2 CAJS01(03) 12 1.6 1.7 CAJS02(01) 2.25 0.44 111 54.1 25.5 0.20 8.2 8.8 CAJS03(01) 0.17 0.03 155 19.1 9.0 0.15 1.7 1.9 47229 100059 0.20 CAJS21(01) 1.55 0.30 50 60.5 28.6 0.21 5.0 5.4 5290 11207 1.27 CAJS21(02) 1.07 46 208.2 98.2 1.00 5.1 5.5 CAJS222(01) 0.55 0.11 183 12.0 5.7 0.12 8.9 9.6 CAJS23(01) 0.90 0.18 73 27.4 12.9 0.11 6.5 7.0 CAJW18(01) 59 3.3 3.6 CAJW18(02) CAJW19(01) 92 3.2 3.5 15349 32519 1.06 CAJW20(01) 0.95 0.19 741 37.8 17.8 0.17 5.0 5.3 68009 144084 1.11 CAJW24(01) 224 5.5 5.9 25504 54032 1.11 CAJW25(01) 770 60.5 12586 26666 1.17 CAJW26(01) 420 5.5 5.9 30472 64558 1.26 COAS02(01) 133 3.6 3.9 COAS04(01) 0.93 0.18 310 32.3 15.2 0.10 5.7 6.1 42506 90053 1.11 COAS06(01) 0.60 0.12 55 32.7 15.5 0.09 3.6 3.9 FLDW07(02) 0.72 0.14 50 63.3 29.9 0.19 2.2 2.4 FLDW08(01) 0.66 0.13 69 33.4 15.7 0.10 3.9 4.2 FLDW10(01) 0.33 0.07 108 10.2 4.8 0.09 6.4 6.9 FLGS01(01) 0.75 0.15 70 42.9 20.2 0.14 3.5 3.7 FLGS04(01) 0.72 0.14 50 30.0 14.2 0.11 4.7 5.1 FLGS04(02) 0.72 0.14 50 30.0 14.2 0.11 4.7 5.1 FLGS11(01) 0.22 0.04 44 15.9 7.5 0.06 2.8 3.0 FLGS11(02) 0.22 0.04 46 15.2 7.2 0.06 2.9 3.1 FLGS12(01) 1.69 0.33 60 61.7 29.1 0.15 5.4 5.8 GADS01(01) 0.42 0.08 67 32.1 15.2 0.10 2.6 2.8 GADS02(01) 0.56 0.11 40 50.0 23.6 0.14 2.2 2.4 GADS02(02) 0.56 0.11 40 50.0 23.6 0.14 2.2 2.4 GADS03(01) 124 5.3 5.7 Occupant density Design return fan capacity Ratio of design supply to

return Ratio of design minimum OA

to supply Number of occupants Design minimum OA per person System ID Design minimum outdoor air intake
per unit floor area4 74 84 9 

### Appendix C: V olumetric Airflow Data Issues

This appendix describes measurement issues identified with the volumetric airflow data and any adjustments that were made to account for these issues.

B u i l d i n g M e a s u r e m e n t I s s u e D a t a a d j u s t m e n t A R F W 0 2 W e d n e s d a y a

. m

. v o l u m e t r i c o u t d o o r a i r v a l u e f o r

s y s t e m # 2 s i g n i f i c a n t l y b e l o w o t h e r m e a s u r e d v a l u e s f o r t h a t s y s t e m , w h i l e o u t d o o r a i r f r a c t i o n f o r t h i s t i m e p e r i o d b a s e d o n C O 2 c o n s i s t e n t w i t h o t h e r v a l u e s

. D e l e t e s u s p e c t v a l u e , n o

s t u d y s p a c e v o l u m e t r i c

o u t d o o r a i r f l o w f o r W e d n e s d a y a

. m

. A Z H S 0 4 S y s t e m # 1 m e a s u r e d r e c i r c u l a t i o n a i r f l o w g r e a t e r t h a n

s u p p l y a i r f l o w f o r 3 o f 4 r e a d i n g s , l e a d i n g t o n e g a t i v e

v a l u e s f o r o u t d o o r a i r f l o w ; n o t s i g n i f i c a n t l y d i f f e r e n t f r o m z e r o b a s e d o n u n c e r t a i n t y i n r e c i r c u l a t i o n a n d

s u p p l y a i r f l o w s

. S e t s y s t e m # 1 o u t d o o r

a i r f l o w e q u a l t o z e r o i n t h o s e 3 c a s e s

.

A Z H W 1 0 N o o u t d o o r a i r f l o w m e a s u r e m e n t o n S y s t e m # 2

, b u t S y s t e m # 1 o u t d o o r a i r f l o w v a l u e s v e r y c l o s e t o s u m o f

s u p p l y a i r f l o w s f o r S y s t e m # 1 a n d # 2 ; s u r v e y n o t e s i n d i c a t e c o m m o n o u t d o o r a i r i n t a k e f o r b o t h s y s t e m s

. C a l c u l a t e s t u d y s p a c e

o u t d o o r a i r f l o w b a s e d o n S y s t e m # 1 v a l u e s a l o n e

.

C A J S 0 1 N o o u t d o o r a i r f l o w m e a s u r e m e n t o n S y s t e m # 1 o f t h r e e

s y s t e m s ; a l l s y s t e m s a r e 1 0 0 % o u t d o o r a i r ; n o t e t h a t S y s t e m # 1 s u p p l y a i r f l o w i s o n l y a b o u t 1 0 % o f s u p p l y

a i r f l o w o f o t h e r t w o s y s t e m s

. A s s u m e S y s t e m # 1 o u t d o o r

a i r f l o w e q u a l s s u p p l y

a i r f l o w

.

C A J W 1 8 T w o s y s t e m s l i s t e d u n d e r s y s t e m d e s i g n i n f o r m a t i o n , b u t n o d e s i g n o r m e a s u r e d d a t a o n S y s t e m # 2 ; s u r v e y

n o t e s i n d i c a t e t h a t S y s t e m # 2 i s h e a t i n g o n l y a n d w a s n ’ t

o p e r a t i n g d u r i n g t e s t w e e k

. R e s u l t s b a s e d o n S y s t e m # 1 m e a s u r e m e n t s a l o n e

.

C A J W 2 6 V o l u m e t r i c o u t d o o r a i r f r a c t i o n g r e a t e r t h a n 1 0 0 % f o r 3

o f 4 r e a d i n g s , b u t n o t s i g n i f i c a n t l y d i f f e r e n t f r o m 1 0 0 % b a s e d o n u n c e r t a i n t y

. U s e t h e 3 c a l c u l a t e d v a l u e s g r e a t e r t h a n 1 0 0 %

.

C O A S 0 4 M e a s u r e d r e c i r c u l a t i o n a i r f l o w g r e a t e r t h a n s u p p l y

a i r f l o w f o r o n e r e a d i n g , l e a d i n g t o n e g a t i v e v a l u e f o r

o u t d o o r a i r f l o w ; n o t s i g n i f i c a n t l y d i f f e r e n t f r o m z e r o b a s e d o n u n c e r t a i n t y i n r e c i r c u l a t i o n a n d s u p p l y

a i r f l o w s

. S e t v a l u e o f o u t d o o r

a i r f l o w e q u a l t o z e r o i n t h a t

c a s e

.

I L B S 0 1 V o l u m e t r i c m e a s u r e m e n t s o f s u p p l y a i r f l o w o n l y f o r b o t h s y s t e m s ; s u r v e y n o t e s i n d i c a t e o u t d o o r a i r i n t a k e d a m p e r c l o s e d d u r i n g t e s t w e e k ; o u t d o o r a i r f l o w s c a n

o n l y b e d e t e r m i n e d b y p r o d u c t o f s u p p l y a i r f l o w a n d

o u t d o o r a i r f r a c t i o n f r o m C O 2 . N o a d j u s t m e n t s m a d e t o d a t a

.

L A G W 0 5 V o l u m e t r i c s u p p l y a i r f l o w v a l u e s m e a s u r e d f o r b o t h

s y s t e m s , o u t d o o r a i r f l o w v a l u e s f o r S y s t e m # 2 a r e d u p l i c a t e s o f S y s t e m # 1 v a l u e s ; s u r v e y n o t e s i n d i c a t e

c o m m o n o u t d o o r a i r i n t a k e s e r v e s b o t h s y s t e m s

. U s e S y s t e m # 1 v a l u e s

a l o n e t o d e t e r m i n e o u t d o o r

a i r f r a c t i o n a n d s t u d y s p a c e

o u t d o o r a i r f l o w

. L A G W 0 6 N o v o l u m e t r i c s u p p l y a i r f l o w v a l u e s a n d o n l y o n e

o u t d o o r a i r f l o w v a l u e f o r S y s t e m # 2 ; s u r v e y n o t e s i n d i c a t e t h a t S y s t e m # 2 d o e s n o t a l w a y s o p e r a t e a n d t h a t

c o m m o n o u t d o o r a i r i n t a k e s e r v e s b o t h s y s t e m s ; S y s t e m # 2 d e s i g n s u p p l y c a p a c i t y a n d m i n i m u m o u t d o o r a i r

o n l y 2 0 % o f S y s t e m # 1

. A d d s i n g l e S y s t e m # 2

o u t d o o r a i r f l o w t o

c o r r e s p o n d i n g S y s t e m # 1

v a l u e w h e n c a l c u l a t i n g

s t u d y s p a c e o u t d o o r

a i r f l o w

. M A B W 0 5 O n e S y s t e m # 2 m e a s u r e d r e c i r c u l a t i o n a i r f l o w v a l u e g r e a t e r t h a n s u p p l y a i r f l o w , l e a d i n g t o n e g a t i v e v a l u e S e t v a l u e o f o u t d o o r

a i r f l o w e q u a l t o z e r o

.5 0 f o r o u t d o o r a i r f l o w ; n o t s i g n i f i c a n t l y d i f f e r e n t f r o m z e r o b a s e d o n u n c e r t a i n t y i n r e c i r c u l a t i o n a n d s u p p l y

a i r f l o w s

. M D D S 0 1 M e a s u r e d r e c i r c u l a t i o n a i r f l o w g r e a t e r t h a n s u p p l y

a i r f l o w f o r t w o r e a d i n g s , l e a d i n g t o n e g a t i v e v a l u e s f o r

o u t d o o r a i r f l o w ; n o t s i g n i f i c a n t l y d i f f e r e n t f r o m z e r o b a s e d o n a s s u m e d u n c e r t a i n t y i n r e c i r c u l a t i o n a n d

s u p p l y a i r f l o w s

. S e t v a l u e o f o u t d o o r

a i r f l o w e q u a l t o z e r o f o r t h e s e t w o e v e n t s

.

N C D W 0 3 F i v e s y s t e m s ; s u r v e y n o t e s i n d i c a t e o u t d o o r a i r n o t

o p e r a t e d d u r i n g s t u d y w e e k ; 5 o f 2 0 p o t e n t i a l o u t d o o r

a i r f l o w v a l u e s l i s t e d

, c o u l d b e l e a k a g e i n t o s y s t e m

. N o v o l u m e t r i c a i r f l o w r a t e s

c a l c u l a t e d f o r t h e s t u d y

s p a c e

. N M E S 0 2 A l l 4 v o l u m e t r i c o u t d o o r a i r f l o w s g r e a t e r t h a n

v o l u m e t r i c s u p p l y a i r f l o w s ; o u t d o o r a i r f r a c t i o n

s i g n i f i c a n t l y g r e a t e r t h a n 1 0 0 % b a s e d o n m e a s u r e m e n t

u n c e r t a i n t y f o r o n l y 1 o f t h e 4 v a l u e s

. U s e a l l v a l u e s a s

c a l c u l a t e d

.

N V A W 0 3 S y s t e m # 1 m e a s u r e d o u t d o o r a i r f l o w s g r e a t e r t h a n

s u p p l y a i r f l o w f o r a l l 4 r e a d i n g s , l e a d i n g t o v o l u m e t r i c

o u t d o o r a i r f r a c t i o n g r e a t e r t h a n 1 0 0 %

, b u t n o t

s i g n i f i c a n t l y g r e a t e r

. N o a d j u s t m e n t s m a d e t o d a t a

.

N Y B S 0 4 T h u r s d a y a

. m

. v o l u m e t r i c o u t d o o r a i r f l o w f o r s y s t e m # 1

m u c h h i g h e r t h a n o t h e r v a l u e s f o r b o t h s y s t e m s # 1 a n d # 2

. N o a d j u s t m e n t s m a d e t o d a t a

.

O R I S 0 3 N o v o l u m e t r i c o u t d o o r a i r f l o w s f o r S y s t e m # 3 ; s u r v e y

n o t e s i n d i c a t e o u t d o o r a i r i n t a k e s e r v e s b o t h s y s t e m s # 1

a n d # 3

. S u p p l y a i r f l o w f o r s y s t e m # 1 b a s e d o n s u m o f s y s t e m # 1 a n d # 3 v a l u e s ; o u t d o o r

a i r f l o w b a s e d o n S y s t e m # 1

v a l u e s

. O R I S 0 4 N o v o l u m e t r i c o u t d o o r o r r e c i r c u l a t i o n a i r f l o w v a l u e s ;

s u r v e y n o t e s i n d i c a t e o u t d o o r a i r d a m p e r l o c a t i o n p r e v e n t e d r e l i a b l e t r a v e r s e

. . O u t d o o r a i r f l o w f r o m C O 2
r a t i o o n l y

.

P A B S 0 3 M e a s u r e d r e c i r c u l a t i o n a i r f l o w g r e a t e r t h a n s u p p l y

a i r f l o w f o r a l l f o u r r e a d i n g s , l e a d i n g t o n e g a t i v e v a l u e s f o r o u t d o o r a i r f l o w ; n o t s i g n i f i c a n t l y d i f f e r e n t f r o m z e r o b a s e d o n a s s u m e d u n c e r t a i n t y i n r e c i r c u l a t i o n a n d

s u p p l y a i r f l o w s

. S e t a l l 4 v a l u e s o f o u t d o o r

a i r f l o w e q u a l t o z e r o

.5 1 

### Appendix D: Measured Data for Air Handlers

This appendix presents the following information for the me asurements in the air handlers serving the study spaces:

Sy stem ID Day and time of measurement Supply , outdoor and recirculation airflows, and associated uncertainties (values in italics were not measured directly but were derived from other airflow rates , i.e., supply = outdoor air + recirculation; outdoor air = supply

–recirculation) Outdoor air fraction, based on volumetric and carbon dioxide ratio methods, and associated uncertainties5 2 System ID Day Period L/s cfm L/s cfm L/s cfm L/s cfm ARFW01(01) Wed AM 6919 14658 692 1466 385 815 115 245 Wed PM 6703 14200 670 1420 363 768 109 231 Thurs AM 6583 13946 658 1395 370 784 111 235 Thurs PM 6655 14099 665 1410 363 768 109 231 ARFW01(02) Wed AM 6328 13407 633 1341 348 737 104 221 Wed PM 6439 13641 644 1364 348 737 104 221 Thurs AM 6477 13722 648 1372 378 800 113 240 Thurs PM 6602 13987 660 1399 355 753 107 226 ARFW02(01) Wed AM 5155 10922 516 1092 4220 8941 1266 2682 Wed PM 4946 10478 495 1048 4159 8810 1248 2643 Thurs AM Thurs PM 4946 10478 495 1048 4183 8862 1255 2659 ARFW02(02) Wed AM 6544 13865 654 1386 Wed PM 6300 13347 630 1335 5013 10620 1504 3186 Thurs AM Thurs PM 6394 13546 639 1355 5221 11062 1566 3319 ARFW03(01) Wed AM 3753 7951 375 795 158 334 47 100 Wed PM 4073 8629 407 863 100 211 30 63 Thurs AM 3961 8392 396 839 108 229 32 69 Thurs PM 3945 8358 395 836 108 229 32 69 ARFW03(02) Wed AM 2317 4908 232 491 254 539 76 162 Wed PM 2515 5328 251 533 287 608 86 182 Thurs AM 2575 5455 257 545 328 695 98 209 Thurs PM 2503 5302 250 530 303 643 91 193 AZHS02(01) Wed AM 4579 9700 458 970 1670 3538 985 2088 Wed PM 5361 11359 536 1136 2600 5508 987 2091 Thurs AM 4233 8967 423 897 1243 2633 992 2101 Thurs PM 4397 9315 440 931 1628 3449 940 1991 AZHS02(02) Wed AM 2541 5383 254 538 1177 2494 482 1020 Wed PM 2511 5319 251 532 1240 2628 456 967 Thurs AM 2041 4323 204 432 545 1155 493 1044 Thurs PM 2481 5256 248 526 692 1466 591 1252 AZHS04(01) Wed AM 10463 22166 1046 2217 0 0 3309 7010 Wed PM 10385 22001 1038 2200 0 0 3424 7254 Thurs AM 10229 21671 1023 2167 1069 2265 2932 6212 Thurs PM 9831 20827 983 2083 0 0 3339 7073 AZHS04(02) Wed AM 698 1478 182 386 99 209 30 63 Wed PM 707 1498 182 386 109 231 33 69 Thurs AM 716 1516 193 408 78 166 23 50 Thurs PM 810 1716 210 446 119 252 36 76 AZHW10(01) Wed AM 8276 17533 828 1753 10637 22536 3191 6761 Wed PM 7891 16717 789 1672 12242 25936 3673 7781 Thurs AM 9031 19132 903 1913 13458 28512 4037 8554 Thurs PM 9179 19446 918 1945 13545 28696 4063 8609 AZHW10(02) Wed AM 4178 8852 418 885 Wed PM 4297 9104 430 910 Thurs AM 4440 9406 444 941 Thurs PM 4321 9154 432 915 AZHW11(01) Wed AM 14204 30093 1420 3009 2705 5732 3731 7904 Wed PM 16743 35472 1674 3547 4916 10415 3923 8312 Thurs AM 16537 35036 1654 3504 5531 11719 3693 7824 Thurs PM 18116 38380 1812 3838 6206 13148 4006 8487 AZHW12(01) Wed AM 3647 7727 365 773 752 1594 226 478 Wed PM 3575 7574 357 757 863 1828 259 548 Thurs AM 3250 6885 325 689 145 307 43 92 Thurs PM 3105 6579 311 658 110 234 33 70 Supply airflow Uncertainty in supply airflow Outdoor airflow Uncertainty in outdoor airflow5 3 System ID Day Period L/s cfm L/s cfm L/s cfm L/s cfm AZHW12(02) Wed AM 5236 11093 524 1109 1595 3380 479 1014 Wed PM 5236 11093 524 1109 1595 3380 479 1014 Thurs AM 5236 11093 524 1109 1617 3427 485 1028 Thurs PM 5705 12087 571 1209 1738 3683 522 1105 CAES17(01) Wed AM 16286 34503 1629 3450 3040 6441 4294 9098 Wed PM 15564 32974 1556 3297 2210 4682 4298 9106 Thurs AM 17549 37179 1755 3718 9895 20963 2890 6123 Thurs PM 16737 35459 1674 3546 5120 10847 3866 8191 CAEW07(01) Wed AM 17522 37122 1752 3712 5371 11380 1611 3414 Wed PM 18569 39341 1857 3934 16134 34182 4840 10255 Thurs AM 17522 37122 1752 3712 13365 28315 4009 8494 Thurs PM 17236 36516 1724 3652 18092 38329 5427 11499 CAEW09(01) Wed AM 11693 24773 1169 2477 3704 7847 1111 2354 Wed PM 12026 25478 1203 2548 3221 6824 966 2047 Thurs AM 12317 26095 1232 2609 1772 3753 531 1126 Thurs PM 11360 24067 1136 2407 1691 3583 507 1075 CAJS01(01) Wed AM 200 423 20 42 200 423 60 127 Wed PM 200 423 20 42 200 423 60 127 Thurs AM 155 329 16 33 155 329 47 99 Thurs PM 200 423 20 42 200 423 60 127 CAJS01(02) Wed AM 1336 2830 134 283 1336 2830 401 849 Wed PM 1315 2786 131 279 1315 2786 394 836 Thurs AM 1416 3000 142 300 1416 3000 425 900 Thurs PM 1323 2804 132 280 1323 2804 397 841 CAJS01(03) Wed AM 1538 3258 154 326 1538 3258 461 977 Wed PM 1739 3685 174 368 1739 3685 522 1105 Thurs AM 1613 3418 161 342 1613 3418 484 1025 Thurs PM 1647 3489 165 349 1647 3489 494 1047 CAJS02(01) Wed AM 14671 31081 1467 3108 12430 26333 3729 7900 Wed PM 13720 29067 1372 2907 12601 26696 3780 8009 Thurs AM 14671 31081 1467 3108 14368 30440 4310 9132 Thurs PM 14331 30362 1433 3036 15508 32856 4653 9857 CAJS03(01) Wed AM 40277 85330 4028 8533 40277 85330 12083 25599 Wed PM 41447 87811 4145 8781 41447 87811 12434 26343 Thurs AM 42384 89795 4238 8979 42384 89795 12715 26938 Thurs PM 41631 88200 4163 8820 41447 87811 12434 26343 CAJS21(01) Wed AM 6088 12897 609 1290 1265 2679 379 804 Wed PM 4911 10405 491 1040 1196 2534 359 760 Thurs AM 4558 9657 456 966 1647 3489 494 1047 Thurs PM 5117 10841 512 1084 1470 3115 441 935 CAJS21(02) Wed AM 2582 5470 258 547 2582 5470 775 1641 Wed PM 2849 6035 285 604 2849 6035 855 1811 Thurs AM 2865 6069 286 607 2865 6069 859 1821 Thurs PM 2902 6149 290 615 2902 6149 871 1845 CAJS222(01) Wed AM 4651 9854 465 985 391 829 1360 2881 Wed PM 5604 11873 560 1187 806 1708 1545 3272 Thurs AM 4494 9521 449 952 929 1968 1160 2458 Thurs PM 5567 11793 557 1179 1172 2483 1431 3032 CAJS23(01) Wed AM 11349 24044 1135 2404 837 1773 251 532 Wed PM 10010 21206 1001 2121 1016 2153 305 646 Thurs AM 11238 23808 1124 2381 967 2048 290 614 Thurs PM 11535 24439 1154 2444 1098 2326 329 698 CAJW18(01) Wed AM 10464 22170 1046 2217 845 1791 254 537 Wed PM 10922 23140 1092 2314 832 1763 250 529 Thurs AM 10709 22687 1071 2269 938 1986 281 596 Thurs PM 12081 25596 1208 2560 938 1986 281 596 Supply airflow Uncertainty in supply airflow Outdoor airflow Uncertainty in outdoor airflow5 4 System ID Day Period L/s cfm L/s cfm L/s cfm L/s cfm CAJW19(01) Wed AM 17769 37645 1777 3764 8828 18703 3217 6816 Wed PM 17430 36926 1743 3693 7045 14925 3570 7563 Thurs AM 17769 37645 1777 3764 8753 18543 3236 6856 Thurs PM 16887 35777 1689 3578 5530 11715 3803 8056 CAJW20(01) Wed AM 33151 70234 3315 7023 39935 84606 11980 25382 Wed PM 36439 77200 3644 7720 41671 88284 12501 26485 Thurs AM 32055 67913 3206 6791 36462 77249 10939 23175 Thurs PM 32877 69654 3288 6965 36936 78252 11081 23476 CAJW24(01) Tues AM 19105 40475 1910 4048 13205 27975 3961 8393 Tues PM 20500 43432 2050 4343 741 1570 222 471 Wed AM 19105 40475 1910 4048 13205 27975 3961 8393 Wed PM 21788 46160 2179 4616 729 1545 219 463 Thurs AM 23076 48889 2308 4889 16164 34245 4849 10274 Thurs PM 23183 49116 2318 4912 20547 43530 6164 13059 CAJW25(01) Wed AM 17130 36292 1713 3629 9230 19555 2769 5867 Wed PM 18047 38233 1805 3823 17256 36560 5177 10968 Thurs AM 15964 33822 1596 3382 11337 24019 3401 7206 Thurs PM 17738 37580 1774 3758 18159 38473 5448 11542 CAJW26(01) Wed AM 29773 63078 2977 6308 33826 71665 10148 21499 Wed PM 33495 70962 3349 7096 37230 78875 11169 23662 Thurs AM 31205 66110 3120 6611 33311 70572 9993 21172 Thurs PM 32779 69446 3278 6945 30939 65547 9282 19664 COAS02(01) Wed AM 11323 23988 3163 6701 810 1717 243 515 Wed PM 10049 21290 2710 5742 1080 2289 324 687 Thurs AM 11012 23330 3021 6401 990 2098 297 629 Thurs PM 12065 25562 3188 6754 1553 3290 466 987 COAS04(01) Wed AM 34210 72477 3421 7248 780 1652 10596 22450 Wed PM 34890 73918 3489 7392 2278 4827 10387 22006 Thurs AM 33529 71036 3353 7104 153 324 10559 22371 Thurs PM 34330 72731 3433 7273 0 0 11020 23348 COAS06(01) Wed AM 3837 8130 384 813 927 1963 278 589 Wed PM 4818 10206 482 1021 999 2116 300 635 Thurs AM 6446 13657 645 1366 1074 2275 322 683 Thurs PM 5066 10733 507 1073 887 1878 266 564 FLDW07(02) Wed AM 7499 15888 1979 4192 977 2069 293 621 Wed PM 6766 14334 1755 3719 1002 2122 300 637 Thurs AM 6340 13431 1634 3461 983 2083 295 625 Thurs PM 6911 14643 1789 3791 1039 2201 312 660 FLDW08(01) Wed AM 6982 14793 698 1479 1307 2769 392 831 Wed PM 7647 16200 765 1620 871 1846 261 554 Thurs AM 7090 15020 709 1502 871 1846 261 554 Thurs PM 7116 15075 712 1508 4773 10112 1432 3034 FLDW10(01) Wed AM 3702 7844 370 784 285 603 85 181 Wed PM 3721 7883 372 788 324 686 97 206 Thurs AM 3783 8015 378 801 356 755 107 226 Thurs PM 3417 7240 342 724 228 482 68 145 FLGS01(01) Thurs AM 4769 10103 477 1010 931 1973 279 592 Thurs PM 5276 11178 528 1118 978 2072 293 622 Fri AM 4615 9778 462 978 905 1917 272 575 Fri PM 5005 10603 500 1060 991 2099 297 630 FLGS04(01) Wed AM 7019 14870 702 1487 246 522 74 157 Wed PM 7372 15618 737 1562 273 579 82 174 Thurs AM 7215 15285 721 1529 242 513 73 154 Thurs PM 7215 15285 721 1529 220 466 66 140 FLGS04(02) Wed AM 9411 19937 941 1994 395 837 118 251 Wed PM 9469 20062 947 2006 381 807 114 242 Thurs AM 9607 20353 961 2035 398 843 119 253 Thurs PM 10058 21308 1006 2131 413 875 124 263 Supply airflow Uncertainty in supply airflow Outdoor airflow Uncertainty in outdoor airflow5 5 System ID Day Period L/s cfm L/s cfm L/s cfm L/s cfm FLGS11(01) Wed AM 2684 5686 268 569 433 917 130 275 Wed PM 4318 9149 432 915 449 950 135 285 Thurs AM 2288 4848 229 485 433 917 130 275 Thurs PM 4542 9623 454 962 399 846 120 254 FLGS11(02) Wed AM 3699 7837 370 784 532 1127 160 338 Wed PM 4594 9732 459 973 508 1077 153 323 Thurs AM 2976 6306 298 631 482 1022 145 307 Thurs PM 4250 9003 425 900 472 1000 142 300 FLGS12(01) Wed AM 10029 21246 2564 5431 1643 3480 493 1044 Wed PM 9658 20462 2452 5194 1655 3507 497 1052 Thurs AM 8985 19036 2252 4772 1664 3525 499 1057 Thurs PM 8774 18589 2219 4702 1538 3258 461 977 GADS01(01) Wed AM 5469 11587 1185 2511 2165 4588 650 1376 Wed PM 5890 12480 1327 2811 1895 4014 568 1204 Thurs AM 5522 11700 1187 2514 2313 4900 694 1470 Thurs PM 5669 12010 1238 2622 2145 4544 643 1363 GADS02(01) Wed AM 5291 11210 529 1121 855 1811 256 543 Wed PM 6143 13014 614 1301 978 2072 293 622 Thurs AM 5017 10630 502 1063 1101 2333 330 700 Thurs PM 6105 12933 610 1293 989 2096 297 629 GADS02(02) Wed AM 5017 10630 502 1063 1269 2688 381 806 Wed PM 5717 12112 572 1211 1118 2368 335 711 Thurs AM 5253 11129 525 1113 1090 2310 327 693 Thurs PM 6409 13577 641 1358 1180 2499 354 750 GADS03(01) Wed AM 11988 25399 1199 2540 956 2026 287 608 Wed PM 11462 24283 1146 2428 973 2061 292 618 Thurs AM 11415 24183 1141 2418 973 2061 292 618 Thurs PM 11274 23885 1127 2388 978 2072 293 622 ILBS01(01) Wed AM 4889 10359 489 1036 Wed PM 4428 9381 443 938 Thurs AM 4161 8816 416 882 Thurs PM 4792 10152 479 1015 ILBS01(02) Wed AM 4460 9450 446 945 Wed PM 4889 10359 489 1036 Thurs AM 4688 9932 469 993 Thurs PM 4720 10001 472 1000 ILBS02(01) Wed AM 7212 15280 721 1528 598 1267 179 380 Wed PM 7488 15864 749 1586 549 1163 165 349 Thurs AM 7015 14862 702 1486 476 1008 143 302 Thurs PM 7173 15196 717 1520 543 1151 163 345 ILBS03(01) Thurs AM 16385 34712 1638 3471 7661 16231 3088 6541 Thurs PM 15682 33225 1568 3322 6606 13995 3142 6657 Wed AM 16229 34382 1623 3438 5875 12446 3505 7425 Wed PM 16931 35870 1693 3587 6027 12768 3683 7804 LAGW04(01) Wed AM 9213 19518 921 1952 570 1207 171 362 Wed PM 9735 20624 973 2062 439 929 132 279 Thurs AM 8967 18997 897 1900 549 1163 165 349 Thurs PM 9827 20819 983 2082 533 1129 160 339 LAGW04(02) Wed AM 10687 22641 1069 2264 776 1644 233 493 Wed PM 10594 22446 1059 2245 821 1739 246 522 Thurs AM 10287 21795 1029 2179 837 1773 251 532 Thurs PM 10533 22315 1053 2232 792 1678 238 504 LAGW05(01) Wed AM 9409 19934 941 1993 2726 5775 818 1732 Wed PM 9075 19226 907 1923 3054 6471 916 1941 Thurs AM 9203 19498 920 1950 2868 6077 860 1823 Thurs PM 8972 19008 897 1901 3023 6405 907 1922 LAGW05(02) Wed AM 4926 10437 493 1044 Wed PM 4876 10331 488 1033 Thurs AM 5026 10649 503 1065 Thurs PM 4939 10464 494 1046 Supply airflow Uncertainty in supply airflow Outdoor airflow Uncertainty in outdoor airflow5 6 System ID Day Period L/s cfm L/s cfm L/s cfm L/s cfm LAGW06(01) Wed AM 9962 21106 996 2111 1259 2668 378 800 Wed PM 10012 21211 1001 2121 1220 2584 366 775 Thurs AM 9933 21043 993 2104 1216 2575 365 773 Thurs PM 9992 21169 999 2117 1232 2609 369 783 LAGW06(02) Wed AM 141 298 42 90 Wed PM Thurs AM Thurs PM MABW05(01) Wed AM 4182 8860 418 886 415 880 1205 2553 Wed PM 6951 14727 695 1473 1938 4107 1657 3510 Thurs AM 6556 13889 656 1389 1288 2728 1711 3625 Thurs PM 6838 14488 684 1449 1740 3687 1675 3549 MABW05(02) Wed AM 6104 12931 610 1293 637 1350 1750 3707 Wed PM 5991 12692 599 1269 0 0 2028 4296 Thurs AM 6443 13650 644 1365 325 689 1945 4121 Thurs PM 6725 14248 673 1425 4 1 8 7 2115 4481 MABW06(01) Wed AM 2112 4474 211 447 1965 4163 589 1249 Wed PM 2085 4417 208 442 2013 4265 604 1279 Thurs AM 1783 3776 178 378 1723 3651 517 1095 Thurs PM 1728 3662 173 366 1675 3548 502 1065 MABW08(01) Wed AM 12910 27352 1291 2735 8083 17124 1940 4110 Wed PM 13508 28619 1351 2862 9097 19273 1891 4006 Thurs AM 12597 26687 1260 2669 6698 14191 2172 4602 Thurs PM 12910 27352 1291 2735 7557 16011 2061 4365 MABW08(02) Wed AM 12379 26225 3588 7602 11952 25322 3586 7597 Wed PM 11883 25176 3431 7269 11427 24210 3428 7263 Thurs AM 11537 24443 3330 7055 11091 23498 3327 7049 Thurs PM 11686 24758 3332 7059 11091 23498 3327 7049 MDDS01(01) Wed AM 21258 45037 2126 4504 2408 5101 6041 12799 Wed PM 22707 48108 2271 4811 1439 3048 6773 14349 Thurs AM 20292 42990 2029 4299 0 0 7794 16512 Thurs PM 19889 42137 1989 4214 0 0 6884 14585 MDDS03(01) Wed AM 1329 2815 133 282 209 442 63 133 Wed PM 1332 2823 133 282 176 372 53 112 Thurs AM 1340 2838 134 284 191 404 57 121 Thurs PM 1332 2823 133 282 181 383 54 115 MDDS03(02) Wed AM 2129 4511 213 451 68 145 21 43 Wed PM 1928 4084 193 408 31 65 9 19 Thurs AM 2047 4336 205 434 65 137 19 41 Thurs PM 1994 4224 199 422 64 135 19 41 MDDS04(01) Wed AM 2558 5420 256 542 293 620 726 1539 Wed PM 2531 5362 253 536 284 601 720 1525 Thurs AM 2545 5391 254 539 260 550 731 1549 Thurs PM 2434 5157 243 516 206 437 711 1507 MDDS04(02) Wed AM 2142 4538 214 454 572 1212 517 1096 Wed PM 1924 4077 192 408 456 966 481 1019 Thurs AM 1993 4223 199 422 446 945 505 1070 Thurs PM 1940 4111 194 411 505 1070 472 1000 MIBW01(01) Wed AM 2857 6053 286 605 1698 3598 450 953 Wed PM 2990 6336 299 634 1949 4128 433 916 Thurs AM 2857 6053 286 605 1599 3387 473 1003 Thurs PM 3009 6375 301 637 1531 3243 536 1135 MIBW01(02) Wed AM 2295 4861 229 486 202 428 668 1416 Wed PM 2765 5857 276 586 1052 2230 583 1236 Thurs AM 2313 4901 231 490 Thurs PM 2443 5175 244 518 Supply airflow Uncertainty in supply airflow Outdoor airflow Uncertainty in outdoor airflow5 7 System ID Day Period L/s cfm L/s cfm L/s cfm L/s cfm MIBW03(01) Wed AM 16081 34070 1608 3407 4577 9696 3808 8067 Wed PM 15998 33894 1600 3389 3486 7385 4080 8645 Thurs AM 16367 34675 1637 3468 3999 8472 4055 8592 Thurs PM 13975 29606 1397 2961 4711 9981 3111 6590 MIBW04(01) Wed AM 4319 9151 432 915 1317 2790 999 2116 Wed PM 4307 9124 431 912 1606 3403 917 1944 Thurs AM 5031 10658 503 1066 1264 2677 1237 2621 Thurs PM 5107 10819 511 1082 1651 3499 1156 2448 MIBW04(02) Wed AM 5624 11915 562 1191 2169 4594 1179 2499 Wed PM 5423 11489 542 1149 1883 3989 1193 2527 Thurs AM 5122 10851 512 1085 1327 2810 1248 2645 Thurs PM 5875 12447 588 1245 2401 5087 1196 2535 MNBW01(01) Wed AM 4257 9019 426 902 1104 2340 331 702 Wed PM 4816 10203 482 1020 1113 2359 334 708 Thurs AM 4284 9076 428 908 1072 2272 322 682 Thurs PM 4710 9978 471 998 1165 2469 350 741 MNBW02(01) Wed AM 5487 11625 549 1162 1526 3232 458 970 Wed PM 5869 12434 587 1243 1730 3666 519 1100 Thurs AM 4342 9199 434 920 1805 3823 541 1147 Thurs PM 5344 11322 534 1132 2233 4730 670 1419 MNBW02(02) Wed AM 8190 17352 819 1735 2419 5124 726 1537 Wed PM 10586 22427 1059 2243 4502 9539 1351 2862 Thurs AM 6853 14519 685 1452 4279 9066 1284 2720 Thurs PM 7689 16289 769 1629 3516 7450 1055 2235 MNBW04(01) Wed AM 9340 19787 934 1979 6735 14269 2021 4281 Wed PM 8931 18920 893 1892 7330 15530 2199 4659 Thurs AM 10270 21758 1027 2176 7256 15373 2177 4612 Thurs PM 9042 19157 904 1916 7740 16398 2322 4919 MOCS01(01) Wed AM 24167 51200 2417 5120 Wed PM 28638 60672 2864 6067 Thurs AM 25979 55040 2598 5504 Thurs PM 28396 60160 2840 6016 MOCS05(01) Wed AM 45207 95775 4521 9578 14860 31482 4458 9445 Wed PM 50117 106178 5012 10618 17710 37519 5313 11256 Thurs AM 40690 86206 4069 8621 8957 18975 2687 5693 Thurs PM 39282 83222 3928 8322 1018 2156 305 647 NCDW02(01) Wed AM 10767 22811 1077 2281 10054 21300 3016 6390 Wed PM 11227 23786 1123 2379 10622 22504 3187 6751 Thurs AM 11043 23396 1104 2340 5595 11854 1679 3556 Thurs PM 11227 23786 1123 2379 9311 19726 2793 5918 NCDW02(02) Wed AM 11595 24566 1160 2457 10054 21300 3016 6390 Wed PM 12976 27490 1298 2749 10622 22504 3187 6751 Thurs AM 12055 25541 1206 2554 5595 11854 1679 3556 Thurs PM 12239 25931 1224 2593 9311 19726 2793 5918 NCDW03(01) Wed AM Wed PM Thurs AM Thurs PM NCDW03(02) Wed AM Wed PM Thurs AM Thurs PM NCDW03(03) Wed AM Wed PM Thurs AM Thurs PM 49 104 12 25 37 79 11 24 Supply airflow Uncertainty in supply airflow Outdoor airflow Uncertainty in outdoor airflow5 8 System ID Day Period L/s cfm L/s cfm L/s cfm L/s cfm NCDW03(04) Wed AM 85 181 22 47 74 156 22 47 Wed PM 83 175 22 46 71 150 21 45 Thurs AM 88 186 23 49 76 161 23 48 Thurs PM 61 128 15 32 49 103 15 31 NCDW03(05) Wed AM Wed PM Thurs AM Thurs PM NCDW06(01) Wed AM 6300 13348 630 1335 2419 5124 726 1537 Wed PM 7078 14996 708 1500 4016 8508 1205 2552 Thurs AM 5322 11276 532 1128 3814 8081 1144 2424 Thurs PM 6300 13348 630 1335 2326 4927 698 1478 NECW01(01) Wed AM 42102 89197 4210 8920 13910 29471 4173 8841 Wed PM 40713 86254 4071 8625 16197 34315 4859 10295 Thurs AM 43810 92816 4381 9282 15625 33104 4688 9931 Thurs PM 43304 91744 4330 9174 25281 53560 7584 16068 NECW02(01) Wed AM 67711 143453 6771 14345 53438 113213 16031 33964 Wed PM 52310 110824 5231 11082 29626 62766 8888 18830 Thurs AM 68229 144550 6823 14455 51499 109107 15450 32732 Thurs PM 66517 140922 6652 14092 48731 103241 14619 30972 NECW03(01) Wed AM 27504 58269 2750 5827 18860 39956 5658 11987 Wed PM 31117 65925 3112 6593 20824 44118 6247 13236 Thurs AM 32121 68052 3212 6805 14980 31736 4494 9521 Thurs PM 28307 59971 2831 5997 24950 52859 7485 15858 NMES01(01) Wed AM 3517 7451 746 1581 1799 3811 540 1143 Wed PM 3384 7168 742 1571 2132 4516 640 1355 Thurs AM 3190 6758 678 1437 1699 3599 510 1080 Thurs PM 3310 7013 714 1512 1954 4140 586 1242 NMES01(02) Wed AM 5609 11884 1408 2983 1030 2182 309 655 Wed PM 5878 12453 1490 3157 1016 2152 305 645 Thurs AM 4957 10502 1298 2749 687 1455 206 436 Thurs PM 5638 11944 1440 3050 930 1970 279 591 NMES02(01) Wed AM 6220 13177 622 1318 8612 18245 2584 5474 Wed PM 6897 14612 690 1461 8561 18136 2568 5441 Thurs AM 7405 15687 740 1569 8021 16993 2406 5098 Thurs PM 5966 12640 597 1264 9075 19226 2722 5768 NMES03(01) Wed AM 3423 7251 342 725 248 526 1012 2144 Wed PM 3498 7410 350 741 466 986 975 2065 Thurs AM 3122 6614 312 661 319 677 897 1900 Thurs PM 3046 6454 305 645 5 8 123 947 2006 NMES03(02) Wed AM 4992 10577 499 1058 548 1161 1424 3016 Wed PM 6468 13704 647 1370 959 2033 1775 3760 Thurs AM 5470 11589 547 1159 1054 2233 1433 3036 Thurs PM 5991 12692 599 1269 865 1833 1650 3496 NVAW01(01) Wed AM 46440 98387 4644 9839 46478 98468 13943 29540 Wed PM 48395 102530 4840 10253 32571 69005 9771 20702 Thurs AM 49699 105291 4970 10529 27074 57358 8122 17207 Thurs PM 50350 106672 5035 10667 13962 29580 4189 8874 NVAW02(01) Wed AM 24729 52391 2473 5239 23554 49902 7066 14971 Wed PM 27597 58466 2760 5847 26457 56051 7937 16815 Thurs AM 24045 50942 2405 5094 23145 49035 6943 14710 Thurs PM 27465 58187 2746 5819 25638 54317 7691 16295 NVAW03(01) Wed AM 5207 11033 521 1103 5679 12031 1704 3609 Wed PM 5074 10751 507 1075 5747 12176 1724 3653 Thurs AM 5188 10992 519 1099 5702 12079 1710 3624 Thurs PM 5207 11033 521 1103 5724 12128 1717 3638 Supply airflow Uncertainty in supply airflow Outdoor airflow Uncertainty in outdoor airflow5 9 System ID Day Period L/s cfm L/s cfm L/s cfm L/s cfm NVAW03(02) Wed AM 3695 7829 370 783 1802 3818 541 1146 Wed PM 3582 7590 358 759 1802 3818 541 1146 Thurs AM 3441 7291 344 729 1764 3737 529 1121 Thurs PM 3653 7739 365 774 1818 3851 545 1155 NYBS01(01) Wed AM 31613 66976 3161 6698 4645 9841 8686 18402 Wed PM 32918 69739 3292 6974 3897 8256 9308 19720 Thurs AM 31951 67692 3195 6769 3478 7369 9120 19322 Thurs PM 32612 69091 3261 6909 4138 8768 9143 19371 NYBS01(02) Wed AM 16430 34808 1643 3481 2423 5134 727 1540 Wed PM 17456 36982 1746 3698 2594 5496 778 1649 Thurs AM 17564 37211 1756 3721 2509 5315 753 1594 Thurs PM 17411 36887 1741 3689 2680 5677 804 1703 NYBS02(01) Wed AM 2861 6061 286 606 286 605 86 182 Wed PM 2981 6315 298 632 286 605 86 182 Thurs AM 3201 6781 320 678 235 498 71 150 Thurs PM 2101 4450 210 445 286 605 86 182 NYBS02(02) Wed AM 3901 8265 390 826 353 748 106 224 Wed PM 3401 7205 340 721 429 908 129 272 Thurs AM 3221 6824 322 682 378 801 113 240 Thurs PM 2321 4917 232 492 378 801 113 240 NYBS04(01) Wed AM 6706 14208 671 1421 91 193 27 58 Wed PM 7003 14838 700 1484 91 193 27 58 Thurs AM 7460 15805 746 1580 5717 12112 1715 3633 Thurs PM 7334 15537 733 1554 84 177 25 53 NYBS04(02) Wed AM 8252 17483 825 1748 306 648 92 195 Wed PM 8005 16959 800 1696 281 594 84 178 Thurs AM 8290 17563 829 1756 7559 16014 2268 4804 Thurs PM 8402 17801 840 1780 298 630 89 189 NYBS05(01) Wed AM 5655 11981 566 1198 1441 3052 432 916 Wed PM 6101 12926 610 1293 1454 3080 436 924 Thurs AM 5890 12478 589 1248 1454 3080 436 924 Thurs PM 5936 12575 594 1258 1347 2854 404 856 NYBS07(01) Wed AM 5071 10743 1256 2660 1008 2137 303 641 Wed PM 5311 11252 1315 2785 1058 2242 317 673 Thurs AM 5230 11080 1288 2729 1072 2272 322 682 Thurs PM 5006 10606 1238 2624 1001 2122 300 636 ORIS03(01) Wed AM 26408 55948 3083 6533 11842 25089 3553 7527 Wed PM 30621 64874 3537 7494 12767 27048 3830 8115 Thurs AM 23088 48915 2682 5683 10415 22065 3124 6619 Thurs PM 26075 55243 3024 6407 12144 25728 3643 7718 ORIS03(03) Wed AM Wed PM Thurs AM Thurs PM ORIS04(01) Wed AM Wed PM 6117 12959 612 1296 Thurs AM 8734 18504 873 1850 Thurs PM 8528 18068 853 1807 PABS03(01) Wed AM 15911 33709 1591 3371 0 0 5214 11046 Wed PM 14736 31220 1474 3122 0 0 5125 10857 Thurs AM 14997 31773 1500 3177 0 0 5598 11860 Thurs PM 16288 34508 1629 3451 0 0 5908 12516 PABS04(01) Wed AM 11128 23577 1113 2358 2195 4651 659 1395 Wed PM 10982 23267 1098 2327 2121 4494 636 1348 Thurs AM 10311 21844 1031 2184 2009 4257 603 1277 Thurs PM 10610 22478 1061 2248 2121 4494 636 1348 PABS04(02) Wed AM 8150 17267 815 1727 309 655 93 196 Wed PM 8070 17098 807 1710 309 655 93 196 Thurs AM 7682 16275 768 1628 268 568 80 170 Thurs PM 8130 17225 813 1722 288 611 87 183 Supply airflow Uncertainty in supply airflow Outdoor airflow Uncertainty in outdoor airflow6 0 System ID Day Period L/s cfm L/s cfm L/s cfm L/s cfm SCDW01(01) Wed AM 6063 12844 606 1284 1463 3100 439 930 Wed PM 5127 10863 513 1086 1279 2709 384 813 Thurs AM 5634 11935 563 1194 1340 2839 402 852 Thurs PM 4830 10234 483 1023 1063 2252 319 676 SCDW02(01) Wed AM 24154 51173 2415 5117 4391 9302 1317 2791 Wed PM 26087 55267 2609 5527 4875 10327 1462 3098 Thurs AM 23560 49914 2356 4991 4502 9539 1351 2862 Thurs PM 24526 51961 2453 5196 3795 8041 1139 2412 SDBW01(01) Wed AM 6419 13600 642 1360 2930 6208 879 1862 Wed PM 6870 14555 687 1455 3551 7524 1065 2257 Thurs AM 6547 13870 655 1387 3425 7256 1028 2177 Thurs PM 6776 14357 678 1436 3697 7832 1109 2350 SDBW02(01) Wed AM 7185 15222 718 1522 3187 6752 956 2026 Wed PM 6560 13898 656 1390 1923 4073 577 1222 Thurs AM 7150 15148 715 1515 2026 4292 608 1288 Thurs PM 6630 14045 663 1405 1561 3308 468 992 SDBW04(01) Wed AM 11859 25125 1186 2512 2541 5383 3037 6433 Wed PM 10063 21320 1006 2132 2001 4239 2620 5550 Thurs AM 9689 20528 969 2053 1891 4007 2532 5365 Thurs PM 9615 20369 961 2037 2081 4408 2456 5204 TNDS05(01) Wed AM 9596 20329 960 2033 9596 20329 2879 6099 Wed PM 10762 22800 1076 2280 10762 22800 3229 6840 Thurs AM 10232 21677 1023 2168 10232 21677 3070 6503 Thurs PM 9649 20442 965 2044 9649 20442 2895 6133 TNDS05(02) Wed AM 4616 9780 462 978 4616 9780 1385 2934 Wed PM 4454 9436 445 944 4454 9436 1336 2831 Thurs AM 4259 9022 426 902 4259 9022 1278 2707 Thurs PM 4031 8540 403 854 4031 8540 1209 2562 TNDS06(01) Wed AM 86266 182763 8627 18276 18357 38892 22124 46871 Wed PM 73705 156152 7371 15615 6302 13352 21522 45597 Thurs AM 67711 143452 6771 14345 8809 18663 18923 40091 Thurs PM 69550 147348 6955 14735 1539 3262 21556 45668 TNDS07(01) Wed AM 4470 9470 447 947 107 226 32 68 Wed PM 4318 9148 432 915 128 271 38 81 Thurs AM 4470 9470 447 947 135 286 40 86 Thurs PM 4516 9567 452 957 717 1520 215 456 TNFS08(01) Wed AM 3023 6405 302 641 616 1305 185 391 Wed PM 3047 6456 305 646 745 1579 224 474 Thurs AM 3262 6910 326 691 745 1579 224 474 Thurs PM 3952 8373 395 837 713 1511 214 453 TNFS08(02) Wed AM 1336 2830 312 662 359 760 108 228 Wed PM 1352 2864 328 695 300 636 90 191 Thurs AM 1364 2889 330 699 308 653 92 196 Thurs PM 1316 2788 319 675 296 628 89 188 TNFS09(01) Wed AM 6846 14504 685 1450 2527 5354 1465 3105 Wed PM 6295 13336 629 1334 2035 4312 1424 3018 Thurs AM 5889 12476 589 1248 1600 3389 1415 2998 Thurs PM 5932 12568 593 1257 1762 3733 1385 2933 TNFS09(02) Wed AM 5493 11637 549 1164 420 890 126 267 Wed PM 5925 12552 592 1255 420 890 126 267 Thurs AM 4057 8595 406 860 216 458 65 137 Thurs PM 4830 10233 483 1023 276 585 83 175 TNFS10(01) Wed AM 10660 22585 1066 2258 7334 15537 1460 3094 Wed PM 12565 26621 1257 2662 6728 14254 2155 4566 Thurs AM 11859 25124 1186 2512 8341 17672 1587 3363 Thurs PM 10446 22131 1045 2213 7362 15597 1395 2956 Supply airflow Uncertainty in supply airflow Outdoor airflow Uncertainty in outdoor airflow6 1 System ID Day Period L/s cfm L/s cfm L/s cfm L/s cfm TXFS01(01) Wed AM 34668 73447 3467 7345 Wed PM 42496 90032 4250 9003 1933 4094 580 1228 Thurs AM 41862 88689 4186 8869 1789 3791 537 1137 Thurs PM 43118 91349 4312 9135 1720 3645 516 1094 TXFS02(01) Wed AM 8906 18868 891 1887 416 881 125 264 Wed PM 8008 16966 801 1697 400 847 120 254 Thurs AM 10773 22824 1077 2282 386 818 116 245 Thurs PM 9480 20085 948 2008 462 978 139 294 TXFS02(02) Wed AM 9588 20313 959 2031 450 954 135 286 Wed PM 10019 21226 1002 2123 462 978 139 294 Thurs AM 10486 22215 1049 2222 448 950 134 285 Thurs PM 9229 19552 923 1955 407 862 122 259 TXFS07(01) Wed AM 31610 66968 3161 6697 4042 8562 1212 2569 Wed PM 31610 66968 3161 6697 4475 9480 1342 2844 Thurs AM 29436 62362 2944 6236 4193 8884 1258 2665 Thurs PM 27596 58464 2760 5846 4382 9284 1315 2785 TXFS08(01) Wed AM 8107 17175 811 1718 373 791 112 237 Wed PM 8891 18837 889 1884 436 923 131 277 Thurs AM 8293 17570 829 1757 479 1014 144 304 Thurs PM 8646 18318 865 1832 512 1085 154 326 TXFS08(02) Wed AM 6913 14646 691 1465 366 776 110 233 Wed PM 7593 16087 759 1609 360 763 108 229 Thurs AM 6985 14799 699 1480 366 776 110 233 Thurs PM 7696 16305 770 1631 378 801 113 240 TXFS09(01) Wed AM 5083 10770 508 1077 975 2065 292 619 Wed PM 5168 10949 517 1095 947 2006 284 602 Thurs AM 5245 11112 525 1111 989 2095 297 628 Thurs PM 5191 10998 519 1100 1003 2124 301 637 TXFS09(02) Wed AM 5156 10924 516 1092 975 2065 292 619 Wed PM 5270 11164 527 1116 947 2006 284 602 Thurs AM 5092 10788 509 1079 989 2095 297 628 Thurs PM 5149 10909 515 1091 1003 2124 301 637 TXFW05(01) Wed AM 35400 74999 3540 7500 9156 19398 8633 18289 Wed PM 34115 72277 3412 7228 8465 17934 8417 17833 Thurs AM 41709 88366 4171 8837 24435 51768 6652 14094 Thurs PM 41826 88613 4183 8861 26065 55220 6313 13375 TXFW06(01) Wed AM 47533 100703 4753 10070 47738 101137 14321 30341 Wed PM 39884 84498 3988 8450 39878 84486 11963 25346 Thurs AM 40703 86234 4070 8623 40752 86336 12225 25901 Thurs PM 45621 96652 4562 9665 45700 96820 13710 29046 WAIW03(01) Wed AM 2958 6266 296 627 2986 6327 896 1898 Wed PM 4093 8672 409 867 3627 7684 1088 2305 Thurs AM 3407 7217 341 722 3469 7350 1041 2205 Thurs PM 4040 8560 404 856 3718 7877 1115 2363 WAIW04(01) Wed AM 1570 3327 157 333 1528 3237 458 971 Wed PM 1570 3327 157 333 1555 3294 466 988 Thurs AM 1570 3327 157 333 1541 3266 462 980 Thurs PM 1537 3256 154 326 1541 3266 462 980

# of values 536 510
Mean 11676 24737 1243 2633 5033 10662 2102 4453 StdDev 12731 26972 1298 2750 9113 19307 3422 7250 Minimum 49 104 12 25 0 0 9 19 10th percentile 2462 5215 252 534 219 465 89 188 25th percentile 4450 9428 449 951 473 1002 251 532 Median 6861 14537 720 1525 1527 3235 590 1251 75th percentile 12259 25972 1514 3207 4606 9759 2580 5465 90th percentile 31161 66018 3200 6780 13374 28334 5921 12544 Maximum 86266 182763 8626 18276 53438 113213 22124 46871 Supply airflow Uncertainty in supply airflow Outdoor airflow Uncertainty in outdoor airflow6 2 System ID Day Period L/s cfm L/s cfm ARFW01(01) Wed AM 0.056 0.018 0.029 0.202 Wed PM 0.054 0.017 0.000 0.203 Thurs AM 0.056 0.018 0.086 0.203 Thurs PM 0.055 0.017 0.125 0.178 ARFW01(02) Wed AM 0.055 0.017 0.000 0.182 Wed PM 0.054 0.017 0.051 0.182 Thurs AM 0.058 0.018 0.125 0.178 Thurs PM 0.054 0.017 0.063 0.177 ARFW02(01) Wed AM 0.819 0.259 0.667 2.833 Wed PM 0.841 0.266 0.611 0.921 Thurs AM Thurs PM 0.846 0.267 0.750 1.473 ARFW02(02) Wed AM 0.833 0.767 Wed PM 0.796 0.252 0.235 0.741 Thurs AM Thurs PM 0.817 0.258 0.850 0.928 ARFW03(01) Wed AM 0.042 0.013 0.120 0.251 Wed PM 0.024 0.008 0.014 0.249 Thurs AM 0.027 0.009 0.041 0.207 Thurs PM 0.027 0.009 0.055 0.279 ARFW03(02) Wed AM 0.110 0.035 0.031 0.217 Wed PM 0.114 0.036 0.032 0.228 Thurs AM 0.127 0.040 0.054 0.175 Thurs PM 0.121 0.038 0.233 0.202 AZHS02(01) Wed AM 2909 6162 873 1849 0.365 0.218 0.418 0.341 Wed PM 2761 5850 828 1755 0.485 0.190 0.320 0.594 Thurs AM 2990 6334 897 1900 0.294 0.236 0.169 0.806 Thurs PM 2769 5866 831 1760 0.370 0.217 0.400 1.015 AZHS02(02) Wed AM 1364 2889 409 867 0.463 0.195 0.353 0.401 Wed PM 1270 2691 381 807 0.494 0.188 0.547 0.630 Thurs AM 1495 3168 449 950 0.267 0.243 0.465 0.549 Thurs PM 1789 3789 537 1137 0.279 0.240 0.365 0.885 AZHS04(01) Wed AM 10463 22167 3139 6650 0.000 0.316 0.100 0.142 Wed PM 10875 23040 3262 6912 0.000 0.330 0.000 0.156 Thurs AM 9160 19405 2748 5822 0.105 0.287 0.746 0.774 Thurs PM 10635 22531 3190 6759 0.000 0.340 0.091 0.129 AZHS04(02) Wed AM 599 1269 180 381 0.141 0.056 0.297 0.144 Wed PM 598 1267 179 380 0.154 0.061 0.375 0.134 Thurs AM 637 1350 191 405 0.109 0.044 0.570 0.546 Thurs PM 691 1464 207 439 0.147 0.058 0.382 0.133 AZHW10(01) Wed AM 0.854 0.264 0.246 0.597 Wed PM 1.004 0.310 0.893 1.264 Thurs AM 0.999 0.309 0.946 1.739 Thurs PM 1.003 0.310 0.967 1.639 AZHW10(02) Wed AM 0.139 0.585 Wed PM 0.627 1.113 Thurs AM 0.446 1.383 Thurs PM 0.550 1.345 AZHW11(01) Wed AM 11499 24361 3450 7308 0.190 0.263 0.162 0.227 Wed PM 11827 25057 3548 7517 0.294 0.236 0.278 0.395 Thurs AM 11006 23317 3302 6995 0.334 0.226 0.196 0.300 Thurs PM 11909 25231 3573 7569 0.343 0.224 0.150 0.335 AZHW12(01) Wed AM 0.206 0.065 Wed PM 0.241 0.076 Thurs AM 0.045 0.014 0.041 0.323 Thurs PM 0.036 0.011 0.072 0.224 OA fraction - CO 2 Uncert. in CO 2 OA fraction Outdoor air

fraction - volumetric Uncert. in vol. OA fraction Recirculation Airflow Uncertainty in recirc. airflow6 3 System ID Day Period L/s cfm L/s cfm AZHW12(02) Wed AM 0.305 0.096 Wed PM 0.305 0.096 Thurs AM 0.309 0.098 0.269 0.468 Thurs PM 0.305 0.096 0.295 0.358 CAES17(01) Wed AM 13246 28062 3974 8419 0.187 0.264 0.250 0.364 Wed PM 13354 28292 4006 8488 0.142 0.277 0.250 0.364 Thurs AM 7654 16216 2296 4865 0.564 0.174 0.167 0.478 Thurs PM 11617 24612 3485 7383 0.306 0.233 0.259 0.541 CAEW07(01) Wed AM 0.307 0.097 0.585 1.638 Wed PM 0.869 0.275 1.148 2.340 Thurs AM 0.763 0.241 0.222 0.805 Thurs PM 1.050 0.332 1.200 4.418 CAEW09(01) Wed AM 0.317 0.100 0.118 0.838 Wed PM 0.268 0.085 0.368 0.603 Thurs AM 0.144 0.045 0.500 1.976 Thurs PM 0.149 0.047 0.281 0.480 CAJS01(01) Wed AM 1.000 0.316 0.000 0.710 Wed PM 1.000 0.316 0.000 0.986 Thurs AM 1.000 0.316 0.000 0.710 Thurs PM 1.000 0.316 0.000 1.775 CAJS01(02) Wed AM 1.000 0.316 0.286 1.051 Wed PM 1.000 0.316 0.722 0.969 Thurs AM 1.000 0.316 0.537 0.743 Thurs PM 1.000 0.316 0.556 0.899 CAJS01(03) Wed AM 1.000 0.316 Wed PM 1.000 0.316 Thurs AM 1.000 0.316 0.200 0.577 Thurs PM 1.000 0.316 0.538 1.236 CAJS02(01) Wed AM 0.847 0.268 0.000 7.100 Wed PM 0.918 0.290 1.000 4.000 Thurs AM 0.979 0.310 0.400 1.523 Thurs PM 1.082 0.342 0.444 1.433 CAJS03(01) Wed AM 1.000 0.316 0.143 2.551 Wed PM 1.000 0.316 0.900 2.378 Thurs AM 1.000 0.316 0.488 1.919 Thurs PM 0.996 0.315 0.667 1.889 CAJS21(01) Wed AM 0.208 0.066 0.200 0.361 Wed PM 0.244 0.077 0.333 0.497 Thurs AM 0.361 0.114 0.278 0.815 Thurs PM 0.287 0.091 0.327 0.715 CAJS21(02) Wed AM 1.000 0.316 Wed PM 1.000 0.316 Thurs AM 1.000 0.316 Thurs PM 1.000 0.316 CAJS222(01) Wed AM 4260 9025 1278 2708 0.084 0.293 0.171 0.410 Wed PM 4798 10165 1439 3050 0.144 0.276 0.175 0.359 Thurs AM 3565 7553 1069 2266 0.207 0.259 0.133 0.476 Thurs PM 4395 9310 1318 2793 0.211 0.258 0.070 0.330 CAJS23(01) Wed AM 0.074 0.023 0.208 0.301 Wed PM 0.102 0.032 0.053 0.373 Thurs AM 0.086 0.027 0.000 0.394 Thurs PM 0.095 0.030 0.000 0.394 CAJW18(01) Wed AM 0.081 0.026 0.224 0.401 Wed PM 0.076 0.024 0.174 0.353 Thurs AM 0.088 0.028 0.170 0.597 Thurs PM 0.078 0.025 0.148 0.379 Outdoor air

fraction - volumetric Uncert. in vol. OA fraction OA fraction - CO 2 Uncert. in CO 2 OA fraction Recirculation Airflow Uncertainty in recirc. airflow6 4 System ID Day Period L/s cfm L/s cfm CAJW19(01) Wed AM 8940 18941 2682 5682 0.497 0.188 0.374 1.054 Wed PM 10385 22001 3115 6600 0.404 0.209 0.506 1.014 Thurs AM 9016 19101 2705 5730 0.493 0.189 0.419 0.776 Thurs PM 11357 24062 3407 7218 0.327 0.228 0.379 1.030 CAJW20(01) Wed AM 1.205 0.381 0.967 1.002 Wed PM 1.144 0.362 0.955 1.051 Thurs AM 1.137 0.360 1.061 0.609 Thurs PM 1.123 0.355 0.970 0.743 CAJW24(01) Tues AM 0.691 0.219 0.143 1.020 Tues PM 0.036 0.011 0.033 0.236 Wed AM 0.691 0.219 0.143 1.020 Wed PM 0.033 0.011 0.033 0.236 Thurs AM 0.700 0.222 0.750 1.105 Thurs PM 0.886 0.280 0.400 1.523 CAJW25(01) Wed AM 0.539 0.170 0.462 0.599 Wed PM 0.956 0.302 0.842 0.973 Thurs AM 0.710 0.225 0.333 0.828 Thurs PM 1.024 0.324 0.842 0.973 CAJW26(01) Wed AM 1.136 0.359 0.667 1.133 Wed PM 1.112 0.351 0.500 1.129 Thurs AM 1.067 0.338 1.000 1.250 Thurs PM 0.944 0.298 1.000 0.870 COAS02(01) Wed AM 10512 22272 3154 6681 0.072 0.029 0.000 0.568 Wed PM 8969 19001 2691 5700 0.108 0.043 0.000 0.473 Thurs AM 10022 21232 3007 6370 0.090 0.037 0.143 0.408 Thurs PM 10512 22272 3154 6681 0.129 0.051 0.143 0.408 COAS04(01) Wed AM 33430 70825 10029 21247 0.023 0.310 0.372 0.623 Wed PM 32611 69091 9783 20727 0.065 0.298 0.270 0.495 Thurs AM 33376 70711 10013 21213 0.005 0.315 0.114 0.407 Thurs PM 34907 73953 10472 22186 0.000 0.321 0.000 0.507 COAS06(01) Wed AM 0.241 0.076 0.216 0.289 Wed PM 0.207 0.066 0.333 0.191 Thurs AM 0.167 0.053 0.065 0.308 Thurs PM 0.175 0.055 0.055 0.216 FLDW07(02) Wed AM 6523 13819 1957 4146 0.130 0.052 0.000 0.309 Wed PM 5764 12212 1729 3664 0.148 0.059 0.000 0.284 Thurs AM 5357 11348 1607 3405 0.155 0.061 0.040 0.283 Thurs PM 5873 12442 1762 3733 0.150 0.060 0.032 0.228 FLDW08(01) Wed AM 0.187 0.059 0.255 0.265 Wed PM 0.114 0.036 0.200 0.240 Thurs AM 0.123 0.039 0.143 1.020 Thurs PM 0.671 0.212 1.000 2.500 FLDW10(01) Wed AM 0.077 0.024 0.250 0.729 Wed PM 0.087 0.028 0.150 0.715 Thurs AM 0.094 0.030 0.192 0.554 Thurs PM 0.067 0.021 0.077 0.546 FLGS01(01) Thurs AM 0.195 0.062 0.268 0.357 Thurs PM 0.185 0.059 0.500 0.395 Fri AM 0.196 0.062 0.237 0.382 Fri PM 0.198 0.063 0.200 0.412 FLGS04(01) Wed AM 0.035 0.011 0.084 0.157 Wed PM 0.037 0.012 0.041 0.125 Thurs AM 0.034 0.011 0.108 0.154 Thurs PM 0.030 0.010 0.016 0.124 FLGS04(02) Wed AM 0.042 0.013 0.053 0.156 Wed PM 0.040 0.013 0.028 0.140 Thurs AM 0.041 0.013 0.069 0.152 Thurs PM 0.041 0.013 0.039 0.138 OA fraction - CO 2 Uncert. in CO 2 OA fraction Recirculation Airflow Uncertainty in recirc. airflow Outdoor air fraction - volumetric Uncert. in vol. OA fraction6 5 System ID Day Period L/s cfm L/s cfm FLGS11(01) Wed AM 0.161 0.051 0.045 0.211 Wed PM 0.104 0.033 0.034 0.122 Thurs AM 0.189 0.060 0.138 0.246 Thurs PM 0.088 0.028 0.038 0.134 FLGS11(02) Wed AM 0.144 0.045 0.036 0.257 Wed PM 0.111 0.035 0.030 0.143 Thurs AM 0.162 0.051 0.074 0.263 Thurs PM 0.111 0.035 0.047 0.165 FLGS12(01) Wed AM 8386 17766 2516 5330 0.164 0.065 Wed PM 8003 16955 2401 5086 0.171 0.067 0.125 0.178 Thurs AM 7322 15512 2196 4653 0.185 0.072 0.085 0.241 Thurs PM 7237 15331 2171 4599 0.175 0.069 0.156 0.159 GADS01(01) Wed AM 3304 6999 991 2100 0.396 0.147 0.250 0.729 Wed PM 3996 8465 1199 2540 0.322 0.121 0.364 0.684 Thurs AM 3209 6799 963 2040 0.419 0.155 0.333 0.621 Thurs PM 3524 7466 1057 2240 0.378 0.140 0.500 0.791 GADS02(01) Wed AM 0.162 0.051 0.171 0.350 Wed PM 0.159 0.050 0.167 0.239 Thurs AM 0.220 0.069 0.083 0.394 Thurs PM 0.162 0.051 0.185 0.266 GADS02(02) Wed AM 0.253 0.080 0.125 0.356 Wed PM 0.196 0.062 0.175 0.252 Thurs AM 0.208 0.066 0.125 0.445 Thurs PM 0.184 0.058 0.188 0.300 GADS03(01) Wed AM 0.080 0.025 0.091 0.125 Wed PM 0.085 0.027 0.000 0.101 Thurs AM 0.085 0.027 0.049 0.137 Thurs PM 0.087 0.027 0.000 0.105 ILBS01(01) Wed AM 0.111 0.264 Wed PM 0.000 0.189 Thurs AM 0.222 0.402 Thurs PM 0.160 0.286 ILBS01(02) Wed AM 0.263 0.385 Wed PM 0.222 0.322 Thurs AM 0.000 0.458 Thurs PM 0.000 0.167 ILBS02(01) Wed AM 7636 16177 2291 4853 0.083 0.026 0.000 0.645 Wed PM 6207 13149 1862 3945 0.073 0.023 0.074 0.525 Thurs AM 6942 14706 2082 4412 0.068 0.021 0.125 0.891 Thurs PM 6737 14274 2021 4282 0.076 0.024 0.000 0.789 ILBS03(01) Wed AM 10354 21935 3106 6581 0.362 0.219 0.333 0.497 Wed PM 10904 23101 3271 6930 0.356 0.220 0.286 0.420 Thurs AM 8723 18481 2617 5544 0.468 0.194 0.333 0.497 Thurs PM 9076 19229 2723 5769 0.421 0.205 0.167 0.478 LAGW04(01) Wed AM 0.062 0.020 0.333 0.994 Wed PM 0.045 0.014 0.000 0.568 Thurs AM 0.061 0.019 0.286 0.420 Thurs PM 0.054 0.017 0.152 0.433 LAGW04(02) Wed AM 0.073 0.023 0.333 0.994 Wed PM 0.077 0.025 0.125 0.356 Thurs AM 0.081 0.026 0.125 0.356 Thurs PM 0.075 0.024 0.111 0.316 LAGW05(01) Wed AM 6913 14646 2074 4394 0.190 0.063 Wed PM 6780 14365 2034 4309 0.219 0.073 Thurs AM 6714 14224 2014 4267 0.202 0.067 Thurs PM 6758 14317 2027 4295 0.217 0.072 LAGW05(02) Wed AM Wed PM 0.443 0.236 Thurs AM Thurs PM OA fraction - CO 2 Uncert. in CO 2 OA fraction Recirculation Airflow Uncertainty in recirc. airflow Outdoor air fraction - volumetric Uncert. in vol. OA fraction6 6 System ID Day Period L/s cfm L/s cfm LAGW06(01) Wed AM 0.126 0.040 Wed PM 0.122 0.039 Thurs AM 0.122 0.039 Thurs PM 0.123 0.039 LAGW06(02) Wed AM Wed PM Thurs AM Thurs PM MABW05(01) Wed AM 3767 7980 1130 2394 0.099 0.288 0.178 0.206 Wed PM 5013 10621 1504 3186 0.279 0.240 0.292 0.192 Thurs AM 5268 11161 1580 3348 0.196 0.262 0.383 0.246 Thurs PM 5098 10801 1529 3240 0.254 0.246 0.250 0.190 MABW05(02) Wed AM 5466 11581 1640 3474 0.104 0.287 0.137 0.192 Wed PM 6458 13681 1937 4104 0.000 0.339 0.101 0.184 Thurs AM 6118 12961 1835 3888 0.050 0.302 0.059 0.244 Thurs PM 6684 14161 2005 4248 0.006 0.314 0.101 0.179 MABW06(01) Wed AM 0.930 0.294 0.857 0.665 Wed PM 0.966 0.305 0.926 0.714 Thurs AM 0.967 0.306 0.839 0.595 Thurs PM 0.969 0.306 0.778 0.398 MABW08(01) Wed AM 4828 10228 1448 3068 0.626 0.163 0.500 0.791 Wed PM 4411 9346 1323 2804 0.673 0.155 0.593 0.609 Thurs AM 5898 12496 1769 3749 0.532 0.180 0.500 0.791 Thurs PM 5353 11341 1606 3402 0.585 0.170 0.500 0.791 MABW08(02) Wed AM 426 903 128 271 0.966 0.403 0.900 0.951 Wed PM 456 966 137 290 0.962 0.400 0.963 0.727 Thurs AM 446 945 134 284 0.961 0.400 1.000 1.000 Thurs PM 595 1260 178 378 0.949 0.393 1.000 1.000 MDDS01(01) Wed AM 18850 39936 5655 11981 0.113 0.284 0.138 0.615 Wed PM 21269 45060 6381 13518 0.063 0.298 0.565 3.531 Thurs AM 25084 53142 7525 15943 0.000 0.385 0.083 0.651 Thurs PM 21969 46543 6591 13963 0.000 0.346 0.000 0.710 MDDS03(01) Wed AM 0.157 0.050 0.143 0.204 Wed PM 0.132 0.042 0.167 0.478 Thurs AM 0.142 0.045 0.125 0.356 Thurs PM 0.136 0.043 0.200 0.288 MDDS03(02) Wed AM 0.032 0.010 0.333 2.485 Wed PM 0.016 0.005 0.012 0.175 Thurs AM 0.032 0.010 0.000 0.284 Thurs PM 0.032 0.010 0.000 0.237 MDDS04(01) Wed AM 2266 4800 680 1440 0.114 0.284 0.023 0.202 Wed PM 2247 4760 674 1428 0.112 0.285 0.000 0.145 Thurs AM 2285 4840 685 1452 0.102 0.288 0.070 0.166 Thurs PM 2228 4720 668 1416 0.085 0.292 0.021 0.149 MDDS04(02) Wed AM 1570 3325 471 998 0.267 0.243 0.197 0.295 Wed PM 1469 3112 441 933 0.237 0.251 0.143 0.255 Thurs AM 1547 3278 464 983 0.224 0.254 0.141 0.264 Thurs PM 1435 3040 431 912 0.260 0.245 0.104 0.205 MIBW01(01) Wed AM 1159 2455 348 737 0.594 0.168 0.469 0.319 Wed PM 1042 2207 313 662 0.652 0.159 0.286 0.420 Thurs AM 1259 2666 378 800 0.560 0.175 0.269 0.563 Thurs PM 1478 3131 443 939 0.509 0.185 0.345 0.516 MIBW01(02) Wed AM 2093 4433 628 1330 0.088 0.291 0.250 0.607 Wed PM 1712 3627 514 1088 0.381 0.214 0.222 0.537 Thurs AM 0.105 0.748 Thurs PM 0.345 0.516 OA fraction - CO 2 Uncert. in CO 2 OA fraction Recirculation Airflow Uncertainty in recirc. airflow Outdoor air fraction - volumetric Uncert. in vol. OA fraction6 7 System ID Day Period L/s cfm L/s cfm MIBW03(01) Wed AM 11505 24374 3451 7312 0.285 0.238 0.250 0.364 Wed PM 12512 26509 3754 7953 0.218 0.256 0.353 0.441 Thurs AM 12368 26203 3710 7861 0.244 0.249 0.313 0.463 Thurs PM 9264 19626 2779 5888 0.337 0.225 0.667 0.567 MIBW04(01) Wed AM 3002 6361 901 1908 0.305 0.233 0.454 0.424 Wed PM 2700 5720 810 1716 0.373 0.216 0.356 0.504 Thurs AM 3767 7980 1130 2394 0.251 0.247 0.326 0.418 Thurs PM 3455 7321 1037 2196 0.323 0.229 0.408 0.502 MIBW04(02) Wed AM 3455 7321 1037 2196 0.386 0.213 0.333 0.414 Wed PM 3540 7500 1062 2250 0.347 0.223 0.400 0.508 Thurs AM 3795 8041 1139 2412 0.259 0.245 0.217 0.524 Thurs PM 3474 7360 1042 2208 0.409 0.208 0.357 0.536 MNBW01(01) Wed AM 0.259 0.082 0.500 0.395 Wed PM 0.231 0.073 0.405 0.412 Thurs AM 0.250 0.079 0.333 0.497 Thurs PM 0.247 0.078 0.429 0.440 MNBW02(01) Wed AM 0.278 0.088 0.412 0.450 Wed PM 0.295 0.093 0.400 0.609 Thurs AM 0.416 0.131 0.400 0.609 Thurs PM 0.418 0.132 0.400 0.609 MNBW02(02) Wed AM 0.295 0.093 0.250 0.729 Wed PM 0.425 0.134 0.333 0.994 Thurs AM 0.624 0.197 0.333 0.994 Thurs PM 0.457 0.145 0.500 1.581 MNBW04(01) Wed AM 0.721 0.228 0.714 0.414 Wed PM 0.821 0.260 1.077 0.799 Thurs AM 0.707 0.223 0.769 0.686 Thurs PM 0.856 0.271 0.867 0.624 MOCS01(01) Wed AM 0.200 0.288 Wed PM 0.273 0.267 Thurs AM 0.211 0.380 Thurs PM 0.200 0.288 MOCS05(01) Wed AM 0.329 0.104 0.333 0.497 Wed PM 0.353 0.112 0.230 0.363 Thurs AM 0.220 0.070 0.250 0.364 Thurs PM 0.026 0.008 0.214 0.258 NCDW02(01) Wed AM 0.934 0.295 0.800 1.207 Wed PM 0.946 0.299 0.750 1.105 Thurs AM 0.507 0.160 0.375 0.944 Thurs PM 0.829 0.262 0.667 1.133 NCDW02(02) Wed AM 0.867 0.274 0.800 1.207 Wed PM 0.819 0.259 0.750 1.105 Thurs AM 0.464 0.147 0.438 0.965 Thurs PM 0.761 0.241 0.667 1.133 NCDW03(01) Wed AM 185 391 55 117 0.288 0.142 Wed PM 141 299 42 90 0.135 0.193 Thurs AM 177 376 53 113 0.213 0.154 Thurs PM 178 378 54 113 0.179 0.171 NCDW03(02) Wed AM 79 167 24 50 0.119 0.170 Wed PM 76 162 23 49 0.213 0.154 Thurs AM 78 166 23 50 0.152 0.144 Thurs PM 81 172 24 51 0.072 0.205 NCDW03(03) Wed AM 12 25 4 8 0.000 0.125 Wed PM 12 25 4 8 0.000 0.222 Thurs AM 12 25 4 8 0.000 0.143 Thurs PM 12 25 4 8 0.759 0.291 0.217 0.629 OA fraction - CO 2 Uncert. in CO 2 OA fraction Recirculation Airflow Uncertainty in recirc. airflow Outdoor air fraction - volumetric Uncert. in vol. OA fraction6 8 System ID Day Period L/s cfm L/s cfm NCDW03(04) Wed AM 12 25 4 7 0.862 0.343 0.000 3.550 Wed PM 12 25 4 7 0.858 0.341 Thurs AM 12 25 4 7 0.866 0.345 Thurs PM 12 25 4 7 0.806 0.314 NCDW03(05) Wed AM 57 121 17 36 Wed PM 61 129 18 39 Thurs AM 63 134 19 40 0.160 0.152 Thurs PM 59 126 18 38 0.119 0.170 NCDW06(01) Wed AM 0.384 0.121 0.489 0.350 Wed PM 0.567 0.179 0.429 0.550 Thurs AM 0.717 0.227 0.529 0.471 Thurs PM 0.369 0.117 0.333 0.331 NECW01(01) Wed AM 0.330 0.104 0.454 0.359 Wed PM 0.398 0.126 0.601 0.598 Thurs AM 0.357 0.113 0.475 0.437 Thurs PM 0.584 0.185 0.625 0.651 NECW02(01) Wed AM 0.789 0.250 0.700 1.726 Wed PM 0.566 0.179 0.667 1.133 Thurs AM 0.755 0.239 0.700 1.726 Thurs PM 0.733 0.232 0.800 1.811 NECW03(01) Wed AM 0.686 0.217 0.331 0.426 Wed PM 0.669 0.212 0.328 0.555 Thurs AM 0.466 0.147 0.263 0.385 Thurs PM 0.881 0.279 0.600 0.550 NMES01(01) Wed AM 1718 3640 515 1092 0.511 0.188 0.536 0.573 Wed PM 1252 2652 376 796 0.630 0.234 0.541 0.434 Thurs AM 1491 3159 447 948 0.533 0.196 0.600 0.471 Thurs PM 1356 2873 407 862 0.590 0.218 0.533 0.534 NMES01(02) Wed AM 4579 9702 1374 2910 0.184 0.072 0.324 0.402 Wed PM 4862 10301 1459 3090 0.173 0.068 0.194 0.400 Thurs AM 4271 9048 1281 2714 0.139 0.055 0.225 0.362 Thurs PM 4708 9974 1412 2992 0.165 0.065 0.108 0.384 NMES02(01) Wed AM 1.385 0.438 0.500 0.791 Wed PM 1.241 0.393 0.968 0.635 Thurs AM 1.083 0.343 0.922 1.503 Thurs PM 1.521 0.481 0.810 1.152 NMES03(01) Wed AM 3174 6725 952 2018 0.073 0.296 0.231 0.279 Wed PM 3032 6424 910 1927 0.133 0.279 0.250 0.243 Thurs AM 2802 5937 841 1781 0.102 0.287 0.130 0.310 Thurs PM 2988 6331 897 1899 0.019 0.311 0.083 0.237 NMES03(02) Wed AM 4444 9416 1333 2825 0.110 0.285 0.120 0.285 Wed PM 5509 11671 1653 3501 0.148 0.275 0.222 0.322 Thurs AM 4416 9355 1325 2807 0.193 0.263 0.240 0.291 Thurs PM 5126 10860 1538 3258 0.144 0.276 0.273 0.267 NVAW01(01) Wed AM 1.001 0.316 0.910 1.427 Wed PM 0.673 0.213 0.882 1.387 Thurs AM 0.545 0.172 0.692 1.323 Thurs PM 0.277 0.088 0.500 0.791 NVAW02(01) Wed AM 1242 2632 373 790 0.950 0.139 0.655 0.768 Wed PM 1210 2563 363 769 0.956 0.139 1.000 1.000 Thurs AM 981 2078 294 623 0.959 0.139 1.000 4.000 Thurs PM 1912 4052 574 1216 0.930 0.138 0.333 0.994 NVAW03(01) Wed AM 1.091 0.345 0.444 1.720 Wed PM 1.133 0.358 0.500 1.581 Thurs AM 1.099 0.348 0.333 0.994 Thurs PM 1.099 0.348 1.000 2.000 OA fraction - CO 2 Uncert. in CO 2 OA fraction Recirculation Airflow Uncertainty in recirc. airflow Outdoor air fraction - volumetric Uncert. in vol. OA fraction6 9 System ID Day Period L/s cfm L/s cfm NVAW03(02) Wed AM 0.488 0.154 0.444 1.720 Wed PM 0.503 0.159 0.700 1.726 Thurs AM 0.513 0.162 0.500 0.791 Thurs PM 0.498 0.157 0.000 2.840 NYBS01(01) Wed AM 26968 57134 8090 17140 0.147 0.275 0.167 0.597 Wed PM 29021 61484 8706 18445 0.118 0.283 0.214 0.517 Thurs AM 28473 60324 8542 18097 0.109 0.286 0.241 0.502 Thurs PM 28473 60324 8542 18097 0.127 0.281 0.080 0.567 NYBS01(02) Wed AM 0.147 0.047 0.308 0.569 Wed PM 0.149 0.047 0.133 0.476 Thurs AM 0.143 0.045 0.267 0.488 Thurs PM 0.154 0.049 0.429 0.440 NYBS02(01) Wed AM 0.100 0.032 0.115 0.583 Wed PM 0.096 0.030 0.513 0.668 Thurs AM 0.074 0.023 0.238 0.433 Thurs PM 0.136 0.043 0.368 0.331 NYBS02(02) Wed AM 0.090 0.029 0.714 1.241 Wed PM 0.126 0.040 0.615 0.639 Thurs AM 0.117 0.037 0.441 0.655 Thurs PM 0.163 0.052 0.494 0.512 NYBS04(01) Wed AM 0.014 0.004 0.000 0.473 Wed PM 0.013 0.004 0.077 0.273 Thurs AM 0.766 0.242 0.444 0.860 Thurs PM 0.011 0.004 0.154 0.550 NYBS04(02) Wed AM 0.037 0.012 0.000 0.473 Wed PM 0.035 0.011 0.040 0.283 Thurs AM 0.912 0.288 0.400 0.762 Thurs PM 0.035 0.011 0.086 0.406 NYBS05(01) Wed AM 0.255 0.081 0.326 0.216 Wed PM 0.238 0.075 0.208 0.234 Thurs AM 0.247 0.078 0.270 0.225 Thurs PM 0.227 0.072 0.328 0.188 NYBS07(01) Wed AM 4062 8606 1219 2582 0.199 0.077 0.400 0.762 Wed PM 4253 9010 1276 2703 0.199 0.077 0.432 0.416 Thurs AM 4157 8808 1247 2642 0.205 0.080 0.364 0.684 Thurs PM 4005 8485 1201 2545 0.200 0.078 0.063 0.443 ORIS03(01) Wed AM 0.448 0.144 0.364 0.684 Wed PM 0.417 0.134 0.174 0.624 Thurs AM 0.451 0.145 0.295 0.604 Thurs PM 0.466 0.150 0.286 0.525 ORIS03(03) Wed AM 0.364 0.684 Wed PM 0.240 0.582 Thurs AM 0.348 0.567 Thurs PM 0.214 0.517 ORIS04(01) Wed AM 0.833 1.534 Wed PM 0.667 1.416 Thurs AM 0.800 1.811 Thurs PM 0.167 1.195 PABS03(01) Wed AM 16550 35064 4965 10519 0.000 0.328 0.205 0.328 Wed PM 16360 34661 4908 10398 0.000 0.348 0.000 0.374 Thurs AM 17977 38087 5393 11426 0.000 0.374 0.091 0.323 Thurs PM 18929 40102 5679 12031 0.000 0.363 0.053 0.373 PABS04(01) Wed AM 0.197 0.062 0.125 0.165 Wed PM 0.193 0.061 0.215 0.159 Thurs AM 0.195 0.062 0.214 0.207 Thurs PM 0.200 0.063 0.188 0.180 PABS04(02) Wed AM 0.038 0.012 0.045 0.167 Wed PM 0.038 0.012 0.047 0.157 Thurs AM 0.035 0.011 0.096 0.208 Thurs PM 0.035 0.011 0.063 0.177 OA fraction - CO 2 Uncert. in CO 2 OA fraction Recirculation Airflow Uncertainty in recirc. airflow Outdoor air fraction - volumetric Uncert. in vol. OA fraction7 0 System ID Day Period L/s cfm L/s cfm SCDW01(01) Wed AM 0.241 0.076 0.212 0.222 Wed PM 0.249 0.079 Thurs AM 0.238 0.075 0.203 0.144 Thurs PM 0.220 0.070 0.185 0.155 SCDW02(01) Wed AM 0.182 0.057 0.286 0.420 Wed PM 0.187 0.059 0.250 0.364 Thurs AM 0.191 0.060 0.286 0.420 Thurs PM 0.155 0.049 0.500 0.527 SDBW01(01) Wed AM 0.456 0.144 0.385 0.389 Wed PM 0.517 0.163 0.471 0.460 Thurs AM 0.523 0.165 0.325 0.372 Thurs PM 0.546 0.173 0.455 0.471 SDBW02(01) Wed AM 0.444 0.140 0.444 0.344 Wed PM 0.293 0.093 0.444 0.344 Thurs AM 0.283 0.090 0.333 0.497 Thurs PM 0.236 0.074 0.250 0.364 SDBW04(01) Wed AM 9318 19742 2795 5922 0.214 0.257 0.094 0.444 Wed PM 8062 17081 2419 5124 0.199 0.261 0.115 0.548 Thurs AM 7798 16521 2339 4956 0.195 0.262 0.140 0.499 Thurs PM 7534 15961 2260 4788 0.216 0.256 0.167 0.478 TNDS05(01) Wed AM 1.000 0.316 Wed PM 1.000 0.316 Thurs AM 1.000 0.316 Thurs PM 1.000 0.316 TNDS05(02) Wed AM 1.000 0.316 Wed PM 1.000 0.316 Thurs AM 1.000 0.316 Thurs PM 1.000 0.316 TNDS06(01) Wed AM 67909 143871 20373 43161 0.213 0.257 0.276 0.343 Wed PM 67403 142799 20221 42840 0.086 0.292 0.335 0.284 Thurs AM 58901 124788 17670 37437 0.130 0.280 0.208 0.301 Thurs PM 68010 144087 20403 43226 0.022 0.310 0.222 0.322 TNDS07(01) Wed AM 0.024 0.008 0.000 0.710 Wed PM 0.030 0.009 0.200 0.577 Thurs AM 0.030 0.010 0.000 0.568 Thurs PM 0.159 0.050 0.000 0.710 TNFS08(01) Wed AM 0.204 0.064 0.196 0.160 Wed PM 0.245 0.077 0.205 0.168 Thurs AM 0.229 0.072 0.200 0.176 Thurs PM 0.180 0.057 0.176 0.191 TNFS085(02) Wed AM 977 2070 293 621 0.269 0.102 0.412 0.197 Wed PM 1051 2227 315 668 0.222 0.086 0.231 0.186 Thurs AM 1056 2236 317 671 0.226 0.087 0.202 0.221 Thurs PM 1019 2160 306 648 0.225 0.087 0.211 0.206 TNFS09(01) Wed AM 4319 9150 1296 2745 0.369 0.217 0.200 0.288 Wed PM 4259 9024 1278 2707 0.323 0.229 0.185 0.266 Thurs AM 4289 9087 1287 2726 0.272 0.242 0.231 0.279 Thurs PM 4170 8835 1251 2650 0.297 0.235 0.200 0.180 TNFS09(02) Wed AM 0.076 0.024 0.165 0.181 Wed PM 0.071 0.022 0.000 0.151 Thurs AM 0.053 0.017 0.056 0.157 Thurs PM 0.057 0.018 0.050 0.142 TNFS10(01) Wed AM 3326 7047 998 2114 0.688 0.153 0.634 0.681 Wed PM 5837 12367 1751 3710 0.535 0.180 0.444 0.860 Thurs AM 3518 7452 1055 2236 0.703 0.151 0.603 0.565 Thurs PM 3084 6534 925 1960 0.705 0.151 0.529 0.941 OA fraction - CO 2 Uncert. in CO 2 OA fraction Recirculation Airflow Uncertainty in recirc. airflow Outdoor air fraction - volumetric Uncert. in vol. OA fraction7 1 System ID Day Period L/s cfm L/s cfm TXFS01(01) Wed AM 0.061 0.173 Wed PM 0.045 0.014 0.058 0.131 Thurs AM 0.043 0.014 0.071 0.204 Thurs PM 0.040 0.013 0.059 0.139 TXFS02(01) Wed AM 0.047 0.015 0.050 0.177 Wed PM 0.050 0.016 0.000 0.167 Thurs AM 0.036 0.011 0.000 0.215 Thurs PM 0.049 0.015 0.000 0.151 TXFS02(02) Wed AM 0.047 0.015 0.040 0.189 Wed PM 0.046 0.015 0.000 0.189 Thurs AM 0.043 0.014 0.000 0.237 Thurs PM 0.044 0.014 0.021 0.150 TXFS07(01) Wed AM 0.128 0.040 0.119 0.327 Wed PM 0.142 0.045 0.240 0.291 Thurs AM 0.142 0.045 0.214 0.258 Thurs PM 0.159 0.050 0.182 0.327 TXFS08(01) Wed AM 0.046 0.015 0.053 0.149 Wed PM 0.049 0.015 0.053 0.149 Thurs AM 0.058 0.018 0.063 0.177 Thurs PM 0.059 0.019 0.080 0.113 TXFS08(02) Wed AM 0.053 0.017 0.100 0.142 Wed PM 0.047 0.015 0.091 0.129 Thurs AM 0.052 0.017 0.056 0.157 Thurs PM 0.049 0.016 0.091 0.129 TXFS09(01) Wed AM 0.192 0.061 0.143 0.204 Wed PM 0.183 0.058 0.200 0.096 Thurs AM 0.188 0.060 0.125 0.178 Thurs PM 0.193 0.061 0.167 0.119 TXFS09(02) Wed AM 0.189 0.060 0.143 0.204 Wed PM 0.180 0.057 0.192 0.111 Thurs AM 0.194 0.061 0.125 0.178 Thurs PM 0.195 0.062 0.083 0.118 TXFW05(01) Wed AM 26244 55602 7873 16680 0.259 0.245 0.516 0.652 Wed PM 25650 54343 7695 16303 0.248 0.248 0.400 0.609 Thurs AM 17274 36598 5182 10979 0.586 0.170 0.161 0.462 Thurs PM 15762 33393 4729 10018 0.623 0.163 0.333 0.497 TXFW06(01) Wed AM 1.004 0.318 0.667 1.133 Wed PM 1.000 0.316 1.000 1.333 Thurs AM 1.001 0.317 0.800 0.724 Thurs PM 1.002 0.317 0.800 0.724 WAIW03(01) Wed AM 1.010 0.319 0.789 0.474 Wed PM 0.886 0.280 0.938 0.606 Thurs AM 1.018 0.322 0.905 0.908 Thurs PM 0.920 0.291 0.929 0.689 WAIW04(01) Wed AM 0.973 0.308 0.600 0.660 Wed PM 0.990 0.313 0.833 0.614 Thurs AM 0.982 0.310 0.500 0.527 Thurs PM 1.003 0.317 0.571 0.465

# of values 186 509 520
Mean 7930 16800 2379 5040 0.377 0.158 0.311 0.601 StdDev 11304 23948 3391 7185 0.350 0.120 0.270 0.625 Minimum 12 25 4 7 0.000 0.004 0.000 0.096 10th percentile 181 384 54 115 0.043 0.017 0.030 0.159 25th percentile 1508 3196 453 959 0.104 0.047 0.110 0.237 Median 4357 9230 1307 2769 0.222 0.144 0.231 0.433 75th percentile 9139 19361 2742 5808 0.594 0.275 0.444 0.711 90th percentile 18414 39012 5524 11703 1.000 0.316 0.750 1.133 Maximum 68010 144087 20403 43226 1.521 0.481 1.200 7.100 OA fraction - CO 2 Uncert. in CO 2 OA fraction Recirculation Airflow Uncertainty in recirc. airflow Outdoor air fraction - volumetric Uncert. in vol. OA fraction7 2 

### Appendix E: Measured Data for Study Spaces

This appendix presents the following information for the measurements in the study spaces:

Study space ID Day and time of measurement Supply airflow per unit floor area and associated uncertainty Out door airflow per person, per unit floor area and in air changes per hour based on volumetric airflow measurements (VOL), and associated uncertainties Outdoor airflow per person, per unit floor area and in air changes per hour based on volumetric supply air flow times CO 2 

### - based outdoor air fraction (RATIO), and associated uncertainties Outdoor airflow rate per person based on peak CO 2 

### analy sis (PEAK), and associated uncertainties

Changes in the table relative to the original 2004 report are highlighted in y ellow

.73 L/s•m 2 cfm/ft 2 L/s•m 2 cfm/ft 2 L/s•person cfm/person L/s•m 2 cfm/ft 2 h - 1 L/s•person cfm/person L/s•m 2 cfm/ft 2 h - 1

ARFW01 Wed AM 8.36 1.65 1.02 0.20 10.3 21.9 0.46 0.09 0.44 2.4 5.1 0.11 0.02 0.13 Wed PM 8.29 1.63 1.02 0.20 14.8 31.4 0.45 0.09 0.42 3.5 7.4 0.11 0.02 0.12 Thur AM 8.24 1.62 1.01 0.20 12.1 25.5 0.47 0.09 0.45 2.8 6.0 0.11 0.02 0.13 Thur PM 8.37 1.65 1.02 0.20 12.6 26.7 0.45 0.09 0.43 3.0 6.3 0.11 0.02 0.12 ARFW02 Wed AM 2.41 0.47 0.34 0.07 Wed PM 2.32 0.46 0.33 0.06 112.7 238.7 1.88 0.37 1.51 27.6 58.5 0.46 0.09 0.45 Thur AM Thur PM 2.33 0.46 0.33 0.06 81.2 172.1 1.94 0.38 1.54 19.9 42.2 0.48 0.09 0.46 ARFW03 Wed AM 5.04 0.99 0.62 0.12 7.6 16.2 0.34 0.07 0.27 1.8 3.9 0.08 0.02 0.08 Wed PM 5.46 1.08 0.68 0.13 8.1 17.1 0.32 0.06 0.25 2.1 4.4 0.08 0.02 0.08 Thur AM 5.42 1.07 0.67 0.13 7.1 15.1 0.36 0.07 0.29 1.8 3.9 0.09 0.02 0.09 Thur PM 5.35 1.05 0.66 0.13 7.9 16.8 0.34 0.07 0.27 2.0 4.3 0.09 0.02 0.08 AZHS02 Wed AM 6.18 1.22 0.77 0.15 45.9 97.3 2.47 0.49 2.43 18.3 38.7 0.98 0.19 1.05 Wed PM 6.83 1.34 0.85 0.17 128.0 271.2 3.33 0.66 3.28 38.4 81.4 1.00 0.20 1.14 Thur AM 5.44 1.07 0.68 0.13 24.8 52.6 1.55 0.31 1.53 15.6 33.0 0.97 0.19 0.99 Thur PM 5.97 1.17 0.74 0.15 33.6 71.2 2.01 0.40 1.98 16.4 34.8 0.98 0.19 1.03 AZHS04 Wed AM 6.25 1.23 0.86 0.17 0.8 1.6 0.06 0.01 0.06 25.6 54.3 2.54 0.50 1.91 Wed PM 6.21 1.22 0.86 0.17 1.8 3.9 0.06 0.01 0.06 58.0 122.9 2.64 0.52 1.97 Thur AM 6.13 1.21 0.85 0.17 1.9 4.0 0.04 0.01 0.05 71.5 151.5 2.29 0.45 1.69 Thur PM 5.96 1.17 0.82 0.16 2.3 4.9 0.07 0.01 0.07 65.5 138.7 2.59 0.51 1.92 AZHW10 Wed AM 5.72 1.13 0.86 0.17 199.5 422.7 5.72 1.13 6.15 30.1 63.8 0.86 0.17 1.41 Wed PM 5.56 1.09 0.83 0.16 247.3 523.8 5.56 1.09 5.97 37.1 78.5 0.83 0.16 1.37 Thur AM 6.21 1.22 0.94 0.18 228.7 484.6 6.21 1.22 6.67 34.6 73.3 0.94 0.18 1.53 Thur PM 6.25 1.23 0.95 0.19 230.2 487.7 6.25 1.23 6.71 34.9 74.0 0.95 0.19 1.55 AZHW11 Wed AM 5.26 1.03 0.91 0.18 25.1 53.1 1.00 0.20 0.98 34.7 73.6 1.39 0.27 1.37 Wed PM 6.20 1.22 1.07 0.21 57.2 121.1 1.82 0.36 1.78 46.3 98.2 1.47 0.29 1.47 Thur AM 6.12 1.20 1.06 0.21 60.1 127.4 2.05 0.40 2.00 41.0 86.9 1.40 0.27 1.41 Thur PM 6.70 1.32 1.16 0.23 75.7 160.3 2.30 0.45 2.25 50.0 106.0 1.52 0.30 1.53 AZHW12 Wed AM 1.40 0.28 0.20 0.04 10.7 22.7 0.38 0.08 0.37 2.9 6.1 0.10 0.02 0.12 Wed PM 1.39 0.27 0.20 0.04 12.6 26.7 0.40 0.08 0.39 3.3 7.1 0.11 0.02 0.12 Thur AM 1.35 0.27 0.20 0.04 9.6 20.3 0.31 0.06 0.30 3.0 6.4 0.10 0.02 0.11 Thur PM 1.42 0.28 0.21 0.04 11.1 23.6 0.33 0.06 0.32 3.6 7.5 0.11 0.02 0.12 CAES17 Wed AM 19.59 3.86 2.77 0.55 64.7 137.0 3.66 0.72 3.60 91.6 194.1 5.18 1.02 5.13 Wed PM 18.72 3.68 2.65 0.52 50.2 106.4 2.66 0.52 2.61 97.8 207.2 5.18 1.02 5.11 Thur AM 21.11 4.15 2.99 0.59 235.6 499.1 11.90 2.34 11.71 72.7 154.1 3.67 0.72 4.14 Thur PM 20.13 3.96 2.85 0.56 113.8 241.0 6.16 1.21 6.06 86.7 183.6 4.69 0.92 4.73 CAEW07 Wed AM 5.28 1.04 0.91 0.18 57.2 121.2 1.62 0.32 1.44 19.0 40.2 0.54 0.11 0.54 Wed PM 5.60 1.10 0.97 0.19 161.3 341.8 4.86 0.96 4.33 53.5 113.4 1.61 0.32 1.62 Thur AM 5.28 1.04 0.91 0.18 155.9 330.3 4.03 0.79 3.59 51.7 109.6 1.34 0.26 1.34 Thur PM 5.20 1.02 0.90 0.18 180.9 383.3 5.45 1.07 4.86 60.0 127.1 1.81 0.36 1.82 Study Space ID Uncertainty in supply airflow

Period Volumetric supply airflow SUPPLY AIRFLOW

Volumetric Uncertainty in volumetric OA OUTDOOR AIRFLOW737475 L/s•m 2 cfm/ft 2 L/s•m 2 cfm/ft 2 L/s•person cfm/person L/s•m 2 cfm/ft 2 h - 1 L/s•person cfm/person L/s•m 2 cfm/ft 2 h - 1
CAJW24 Tues AM 6.26 1.23 1.08 0.21 63.2 133.8 4.33 0.85 4.12 20.9 44.4 1.44 0.28 1.54 Tues PM 6.72 1.32 1.16 0.23 3.3 7.0 0.24 0.05 0.23 1.1 2.3 0.08 0.02 0.09 Wed AM 6.26 1.23 1.08 0.21 64.1 135.8 4.33 0.85 4.12 21.3 45.0 1.44 0.28 1.54 Wed PM 7.14 1.41 1.24 0.24 3.8 8.0 0.24 0.05 0.23 1.2 2.6 0.08 0.02 0.09 Thur AM 7.56 1.49 1.31 0.26 77.3 163.8 5.30 1.04 5.04 25.6 54.3 1.76 0.35 1.89 Thur PM 7.60 1.50 1.32 0.26 113.0 239.4 6.73 1.33 6.41 37.5 79.4 2.23 0.44 2.40 CAJW25 Wed AM 4.96 0.98 0.86 0.17 47.6 100.9 2.67 0.53 2.56 15.8 33.5 0.89 0.17 0.96 Wed PM 5.23 1.03 0.91 0.18 85.0 180.0 5.00 0.98 4.79 28.2 59.7 1.66 0.33 1.79 Thur AM 4.62 0.91 0.80 0.16 61.5 130.3 3.28 0.65 3.14 20.4 43.2 1.09 0.21 1.18 Thur PM 5.14 1.01 0.89 0.18 78.5 166.4 5.26 1.04 5.04 26.0 55.2 1.74 0.34 1.88 CAJW26 Wed AM 5.26 1.04 0.91 0.18 133.7 283.3 5.98 1.18 5.73 44.4 94.0 1.98 0.39 2.14 Wed PM 5.92 1.17 1.03 0.20 115.1 243.8 6.58 1.30 6.30 38.2 80.9 2.18 0.43 2.36 Thur AM 5.52 1.09 0.96 0.19 88.5 187.5 5.89 1.16 5.64 29.3 62.2 1.95 0.38 2.11 Thur PM 5.80 1.14 1.00 0.20 87.7 185.7 5.47 1.08 5.24 29.1 61.6 1.81 0.36 1.96 COAS02 Wed AM 3.37 0.66 1.06 0.21 6.9 14.6 0.24 0.05 0.17 2.3 4.8 0.08 0.02 0.06 Wed PM 2.99 0.59 0.91 0.18 9.5 20.2 0.32 0.06 0.23 3.2 6.7 0.11 0.02 0.09 Thur AM 3.28 0.65 1.01 0.20 9.6 20.4 0.29 0.06 0.21 3.2 6.8 0.10 0.02 0.08 Thur PM 3.59 0.71 1.08 0.21 15.8 33.4 0.46 0.09 0.33 5.2 11.1 0.15 0.03 0.12 COAS04 Wed AM 5.83 1.15 1.01 0.20 4.4 9.4 0.13 0.03 0.10 60.0 127.1 1.81 0.36 1.30 Wed PM 5.94 1.17 1.03 0.20 12.7 26.8 0.39 0.08 0.28 57.7 122.3 1.77 0.35 1.28 Thur AM 5.71 1.12 0.99 0.19 1.0 2.1 0.03 0.01 0.02 67.4 142.8 1.80 0.35 1.30 Thur PM 5.85 1.15 1.01 0.20 0.0 0.0 0.00 0.00 0.00 60.1 127.3 1.9 0.37 1.35 COAS06 Wed AM 2.80 0.55 0.40 0.08 27.3 57.7 0.68 0.13 0.64 8.6 18.3 0.21 0.04 0.23 Wed PM 3.52 0.69 0.50 0.10 25.6 54.3 0.73 0.14 0.69 8.1 17.2 0.23 0.05 0.25 Thur AM 4.71 0.93 0.67 0.13 22.8 48.4 0.78 0.15 0.75 7.2 15.3 0.25 0.05 0.27 Thur PM 3.70 0.73 0.52 0.10 21.6 45.8 0.65 0.13 0.62 6.8 14.5 0.20 0.04 0.22 FLDW07 Wed AM 3.75 0.74 1.06 0.21 22.7 48.1 0.49 0.10 0.40 7.2 15.2 0.15 0.03 0.15 Wed PM 3.38 0.67 0.94 0.19 25.0 53.0 0.50 0.10 0.41 7.9 16.8 0.16 0.03 0.15 Thur AM 3.17 0.62 0.88 0.17 25.2 53.4 0.49 0.10 0.40 8.0 16.9 0.16 0.03 0.15 Thur PM 3.46 0.68 0.96 0.19 24.7 52.4 0.52 0.10 0.43 7.8 16.6 0.16 0.03 0.15 FLDW08 Wed AM 4.55 0.90 0.79 0.16 25.0 53.0 0.85 0.17 0.72 8.3 17.6 0.28 0.06 0.27 Wed PM 4.99 0.98 0.86 0.17 16.3 34.6 0.57 0.11 0.48 5.4 11.5 0.19 0.04 0.18 Thur AM 4.62 0.91 0.80 0.16 12.0 25.4 0.57 0.11 0.48 4.0 8.4 0.19 0.04 0.18 Thur PM 4.64 0.91 0.80 0.16 89.4 189.3 3.11 0.61 2.62 29.6 62.8 1.03 0.20 0.98 FLDW10 Wed AM 2.38 0.47 0.34 0.07 3.7 7.7 0.18 0.04 0.18 1.2 2.4 0.06 0.01 0.06 Wed PM 2.39 0.47 0.34 0.07 4.5 9.5 0.21 0.04 0.20 1.4 3.0 0.07 0.01 0.07 Thur AM 2.43 0.48 0.34 0.07 3.8 8.0 0.23 0.05 0.23 1.2 2.5 0.07 0.01 0.08 Thur PM 2.20 0.43 0.31 0.06 3.3 7.0 0.15 0.03 0.14 1.0 2.2 0.05 0.01 0.05 FLGS01 Thur AM 2.99 0.59 0.42 0.08 16.3 34.6 0.58 0.11 0.57 5.2 10.9 0.18 0.04 0.21 Thur PM 3.31 0.65 0.47 0.09 17.2 36.3 0.61 0.12 0.60 5.4 11.5 0.19 0.04 0.22 Fri AM 2.89 0.57 0.41 0.08 18.1 38.3 0.57 0.11 0.56 5.7 12.1 0.18 0.04 0.20 Fri PM 3.14 0.62 0.44 0.09 18.0 38.2 0.62 0.12 0.61 5.7 12.1 0.20 0.04 0.22 OUTDOOR AIRFLOW SUPPLY AIRFLOW
Volumetric supply airflow Uncertainty in supply airflow Volumetric Uncertainty in volumetric OA Study Space ID Period757676 L/s•m 2 cfm/ft 2 L/s•m 2 cfm/ft 2 L/s•person cfm/person L/s•m 2 cfm/ft 2 h - 1 L/s•person cfm/person L/s•m 2 cfm/ft 2 h - 1

FLGS04 Wed AM 9.70 1.91 1.41 0.28 6.9 14.6 0.38 0.08 0.38 1.8 3.8 0.10 0.02 0.12 Wed PM 9.90 1.95 1.43 0.28 7.5 15.8 0.39 0.08 0.38 1.9 4.1 0.10 0.02 0.12 Thur AM 9.93 1.95 1.44 0.28 7.8 16.6 0.38 0.08 0.38 2.1 4.4 0.10 0.02 0.12 Thur PM 10.24 2.01 1.49 0.29 7.9 16.6 0.39 0.08 0.38 2.1 4.4 0.10 0.02 0.12 FLGS11 Wed AM 2.15 0.42 0.26 0.05 11.9 25.2 0.32 0.06 0.37 2.8 5.9 0.08 0.02 0.11 Wed PM 3.00 0.59 0.37 0.07 13.1 27.8 0.32 0.06 0.36 3.1 6.5 0.08 0.01 0.11 Thur AM 1.77 0.35 0.22 0.04 12.0 25.5 0.31 0.06 0.35 2.8 6.0 0.07 0.01 0.10 Thur PM 2.96 0.58 0.36 0.07 11.6 24.6 0.29 0.06 0.33 2.7 5.8 0.07 0.01 0.10 FLGS12 Wed AM 9.03 1.78 2.48 0.49 37.3 79.1 1.48 0.29 1.58 11.8 25.0 0.47 0.09 0.57 Wed PM 8.69 1.71 2.37 0.47 34.5 73.1 1.49 0.29 1.60 10.9 23.1 0.47 0.09 0.58 Thur AM 8.09 1.59 2.18 0.43 35.4 75.0 1.50 0.29 1.60 11.2 23.7 0.47 0.09 0.58 Thur PM 7.90 1.55 2.15 0.42 25.6 54.3 1.38 0.27 1.48 8.1 17.2 0.44 0.09 0.53 GADS01 Wed AM 2.42 0.48 0.58 0.11 32.8 69.5 0.96 0.19 0.91 10.4 22.0 0.30 0.06 0.33 Wed PM 2.61 0.51 0.64 0.13 35.7 75.7 0.84 0.17 0.79 11.3 24.0 0.27 0.05 0.29 Thur AM 2.44 0.48 0.58 0.11 41.3 87.5 1.02 0.20 0.97 13.1 27.7 0.32 0.06 0.35 Thur PM 2.51 0.49 0.60 0.12 39.0 82.6 0.95 0.19 0.90 12.3 26.1 0.30 0.06 0.32 GADS02 Wed AM 3.06 0.60 0.37 0.07 36.0 76.3 0.63 0.12 0.60 8.6 18.2 0.15 0.03 0.18 Wed PM 3.52 0.69 0.43 0.08 29.9 63.4 0.62 0.12 0.59 7.0 14.9 0.15 0.03 0.17 Thur AM 3.05 0.60 0.37 0.07 35.4 74.9 0.65 0.13 0.61 8.3 17.6 0.15 0.03 0.18 Thur PM 3.71 0.73 0.45 0.09 33.9 71.8 0.64 0.13 0.61 8.0 16.9 0.15 0.03 0.18 GADS03 Wed AM 5.79 1.14 0.82 0.16 11.7 24.7 0.46 0.09 0.46 3.7 7.8 0.15 0.03 0.17 Wed PM 5.53 1.09 0.78 0.15 9.9 21.0 0.47 0.09 0.47 3.1 6.6 0.15 0.03 0.17 Thur AM 5.51 1.08 0.78 0.15 10.8 22.9 0.47 0.09 0.47 3.4 7.2 0.15 0.03 0.17 Thur PM 5.44 1.07 0.77 0.15 11.6 24.7 0.47 0.09 0.47 3.7 7.8 0.15 0.03 0.17 ILBS01 Wed AM 5.55 1.09 0.72 0.14 Wed PM 5.61 1.10 0.73 0.14 Thur AM 5.34 1.05 0.69 0.14 Thur PM 5.68 1.12 0.74 0.15 ILBS02 Wed AM 7.32 1.44 1.04 0.20 18.1 38.4 0.61 0.12 0.68 5.7 12.1 0.19 0.04 0.25 Wed PM 7.60 1.50 1.08 0.21 18.9 40.1 0.56 0.11 0.63 6.0 12.7 0.18 0.03 0.23 Thur AM 7.12 1.40 1.01 0.20 21.6 45.8 0.48 0.10 0.55 6.8 14.5 0.15 0.03 0.20 Thur PM 7.28 1.43 1.03 0.20 23.6 50.0 0.55 0.11 0.62 7.5 15.8 0.17 0.03 0.22 ILBS03 Wed AM 10.25 2.02 1.45 0.29 139.9 296.3 3.71 0.73 3.82 84.6 179.2 2.24 0.44 2.40 Wed PM 10.70 2.11 1.51 0.30 113.7 240.9 3.81 0.75 3.92 70.4 149.2 2.36 0.46 2.52 Thur AM 10.35 2.04 1.46 0.29 218.9 463.7 4.84 0.95 4.98 90.9 192.6 2.01 0.40 2.24 Thur PM 9.91 1.95 1.40 0.28 132.1 279.9 4.17 0.82 4.29 64.2 136.1 2.03 0.40 2.21 LAGW04 Wed AM 5.49 1.08 0.78 0.15 14.9 31.5 0.36 0.07 0.37 3.7 7.7 0.09 0.02 0.11 Wed PM 5.65 1.11 0.81 0.16 12.4 26.4 0.33 0.06 0.34 3.1 6.5 0.08 0.02 0.10 Thur AM 5.32 1.05 0.76 0.15 15.6 33.0 0.37 0.07 0.38 3.8 8.1 0.09 0.02 0.11 Thur PM 5.67 1.12 0.81 0.16 15.2 32.2 0.35 0.07 0.36 3.7 7.9 0.09 0.02 0.11 OUTDOOR AIRFLOW SUPPLY AIRFLOW

Study Space ID Period Volumetric supply airflow Uncertainty in supply airflow Volumetric Uncertainty in volumetric OA77

L/s•m 2 cfm/ft 2 L/s•m 2 cfm/ft 2 L/s•person cfm/person L/s•m 2 cfm/ft 2 h - 1 L/s•person cfm/person L/s•m 2 cfm/ft 2 h - 1

LAGW05 Wed AM 16.24 3.20 2.02 0.40 56.8 120.3 3.09 0.61 3.05 18.0 38.0 0.98 0.19 1.10 Wed PM 15.81 3.11 1.97 0.39 95.4 202.2 3.46 0.68 3.41 30.2 63.9 1.09 0.22 1.23 Thur AM 16.12 3.17 2.00 0.39 34.1 72.3 3.25 0.64 3.21 10.8 22.9 1.03 0.20 1.16 Thur PM 15.76 3.10 1.96 0.39 63.0 133.4 3.43 0.67 3.38 19.9 42.2 1.08 0.21 1.22 LAGW06 Wed AM 5.11 1.00 0.72 0.14 14.8 31.4 0.65 0.13 0.64 4.7 9.9 0.20 0.04 0.23 Wed PM 5.14 1.01 0.73 0.14 23.0 48.7 0.63 0.12 0.62 7.3 15.4 0.20 0.04 0.22 Thur AM 5.12 1.01 0.72 0.14 19.9 42.2 0.62 0.12 0.62 6.3 13.4 0.20 0.04 0.22 Thur PM 5.15 1.01 0.73 0.14 17.8 37.8 0.63 0.12 0.62 5.6 12.0 0.20 0.04 0.23 MABW05 Wed AM 0.88 0.17 0.13 0.03 2.7 5.7 0.09 0.02 0.08 6.4 13.5 0.21 0.04 0.19 Wed PM 1.34 0.26 0.21 0.04 10.9 23.0 0.32 0.06 0.30 9.6 20.4 0.29 0.06 0.27 Thur AM 1.29 0.25 0.20 0.04 6.9 14.6 0.23 0.04 0.21 9.0 19.0 0.29 0.06 0.28 Thur PM 1.34 0.26 0.21 0.04 9.3 19.8 0.29 0.06 0.27 9.3 19.6 0.29 0.06 0.27 MABW06 Wed AM 2.23 0.44 0.31 0.06 39.3 83.3 2.07 0.41 2.08 12.4 26.3 0.65 0.13 0.75 Wed PM 2.20 0.43 0.31 0.06 41.1 87.0 2.12 0.42 2.13 13.0 27.5 0.67 0.13 0.77 Thur AM 1.88 0.37 0.27 0.05 41.0 86.9 1.82 0.36 1.82 13.0 27.5 0.57 0.11 0.66 Thur PM 1.82 0.36 0.26 0.05 32.2 68.2 1.77 0.35 1.77 10.2 21.6 0.56 0.11 0.64 MABW08 Wed AM 4.48 0.88 0.76 0.15 54.1 114.6 3.30 0.65 3.30 24.7 52.3 1.50 0.30 1.61 Wed PM 4.56 0.90 0.77 0.15 44.9 95.1 3.47 0.68 3.48 19.9 42.1 1.54 0.30 1.66 Thur AM 4.31 0.85 0.73 0.14 38.3 81.1 2.87 0.56 2.88 9.8 20.7 0.73 0.14 0.89 Thur PM 4.40 0.87 0.74 0.15 36.4 77.1 3.07 0.60 3.08 8.6 18.2 0.73 0.14 0.90 MDDS01 Wed AM 5.06 1.00 0.88 0.17 14.6 30.9 0.57 0.11 0.44 36.7 77.7 1.44 0.28 1.10 Wed PM 5.41 1.06 0.94 0.18 13.7 29.0 0.34 0.07 0.26 64.5 136.7 1.61 0.32 1.23 Thur AM 4.83 0.95 0.84 0.16 0.0 0.0 0.0 0.00 0.00 57.7 122.3 1.88 0.37 1.41 Thur PM 4.73 0.93 0.82 0.16 0.0 0.0 0.0 0.00 0.00 45.9 97.2 1.63 0.32 1.25 MDDS03 Wed AM 2.29 0.45 0.28 0.06 3.8 8.0 0.18 0.04 0.22 1.0 2.1 0.05 0.01 0.07 Wed PM 2.16 0.43 0.27 0.05 2.9 6.2 0.14 0.03 0.16 0.8 1.7 0.04 0.01 0.05 Thur AM 2.25 0.44 0.28 0.05 3.6 7.5 0.17 0.03 0.20 0.9 1.9 0.04 0.01 0.06 Thur PM 2.21 0.43 0.27 0.05 4.0 8.5 0.16 0.03 0.19 1.0 2.2 0.04 0.01 0.06 MDDS04 Wed AM 4.02 0.79 0.49 0.10 17.6 37.4 0.74 0.15 0.60 18.3 38.7 0.77 0.15 0.63 Wed PM 3.81 0.75 0.47 0.09 15.7 33.3 0.63 0.12 0.52 18.5 39.2 0.74 0.15 0.61 Thur AM 3.88 0.76 0.48 0.09 16.4 34.8 0.60 0.12 0.49 20.7 43.9 0.76 0.15 0.63 Thur PM 3.74 0.74 0.46 0.09 13.9 29.5 0.61 0.12 0.50 16.8 35.6 0.73 0.14 0.60 MIBW01 Wed AM 3.08 0.61 0.40 0.08 32.0 67.9 1.15 0.23 1.12 13.6 28.8 0.49 0.10 0.51 Wed PM 3.43 0.67 0.45 0.09 45.4 96.1 1.80 0.35 1.74 11.8 25.1 0.47 0.09 0.55 Thur AM 3.09 0.61 0.40 0.08 Thur PM 3.25 0.64 0.42 0.08 MIBW03 Wed AM 5.37 1.06 0.93 0.18 36.0 76.3 1.53 0.30 1.53 30.4 64.4 1.29 0.25 1.32 Wed PM 5.35 1.05 0.93 0.18 21.2 44.9 1.16 0.23 1.16 25.0 52.9 1.37 0.27 1.39 Thur AM 5.47 1.08 0.95 0.19 27.4 58.1 1.34 0.26 1.34 28.1 59.5 1.37 0.27 1.39 Thur PM 4.67 0.92 0.81 0.16 24.8 52.6 1.57 0.31 1.57 16.8 35.5 1.06 0.21 1.10 SUPPLY AIRFLOW OUTDOOR AIRFLOW

Study Space ID Period Volumetric supply airflow Uncertainty in supply airflow Volumetric Uncertainty in volumetric OA77787879 L/s•m 2 cfm/ft 2 L/s•m 2 cfm/ft 2 L/s•person cfm/person L/s•m 2 cfm/ft 2 h - 1 L/s•person cfm/person L/s•m 2 cfm/ft 2 h - 1

NECW02 Wed AM 8.20 1.61 1.42 0.28 226.7 480.3 6.47 1.27 4.89 75.2 159.3 2.15 0.42 1.83 Wed PM 6.34 1.25 1.10 0.22 109.1 231.2 3.59 0.71 2.71 36.2 76.7 1.19 0.23 1.02 Thur AM 8.26 1.63 1.43 0.28 175.9 372.6 6.24 1.23 4.72 58.3 123.6 2.07 0.41 1.76 Thur PM 8.06 1.59 1.40 0.27 310.1 657.0 5.90 1.16 4.46 102.8 217.9 1.96 0.39 1.67 NECW03 Wed AM 6.28 1.24 1.09 0.21 65.8 139.4 4.31 0.85 4.32 21.8 46.2 1.43 0.28 1.62 Wed PM 7.11 1.40 1.23 0.24 78.1 165.4 4.76 0.94 4.77 25.9 54.9 1.58 0.31 1.79 Thur AM 7.34 1.44 1.27 0.25 51.7 109.4 3.42 0.67 3.43 17.1 36.3 1.14 0.22 1.28 Thur PM 6.47 1.27 1.12 0.22 87.0 184.4 5.70 1.12 5.72 28.9 61.2 1.89 0.37 2.14 NMES01 Wed AM 4.88 0.96 0.98 0.19 72.5 153.7 1.51 0.30 1.52 17.5 37.1 0.37 0.07 0.45 Wed PM 4.95 0.97 1.02 0.20 69.9 148.2 1.68 0.33 1.69 17.2 36.5 0.41 0.08 0.51 Thur AM 4.35 0.86 0.90 0.18 68.2 144.4 1.27 0.25 1.28 17.1 36.3 0.32 0.06 0.39 Thur PM 4.78 0.94 0.98 0.19 57.7 122.2 1.54 0.30 1.55 14.2 30.1 0.38 0.07 0.47 NMES02 Wed AM 5.30 1.04 0.75 0.15 183.2 388.2 7.34 1.44 6.85 57.9 122.8 2.32 0.46 2.47 Wed PM 5.88 1.16 0.83 0.16 203.8 431.8 7.30 1.44 6.81 64.5 136.6 2.31 0.45 2.45 Thur AM 6.31 1.24 0.89 0.18 186.5 395.2 6.84 1.35 6.38 59.0 125.0 2.16 0.43 2.30 Thur PM 5.09 1.00 0.72 0.14 201.7 427.2 7.74 1.52 7.21 63.8 135.1 2.45 0.48 2.60 NMES03 Wed AM 4.69 0.92 0.58 0.11 7.2 15.3 0.44 0.09 0.41 15.9 33.7 0.97 0.19 0.91 Wed PM 5.55 1.09 0.69 0.14 20.4 43.1 0.79 0.16 0.74 29.0 61.4 1.13 0.22 1.06 Thur AM 4.79 0.94 0.59 0.12 17.0 35.9 0.77 0.15 0.71 20.9 44.4 0.95 0.19 0.89 Thur PM 5.04 0.99 0.63 0.12 12.3 26.1 0.51 0.10 0.48 25.4 53.8 1.06 0.21 0.99 NVAW01 Wed AM 6.31 1.24 1.09 0.22 151.8 321.5 6.31 1.24 6.62 50.3 106.6 2.09 0.41 2.48 Wed PM 6.57 1.29 1.14 0.22 104.2 220.8 4.42 0.87 4.64 34.6 73.2 1.47 0.29 1.74 Thur AM 6.75 1.33 1.17 0.23 86.6 183.5 3.68 0.72 3.86 28.7 60.9 1.22 0.24 1.44 Thur PM 6.84 1.35 1.18 0.23 50.8 107.6 1.90 0.37 1.99 16.8 35.7 0.63 0.12 0.74 NVAW02 Wed AM 4.15 0.82 0.72 0.14 82.9 175.6 3.95 0.78 3.73 27.5 58.2 1.31 0.26 1.40 Wed PM 4.63 0.91 0.80 0.16 132.3 280.3 4.44 0.87 4.19 43.9 93.0 1.47 0.29 1.57 Thur AM 4.04 0.79 0.70 0.14 133.3 282.3 3.88 0.76 3.67 44.2 93.6 1.29 0.25 1.37 Thur PM 4.61 0.91 0.80 0.16 121.8 258.0 4.30 0.85 4.07 40.4 85.6 1.43 0.28 1.52 NVAW03 Wed AM 8.78 1.73 1.08 0.21 174.0 368.6 7.38 1.45 6.97 45.1 95.5 1.91 0.38 2.17 Wed PM 8.54 1.68 1.05 0.21 148.0 313.6 7.44 1.47 7.03 38.4 81.4 1.93 0.38 2.19 Thur AM 8.51 1.67 1.05 0.21 106.6 225.9 7.36 1.45 6.95 27.7 58.7 1.91 0.38 2.17 Thur PM 8.74 1.72 1.08 0.21 127.8 270.8 7.44 1.46 7.03 33.1 70.1 1.93 0.38 2.19 NYBS01 Wed AM 9.42 1.85 1.37 0.27 35.3 74.9 1.39 0.27 1.43 43.8 92.8 1.72 0.34 1.78 Wed PM 9.88 1.94 1.43 0.28 54.1 114.6 1.27 0.25 1.31 78.1 165.5 1.84 0.36 1.90 Thur AM 9.71 1.91 1.40 0.28 40.8 86.5 1.17 0.23 1.21 62.6 132.6 1.80 0.35 1.86 Thur PM 9.81 1.93 1.42 0.28 35.3 74.7 1.34 0.26 1.38 47.7 101.0 1.81 0.36 1.87 NYBS02 Wed AM 6.72 1.32 0.83 0.16 16.4 34.7 0.63 0.12 0.58 3.9 8.2 0.15 0.03 0.17 Wed PM 6.34 1.25 0.78 0.15 14.6 30.9 0.71 0.14 0.65 3.5 7.4 0.17 0.03 0.19 Thur AM 6.38 1.26 0.78 0.15 13.6 28.9 0.61 0.12 0.55 3.3 6.9 0.15 0.03 0.16 Thur PM 4.39 0.86 0.54 0.11 17.5 37.0 0.66 0.13 0.60 4.1 8.7 0.16 0.03 0.18 SUPPLY AIRFLOW

Period Volumetric supply airflow Uncertainty in supply airflow Volumetric OUTDOOR AIRFLOW

Study Space ID Uncertainty in volumetric OA80 L/s•m 2 cfm/ft 2 L/s•m 2 cfm/ft 2 L/s•person cfm/person L/s•m 2 cfm/ft 2 h - 1 L/s•person cfm/person L/s•m 2 cfm/ft 2 h - 1

NYBS04 Wed AM 5.40 1.06 0.76 0.15 3.3 7.1 0.14 0.03 0.14 0.9 1.9 0.04 0.01 0.05 Wed PM 5.42 1.07 0.77 0.15 3.9 8.3 0.13 0.03 0.13 1.0 2.2 0.04 0.01 0.04 Thur AM 5.70 1.12 0.81 0.16 99.0 209.8 4.78 0.94 4.84 24.4 51.6 1.18 0.23 1.46 Thur PM 5.69 1.12 0.80 0.16 3.5 7.5 0.14 0.03 0.14 1.0 2.0 0.04 0.01 0.04 NYBS05 Wed AM 2.50 0.49 0.43 0.09 12.8 27.1 0.64 0.13 0.54 4.2 9.0 0.21 0.04 0.20 Wed PM 2.69 0.53 0.47 0.09 13.8 29.2 0.64 0.13 0.55 4.6 9.7 0.21 0.04 0.20 Thur AM 2.60 0.51 0.45 0.09 14.5 30.8 0.64 0.13 0.55 4.8 10.2 0.21 0.04 0.20 Thur PM 2.62 0.52 0.45 0.09 12.3 26.2 0.59 0.12 0.51 4.1 8.7 0.20 0.04 0.19 NYBS07 Wed AM 4.87 0.96 1.30 0.26 18.3 38.8 0.97 0.19 0.90 5.8 12.3 0.31 0.06 0.32 Wed PM 5.10 1.00 1.36 0.27 27.1 57.5 1.02 0.20 0.94 8.6 18.2 0.32 0.06 0.34 Thur AM 5.03 0.99 1.34 0.26 21.4 45.4 1.03 0.20 0.96 6.8 14.4 0.33 0.06 0.34 Thur PM 4.81 0.95 1.28 0.25 23.8 50.5 0.96 0.19 0.89 7.5 16.0 0.30 0.06 0.32 ORIS03 Wed AM 3.89 0.77 0.71 0.14 64.9 137.6 1.75 0.34 1.62 21.5 45.6 0.58 0.11 0.61 Wed PM 4.52 0.89 0.82 0.16 74.8 158.6 1.88 0.37 1.75 24.8 52.6 0.62 0.12 0.65 Thur AM 3.40 0.67 0.62 0.12 65.6 138.9 1.54 0.30 1.42 21.7 46.1 0.51 0.10 0.53 Thur PM 3.84 0.76 0.70 0.14 108.7 230.2 1.79 0.35 1.66 36.0 76.3 0.59 0.12 0.62 ORIS04 Wed AM Wed PM 3.98 0.78 0.69 0.14 Thur AM 5.68 1.12 0.98 0.19 Thur PM 5.55 1.09 0.96 0.19 PABS03 Wed AM 3.37 0.66 0.58 0.11 0.0 0.0 0.00 0.00 0.00 34.7 73.6 1.12 0.22 1.09 Wed PM 3.12 0.61 0.54 0.11 0.0 0.0 0.00 0.00 0.00 38.7 81.9 1.07 0.21 1.07 Thur AM 3.18 0.63 0.55 0.11 0.0 0.0 0.00 0.00 0.00 43.9 93.0 1.17 0.23 1.17 Thur PM 3.45 0.68 0.60 0.12 0.0 0.0 0.00 0.00 0.00 42.2 89.4 1.27 0.25 1.23 PABS04 Wed AM 4.88 0.96 0.69 0.14 8.5 17.9 0.63 0.12 0.60 2.5 5.3 0.19 0.04 0.21 Wed PM 4.82 0.95 0.69 0.13 9.0 19.1 0.61 0.12 0.58 2.7 5.6 0.18 0.04 0.20 Thur AM 4.55 0.90 0.65 0.13 7.5 16.0 0.58 0.11 0.54 2.3 4.8 0.17 0.03 0.19 Thur PM 4.74 0.93 0.67 0.13 9.2 19.5 0.61 0.12 0.58 2.7 5.8 0.18 0.04 0.20 SCDW01 Wed AM 5.88 1.16 0.83 0.16 18.5 39.2 1.42 0.28 1.42 5.9 12.4 0.45 0.09 0.51 Wed PM 4.97 0.98 0.70 0.14 18.3 38.7 1.24 0.24 1.24 5.8 12.2 0.39 0.08 0.45 Thur AM 5.46 1.08 0.77 0.15 18.1 38.4 1.30 0.26 1.30 5.7 12.1 0.41 0.08 0.47 Thur PM 4.68 0.92 0.66 0.13 15.9 33.6 1.03 0.20 1.03 5.0 10.6 0.33 0.06 0.37 SCDW02 Wed AM 7.58 1.49 1.31 0.26 26.1 55.4 1.38 0.27 1.15 8.7 18.4 0.46 0.09 0.43 Wed PM 8.18 1.61 1.42 0.28 25.9 54.9 1.53 0.30 1.28 8.6 18.2 0.51 0.10 0.48 Thur AM 7.39 1.45 1.28 0.25 23.9 50.7 1.41 0.28 1.18 7.9 16.8 0.47 0.09 0.44 Thur PM 7.69 1.51 1.33 0.26 22.6 47.9 1.19 0.23 0.99 7.5 15.9 0.39 0.08 0.37 SDBW01 Wed AM 3.87 0.76 0.55 0.11 43.1 91.3 1.77 0.35 1.96 13.6 28.9 0.56 0.11 0.71 Wed PM 4.15 0.82 0.59 0.12 64.6 136.8 2.14 0.42 2.37 20.4 43.3 0.68 0.13 0.86 Thur AM 3.95 0.78 0.56 0.11 56.1 119.0 2.07 0.41 2.29 17.8 37.6 0.65 0.13 0.83 Thur PM 4.09 0.80 0.58 0.11 60.6 128.4 2.23 0.44 2.47 19.2 40.6 0.71 0.14 0.89 Study Space ID Period Volumetric supply airflow Uncertainty in supply airflow Volumetric Uncertainty in volumetric OA SUPPLY AIRFLOW OUTDOOR AIRFLOW81 L/s•m 2 cfm/ft 2 L/s•m 2 cfm/ft 2 L/s•person cfm/person L/s•m 2 cfm/ft 2 h - 1 L/s•person cfm/person L/s•m 2 cfm/ft 2 h - 1

SDBW02 Wed AM 3.66 0.72 0.63 0.12 49.9 105.6 1.62 0.32 1.80 16.5 35.0 0.54 0.11 0.67 Wed PM 3.34 0.66 0.58 0.11 53.3 112.9 0.98 0.19 1.08 17.7 37.5 0.32 0.06 0.41 Thur AM 3.64 0.72 0.63 0.12 35.3 74.8 1.03 0.20 1.14 11.7 24.8 0.34 0.07 0.43 Thur PM 3.37 0.66 0.58 0.12 31.7 67.3 0.79 0.16 0.88 10.5 22.3 0.26 0.05 0.33 SDBW04 Wed AM 11.17 2.20 1.58 0.31 47.1 99.7 2.39 0.47 2.68 56.4 119.6 2.87 0.57 3.24 Wed PM 9.48 1.87 1.34 0.26 55.6 117.8 1.89 0.37 2.11 73.0 154.6 2.48 0.49 2.79 Thur AM 9.13 1.80 1.29 0.25 44.0 93.2 1.78 0.35 1.99 59.1 125.1 2.39 0.47 2.70 Thur PM 9.06 1.78 1.28 0.25 39.3 83.2 1.96 0.39 2.19 46.5 98.5 2.32 0.46 2.62 TNDS05 Wed AM 2.08 0.41 0.32 0.06 59.1 125.1 2.08 0.41 2.32 16.7 35.3 0.59 0.12 0.77 Wed PM 2.27 0.45 0.35 0.07 89.6 189.8 2.27 0.45 2.54 25.7 54.5 0.65 0.13 0.85 Thur AM 2.16 0.42 0.34 0.07 65.3 138.3 2.16 0.42 2.41 18.7 39.7 0.62 0.12 0.81 Thur PM 2.04 0.40 0.32 0.06 82.7 175.3 2.04 0.40 2.28 23.7 50.2 0.58 0.11 0.76 TNDS06 Wed AM 2.64 0.52 0.46 0.09 17.3 36.7 0.56 0.11 0.51 21.0 44.5 0.68 0.13 0.62 Wed PM 2.25 0.44 0.39 0.08 6.7 14.2 0.19 0.04 0.17 22.9 48.5 0.66 0.13 0.59 Thur AM 2.07 0.41 0.36 0.07 5.4 11.5 0.27 0.05 0.24 11.7 24.8 0.58 0.11 0.52 Thur PM 2.13 0.42 0.37 0.07 1.3 2.8 0.05 0.01 0.04 18.3 38.7 0.66 0.13 0.59 TNDS07 Wed AM 5.55 1.09 0.79 0.15 3.1 6.6 0.13 0.03 0.14 1.0 2.1 0.04 0.01 0.05 Wed PM 5.36 1.06 0.76 0.15 2.6 5.5 0.16 0.03 0.17 0.8 1.7 0.05 0.01 0.06 Thur AM 5.55 1.09 0.79 0.15 2.6 5.6 0.17 0.03 0.18 0.8 1.8 0.05 0.01 0.06 Thur PM 5.61 1.10 0.79 0.16 14.6 31.0 0.89 0.18 0.96 4.6 9.8 0.28 0.06 0.35 TNFS08 Wed AM 3.59 0.71 0.51 0.10 14.5 30.8 0.80 0.16 0.86 3.5 7.4 0.19 0.04 0.26 Wed PM 3.63 0.71 0.52 0.10 20.9 44.3 0.86 0.17 0.93 5.3 11.1 0.22 0.04 0.28 Thur AM 3.81 0.75 0.54 0.11 15.7 33.3 0.87 0.17 0.93 3.9 8.3 0.22 0.04 0.28 Thur PM 4.34 0.85 0.60 0.12 15.3 32.4 0.83 0.16 0.89 3.8 8.1 0.21 0.04 0.27 TNFS09 Wed AM 3.29 0.65 0.48 0.10 10.7 22.8 0.93 0.18 0.96 5.9 12.5 0.51 0.10 0.55 Wed PM 3.18 0.63 0.46 0.09 12.2 25.8 0.76 0.15 0.78 7.9 16.7 0.49 0.10 0.53 Thur AM 2.71 0.53 0.40 0.08 7.5 15.8 0.58 0.11 0.60 6.2 13.2 0.49 0.10 0.51 Thur PM 2.86 0.56 0.42 0.08 8.4 17.9 0.65 0.13 0.66 6.2 13.2 0.48 0.09 0.50 TNFS10 Wed AM 6.20 1.22 1.07 0.21 84.9 179.9 4.27 0.84 3.53 20.7 43.9 1.04 0.21 1.06 Wed PM 7.31 1.44 1.27 0.25 75.3 159.5 3.92 0.77 3.24 26.4 55.8 1.37 0.27 1.27 Thur AM 6.90 1.36 1.20 0.24 103.9 220.1 4.85 0.96 4.02 24.6 52.2 1.15 0.23 1.18 Thur PM 6.08 1.20 1.05 0.21 81.0 171.6 4.28 0.84 3.55 19.2 40.6 1.01 0.20 1.04 TXFS01 Wed AM 3.58 0.71 0.62 0.12 Wed PM 4.39 0.86 0.76 0.15 5.9 12.4 0.20 0.04 0.17 1.9 4.1 0.07 0.01 0.06 Thur AM 4.33 0.85 0.75 0.15 4.6 9.7 0.19 0.04 0.15 1.5 3.2 0.06 0.01 0.06 Thur PM 4.46 0.88 0.77 0.15 6.5 13.8 0.18 0.04 0.15 2.2 4.6 0.06 0.01 0.06 TXFS02 Wed AM 6.64 1.31 0.81 0.16 10.8 22.9 0.31 0.06 0.35 2.5 5.4 0.07 0.01 0.10 Wed PM 6.47 1.27 0.79 0.16 12.9 27.2 0.31 0.06 0.35 3.0 6.4 0.07 0.01 0.10 Thur AM 7.63 1.50 0.93 0.18 9.5 20.1 0.30 0.06 0.34 2.2 4.7 0.07 0.01 0.10 Thur PM 6.71 1.32 0.82 0.16 14.7 31.2 0.31 0.06 0.35 3.5 7.3 0.07 0.01 0.10 SUPPLY AIRFLOW OUTDOOR AIRFLOW

Study Space ID Period Volumetric supply airflow Uncertainty in supply airflow Volumetric Uncertainty in volumetric OA82828383848485858687888889899090919192

### 93 Appendix F: Re anal y sis of BASE V entilation Data

This appendix presents the letter report published in October 2008 discussing the BASE ventilation data reanaly sis that led to the revision of the original (2004) NIST report.



## R e a n a l y s i s o f B A S E V e n t i l a t i o n D a t a

L e t t e r R e p o r t t o U

. S

. E n v i r o n m e n t a l P r o t e c t i o n A g e n c y O c t o b e r 1 0 , 2 0 0 8

A n d r e w P e r s i l y B u i l d i n g a n d F i r e R e s e a r c h L a b o r a t o r y N a t i o n a l I n s t i t u t e o f S t a n d a r d s a n d T e c h n o l o g y

ABSTRACT In 2004, the National Institute of Standards and Technology (NIST) published an analy sis of the ventilation data collected as part of the U.S. Environmental Protection Agency (EPA) Building Assessment Survey and Evaluation (BASE) study [1] . That analy sis provided a unique dataset of office building ventilation rates, both design and measured, along with many insights into building ventilation. The analy sis also raised questions regarding the use of the difference between peak indoor carbon dioxide (CO 2 

### ) concentrations and the corresponding outdoor CO 2 

### concentrations to estimate building ventilation rates, as there was a sy stematic difference between the ventilation rates based on this method and those based on duct traverse measurements. The current study examined the discrepancies between t he peak indoor CO 2 

### - based and traverse

- based ventilation rates in more detail. In addition, the overall ventilation rate dataset was re

- examined for consistency and, as a result, some errors were corrected.

SUMMARY OF ANALYSIS AND REPORT CONTENT The BASE v entilation data reanaly sis effort focused on two primary areas: 1) general corrections and adjustments to the original data; and 2) the disagreement between the outdoor air ventilation rates based on peak indoor CO 2 

### concentrations and those based on traver se measurements at the air handlers (sometimes referred to as volumetric rates). The corrections involved a detailed review of the data files generated by National Institute of Standards and Technology (NIST) and provided to U.S. Environmental Protection A gency (EPA) for the BASE (Building Assessment Survey and Evaluation) CD distributed by EPA [2] . In addition, outliers (primarily those with high measured ventilation rates) were examined in more detail. Regarding the second issue, a number of potential explanations wer e examined for the differences between the ventilation rates estimated from peak indoor CO 2 

### concentrations and the traverse

- based or volumetric rates.

DATABASE CORRECTIONS As part of the data review, the various files used in the ventilation data analy sis were studied and compared with the files on the CD distributed by EPA [2] . As a result, a number of changes were made to the dataset, which are identified below. However, none of the changes modify the overall conclusions of the study , only some of the summary statist ics. An updated version of the original NIST report on the dataset [1] will be published with these corrections.

### 94 This data review effort involved a detailed examination of the data analy sis files generated by the original analy sis, including the following design parameters: Supply capacity of each air handli ng unit (AHU) AHU return capacity Floor area served by each AHU AHU design minimum outdoor air intake Number of occupants served by each AHU AHU supply capacity divided by floor area served AHU design minimum outdoor air per person AHU ratio of minimum ou tdoor air to supply capacity
N u m b e r o f o c c u p a n t s p e r u n i t f l o o r a r e a ( f o r e a c h A H U ) R a t i o o f s u p p l y t o r e t u r n a i r f l o w ( f o r e a c h A H U ) 

### In addition, the following measured parameters were also reviewed: AHU supply airflow and associated uncertainty AHU outdoo r airflow and associated uncertainty AHU recirculation airflow and associated uncertainty AHU outdoor air intake fraction and associated uncertainty Study space supply airflow per unit floor area and associated uncertainty Study space outdoor airflow (per person, per unit floor area and per unit volume) and associated uncertainty The changes made to the data files as a result of this effort are documented in Table 1.

B u i l d i n g P a r a m e t e r M o d i f i c a t i o n C o m m e n t C A J S 0 1 P e a k C O 2 v a l u e a n d

o u t d o o r a i r f l o w

c a l c u l a t e d f r o m p e a k A l l v a l u e s d e l e t e d

. A l l i n d o o r C O 2 c o n c e n t r a t i o n s a r e

v e r y e r r a t i c ; t w o l o c a t i o n s a r e

c o n s i s t e n t l y b e l o w o u t d o o r s a t

n i g h t

. C A J W 2 0 % o f A H U c a p a c i t y

s e r v i n g t e s t s p a c e ( C 1 T S 1 P C T * ) C h a n g e d f r o m 1 0 0 % t o 1 4 %

, b a s e d o n f l o o r a r e a

a n d n u m b e r o f o c c u p a n t s

s e r v e d

. F i e l d n o t e s i n d i c a t e A H U s e r v e s 7 f l o o r s , n o t 1 a s i n d i c a t e d b y

o r i g i n a l v a l u e o f C 1 T S 1 P C T

. R e s u l t s i n 8 6 % r e d u c t i o n i n s u p p l y

a n d o u t d o o r a i r f l o w s , a n d

a s s o c i a t e d r e d u c t i o n i n u n c e r t a i n t y

. C A J W 2 4 U n c e r t a i n t y i n C O 2
r a t i o o u t d o o r a i r f l o w p e r p e r s o n

. F i x e d s m a l l e r r o r i n

u n c e r t a i n t y i n L / s • p e r s o n

a n d c f m / p e r s o n R o u g h l y 1 0 % r e d u c t i o n i n t h e s e t w o u n c e r t a i n t y v a l u e s ; n o i m p a c t

o n a i r f l o w r e s u l t s

. M O C S 0 1 F l o o r a r e a s e r v e d b y

s y s t e m ( C 7 A A R E A * ) I n c r e a s e d b y r o u g h l y a f a c t o r o f 8 ( # o f b u i l d i n g f l o o r s ) a s l i s t e d v a l u e i s

o n l y f o r a s i n g l e f l o o r

. R e d u c e s d e s i g n v a l u e o f s u p p l y

a i r f l o w p e r u n i t f l o o r a r e a a n d

o c c u p a n t d e n s i t y b y f a c t o r o f 8

.

N C D W 0 2 % o f A H U c a p a c i t y

s e r v i n g t e s t s p a c e ( C 1 T S 1 P C T ) C h a n g e f r o m 5 0 % t o 2 0 % f o r A H U # 1 a n d t o 3 0 % f o r A H U # 2

, b a s e d

o n f l o o r a r e a a n d n u m b e r

o f o c c u p a n t s s e r v e d

. R e s u l t s i n r o u g h l y 5 0 % r e d u c t i o n i n r e p o r t e d s u p p l y a n d o u t d o o r

a i r f l o w s , a n d a s s o c i a t e d r e d u c t i o n i n u n c e r t a i n t i e s

.

P A B S 0 4 D e s i g n # o f o c c u p a n t s ( C 7 A O C C U ) R e p l a c e d v a l u e o f 0 w i t h b l a n k c e l l f o r A H U # 2 A H U s e r v e s p e r i m e t e r ; o c c u p a n t s

a c c o u n t e d f o r b y o t h e r s y s t e m s

. T N D S 0 5 D e s i g n # o f o c c u p a n t s ( C 7 A O C C U ) R e p l a c e d v a l u e o f 0 w i t h b l a n k c e l l f o r A H U # 2

. A H U s e r v e s c o r r i d o r ; o c c u p a n t s

a c c o u n t e d f o r b y o t h e r s y s t e m s

.

### 95 T X F S 0 2 U n c e r t a i n t y i n C O 2
r a t i o o u t d o o r a i r f l o w p e r f l o o r a r e a

. F i x e d e r r o r i n

u n c e r t a i n t y i n L / s • m 2 a n d

c f

m / f t 2

. C o r r e c t e d u n c e r t a i n t y v a l u e s t e n t i m e s u n c o r r e c t e d ; n o i m p a c t o n

a i r f l o w r e s u l t s

.

* V a r i a b l e n a m e f r o m B A S E d a t a d i c t i o n a r y

.



### Table 1 Modifications to BASE ventilation d ata parameters
As a result of these modifications, some of the summary statistics in the original NIST report to EPA (NISTIR 7145) also change. The affected tables and figures are presented below, with the table and figure number from the original report in parentheses. In the tables, the revised values are highlighted in bold font.

D e s i g n s u p p l y a i r f l o w c a p a c i t y L / s • m 2 ( c f m / f t 2 ) F l o o r a r e a s e r v e d

m 2 ( f t 2 ) A l l s y s t e m s C V V A V S u p p l y / R e t u r n # o f v a l u e s 1 4 1 1 3 4 4 7 8 7 4 1
M e a n 3 1 0 0 ( 3 3 3 0 0 ) 5

. 8 6 ( 1

. 1 5 ) 7

. 0 1 ( 1

. 3 8 ) 5

. 2 5 ( 1

. 0 3 ) 1

. 1 4
S t d

. D e v

. 4 2 3 0 ( 4 5 6 0 0 ) 3

. 5 7 ( 0

. 7 0 ) 5

. 3 3 ( 1

. 0 5 ) 1

. 8 5 ( 0

. 3 6 ) 0

. 2 2
M i n i m u m 1 1 0 ( 1 2 0 0 ) 1

. 1 3 ( 0

. 2 2 ) 1

. 1 3 ( 0

. 2 2 ) 1

. 6 7 ( 0

. 3 3 ) 0

. 2 0
1 0 t h p e r c e n t i l e 5 4 0 ( 5 8 0 0 ) 2

. 9 0 ( 0

. 5 7 ) 2

. 7 4 ( 0

. 5 4 ) 3

. 2 6 ( 0

. 6 4 ) 1

. 0 0
2 5 t h p e r c e n t i l e 9 9 0 ( 1 0 7 0 0 ) 4

. 1 5 ( 0

. 8 2 ) 4

. 1 9 ( 0

. 8 3 ) 4

. 1 5 ( 0

. 8 2 ) 1

. 0 7
M e d i a n 1 6 4 0 ( 1 7 6 0 0 ) 5

. 2 1 ( 1

. 0 3 ) 5

. 6 3 ( 1

. 1 1 ) 4

. 9 9 ( 0

. 9 8 ) 1

. 1 1
7 5 t h p e r c e n t i l e 3 4 4 0 ( 3 7 0 0 0 ) 6

. 7 8 ( 1

. 3 3 ) 7

. 8 3 ( 1

. 5 4 ) 6

. 1 7 ( 1

. 2 2 ) 1

. 2 5
9 0 t h p e r c e n t i l e 7 6 2 0 ( 8 2 1 0 0 ) 8

. 4 5 ( 1

. 6 6 ) 1 1

. 2 1 ( 2

. 2 1 ) 7

. 5 6 ( 1

. 4 9 ) 1

. 2 8
M a x i m u m 3 3 7 8 0 ( 3 6 3 6 0 0 ) 3 0

. 1 8 ( 5

. 9 4 ) 3 0

. 1 8 ( 5

. 9 4 ) 1 2

. 4 7 ( 2

. 4 5 ) 1

. 8 5

D e s i g n m i n i m u m o u t d o o r a i r i n t a k e L / s ( c f m ) p e r p e r s o n L / s • m 2 ( c f m / f t 2 ) M i n i m u m O A / S u p p l y O c c u p a n t d e n s i t y # / 1 0 0 m 2 ( 1 0 0 0 f t 2 )

# o f v a l u e s 7 4 7 6 7 6 1 3 7
M e a n 1 8

. 4 ( 3 9

. 0 ) 0

. 9 4 ( 0

. 1 8 ) 0

. 1 9 5

. 3 ( 4

. 9 )
S t d

. D e v

. 1 3

. 7 ( 2 9

. 0 ) 1

. 0 6 ( 0

. 2 1 ) 0

. 2 2 6

. 5 ( 6

. 1 )
M i n i m u m 1

. 3 ( 2

. 9 ) 0

. 1 7 ( 0

. 0 3 ) 0

. 0 6 0

. 9 ( 0

. 8 )
1 0 t h p e r c e n t i l e 7

. 5 ( 1 6

. 0 ) 0

. 3 1 ( 0

. 0 6 ) 0

. 0 8 2

. 2 ( 2

. 0 )
2 5 t h p e r c e n t i l e 1 0

. 6 ( 2 2

. 4 ) 0

. 4 2 ( 0

. 0 8 ) 0

. 1 0 2

. 9 ( 2

. 7 )
M e d i a n 1 5

. 2 ( 3 2

. 1 ) 0

. 6 0 ( 0

. 1 2 ) 0

. 1 2 3

. 9 ( 3

. 7 )
7 5 t h p e r c e n t i l e 2 3

. 6 ( 5 0

. 0 ) 0

. 9 2 ( 0

. 1 8 ) 0

. 1 5 5

. 9 ( 5

. 4 )
9 0 t h p e r c e n t i l e 2 9

. 7 ( 6 3

. 0 ) 1

. 8 2 ( 0

. 3 6 ) 0

. 3 1 8

. 0 ( 7

. 4 )
M a x i m u m 9 8

. 3 ( 2 0 8

. 2 ) 6

. 6 7 ( 1

. 3 1 ) 1

. 0 0 6 5

. 1 ( 6 0

. 5 ) 

### Table 2 Sy stem Design Values (Table 6 in NISTIR 7145)

### 96 S y s t e m * I s s u e C o m m e n t s A Z H W 1 0 ( 2 o f 2 ) H i g h s u p p l y c a p a c i t y , 2 4 L / s • m 2 ( 4

. 7 c f m / f t 2 ) S y s t e m ( 1 ) a t 8 L / s • m 2 ( 1

. 5 c f m / f t 2 )

L A G W 0 5 ( 1 o f 2 ) H i g h s u p p l y c a p a c i t y , 1 8 L / s • m 2 ( 3

. 6 c f m / f t 2 ) S y s t e m ( 2 ) a t 4 L / s • m 2 ( 0

. 7 c f m / f t 2 ) ;

o c c u p a n t d e n s i t y 5 t i m e s t h a t o f s y s t e m ( 2 ) ; f l o o r a r e a c o u l d b e l o w M O C S 0 1 ( 1 o f 1 ) H i g h s u p p l y c a p a c i t y , 2 7 L / s • m 2 ( 5

. 3 c f m / f t 2 ) P A B S 0 4 ( 2 o f 2 ) H i g h s u p p l y c a p a c i t y , 2 5 L / s • m 2 ( 5

. 9 c f m / f t 2 ) S y s t e m ( 1 ) a t 4 L / s • m 2 ( 0

. 8 c f m / f t 2 )

C A E W 0 9 ( 1 o f 1 ) H i g h m i n i m u m o u t d o o r a i r 5 3 L / s ( 1 1 3 c f m ) p e r p e r s o n , M i n i m u m o u t d o o r a i r b a s e d o n s u p p l y a n d

r e t u r n c a p a c i t i e s C A J S 2 1 ( 2 o f 2 ) H i g h m i n i m u m o u t d o o r a i r , 9 8 L / s ( 2 0 8 c f m ) p e r p e r s o n 1 0 0 % o u t d o o r a i r s y s t e m ; S y s t e m ( 1 ) a t 2 9 L / s ( 6 1 c f m ) p e r p e r s o n M D D S 0 1 ( 1 o f 1 ) H i g h m i n i m u m o u t d o o r a i r , 5 1 L / s ( 1 0 9 c f m ) p e r p e r s o n N C D W 0 3 ( 2 o f 5 ) H i g h m i n i m u m o u t d o o r a i r , 3 8 L / s ( 8 0 c f m ) p e r p e r s o n O t h e r 4 s y s t e m s f r o m 9 L / s ( 2 0 c f m ) p e r p e r s o n t o 1 6 L / s ( 3 3 c f m ) p e r p e r s o n ;

s y s t e m ( 2 ) o c c u p a n t d e n s i t y a b o u t 2 5 % o f

o t h e r 4 s y s t e m s

. N E C W 0 2 ( 1 o f 1 ) H i g h m i n i m u m o u t d o o r a i r , 3 8 L / s ( 8 0 c f m ) p e r p e r s o n H i g h o c c u p a n t d e n s i t y , 1 6 o c c u p a n t s p e r 1 0 0 m 2 ( 1 0 0 0 f t 2 ) T N F S 1 0 ( 1 o f 1 ) H i g h m i n i m u m o u t d o o r a i r , 3 4 L / s ( 7 2 c f m ) p e r p e r s o n L o w o c c u p a n t d e n s i t y , 1

. 1 o c c u p a n t s p e r 1 0 0 m 2 ( 1 0 0 0 f t 2 ) C A J W 2 5 ( 1 o f 1 ) H i g h o c c u p a n t d e n s i t y , 6 1

o c c u p a n t s p e r 1 0 0 m 2 ( 1 0 0 0 f t 2 ) S u p p l y a i r f l o w 2 4 L / s • m 2 ( 2

. 5 c f m / f t 2 ) ; f l o o r a r e a c o u l d b e l o w M O C S 0 1 ( 1 o f 1 ) H i g h o c c u p a n t d e n s i t y , 2 4

o c c u p a n t s p e r 1 0 0 m 2 ( 1 0 0 0 f t 2 ) N E C W 0 2 ( 1 o f 1 ) H i g h o c c u p a n t d e n s i t y , 1 6

o c c u p a n t s p e r 1 0 0 m 2 ( 1 0 0 0 f t 2 ) S D B W 0 2 ( 1 o f 1 ) H i g h o c c u p a n t d e n s i t y , 3 8

o c c u p a n t s p e r 1 0 0 m 2 ( 1 0 0 0 f t 2 ) L o w m i n i m u m o u t d o o r a i r 1 L / s ( 3 c f m )
p e r p e r s o n , c o n s i s t e n t w i t h h i g h o c c u p a n t d e n s i t y v a l u e T N D S 0 5 ( 1 o f 2 ) H i g h o c c u p a n t d e n s i t y , j u s t o v e r 1 2 o c c u p a n t s p e r 1 0 0 m 2 ( 1 0 0 0 f t 2 ) S y s t e m ( 2 ) l i s t s n o o c c u p a n t s

* V a l u e s i n p a r e n t h e s e s r e f e r s t o a i r h a n d l e r n u m b e r r e l a t i v e t o t o t a l n u m b e r o f a i r h a n d l e r s , e

. g

. ( 2 o f 2 )

m e a n s s e c o n d o f t w o a i r h a n d l e r s s e r v i n g t h e s t u d y s p a c e

. 

### Table 3 Sy stem design outliers * 

### (Table 7 in NISTIR 7145)

* T h e t e x t i n t h e t a b l e n o t e d w i t h a s t r i k e t h r o u g h c o r r e s p o n d s t o t w o o c c u r r e n c e s t h a t a r e n o l o n g e r

o u t l i e r s g i v e n t h e m o d i f i c a t i o n s t o t h e d a t a d e s c r i b e d e a r l i e r

.

### 97 S t u d y s p a c e o u t d o o r a i r r e q u i r e m e n t L / s ( c f m ) p e r p e r s o n M e a n 9

. 0 ( 1 9

. 1 )
S t d

. D e v

. 3

. 3 ( 6

. 9 )
M i n i m u m 4

. 8 ( 1 0

. 2 )
1 0 t h p e r c e n t i l e 6

. 5 ( 1 3

. 7 )
2 5 t h p e r c e n t i l e 7

. 2 ( 1 5

. 3 )
M e d i a n 8

. 7 ( 1 8

. 3 )
7 5 t h p e r c e n t i l e 1 0

. 0 ( 2 1

. 1 )
9 0 t h p e r c e n t i l e 1 2

. 1 ( 2 5

. 7 )
M a x i m u m 3 3

. 5 ( 7 1

. 0 ) 

### Table 4 Study space outdoor air requirements based on Standard 62 addendum n (Table 8 in NISTIR 7145)

Figure 1 Design supply airflow capacity versus y ear built (Figure 3 in NISTIR 7145)

### 98 Figure 2 Design occupant density versus y ear built (Figure 5 in NISTIR 7145)

Figure 3 Measured study space supply airflow vs. outdoor temperature (Figure 7 in NISTIR 7145) 0 1 2 3 4 5

0 5 10 15 20 25

-20 -10 0 10 20 30 40 0 20 40 60 80 100

CV

VAV Outdoor temperature (°F)

Outdoor temperature (°C)Supply airflow to test space (L/s•m2)Supply airflow to test space (cfm/ft2)

### 99 S u p p l y a i r f l o w / F l o o r a r e a L / s • m 2 ( c f m / f t 2 ) A l l s y s t e m s V A V C V
# o f v a l u e s 3 8 4 2 8 9 9 5
M e a n 5

. 1 2 ( 1

. 0 1 ) 4

. 5 5 ( 0

. 9 0 ) 6

. 8 6 ( 1

. 3 5 ) S t d

. D e v

. 3

. 0 2 ( 0

. 5 9 ) 2

. 6 2 ( 0

. 5 2 ) 3

. 4 6 ( 0

. 6 8 )
M i n i m u m 0

. 8 8 ( 0

. 1 7 ) 0

. 8 8 ( 0

. 1 7 ) 1

. 8 0 ( 0

. 3 5 )
1 0 t h p e r c e n t i l e 2

. 1 6 ( 0

. 4 3 ) 2

. 1 2 ( 0

. 4 2 ) 2

. 2 5 ( 0

. 4 4 )
2 5 t h p e r c e n t i l e 2

. 9 9 ( 0

. 5 9 ) 2

. 8 9 ( 0

. 5 7 ) 4

. 8 2 ( 0

. 9 5 )
M e d i a n 4

. 6 9 ( 0

. 9 2 ) 4

. 3 0 ( 0

. 8 5 ) 5

. 7 2 ( 1

. 1 3 )
7 5 t h p e r c e n t i l e 6

. 2 5 ( 1

. 2 3 ) 5

. 6 9 ( 1

. 1 2 ) 9

. 0 4 ( 1

. 7 8 )
9 0 t h p e r c e n t i l e 8

. 4 7 ( 1

. 6 7 ) 7

. 1 9 ( 1

. 4 1 ) 1 1

. 3 4 ( 2

. 2 3 )
M a x i m u m 2 1

. 1 1 ( 4

. 1 5 ) 2 1

. 1 1 ( 4

. 1 5 ) 1 6

. 2 4 ( 3

. 2 0 ) 

### Table 5 Summary of measured supply airflows (Table 13 in NISTIR 7145)

B e s t v o l u m e t r i c C a r b o n d i o x i d e # o f v a l u e s 5 0 9 5 2 0
M e a n 0

. 3 8 0

. 3 1
S t a n d a r d d e v i a t i o n 0

. 3 5 0

. 2 7
M i n i m u m 0

. 0 0 0

. 0 0
1 0 t h p e r c e n t i l e 0

. 0 4 0

. 0 3
2 5 t h p e r c e n t i l e 0

. 1 0 0

. 1 1
M e d i a n 0

. 2 2 0

. 2 3
7 5 t h p e r c e n t i l e 0

. 5 9 0

. 4 4
9 0 t h p e r c e n t i l e 1

. 0 0 0

. 7 5
M a x i m u m 1

. 5 2 1

. 2 0 

### Table 6 Summary of measured outdoor air fr action (Table 14 in NISTIR 7145)

### 100 P e r p e r s o n L / s ( c f m ) p e r p e r s o n P e r u n i t f l o o r a r e a L / s • m 2 ( c f m / f t 2 ) A i r c h a n g e s p e r h o u r , h - 1

# o f v a l u e s 3 6 7 3 6 9 3 6 9
M e a n 4 9 ( 1 0 5 ) 1

. 8 7 ( 0

. 3 7 ) 1

. 8 3
S t d

. D e v

. 5 4 ( 1 1 4 ) 2

. 0 8 ( 0

. 4 1 ) 2

. 0 7
M i n i m u m 0 ( 0 ) 0 ( 0 ) 0

. 0 0
1 0 t h p e r c e n t i l e 6 ( 1 3 ) 0

. 2 4 ( 0

. 0 5 ) 0

. 2 2
2 5 t h p e r c e n t i l e 1 3 ( 2 7 ) 0

. 5 0 ( 0

. 1 0 ) 0

. 4 7
M e d i a n 3 0 ( 6 3 ) 1

. 0 3 ( 0

. 2 0 ) 0

. 9 8
7 5 t h p e r c e n t i l e 6 6 ( 1 4 0 ) 2

. 3 0 ( 0

. 4 5 ) 2

. 4 6
9 0 t h p e r c e n t i l e 1 1 6 ( 2 4 5 ) 4

. 6 4 ( 0

. 9 1 ) 4

. 4 6
M a x i m u m 3 1 0 ( 6 5 7 ) 1 2

. 3 1 ( 2

. 4 2 ) 1 3

. 2 3



### Table 7 Summary of Measured Outdoor Air Ventilation

–Volumetric (Table 15 in NISTIR 7145 )

O u t d o o r a i r p e r p e r s o n , L / s ( c f m ) # o f v a l u e s 3 5 6 M e a n 4 4 ( 9 4 ) S t d

. D e v

. 4 7 ( 1 0 1 ) M i n i m u m 0 ( 0 ) 1 0 t h p e r c e n t i l e 5 ( 1 1 ) 2 5 t h p e r c e n t i l e 1 2 ( 2 6 ) M e d i a n 3 1 ( 6 5 ) 7 5 t h p e r c e n t i l e 5 9 ( 1 2 5 ) 9 0 t h p e r c e n t i l e 9 6 ( 2 0 3 ) M a x i m u m 3 3 9 ( 7 1 7 ) 

### Table 8 Summary of Measured Outdoor Air Ventilation

–CO 2 

### Ratio (Table 16 in NISTIR 7145)

### 101 Figure 4 Outdoor air ventilation, CO 2 

### - ratio vs. volumetric (Figure 14 in NISTIR 7145)

A d j u s t e d t o 1 5 % o u t d o o r a i r M e a s u r e d ( T a b l e 1 5 * ) A d j u s t e d t o #

o f w o r k s t a t i o n s # o f w o r k s t a t i o n s S t a n d a r d 6 2 d e f a u l t

o c c u p a n t d e n s i t y * *
L / s ( c f m ) p e r p e r s o n M e a n 4 9 ( 1 0 5 ) 3 6 ( 7 6 ) 1 2 ( 2 6 ) 8 ( 1 8 )
S t d

. D e v

. 5 4 ( 1 1 4 ) 3 7 ( 7 9 ) 8 ( 1 7 ) 6 ( 1 3 )
M i n i m u m 0 ( 0 ) 0 ( 0 ) 0 ( 0 ) 0 ( 0 )
1 0 t h p e r c e n t i l e 6 ( 1 3 ) 5 ( 1 0 ) 4 ( 9 ) 3 ( 5 )
2 5 t h p e r c e n t i l e 1 3 ( 2 7 ) 1 0 ( 2 2 ) 7 ( 1 4 ) 5 ( 1 0 )
M e d i a n 3 0 ( 6 3 ) 2 1 ( 4 5 ) 1 1 ( 2 3 ) 7 ( 1 5 )
7 5 t h p e r c e n t i l e 6 6 ( 1 4 0 ) 5 2 ( 1 1 0 ) 1 6 ( 3 4 ) 1 1 ( 2 3 )
9 0 t h p e r c e n t i l e 1 1 6 ( 2 4 5 ) 8 7 ( 1 8 4 ) 2 1 ( 4 4 ) 1 6 ( 3 4 )
M a x i m u m 3 1 0 ( 6 5 7 ) 2 1 0 ( 4 4 4 ) 4 7 ( 1 0 0 ) 4 2 ( 8 9 )

* R e f e r s t o T a b l e 1 5 i n t h e o r i g i n a l r e p o r t

. * * A d j u s t m e n t b a s e d o n d e f a u l t o c c u p a n t d e n s i t y i n S t a n d a r d 6 2

. 1 2 0 0 1 ( s a m e a s 1 9 8 9 ) a n d n o t i n 2 0 0 4

a n d 2 0 0 7 v e r s i o n s

. 

### Table 9 Outdoor air ventilation adjusted for occupancy and outdoor air fraction (Table 17 in NISTIR 7145)

### 102 O u t d o o r a i r v e n t i l a t i o n , L / s ( c f m ) p e r p e r s o n

A l l p e a k C O 2 d a t a P e a k C O 2 d a t a o n

“ t e s t d a y s ” V o l u m e t r i c r e s u l t s f r o m T a b l e 1 5 *
# o f v a l u e s 5 4 8 3 5 3 3 6 7
M e a n 2 0 ( 4 3 ) 2 1 ( 4 5 ) 4 9 ( 1 0 5 )
S t d

. D e v

. 1 4 ( 3 1 ) 1 7 ( 3 5 ) 5 4 ( 1 1 4 )
M i n i m u m 6 ( 1 3 ) 6 ( 1 3 ) 0 ( 0 )
1 0 t h p e r c e n t i l e 1 0 ( 2 0 ) 1 0 ( 2 1 ) 6 ( 1 3 )
2 5 t h p e r c e n t i l e 1 2 ( 2 6 ) 1 3 ( 2 7 ) 1 3 ( 2 7 )
M e d i a n 1 8 ( 3 7 ) 1 8 ( 3 8 ) 3 0 ( 6 3 )
7 5 t h p e r c e n t i l e 2 4 ( 5 0 ) 2 5 ( 5 3 ) 6 6 ( 1 4 0 )
9 0 t h p e r c e n t i l e 3 2 ( 6 8 ) 3 3 ( 7 1 ) 1 1 6 ( 2 4 5 )
M a x i m u m 2 1 3 ( 4 5 2 ) 2 1 3 ( 4 5 2 ) 3 1 0 ( 6 5 7 )

* R e f e r s t o T a b l e 1 5 i n t h e o r i g i n a l r e p o r t

. 

### Table 10 Summary of Measured Outdoor Air Ventilation

–Peak CO 2 

### (Table 18 in NISTIR 7145)

Figure 5 Outdoor air ventilation, CO 2 

### peak vs. volumetric (Figure 15 i n NISTIR 7145)

### 103 In reviewing the data, the issue of low values of traverse measurements of airflow was examined but no changes were made to the dataset as a result. For the airflow traverses, the concern is the
accuracy of the anemometer or pitot tube meas urements at lower air speeds. W hile a small number of traverse measurements of airflow are in the range of 50 L/s (100 cfm), it is actually the air speed measured in the duct that is most relevant to its accuracy . For the supply duct traverses, the mean me asured air speed is 5.3 m/s (1000 ft/min), which is within the range at which such measurements are expected to be accurate. A small number of the air speeds are low enough to be of potential concern, but less than 1 % are below 0.3 m/s (60 ft/min). The me an air speed for the outdoor air intake traverses is 3.1 m/s (600 ft/min), again in a reliable range, with only about 3 % below about 0.3 m/s (60 ft/min). No modifications were made to the dataset to eliminate the low readings, but given the small number o f such values, their removal would not have a major effect on the overall conclusions of the study

.

OUTDOOR AIRFLOW: COMPARISON OF PEAK INDOOR CO 2 

### - BASED AND DUCT TRAV ERSE

- BASED V ALUES A key finding of the original study , and a primary motivation for this reanaly sis, is the consistent difference between the outdoor airflow rates based on the duct traverse measurements and the estimates based on peak CO 2 

### concentrations in the study spaces. The latter estimates were based on indoor CO 2 

### concentrations measure d continuously during several day s of the study period using 3 to 4 fixed monitors distributed randomly in the study space. The concentrations were then averaged and peak values of those averages were determined for each morning and afternoon. This approac h to ventilation rate estimation has been used for a number of y ears though often without a complete understanding of the assumptions inherent in the method [ 3 ]

. The peak indoor CO 2 

### method for estimating outdoor air ventilation rates is essentially a single

zone, constant injection tracer gas technique. Therefore, it is based on the assumption that the indoor CO 2 

### concentration is uniform throughout the study space and that the test space is isolated from the rest of the building or that the rest of the building is at the same CO 2 

### concentration as the study space. In addition, the approach as ty pically applied assumes that the in door CO 2 

### concentration is at steady

- state and that the following quantities are constant: outdoor concentration, ventilation airflow rate, and building occupancy . The validity of these assumptions was not assessed as part of the BASE study and most of them cannot be assessed based on the available data.

As seen in Figure 5 above (corrected Figure 15 from the original report), for volumetric (traverse

- based) outdoor airflow rates above about 20 L/s• person (40 cfm/person), the values based on peak CO 2 

### concen trations are consistently lower than the volumetric values. This issue was discussed in the original report as follows:

“The reason that the peak CO 2 

### values tend to be lower than expected has been investigated, but no explanation has y et been verified. Co nsidering the methodology behind the peak CO 2 

### analy sis, one might suspect the lack of steady

- state CO 2 

### concentrations could be impacting the agreement between the two values. However, steady state is more likely to occur at the higher ventilation rates due to the shorter sy stem time constants, resulting in better agreement at higher rates, which is contrary to what is seen in Figure 15. Another potential explanation is the existence of significant CO 2 

### concentration gradients within the study spaces, as well as between them and adjoining spaces, given that the single

- zone analy sis method assumes a uniform concentration within the zone and neglects interzone transfer of CO 2 

### . W hile it is

### 104 certainly possible that the CO 2 

### concentrations were different in adjoining zones, one would expect the impact to be positive in some cases and negative in others. However, the differences in the data tend to all be in one direction. The level of agreement was examined in those study spaces that corresponded to an entire building , for which concentration differences in adjoining spaces are not an issue, and the peak CO 2 

### and volumetric ventilation rates were not observed to agree any better. Note that the fixed CO 2 

### monitors in the study spaces were placed at a height of 1.1 m (43 i n.) above the floor and at locations representative of workstation lay out and work activities, i.e., locations in hallway s and
passageway s were intentionally avoided (EPA 2003) 1 

### . Given these guidelines on location, it is possible that the measured CO 2 

### conc entrations are higher than the study

- space average. If the measured CO 2 

### concentration is indeed higher than the true space average, then the calculated ventilation rates would be low relative to their actual value. Also, it is reasonable to expect that the lack of uniformity would be more pronounced at higher outdoor air ventilation with less recirculation of return air, leading to the observed increase in errors. However, it is not possible to verify the magnitude of the concentration nonuniformity in thes e spaces based on the available data, and therefore it cannot be confirmed whether this is necessarily a valid explanation for the observed differences. The peak CO 2 

### concentrations were examined with the issue of nonuniformity in mind, and it was determine d that the actual average concentration in the study space would have to be 360 mg/m 3 

### to 720 mg/m 3 

### (200 ppm(v) to 400 ppm(v)) lower than that measured by the fixed monitors to explain the observed differences.”

Figure 15 in the original report actually in cluded only a subset of the values, i.e., those with volumetric outdoor air ventilation rates less than 200 L/s• person (400 cfm/person). The corrected version above in Figure 5 contains all the points in the corrected dataset. The corrected dataset include s many outdoor airflow values with high uncertainties. These uncertainties were calculated using standard approaches to the propagation of error in which the estimated uncertainties in the values used to calculate the airflows were propagated through the

m athematical operations used to determine the airflow rates. Note that these uncertainty estimates do not account for biases in the measurement methods or the impact of the assumptions behind the peak CO 2 

### method not being valid. For the volumetric values, t he mean value of the ratio of the uncertainty in the outdoor airflow per person to the corresponding measured value is close to 1.1; the median ratio is about 0.3. The mean ratio of the uncertainty to the measured value for the peak indoor CO 2 

### - based values is much smaller, about 0.3, and there are values over 1.0. The relative uncertainties for the volumetric flows tend to be larger due in part to the existence of a small number of measurement events with very low outdoor airflow rates but very high uncerta inties. These high uncertainty cases occur when the outdoor airflow is determined by subtracting the recirculation airflow from the supply

. Figure 6 is a plot of the same data shown in Figure 5, but with only those values for which the ratio of the uncerta inty to the measured value is less than one. These data exhibit less scatter than that seen in Figure 5. Figure 7 restricts the data plotted even further to values for which the ratio is less than 0.5. This plot is particularly striking in the very flat di stribution of the data in which the volumetric values range from 0 L/s

- person to about 250 L/s

- person (500 cfm/person) while the peak indoor CO 2 

### - based values cover a much more narrow range from about 7 L/s

- person (15 cfm/person) to 35 L/s• person (74 cfm/pe rson). The ratio of the standard deviation to the

1 

### This is reference number 4 in the list of refer ences for this report.

### 105 mean for the values in Figure 7 is 1.0 for the volumetric rates but only 0.4 for the peak CO 2 

### values. The lack of variability in the peak CO 2 

### values relative to the volumetric rates is notable and is discus sed further below.

Figure 6 Updated

- Outdoor air ventilation, CO 2 

### peak vs. volumetric (relative uncertainty < 1)

### 106 Figure 7 Updated

- Outdoor air ventilation, CO 2 

### peak vs. volumetric (rel. uncertainty < 0.5)

Nonuniform CO 2 

### concentrations As noted in th e original report, one potential explanation for the discrepancy between the traverse and peak CO 2 

### rates is nonuniformity in the CO 2 

### concentrations in the space. Specifically , the fact that the CO 2 

### concentrations were sampled “at a height of 1.1 m (43 in.) above the floor and at locations representative of workstation lay out and work activities” raises the question of whether the readings were impacted by the occupants’ local exhalations. In addition, the BASE protocol requires that these monitoring locatio ns be selected among 5 m by 5 m grids of which more than 50 % of the area is occupied full time [4] . CO 2 

### concentrations in the exhaled breath from people are in the range of 72 000 mg/m 3 

### (40 000 ppm(v)) [ 3 ] , which is well above the concentrations measured in the study spaces. Therefore the proximity of occupants to the indoor monitoring locations does lead to the potential for the measured concentrations being elevated relative to the space average.

The issue of nonuniform concentration was evaluated in two way s, by comparing the space concentrations to those measured in the air handler returns and by examining the uniformity

a mong the various sample locations in each study space.
As part of the ventilation evaluations, CO 2 

### concentrations were measured on four occasions during the test week (ty pically on W ednesday and Thursday of the study week in the morning and afternoon) in the air handler return, supply , and outdoor airstreams to calculate the outdoor air intake fraction based on a mass balance of CO 2 

### in the air handler. These discrete measurements of CO 2 

### in the return were compared with the average of the concentrations in the study space taken at the same time, which is generally not the same time as peak in the study

### 107 space concentration. Note that the return airstreams sometimes contained air drawn from other spaces in addition to the study space, therefore the comparisons were only made for study spaces served by a dedicated air handler, i.e., an air handler that doesn’t serve any other spaces. Figure 8 is a plot of the space concentration versus the corresponding concentration in the air handler return (open squares) as w ell as the difference between the space and return concentrations again plotted against the return concentration (open circles). The space concentrations do tend to exceed the return concentrations, though there are a small number of cases for which the sp ace concentration is lower. The average difference for the 183 cases where both values exist equals 108 mg/m 3 

### (60 ppm(v)). The differences tend be higher for lower return concentrations, which correspond to higher ventilation rates. These higher ventilatio n rates are associated with higher outdoor air intake fractions, which result in less mixing of the indoor air and are consistent with the greater differences between space and return concentrations.

Figure 8 Space and space

- minus

- return CO 2 

### concentratio ns vs. return concentration

The return versus space concentration differences were also examined for study spaces that correspond to an entire building. One might expect the concentration differences to be more clearly defined in such situations because t here is no interzone airflow and CO 2 

### transport to confound the return

- versus

- space relationship. However, those study spaces revealed no significant differences relative to other spaces.

Some of the buildings tested later in the BASE project were also sub ject to continuous measurements of CO 2 

### in the air handler returns. Several of these datasets were examined for
sy stematic differences between the study space and air handler return peak CO 2 

### concentrations.

### 108 The results were largely consistent with those see n between the space and spot measurements in the return.

W hile the observed differences between the return and space concentrations indicate that the space concentrations may be elevated due to the presence of occupants, the magnitude of the impact is not sufficient to explain the observed differences between the volumetric and peak CO 2 

### based ventilation rates. Figure 9 is a plot of the peak CO 2 

### rates adjusted using the average space

return difference of 108 mg/m 3 

### (60 ppm(v)), i.e., with the peak space con centration reduced by that average difference. In this figure, the adjusted rates are superimposed on the unadjusted data from Figure 6.

F i g u r e 9 C O 2 p e a k v s

. v o l u m e t r i c v e n t i l a t i o n r a t e a d j u s t e d f o r s p a c e

- r e t u r n c o n c e n t r a t i o n


### The second approach used to examine the issue of nonuniform CO 2 

### concentrations in the study spaces was to consider the concentration variations within the space. As noted earlier, the CO 2 

### concentrations were measured at multiple locations in each study space, and the concentrations among these locations varied. In an attempt to examine the impact of those nonuniformities, the ventilation rates were recalculated using the CO 2 

### sampling location that y ielded the lowest peak value. Figure 10 is a plot of the measured CO 2 

### concentrations f or study space MIBW 03, including the outdoor and three indoor locations. The difference between the indoor locations is evident in this plot. Note that ASTM D6245 [ 3 ] requires that CO 2 

### concentrations within the study space not vary from the space average by more than 10 % when estimating ventilation rates based on peak CO 2 

### concentrations. This requirement is not met for this st udy space and for
many of the other BASE study spaces.

### 109 Figure 10 Variation in CO 2 

### concentrations among indoor locations (study space MIBW 03)

For each study space, the indoor location with the lowest peak CO 2 

### value was used to estimate the outdoor air ventilation values. Figure 11 is a plot of the outdoor airflows estimated using the monitoring location with the minimum peak CO 2 

### value against the volumetric rates, with the airflows based on the peak average CO 2 

### concentration from Figure 6 included as we ll. Using the minimum peak CO 2 

### concentrations does increase the outdoor airflow values, but not enough to result in good agreement with the volumetric values. The improvement is more pronounced than that seen for the adjustment based on the average return

- space concentration difference seen in Figure 9.

### 110 Figure 11 CO 2 

### peak vs. volumetric ventilation rate, using monitoring location with minimum peak concentration

W hile using the return concentrations and the minimum peak CO 2 

### concentrations instead of the study space concentrations is not sufficient to explain the difference between the peak CO 2 

### and the volumetric values, these two explanations are consistent with the existence of nonuniform concentrations in the study spaces.

If CO 2 

### concentration variati ons between the study space and the rest of the building is an issue, then study spaces that are a whole building or are served by dedicated air handlers might be expected to exhibit better agreement between the peak indoor CO 2 

### - based and volumetric airflow values. The level of agreement between the two airflow rates was examined for test spaces corresponding to a whole building (only 6 cases) or which were served by dedicated air handlers (43 cases), but no obvious difference in the agreement was evident. N ote that within

- space nonuniformity may have been an issue in these spaces as well.

Association of peak

- volumetric difference with various factors In investigating the differences between the peak indoor CO 2 

### - based estimates and volumetric measurements of the outdoor airflows in the BASE buildings, a number of parameters were considered to see if they were associated with the magnitudes of the differences and therefore might offer some explanation.

Given the hy pothesis that nonuniform indoor CO 2 

### concentra tions might be important, the standard deviation of the peak concentrations for the various indoor locations was computed for

### 111 each study space. This standard deviation was then divided by the mean peak to determine the coefficient of variation (COV). Figur e 12 is a plot of the relative difference between the volumetric and peak indoor CO 2 

### - based airflows (volumetric minus peak indoor CO 2 

### - based, divided by peak value) against the COV. The data in this figure do not show a strong dependence of the flow discrep ancy on the COV.

Figure 12 Relative difference between airflows vs. coefficient of variation

Given that the indoor concentrations are expected to be more uniform with more mixing, i.e., lower outdoor air fractions (%OA), the differences between the pea k indoor CO 2 

### - based and volumetric airflows were also examined relative to %OA for the study space. The results are plotted in Figure 13. The volumetric airflows are below the peak indoor CO 2 

### - based values at the lowest values of %OA and become increasingly larger than the peak values as the %OA increases. Note that the low %OA values are consistent with more air mixing in the building, while higher values correspond to less. The trend seen here does support poor mixing as a potential explanation of the obser ved discrepancy

.

### 112 Figure 13 Relative difference between airflows vs. study space outdoor air fraction

However, low %OA values also correspond to low outdoor airflow rates, and as seen in Figures 5 through 7, the discrepancy is largest as the volumetric outdoor airflow rate increases. Therefore the trend in Figure 13 may be simply a manifestation of the dependency already noted.

The discrepancy between the volumetric and peak indoor CO 2 

### - based airflow values were also examined for any dependence on a num ber of other factors, including the measured occupant density in the study space (number of people per unit floor area) and the estimated uncertainty of the peak indoor CO 2 

### - based airflow rate, but no dependence was observed.

Accuracy of volumetric airflow s W hile questions have been raised above regarding the precision and bias of the peak indoor CO 2 

### - based airflow rates, it is also reasonable to consider the accuracy of the traverse measurements. Industry guidance generally cites a measurement uncertainty o f about 10 % for duct traverses under good field conditions [5

- 7 ] , but the basis for this estimate is not well defined. The key question in the current study is whether there is a reason to suspect that the traverse measurements are biased high, particularly for the higher values of outdoor airflow per person. These higher values are associated with higher duct velocities. In general, traverse errors are more of a concern for low velocities, and therefore there is no particular reason to suspect the higher airflow rates to be inaccurate. W hile duct leakage would cause the delivered outdoor airflow to the space to be lower than that measured at the air handler, the amount of leakag e required to account for the observed differences would have to be extremely high, as much as 90 % of the supply air leaking out of the ductwork. This is much larger than the commercial

### 113 building duct leakage values that have been measured in the field to date, which are more in the 10 % to 20 % range [8]

. One indication of the reliability of the duct traverse measurements is the comparison of the outdoor air fraction determined from the measured supply and outdoor airflow rates with the outdoor air fracti on estimated from the CO 2 

### concentrations in the return, outdoor, and supply airstreams. As discussed in the original report, these two independent measurements of the outdoor air fraction are on average consistent. These data are replotted in Figure 14, an d while there is some scatter in the data, no strong bias is evident.

Figure 14 Outdoor air fraction based on CO 2 

### ratio vs. based on volumetric flows

A similar comparison can be made by comparing the outdoor airflow intake of the air handlers calculated from the supply traverse value times the outdoor air fraction determined from the airstream CO 2 

### concentrations with the outdoor airflow measured by the traverse measurements. These data are plotted in Figure 15, and while there is significant scatter in th e plot the two methods of determining this quantity are on average consistent. The mean value of the former (Q s u p p l y 

### x %OA) is about 4800 L/s (10 200 cfm), while the mean of the latter is about 5600 L/s (11 900 cfm). Therefore, the traverse measurements of outdoor airflow are somewhat higher on average, but not enough to account for the differences noted related to the peak indoor CO 2 

### - based airflows.

### 114 Figure 15 Outdoor airflow from CO 2 

### ratio times supply airflow vs. volumetric outdoor airflow

Another ch eck on the internal consistency of traverses was performed by calculating the ratio of the measured supply airflow to the sum of the outdoor and recirculation airflows. Only twelve events exist in which all three airflows were measured by duct traverses. F our of them are in one building where the supply and recirculation airflows are very close to each other, i.e., the outdoor air intake rate is quite low. The mean value of this ratio for all twelve events is 1.3; without the first building the mean is 1.1. This comparison does not prove that the traverse measurements are accurate but it does demonstrate their internal consistency . However, if a large and consistent
sy stematic error existed, it might have been evident in these ratios.

Another confirmation of the validity of the traverses is the comparison of the supply airflow traverse measurements with the design values. W hile there is much variation expected in this comparison, the mean measured supply airflow rate is 5.12 L/s• m 2 

### (1.01 cfm/ft 2 

### ), while the mean of the corresponding design value is 4.98 L/s• m 2 

### (0.98 cfm/ft 2 

### ). This comparison does not prove that the traverse values are accurate, but if there were a large sy stematic error, it should be evident in comparing the mean measured to the mean design value.

Limited range of peak CO 2 

### ventilation rates As noted earlier, the ventilation rates based on the indoor peak CO 2 

### concentrations do not exhibit the range of rates seen for the volumetric rates. Considering the data in Figure 7, the peak CO 2 

### ventilat ion rates never exceed about 35 L/s (74 cfm) per person, which corresponds to an indoor

outdoor concentration difference of about 270 mg/m 3 

### (150 ppm(v)). In other words, the peak indoor CO 2 

### concentrations are seldom less than 270 mg/m 3 

### (150 ppm(v)) above t he outdoors.

### 115 This lower limit on the peak values is a very curious result, for which no explanation has been identified.

Conclusion on Peak CO 2 

### versus Traverse Issue The final comparison worth noting is a “reality

- check” on the air change rates calculated from the traverse measurements and from the peak CO 2 

### estimates. The mean test space outdoor air change rate based on traverse measurements is 1.83 h - 1 

### , or 1.87 L/s• m 2 

### (0.37 cfm/ft 2 

### ). Dividing this value by the mean outdoor air fraction of 0.31 (based on C O 2 

### concentrations in the supply

, return, and outdoor airstreams) y ields 5.9 h - 1 

### or 6.03 L/s• m 2 

### (1.19 cfm/ft 2 

### ), which is a very reasonable value for the supply airflow rate in an office building. The mean outdoor air change rate based on peak indoor CO 2 

### lev els equals 0.83 h - 1 

### , or 0.85 L/s• m 2 

### (0.17 cfm/ft 2 

### ), which when divided by the average outdoor air fraction is 2.7 h - 1 

### or 2.74 L/s• m 2 

### (0.55 cfm/ft 2 

### ). These supply airflow rates based on the peak CO 2 

### values are well below, about half of, ty pical supply airfl ow rates for an office building.

In conclusion, the discrepancy between the peak indoor CO 2 

### - based and traverse

- based outdoor airflow rates has not been fully explained. However, there is good reason to suspect that the peak indoor CO 2 

### - based values may not provide reliable estimates of the BASE study space outdoor air ventilation rates. In particular, the measured test space CO 2 

### concentrations may be elevated relative to the actual space concentrations based on the observed differences between the space

con centrations and return concentrations, the concentration variation among the test space locations, and the fact that the study space concentration is seldom less than 270 mg/m 3 

### (150 ppm(v)) above the outdoor concentration.

CONCLUSIONS This reanaly sis of t he BASE ventilation data has uncovered a small number of corrections, none of which impact the conclusions of the study . However, the updated dataset is now more reliable and should be used instead of the original version released in 2004 [1] . The attempt to explain the difference between the outdoor air ventilation rates determined by the duct traverses and those based on the peak CO 2 

### concentrations in the study spaces revealed some potential explanations related to concentration nonuniformities but they w ere not able to fully explain the magnitude of the differences. It is unlikely that these differences will be explained through additional analy ses of the BASE data. However, future efforts to understand these differences are warranted through experimental efforts specifically designed to investigate the problem. Other potential explanations could also be studied in the future, such as those related to assumed values for the CO 2 

### generation rates by the occupants.

ACKNOWLEDGEMENTS This effort was supported by the U.S. Environmental Protection Agency under Interagency Agreement No. DW

- 13

- 93936601. The authors express their appreciation to Gregory Brunner and John Girman at EPA for their support and assistance in this work.

### 116 REFERENCES [ 1] Persily , A. and Gorfain, J. 2004. Analy sis of Ventilation Data from the U.S. Environmental Protection Agency Building Assessment Survey and Evaluation (BASE) Study , NIST 7145, National Institute of Standards and Technology

. [2] EPA. 2006. Building Asses sment Survey and Evaluation (BASE) Study Data on Indoor Air Quality in Public and Commercial Buildings, (402

- C

- 06

- 002).
[3] ASTM. 2007. D6245, Standard Guide for Using Indoor Carbon Dioxide Concentrations to Evaluate Indoor Air Quality and Ventilation.
[4] EPA. 2003. A Standardized EPA Protocol for Characterizing Indoor Air Quality in Large Office Building.
[5] ASHRAE. 1988. Standard 111

- 1988, Practices for Measurement, Testing, Adjusting, and Balancing of Building Heating, Ventilation, Air

- Conditioning, an d Refrigeration Sy stems. [6] NEBB. 1991. Procedural Standards for Testing Adjusting Balancing of Environmental Sy stems. Rockville, Mary land, National Environmental Balancing Bureau.
[7] AABC. 1989. National Standards for Testing and Balancing Heating, Vent ilating, and Air Conditioning Sy stems. W ashington, DC, Associated Air Balance Council.
[8] Fisk. W .J., Delp, W .W ., Diamond, R.C., Dickerhoff, D.J., Levinson, R., Modera, M.P., Nematollahi, M., and W ang, D. 2000. Duct Sy stems in Large Commercial Buildings: Phy sical Characterization, Air Leakage, and Heat Conduction Gains. Lawrence Berkeley National Laboratory Report No. LBNL

- 42339.