TECHNICAL SUPPORT DOCUMENT: ENERGY EFFICIENCY PROGRAM FOR

COMMERCIAL AND INDUSTRIAL EQUIPMENT: EFFICIENCY STANDARDS FOR

COMMERCIAL HEATING, AIR­CONDITIONING, AND WATER­HEATING

EQUIPMENT

Including Water­cooled and Evaporatively­cooled Air Conditioners, Water­source

Variable Refrigerant Flow Systems, Single Package Vertical Air Conditioners, and Single

Package Vertical Heat Pumps, and Air Conditioners and Condensing Units Serving

Computer Rooms

May 2, 2011

U.S. Department of Energy

Office of Energy Efficiency and Renewable Energy

Building Technologies Program

Appliances and Commercial Equipment Standards

Washington, DC 20585
                 

         

     

       

       

This Document was prepared for the Department of Energy
 

by the staff members of
 

Navigant Consulting, Inc.,
 

Lawrence Berkeley National Laboratory,
 

And
 

Pacific Northwest National Laboratory
 
   

     

           

     


 

 
 

	 
 

	 

 

	 
 


 

CHAPTER 1.INTRODUCTION
 

TABLE OF CONTENTS
 

1.1	 PURPOSE OF THE DOCUMENT ................................................................................. 1­1
 

1.2	 PROCESS FOR AMENDED ENERGY CONSERVATION STANDARDS FOR

ASHRAE EQUIPMENT ................................................................................................. 1­1

1.3	 STRUCTURE OF THIS DOCUMENT .......................................................................... 1­2
 

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1.1	 PURPOSE OF THE DOCUMENT

This technical support document (TSD) is a stand­alone report that provides the technical

analysis and results supporting the information presented in the Notice of Data Availability

(NODA) for ASHRAE Standard 90.1­2010 equipment.

1.2	 PROCESS FOR AMENDED ENERGY CONSERVATION STANDARDS FOR

ASHRAE EQUIPMENT

Title III of the Energy Policy and Conservation Act (EPCA), Pub. L. 94­163, as

amended, sets forth a variety of provisions concerning energy efficiency. Part C1 of Title III

created the energy conservation program for “Certain Industrial Equipment.” (42 U.S.C. 6311­

6317) Of particular relevance for this rulemaking is 42 U.S.C 6313(a)(6) which directs DOE, in

the event that ASHRAE Standard 90.1 is amended for certain types of commercial and industrial

equipment, to adopt that efficiency level unless clear and convincing evidence supports a

determination that adopting a more stringent level would produce significant additional energy

savings and is technologically feasible and economically justified.

On October 29, 2010, American Society of Heating, Refrigeration and Air­Conditioning

Engineers (ASHRAE) officially released the American National Standards Institute

(ANSI)/ASHRAE/Illuminating Engineering Society of North America (IESNA) Standard 90.1­

2010 (hereinafter referred to as ASHRAE Standard 90.1­2010), which addressed efficiency

levels for certain categories of commercial heating, ventilating and air­conditioning (HVAC) and

water heating equipment covered by the Energy Policy and Conservation Act (EPCA). The new

Standard 90.1 revised the efficiency levels of the existing ASHRAE Standard 90.1­2007 for

certain equipment, such as water­cooled and evaporatively­cooled air conditioning and heating

equipment and water­source variable refrigerant flow (VRF) systems with a cooling capacity less

than 17,000 Btu/h. The standard also created new energy efficiency levels for water­source VRF

systems with a cooling capacity greater than or equal to 135,000 Btu/h and for air conditioners

and condensing units serving computer rooms, which were previously uncovered by DOE’s

energy conservation standards..

The Energy Independence and Security Act of 2007 (EISA 2007) further amended EPCA

by setting definitions and minimum energy conservation standards for single package vertical air

conditioners (SPVACs) and single package vertical heat pumps (SPVHPs). EISA 2007 also

amended EPCA to include a provision specifically for these equipment classes (and no others),

which required DOE to review the most recently published ASHRAE Standard 90.1 in

1 This Part was subsequently redesignated as Part A­1 for editorial reasons after Part C of Title III of EPCA was

repealed by Pub. L. 109­58.

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accordance with the procedures established for ASHRAE products under paragraph 42 U.S.C.

63131(a)(6). (42 U.S.C. 6313(a)(10)(B))

The NODA that this TSD accompanies is the first step in fulfilling DOE’s obligations as

set forth by the language in EPCA and its amendments. The NODA identifies the equipment for

which the current ASHRAE Standard 90.1 amended its efficiency levels and presents the

analysis of the potential energy savings at those levels as well as more stringent levels. In

addition, the NODA presents the analysis of the potential energy savings from adopting more

stringent energy conservation standards for SPVACs and SPVHPs as required by 42 U.S.C.

6313(a)(10)(B). This TSD provides a detailed description of the analyses performed in support of

the NODA.

1.3 STRUCTURE OF THIS DOCUMENT

This NODA TSD outlines the analytical approaches used in this rulemaking. The TSD

consists of 4 chapters:

Chapter 1	 Introduction: Provides an overview of process to amend energy

conservation standards for ASHRAE equipment and outlines the structure

of the document.

Chapter 2	 Market Assessment: Characterizes the market for water­cooled and

evaporatively­cooled air conditioners, water­source variable refrigerant

flow systems, single package vertical air conditioners and heat pumps, and

air conditioners and condensing units serving computer rooms.

Chapter 3	 Energy Use Characterization: Discusses the process used for generating

energy use estimates for water­cooled and evaporatively­cooled air

conditioners, single package vertical air conditioners, and single package

vertical heat pumps at the current standard levels and at potential amended

standard levels.

Chapter 4	 National Energy Savings Analysis: Discusses the methodology and inputs

for estimating the potential energy savings of various potential amended

standard levels.

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CHAPTER 2.MARKET ASSESSMENT

TABLE OF CONTENTS

2.1 BACKGROUND ............................................................................................................. 2­1 


2.1.1 Water­cooled and Evaporatively­cooled Air Conditioners.................................. 2­1 


2.1.2 Single Package Vertical Air Conditioners and Heat Pumps................................ 2­2 


2.1.3 Variable Refrigerant Flow Commercial Package Air Conditioning and Heating 

Equipment............................................................................................................ 2­3 

2.1.4 Air Conditioners and Condensing Units Serving Computer Rooms ................... 2­4 


2.1.5 Federal Energy Conservation Standards.............................................................. 2­5 


2.1.6 ASHRAE Standard 90.1­2010 Efficiency Levels................................................ 2­8 


2.2 MARKET ASSESSMENT ............................................................................................ 2­11 


2.2.1 Trade Associations............................................................................................. 2­11 


2.2.2 Manufacturers .................................................................................................... 2­12 


2.2.3 Market Performance Data.................................................................................. 2­13 


LIST OF TABLES

Table 2.1.1 Current Federal Energy Conservation Standards for Commercial Package Air 

Conditioning and Heating Equipment Classes with Increased Standard Levels in 

ASHRAE Standard 90.1­2010............................................................................. 2­7 

Table 2.1.2 Federal Energy Conservation Standards for Single Package Vertical Air Conditioners 

.............................................................................................................................. 2­7 

Table 2.1.3 Equipment Classes With Updated Efficiency Levels in ASHRAE Standard 90.1­

2010...................................................................................................................... 2­8 


Table 2.2.1 Manufacturers of the Commercial Equipment Included in this Rulemaking ......... 2­12 


Table 2.2.2 CEC Computer Room Air Conditioners Minimum Efficiency Levels................... 2­20 


LIST OF FIGURES

Figure 2.2.1 EER Histogram of Small Water­cooled Air Conditioners .................................... 2­15 


Figure 2.2.2 EER Histogram of Large Water­cooled Air Conditioners .................................... 2­15 


Figure 2.2.3 EER Histogram of Very Large Water­cooled Air Conditioners ........................... 2­16 


Figure 2.2.4 EER Histogram of SPVACs <65,000 Btu/h.......................................................... 2­18 


Figure 2.2.5 EER Histogram of SPVHPs .................................................................................. 2­18 


Figure 2.2.6 COP Histogram of SPVHPs .................................................................................. 2­19 


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2.1 BACKGROUND

The American Society of Heating, Refrigeration, and Air­Conditioning Engineers 

(ASHRAE) released an updated version of the American National Standards Institute 

(ANSI)/ASHRAE/Illuminating Engineering Society of North America (IESNA) Standard 90.1 

(hereinafter referred to as ASHRAE Standard 90.1­2010) on October 29, 2010. ASHRAE 

Standard 90.1­2010 included increased efficiency levels for water­cooled and evaporativelycooled commercial package air conditioners (triggering DOE review of the minimum standards 

for these equipment classes), and created a new set of equipment classes for variable refrigerant 

flow (VRF) products and for air conditioners and condensing units serving computer rooms. 

ASHRAE Standard 90.1­2010 also updated the standards for certain classes of water­source 

VRF commercial package air conditioning and heating equipment in comparison to the existing 

Federal standards that would apply, thereby triggering DOE review of the standards for those 

equipment classes. 

In addition, DOE is required by EPCA to review the most recently published ASHRAE 

Standard 90.1 with respect to single package vertical air conditioners and single package vertical 

heat pumps in accordance with the procedures for ASHRAE equipment established under 

paragraph 42 U.S.C. 6313(a)(6). (42 U.S.C. 6313(a)(10)(B)) Therefore, although ASHRAE 

Standard 90.1­2010 did not increase the efficiency levels for single package vertical air 

conditioners and heat pumps, DOE is reviewing the minimum standards for these equipment 

classes under the requirements of 42 U.S.C. 6313(a)(10)(B). 

2.1.1 Water­cooled and Evaporatively­cooled Air Conditioners

Water­cooled and evaporatively­cooled air conditioners are part of a subset of 

commercial package air conditioning and heating equipment. EPCA defines a “commercial 

package air conditioning and heating equipment” as an “air­cooled, water­cooled, evaporativelycooled, or water­source (not including ground water­source) electrically operated, unitary central 

air conditioners and central air conditioning heat pumps for commercial application.” (42 U.S.C. 

6311(8)(A)) 

Air conditioners use a refrigeration cycle to cool an indoor space by moving heat from 

the cold location to a hotter location by means of evaporating and condensing a fluid, typically a 

refrigerant. An air conditioner typically has four major components: a compressor, condensing 

coil, expansion valve, and an evaporator coil. The compressor turns the refrigerant from a low 

pressure gas into a high pressure gas, which raises the temperature of the gas. At the next step, 

the condensing coil convects the heat from the hot refrigerant, which condenses into a liquid, still 

at a high temperature and high pressure. This liquid refrigerant then goes through an expansion 

valve that lowers its pressure and temperature before entering the evaporator coil. The evaporator 

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coil cools the indoor air by transferring heat from the indoor air to the low temperature 

refrigerant. 

Commercial­size water­cooled and evaporatively­cooled air conditioners cool 

commercial facilities and utilize water instead of ambient air (as is used in air­cooled equipment) 

to cool the condensing coil. In the case of a water­cooled air conditioner, the condensing coil is 

submerged in circulating water; whereas in the case of evaporatively­cooled air conditioner, the 

condensing coil is sprayed with water that evaporates as air passes over the coil. Both systems 

utilize the high heat capacity of water to optimize the heat transfer from the refrigerant in the 

condensing coil. Water­cooled air conditioners can be used effectively in any type of 

environment, while evaporatively­cooled air conditioners are most effective in hot­dry climate 

regions (i.e., the southwestern United States). 

Although EPCA initially set the same standard levels for water­cooled and evaporativelycooled air conditioners, ASHRAE Standard 90.1­2010 specifies different standard levels for 

each. EPCA and ASHRAE Standard 90.1 both further divide this equipment into four categories 

based on cooling capacity ranges: <65,000 Btu/h, ≥65,000 and <135,000 Btu/h, ≥135,000 and 

<240,000 Btu/h, and ≥240,000 and < 760,000 Btu/h.a EPCA identifies equipment with cooling 

capacities of <135,000 Btu/h, ≥135,000 and <240,000 Btu/h, ≥240,000 and <760,000 Btu/h as 

“small,” “large,” and “very large,” respectively. (42 U.S.C. 6311(8)(B)­(D)) EPCA and 

ASHRAE Standard 90.1 also divide these products further based on whether they have electric 

resistance or no heating or any other kind of heating. 

2.1.2 Single Package Vertical Air Conditioners and Heat Pumps

Single package vertical air conditioners and heat pumps are also a subset of commercial 

package air conditioning and heating equipment as defined by EPCA. EPCA further defines 

single package vertical air conditioners as “air­cooled commercial package air conditioning and 

heating equipment that­­­

(1) Is factory­assembled as a single package that— 

(i) Has major components that are arranged vertically; 

(ii) Is an encased combination of cooling and optional heating components; and 

(iii) Is intended for exterior mounting on, adjacent interior to, or through an 

outside wall; 

(2) Is powered by a single­or 3­phase current; 

(3) May contain 1 or more separate indoor grilles, outdoor louvers, various ventilation 

options, indoor free air discharges, ductwork, well plenum, or sleeves; and 

a ASHRAE Standard 90.1 does not specify an upper limit on the cooling capacity for the largest capacity equipment 

class (i.e., ≥240,000 Btu/h). However, EPCA limits the size of very large commercial package air conditioning and 

heating equipment to cooling capacities below 760,000 Btu/h. 

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(4) Has heating components that may include electrical resistance, steam, hot water, or 

gas, but may not include reverse cycle refrigeration as a heating means.” (42 U.S.C. 

6311(23)) 

EPCA also defines single package vertical heat pump as “a single package vertical air 

conditioner that (1) uses reverse cycle refrigeration as its primary heat source; and (2) may 

include secondary supplemental heating by means of electrical resistance, steam, hot water, or 

gas.” (42 U.S.C. 6311(24)) ASHRAE Standard 90.1­2010 also defines both of these terms in the 

same way. 

Single Package Vertical Air Conditioners (SPVACs) and Single Package Vertical Heat 

Pumps (SPVHPs) are mainly used for cooling and heating classrooms, modular buildings, 

telecommunication shelters, and portable buildings. Although this equipment is typically sized in 

cooling capacities similar to products used in residential applications, they are subject to 

different operational cycles and operating hours than are typically encountered in residential 

applications. The types of buildings in which SPVACs and SPVHPs are installed all have high 

internal loads stemming from a high number of occupants and heat sources when the building is 

in use. Also, since these buildings are usually high density buildings, floor space is at a premium; 

thus, having the components for these units arranged in a vertical fashion allows them to be 

placed in closets or mounted through the wall in order to minimize the amount of floor space 

occupied by the equipment. 

EPCA and ASHRAE Standard 90.1 both divide SPVACs and SPVHPs into 3 size 

categories based on cooling capacity: <65,000 Btu/h, ≥65,000 Btu/h and < 135,000 Btu/h, and 

≥135,000 and <240,000 Btu/h. 

2.1.3	 Variable Refrigerant Flow Commercial Package Air Conditioning and Heating

Equipment

Variable refrigerant flow systems are a subset of commercial package air conditioning 

and heating equipment that is newly defined in ASHRAE 90.1­2010. Neither EPCA nor DOE’s 

regulations in the Code of Federal Regulations define variable refrigerant flow systems. 

ASHRAE Standard 90.1­2010 defines a variable refrigerant flow system as “an engineered direct 

expansion (DX) multi­split system incorporating at least one variable capacity compressor 

distributing refrigerant through a piping network to multiple indoor fan coil units each capable of 

individual zone temperature control, through integral zone temperature control devices and 

common communications network. Variable refrigerant flow utilizes three or more steps of 

control, on common, interconnecting piping.” 

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VRF systems are most commonly used in hotels, schools, and office buildings where 

different zones have different heating and cooling load requirements depending on occupancy 

and time of day. VRF systems have one outdoor condensing unit that is connected to multiple 

indoor evaporator coils, as opposed to the single evaporator coil typically found in conventional 

air conditioners and heat pumps. Each evaporator coil in a VRF system can be individually 

controlled, and VRF systems are capable of monitoring and adjusting the refrigerant flow to each 

evaporator to meet the requirements of heating and cooling loads in specific zones. Some VRF 

heat pumps have a heat recovery option, which allows the system to move heat within a building 

via a third refrigerant line that connects indoor evaporator coils. The heat recovery feature allows 

a zone requiring heat to be warmed using the heat extracted from a zone requiring cooling, and 

vice versa. However, if all zones need to be heated at the same time, then the heat would need to 

be provided by other means. 

Water­source VRF systems utilize a condensing unit that transfers heat to or from 

circulating water depending on whether the system is in cooling or heating mode. These systems 

allow the condensing unit of the system to be placed indoors, such as in a mechanical closet or a 

basement. Having the condensing unit indoors decreases the amount of refrigerant piping to the 

individual evaporator coils, which is especially useful for equipment installed in high rise office 

buildings. 

ASHRAE 90.1­2010 divides air­cooled VRF systems into 4 size categories: <65,000 

Btu/h, ≥65,000 and <135,000 Btu/h, ≥135,000 and <240,000 Btu/h, and ≥240,000 and < 760,000 

Btu/h.b ASHRAE 90.1­2010 also divides water­source VRF systems into 3 size categories, 

<65,000 Btu/h, ≥65,000 and <135,000 Btu/h, and ≥135,000. For both air­cooled and watersource VRF systems, ASHRAE also further divides the equipment classes with a cooling 

capacity greater than 65,000 Btu/h based on whether or not a heat recovery system is present. 

2.1.4 Air Conditioners and Condensing Units Serving Computer Rooms

“Air conditioners and condensing units serving computer rooms” is a new equipment 

class established in ASHRAE Standard 90.1­2010. ASHRAE Standard 90.1­2010 specifies the 

efficiency metric for this equipment class as sensible coefficient of performance (SCOP) as 

measured by ASHRAE 127­2007, Method of Testing for Rating Computer and Data Processing

Room Unitary Air Conditioners. ASHRAE Standard 90.1­2010 does not contain a definition for 

“air conditioners and condensing units serving computer rooms,” but does define a “computer 

room” as “a room whose primary function is to house equipment for the processing and storage 

b ASHRAE Standard 90.1 does not specify an upper limit on the cooling capacity for the largest capacity equipment 

class (i.e., ≥240,000 Btu/h). However, EPCA limits the size of very large commercial package air conditioning and 

heating equipment to cooling capacities below 760,000 Btu/h. 

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of electronic data and that had a design electronic data equipment power density exceeding 20 

watts/ft2 of conditioned floor area.” 

Cooling computer rooms, server rooms, and data centers presents unique challenges 

because these areas contain valuable equipment that are sensitive to small changes in 

temperature and humidity. Too much humidity can lead to water condensing on electronic 

equipment, and too little humidity may cause static discharges. Computer equipment are also 

constantly producing dynamic, high density heating loads, which means that the air conditioning 

also would need to be running constantly and needs to be able to cool any “hot spots.” Server 

rooms and data centers are typically located in the center of buildings away from windows and 

often have limited floor space, which limits the size and positioning of the air conditioner and 

causes issues related to removing the heat from the computer room. 

Because of these challenges air conditioners serving computer rooms have different 

design requirements than standard air conditioners, even though they use the same process and 

components as conventional air conditioners (i.e., a refrigeration cycle with a compressor, 

condensing coil, expansion valve, and evaporator coil). Air conditioners serving computer rooms 

have to maintain a precise temperature, usually 72 °F or 75 °F, and maintain a specific relative 

humidity (usually between 40 and 55 percent) so in addition to cooling, these equipment have to 

be capable of both humidifying and dehumidifying the air. These air conditioners are often called 

“precision air conditioners” because of this control requirement. These units can be installed in 

various configurations, including floor mounted, ceiling mounted, or portable units for moving 

around the room. The condensing units can be cooled by air, water, or a glycol­water mixture. 

ASHRAE Standard 90.1­2010 first divides air conditioners and condensing units serving 

computer rooms into 5 classes depending on cooling mechanism: air­cooled, water­cooled, 

water­cooled with a fluid economizer, glycol­cooled (rated at 40% propylene glycol), and glycolcooled with a fluid economizer. ASHRAE Standard 90.1­2010 further divides these classes into 

3 size categories (<65,000 Btu/h, ≥65,000 and <240,000 Btu/h, and ≥240,000 Btu/h) and 

orientation (upflow and downflow) to make up a total of 30 unique efficiency levels for this 

equipment class. 

2.1.5 Federal Energy Conservation Standards

On January 12, 2001, DOE published in the Federal Register a final rule promulgating 

the current standards for 5 equipment classes of small (i.e., cooling capacity <135,000 Btu/h) and 

large (i.e., cooling capacity ≥135,000 Btu/h and <240,000 Btu/h) water­cooled and 

evaporatively­cooled air conditioners. 66 FR 3336. This final rule adopted the energy 

conservation standards set by ASHRAE Standard 90.1­1999. On July 22, 2009, DOE published 

in the Federal Register a final rule setting the standards for very large water­cooled and 

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evaporatively­cooled equipment with a cooling capacity ≥240,000 and <760,000 Btu/h. 74 FR 

36312. In the July final rule, DOE adopted the standard levels for those products specified by 

ASHRAE Standard 90.1­2007. 

The existing energy conservation standards for all classes of SPVACs and SPVHPs were 

established by the Energy Independence and Security Act of 2007 (EISA 2007) amendments to 

EPCA. These standards were codified by DOE in a Technical Amendment published in the 

Federal Register on March 23, 2009. 74 FR 12058. ASHRAE Standard 90.1­2010 specifies 

efficiency levels for SPVACs and SPVHPs that are the same as the energy conservation 

standards promulgated by EISA 2007. 

As noted previously, variable refrigerant flow systems are new classes of equipment in 

ASHRAE Standard 90.1­2010. However, these equipment classes are currently covered under 

the more broad federal equipment classes of commercial package air conditioning and heating 

equipment. ASHRAE Standard 90.1­2010 set its efficiency levels for all classes of VRF systems 

equal to the federal energy conservation standards for commercial package air conditioning and 

heating equipment, except for the equipment class of water­source VRF heat pumps with a 

cooling capacity <17,000 Btu/h. Therefore, with the exception of water­source VRF heat pumps 

with a cooling capacity <17,000 Btu/h, DOE was not required to perform an analysis of those 

equipment classes. In addition, ASHRAE Standard 90.1­2010 includes efficiency levels for 

water­source VRF heat pumps with cooling capacity ≥135,000 Btu/h, which are not currently 

regulated by federal energy conservation standards. The current federal energy conservation 

standard for water­source heat pumps was set by the January 2001 final rule, which adopted the 

ASHRAE Standard 90.1­1999 levels. 66 FR 3336. The Energy Policy Act of 2005 (EPACT 

2005) set the current federal standard for the other classes of commercial package air 

conditioners and heating equipment with the exception of air­cooled heat pumps with a cooling 

capacity less than 65,000 Btu/h, which were included in EISA 2007. 

Table 2.1.1 shows the current federal energy conservation levels for equipment classes 

where ASHRAE Standard 90.1­2010 increased the standard levels in comparison to the federal 

levels. Table 2.1.2 shows the current federal energy conservation levels for single package 

vertical air conditioners, which DOE is required to review according to EPCA, as amended by 

EISA 2007. 

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Table 2.1.1 Current Federal Energy Conservation Standards for Commercial Package Air

Conditioning and Heating Equipment Classes with Increased Standard Levels in ASHRAE

Standard 90.1­2010

Equipment Type Cooling Capacity Subcategory Federal Standard

Small Commercial 

Package Air Conditioning 

≥65,000 Btu/h and 

<135,000 Btu/h 

Electric Resistance or no 

heating 

11.5 EER 

Equipment, Water­cooled 

and Evaporatively­cooled 

All other 11.3 EER 

Large Commercial 

Package Air Conditioning 

≥135,000 Btu/h and 

<240,000 Btu/h 

Electric Resistance or no 

heating 

11.0 EER 

and Heating Equipment, 

Water­cooled and 

Evaporatively­cooled 

All other 11.0 EER 

Very Large Commercial 

Package Air Conditioning 

≥240,000 Btu/h and 

<760,000 Btu/h 

Electric Resistance or no 

heating 

11.0 EER 

and Heating Equipment, 

Water­cooled and 

Evaporatively­cooled 

All other 10.8 EER 

Small Commercial 

Package Air Conditioning 

and Heating Equipment, 

Water­source* 

<17,000 Btu/h HP 11.2 EER 

4.2 COP 

Large Commercial 

Package Air Conditioning 

and Heating Equipment, 

Water­source* 

>135,000 Btu/h HP None 

* This product class includes VRF systems, for which ASHRAE Standard 90.1­2010 updated its standard levels. 

Table 2.1.2 Federal Energy Conservation Standards for Single Package Vertical Air

Conditioners

Equipment Type Cooling Capacity Subcategories

Federal Minimum Energy

Conservation Standards

Single Package Vertical Air Single Phase 

9.0 EER Conditioners <65,000 Btu/h 

Three­Phase 

Single Package Vertical Air 

Conditioners 

≥65,000 and 

<135,000Btu/h ­ 8.9 EER 

Single Package Vertical Air 

Conditioners 

≥135,000 and 

<240,000Btu/h ­ 8.6 EER 

Single Package Vertical Heat Single Phase 9.0 EER 

Pumps 3.0 COP <65,000 Btu/h 

Three­Phase 

Single Package Vertical Heat 

Pumps 

≥65,000 and 

<135,000Btu/h ­ 8.9 EER 3.0 COP 

Single Package Vertical Heat 

Pumps 

≥135,000 and 

<240,000Btu/h ­ 8.6 EER 2.9 COP 

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2.1.6 ASHRAE Standard 90.1­2010 Efficiency Levels

The previous version of ASHRAE Standard 90.1 (ASHRAE Standard 90.1­2007) 

specified the efficiency levels for water­cooled and evaporatively­cooled air conditioners as part 

of a single equipment class including both types of equipment. In ASHRAE Standard 90.1­2010, 

ASHRAE specified different efficiency levels for water­cooled air conditioners and 

evaporatively­cooled air conditioners, while retaining the same cooling capacity divisions 

separating the equipment classes. For the water­cooled and evaporatively­cooled equipment class 

with a cooling capacity between 65,000 Btu/h and 135,000 Btu/h, ASHRAE divides the class 

into two more classes based on whether the system has no heating or electric resistance heating 

or any other type of heating, similar to the other size categories. ASHRAE also created new 

equipment classes for variable refrigerant flow systems and raised the efficiency level above the 

federal standard for those with a cooling capacity less than 17,000 Btu/h and with a cooling 

capacity greater than or equal to 135,000 Btu/h (for which no federal standard exists). ASHRAE 

also created new equipment classes for air conditioners and condensing units serving computer 

rooms. Table 2.1.3 below shows the ASHRAE Standard 90.1­2010 efficiency level for the 

updated equipment classes along with the currently applicable Federal minimum efficiency 

standards for comparison. 

Table 2.1.3 Equipment Classes With Updated Efficiency Levels in ASHRAE Standard

90.1­2010

ASHRAE Equipment

Type

Cooling

Capacity Subcategories

ASHRAE

Standard

90.1­2010

Federal Minimum

Energy

Conservation

Standards

≥65,000 and 

Electric 

Resistance or 

No Heating 

Split System 

and Single 

Package 

12.1 EER 

(as of 

6/1/11) 

11.5 EER 

<135,000Btu/h 

All Others 

Split System 

and Single 

Package 

11.9 EER 

(as of 

6/1/11) 

11.3 EER 

Water­cooled Air ≥135,000 and 

Electric 

Resistance or 

No Heating 

Split System 

and Single 

Package 

12.5 EER 

(as of 

6/1/11) 11.0 EER Conditioner <240,000Btu/h 

All Others 

Split System 

and Single 

Package 

12.3 EER 

(as of 

6/1/11) 

≥240,000 and 

<760,000Btu/h 

Electric 

Resistance or 

No Heating 

Split System 

and Single 

Package 

12.4 EER 

(as of 

6/1/11) 

11.0 EER 

All Others 

Split System 

and Single 

Package 

12.2 EER 

(as of 

6/1/11) 

10.8 EER 

2­8
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ASHRAE Equipment

Type

Cooling

Capacity Subcategories

ASHRAE

Standard

90.1­2010

Federal Minimum

Energy

Conservation

Standards

Evaporatively­cooled 

Air Conditioner 

≥65,000 and 

<135,000Btu/h 

Electric 

Resistance or 

No Heating 

Split System 

and Single 

Package 

12.1 EER 

(as of 

6/1/11) 

11.5 EER 

All Others 

Split System 

and Single 

Package 

11.9 EER 

(as of 

6/1/11) 

11.3 EER 

≥135,000 and 

<240,000Btu/h 

Electric 

Resistance or 

No Heating 

Split System 

and Single 

Package 

12.0 EER 

(as of 

6/1/11) 11.0 EER 

All Others 

Split System 

and Single 

Package 

11.8 EER 

(as of 

6/1/11) 

≥240,000 and 

<760,000Btu/h 

Electric 

Resistance or 

No Heating 

Split System 

and Single 

Package 

11.9 EER 

(as of 

6/1/11) 

11.0 EER 

All Others 

Split System 

and Single 

Package 

12.2 EER * 

(as of 

6/1/11) 

10.8 EER 

Variable Refrigerant 

Flow, Water­source 

<17,000 Btu/h All heating 

types 

Multi­split 

system 

12.0 EER 

4.2 COP 

11.2 EER 

4.2 COP 

Multi­split 

system with 

Heat 

Recovery 

11.8 EER 

4.2 COP 

11.2 EER 

4.2 COP 

≥135,000 Btu/h All heating 

types 

Multi­split 

system 

10.0 EER 

3.9 COP 

None Multi­split 

system with 

Heat 

Recovery 

9.8 EER 

3.9 COP 

Air Conditioners 

Serving Computer 

Rooms, Air­Cooled 

<65,000 Btu/h ­

Downflow 2.20 SCOP 

None 

Upflow 2.09 SCOP 

≥65,000 Btu/h 

and <240,000 

Btu/h 

­

Downflow 2.10 SCOP 

Upflow 1.99 SCOP 

≥240,000 Btu/h ­

Downflow 1.90 SCOP 

Upflow 1.79 SCOP 

Air Conditioners 

Serving Computer 

Rooms, Water Cooled 

<65,000 Btu/h ­

Downflow 2.60 SCOP 

None 

Upflow 2.49 SCOP 

2­9
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ASHRAE Equipment

Type

Cooling

Capacity Subcategories

ASHRAE

Standard

90.1­2010

Federal Minimum

Energy

Conservation

Standards

≥65,000 Btu/h 

and <240,000 

Btu/h 

­

Downflow 2.50 SCOP 

Upflow 2.39 SCOP 

≥240,000 Btu/h ­

Downflow 2.40 SCOP 

Upflow 2.29 SCOP 

Air Conditioners 

Serving Computer 

Rooms, Water Cooled 

with fluid economizer 

<65,000 Btu/h ­

Downflow 2.55 SCOP 

None 

Upflow 2.44 SCOP 

≥65,000 Btu/h 

and <240,000 

Btu/h 

­

Downflow 2.45 SCOP 

Upflow 2.34 SCOP 

≥240,000 Btu/h ­

Downflow 2.35 SCOP 

Upflow 2.24 SCOP 

Air Conditioners 

Serving Computer 

Rooms, glycol­cooled 

<65,000 Btu/h ­

Downflow 2.50 SCOP 

None 

Upflow 2.39 SCOP 

≥65,000 Btu/h 

and <240,000 

Btu/h 

­

Downflow 2.15 SCOP 

Upflow 2.04 SCOP 

≥240,000 Btu/h ­

Downflow 2.10 SCOP 

Upflow 1.99 SCOP 

Air Conditioners 

Serving Computer 

Rooms, glycol­cooled 

with fluid economizer 

<65,000 Btu/h ­

Downflow 2.45 SCOP 

None 

Upflow 2.34 SCOP 

≥65,000 Btu/h 

and <240,000 

Btu/h 

­

Downflow 2.10 SCOP 

Upflow 1.99 SCOP 

≥240,000 Btu/h ­

Downflow 2.05 SCOP 

Upflow 1.94 SCOP 

*Given the historical approach of the ASHRAE committee to setting efficiency levels with for commercial air 

conditioning and heating equipment, this efficiency level appears to be a mistake in ASHRAE Standard 90.1­2010. 

DOE believes the intended level is 11.7 EER, and an addendum to lower the value to 11.7 EER is currently being 

considered by ASHRAE. Accordingly, DOE considered the value 11.7 EER as the ASHRAE Standard 90.1­2010 

efficiency level in its potential energy savings analysis. 

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ASHRAE Standard 90.1­2010 raised the efficiency level in comparison to the current 

Federal minimum energy conservation standards for 6 water­cooled air conditioner equipment 

classes, 6 evaporatively­cooled air conditioner equipment classes, and 1 water­source VRF 

commercial air conditioner and heat pump equipment classes. In addition, ASHRAE Standard 

90.1­2010 included efficiency levels for one water­source VRF commercial air conditioner and 

heat pump equipment class and for 15 classes of air conditioners serving computer rooms that 

were not previously covered by DOE’s regulations. ASHRAE did not raise the efficiency level 

for any equipment classes of SPVACs and SPVHPs; however, DOE is required by EPCA (as 

amended by EISA 2007) to assess the potential for energy savings from more stringent energy 

conservation standards for these equipment classes. DOE assessed the current market and 

performed a potential energy savings analysis for each equipment class. The market assessment 

is described in the sections immediately below; while the energy use characterization and 

assessment of the potential energy savings are described in detail in chapters 3 and 4 of this TSD, 

respectively. 

2.2 MARKET ASSESSMENT

The following market assessment identifies the manufacturer trade associations and 

domestic and international manufacturers of commercial water­cooled and evaporatively­cooled 

air conditioners, single package vertical air conditioners and heat pumps, variable refrigerant 

flow systems, and air conditioners and condensing units serving computer rooms. The market 

assessment also summarizes the relevant market performance data for each equipment class 

where such data was available. 

2.2.1 Trade Associations

DOE researched various trade groups who represent manufacturers, distributors, and 

installers of the various types of equipment being analyzed this rulemaking. The AirConditioning, Heating, and Refrigeration Institute (AHRI) is one of the largest trade associations 

for manufacturers of space heating and cooling equipment, representing over 90% of the 

residential and commercial air­conditioning, space­heating, water­heating, and commercial 

refrigeration equipment manufactured in the US.1 AHRI also develops and publishes test 

procedures standards for residential and commercial heating, ventilation, and air conditioning 

(HVAC) equipment and coordinates with the International Organization for Standardization 

(ISO) to help harmonize the US standards with international standards, if feasible. AHRI also 

maintains the AHRI Directory of Certified Product Performance that lists all the products and 

equipment that have been certified by AHRI. AHRI keeps a separate directory for single package 

vertical air conditioners and single package vertical heat pumps. Water­cooled air conditioners 

can be found in the commercial unitary large equipment directory. There are no evaporativelycooled air conditioners listed in the AHRI directory. 

2­11 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                   

   

   

   

   

   

   

       

 

 

 

 

 

 

 

 

 

 

 

 


 

Heating, Airconditioning & Refrigeration Distributors International (HARDI) is a trade 

association that represents over 450 wholesale heating, ventilation, air conditioning, and 

refrigeration (HVACR) companies plus over 300 manufacturing associates and nearly 140 

manufacturing representatives. HARDI estimates that 80% of the revenue of HVACR systems 

goes through its members.2 

Air Conditioning Contractors of America (ACCA) is another trade association whose 

members include over 4,000 contractors and 60,000 professionals. ACCA provides contractors 

technical, legal, and market resources, helping to promote good practices and to keep buildings 

safe, clean, and affordable.3 

2.2.2 Manufacturers

DOE reviewed the efficiency data for water­cooled and evaporatively­cooled air 

conditioners currently on the market by examining the AHRI Directory of Certified Product 

Performance4 and the California Energy Commission (CEC) Appliance Efficiency Database.5 To 

supplement the data in the AHRI and CEC databases, DOE gathered additional information from 

the websites of individual manufacturers of that equipment. For single package vertical air 

conditioners and heat pumps, DOE gathered market data from the AHRI directory as well as 

additional information from manufacturer’s websites. Because the AHRI directory does not 

break out VRF systems separately in its database, DOE gathered data from manufacturers’ 

websites for that equipment. DOE gathered data on air conditioners and condensing units serving 

computer rooms from the CEC website and from manufacturer’s websites. 

DOE identified eight manufacturers of water­cooled air conditioners, five manufacturers 

of evaporatively­cooled air conditioners, eight manufacturers of single package vertical air 

conditioners and heat pumps, and two manufactures of water­source variable refrigerant flow 

systems, and 7 manufacturers of air conditioners and condenser serving computer rooms. The 

manufacturers for each equipment class are listed in Table 2.2.1. 

Table 2.2.1 Manufacturers of the Commercial Equipment Included in this Rulemaking

Water­Cooled Air

Conditioner

Manufacturers

Evaporativelycooled Air

Conditioner

Manufacturers

Single Package

Vertical Air

Conditioner and

Heat Pump

Manufacturers

Water­source

Variable

Refrigerant Flow

System

Manufacturers

Air Conditioners

and Condensers

Serving Computer

Room

Manufacturers

Aaon, Inc. Aaon, Inc. Allied Air 

Enterprises 

Daikin Industries, 

Ltd. 

Airedale (Modine) 

Allied Thermal 

Systems 

Beutler Corp. Bard Manufacturing 

Company 

Mitsubishi Electric American Power 

Conversion 

Carrier Corp. EP Investments, Inc. Enviromaster 

International 

CES Group, Inc 

(Nordyne) 

Lennox International Trane Inc. Friedrich Air Emerson Network 

2­12
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Conditioning Co. Power 

RSI Co. York International 

Corp. 

GE Appliances & 

Lighting 

CompuAire 

Thermoplus Air, Inc. Marvair, division of 

Airxcel, Inc. 

Data Aire, Inc. 

Trane Inc. National Coil 

Company 

Stulz Air 

Technology Systems 

York International 

Corp. 

National Comfort 

Products 

2.2.3 Market Performance Data

For each equipment class analyzed, DOE began by gathering market data to characterize 

the efficiency and performance of models currently on the market. As noted earlier, DOE 

gathered information from the AHRI directory of certified product performance, as well as the 

CEC appliance database. DOE also examined individual manufacturer websites and literature to 

compile a complete database of models for each equipment class. 

For the analysis, DOE only examined the water­cooled and evaporatively­cooled air 

conditioner equipment classes with cooling capacities greater than 65,000 Btu/h because 

ASHRAE Standard 90.1­2010 did not change the efficiency levels for the commercial equipment 

classes with a cooling capacity under 65,000 Btu/h. 

Using the AHRI and CEC directories as a starting point and augmenting the data with 

information from manufacturer websites, DOE compiled a database of water­cooled air 

conditioner models with efficiency data available and separated them into the appropriate 

equipment classes based on cooling capacity: small (i.e., <135,000 Btu/h), large (i.e., ≥135,000 

Btu/h and <240,000 Btu/h), and very large (i.e., ≥240,000 Btu/h and <760,000 Btu/h). 

DOE found no evaporatively­cooled air conditioners in the AHRI Directory of Certified 

Product Performance and found few evaporatively­cooled air conditioners from manufacturers’ 

websites. DOE compiled a database of evaporatively­cooled air conditioner models with 

efficiency data available, and found no models that would fall into the small and large equipment 

classes. Accordingly, all evaporatively­cooled models identified were in the very large 

equipment class. 

DOE compiled a database of SPVACs and SPVHPs from the AHRI directory and 

separated them into three equipment classes based on cooling capacity (<65,000 Btu/h; ≥65,000 

Btu/h and <135,000 Btu/h; and ≥135,000 Btu/h and <240,000 Btu/h). DOE did not identify any 

SPVAC models that would fall into the largest cooling capacity (i.e., ≥135,000 Btu/h and 

<240,000 Btu/h) and did not find any SPVHP models that would fall into either of the two 

largest cooling capacity equipment classes (i.e., ≥65,000 Btu/h and <135,000 Btu/h; and 

2­13
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≥135,000 Btu/h and <240,000 Btu/h). The majority of SPVAC and SPVHP models fell in the 

smallest cooling capacity equipment classes (i.e., <65,000 Btu/h). 

DOE also compiled a database from manufacturers’ websites of water­source VRF heat 

pumps with a cooling capacity greater than or equal to 135,000 Btu/h. However, DOE found no 

water­source VRF heat pumps with a cooling capacity less than 17,000 Btu/h on the market. 

Lastly, for air conditioners and condensing units serving computer rooms, DOE compiled 

a database of available models using information from the CEC directory and from 

manufacturers’ websites. DOE then divided the computer room air conditioner models into 15 

equipment classes, by net sensible cooling capacity (<65,000 Btu/h, ≥65,000 Btu/h and <240,000 

Btu/h, and ≥240,000 Btu/h) and by cooling type (air­cooled, water­cooled, water­cooled with a 

fluid economizer, glycol­cooled, and glycol­cooled with a fluid economizer). DOE further 

divided each equipment class by orientation (i.e., whether it is upflow or downflow). 

2.2.3.1 Water­Cooled Air Conditioners

Small water­cooled Air Conditioners. Small water­cooled air conditioners have a 

cooling capacity greater than or equal to 65,000 Btu/h and less than 135,000 Btu/h and have their 

condensing coil completely submerged in water. Small water­cooled air conditioners are part of 

the water­cooled and evaporatively­cooled air conditioners equipment class, whose Federal 

energy conservation standard is 11.5 EER for systems with electric resistance or no heating and 

11.3 EER for systems that use any other type of heating (66 FR 3336; 10 CFR 431.97). 

ASHRAE Standard 90.1­2010 changes the efficiency rating to 12.1 for systems with electric 

resistance or no heating and 11.9 for systems that use any other type of heating. DOE analyzed 

the distribution of energy efficiency ratios (EERs) for these products as well as the minimum, 

maximum, and average cooling input capacities and EER values. The average EER value for this 

equipment class is 13.9. Of the models identified by DOE, two (13 percent of the total models) 

have EERs rated below the ASHRAE Standard 90.1­2010 levels. 

2­14
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Frequency

4 

3 

2 

1 

0 

EER

Figure 2.2.1 EER Histogram of Small Water­cooled Air Conditioners

Large water­cooled air conditioners. Large water­cooled air conditioners have a 

cooling capacity greater than or equal to 135,000 Btu/h and less than 240,000 Btu/h and have 

their condensing coil completely submerged in water. Large water­cooled air conditioners are 

part of the water­cooled and evaporatively­cooled air conditioners equipment class, whose 

Federal energy conservation standard is 11.0 EER regardless of what kind of heating is used (66 

FR 3336; 10 CFR 431.97). ASHRAE Standard 90.1­2010 changes the efficiency rating to 12.5 

for systems with electric resistance or no heating and 12.3 for systems that use any other type of 

heating. DOE analyzed the distribution of efficiencies for these products. The average EER for 

these units was 13.1. DOE identified 6 models (43 percent of the total models in this equipment 

class) that would fall below the ASHRAE Standard 90.1­2010 levels for this equipment class. 

0 

1 

2 

3 

4 

Frequency

EER

Figure 2.2.2 EER Histogram of Large Water­cooled Air Conditioners

Very large water­cooled air conditioners. Very large water­cooled air conditioners 

have a cooling capacity greater than or equal to 240,000 Btu/h and less than 760,000 Btu/h, and 

have their condensing coil completely submerged in water. Very large water­cooled air 

conditioners are part of the water­cooled and evaporatively­cooled air conditioners equipment 

2­15 
 

 

 

 

 

 

 

                 

   

    

 

 

 

 

 

 

 

 

    

 

 

 

 

 

 

 

 

 

 


 

class, whose Federal energy conservation standard is 11.0 EER for units with electric resistance 

or no heating and 10.8 for units with all other kinds of heating (74 FR 36312; 10 CFR 431.97). 

ASHRAE Standard 90.1­2010 changes the efficiency rating to 12.5 for systems with electric 

resistance or no heating and 12.3 for systems that use any other type of heating. DOE analyzed 

the distribution of efficiencies for these products. The average EER rating for these units is 13.0. 

DOE identified 12 models (34 percent of the total models identified) that would fall below the 

ASHRAE Standard 90.1­2010 efficiency level for this equipment class. 

5 

Frequency

0 

1 

2 

3 

4 

EER

Figure 2.2.3 EER Histogram of Very Large Water­cooled Air Conditioners

2.2.3.2 Evaporatively­Cooled Air Conditioners

Small evaporatively­cooled air conditioners. Small evaporatively­cooled air 

conditioners have a cooling capacity greater than or equal to 65,000 Btu/h and less than 135,000 

Btu/h. Small evaporatively­cooled air conditioners are covered as part of the water­cooled and 

evaporatively­cooled air conditioners equipment class, whose Federal energy conservation 

standard is 11.5 EER for systems with electric resistance or no heating and 11.3 EER for systems 

that use any other type of heating (66 FR 3336; 10 CFR 431.97). ASHRAE Standard 90.1­2010 

changes the efficiency rating to 12.1 EER for systems with electric resistance or no heating and 

11.9 EER for systems that use any other type of heating. DOE did not find any models on the 

market that would be classified as small evaporatively­cooled air conditioners. 

Large evaporatively­cooled air conditioners. Large evaporatively­cooled air 

conditioners have a cooling capacity greater than or equal to 135,000 Btu/h and less than 

240,000 Btu/h. Large evaporatively­cooled air conditioners are covered as part of the watercooled and evaporatively­cooled air conditioners equipment class, whose Federal energy 

conservation standard is 11.0 EER regardless of what type of heating is used (66 FR 3336; 10 

CFR 431.97). ASHRAE Standard 90.1­2010 changes the efficiency rating to 12.0 EER for 

systems with electric resistance or no heating and 11.8 EER for systems that use any other type 

2­16
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of heating. DOE also did not find any models on the market that would be classified as large 

evaporatively­cooled air conditioners. 

Very large evaporatively­cooled air conditioners. Very large evaporatively­cooled air 

conditioners have an input capacity greater than or equal to 240,000 Btu/h and less than 760,000 

Btu/h. Very large evaporatively­cooled air conditioners are covered as part of the water­cooled 

and evaporatively­cooled air conditioners equipment class, whose Federal energy conservation 

standard is 11.0 EER for systems with electric resistance or no heating and 10.8 EER for systems 

that use any other type of heating (74 FR 36312; 10 CFR 431.97). ASHRAE Standard 90.1­2010 

changes the efficiency rating to 12.0 EER for systems with electric resistance or no heating and 

11.8 EER for systems that use any other type of heating. During the market research, DOE 

identified several models from manufacturers that would be classified as very large 

evaporatively­cooled air conditioners. However, the efficiency rating for these models was not 

readily available, and DOE was unable to obtain it. Although DOE could not obtain efficiency 

information from manufacturer literature, DOE did develop an estimate of the potential energy 

savings for very large evaporatively­cooled air conditioners. See chapter 4 of this TSD for details 

on DOE’s potential energy savings analysis. 

2.2.3.3 Single Package Vertical Air Conditioners and Heat Pumps

Single package vertical air conditioners. EISA 2007 divided single package vertical air 

conditioners into three equipment classes and set the efficiency level for each class. SPVACs 

with a cooling capacity <65,000 Btu/h have a federal conservation standard of 9.0 EER. 

SPVACs with a cooling capacity ≥65,000 Btu/h and <135,000 Btu/h have a federal conservation 

standard of 8.9 EER. SPVACs with a cooling capacity ≥135,000 Btu/h and <240,000 Btu/h have 

a federal conservation standard of 8.6 EER (10 CFR 431.97). DOE found 364 SPVACs listed in 

the AHRI database. Of the models listed, 359 have an input capacity less than 65,000 Btu/h and 

only 5 have a cooling capacity greater than or equal to 65,000 Btu/h. DOE did not find any large 

SPVACs (with a cooling capacity greater than or equal to 135,000 Btu/h and less than 240,000 

Btu/h). There were 108 models (30 percent of the total models) with a cooling capacity less than 

65,000 Btu/h that are minimally compliant with the current federal energy conservation 

standards. The 5 models with a input capacity greater than 65,000 Btu/h had an average EER 

value of 9.7 with a minimum EER of 9.5 and a maximum EER of 10.0. All of these models are 

compliant with the federal standard of 8.9 for this equipment class. 

2­17
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Frequency

120 

100 

80 

60 

40 

20 

0 

EER

Figure 2.2.4 EER Histogram of SPVACs <65,000 Btu/h

Single package vertical heat pumps. EISA 2007 divided single package vertical heat 

pumps into three equipment classes and set the efficiency level for each class. SPVHPs with a 

cooling capacity <65,000 Btu/h have federal conservation standard of 9.0 EER and 3.0 

coefficient of performance (COP). SPVHPs with a cooling capacity ≥65,000 Btu/h and <135,000 

Btu/h have a federal conservation standard of 8.9 EER and 3.0 COP. SPVHPs with a cooling 

capacity ≥135,000 Btu/h and <240,000 Btu/h have a federal conservation standard of 8.6 EER 

and 2.9 COP (10 CFR 431.97). DOE found 245 SPVHP models listed in the AHRI directory. All 

of them have a cooling capacity less than 65,000 Btu/h. Of the models identified, 64 (26 percent 

of the total) are minimally compliant with the current federal EER standard and 135 (55 percent 

of the total) are minimally compliant with the federal COP standard. 

70 

60 

Frequency

50 

40 

30 

20 

10 

0 

Bin

Figure 2.2.5 EER Histogram of SPVHPs
 

2­18
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Frequency

150 

100 

50 

0 

3.0 3.1 3.2 3.3 3.4 3.5 

COP

Figure 2.2.6 COP Histogram of SPVHPs

2.2.3.4 Variable Refrigerant Flow Water­source Heat Pumps

Water­source VRF heat pumps with a cooling capacity less than 17,000 Btu/h have a 

federal energy conservation standard of 11.2 EER and 4.2 COP. ASHRAE Standard 90.1­2010 

changes the efficiency rating for water cooled VRF systems with a cooling capacity less than 

17,000 Btu/h to 12.0 EER and 4.2 COP for those systems with no heat recovery technology and 

to 11.8 EER and 4.2 COP for those systems with heat recovery technology. DOE surveyed the 

market to find VRF water­source heat pumps with cooling capacities below 17,000 Btu/h, and 

did not find any on the market. 

Water­source VRF heat pumps with a cooling capacity greater than or equal to 135,000 

Btu/h currently do not have a federal energy conservation standard. ASHRAE is also adding new 

efficiency standards for those systems with a cooling capacity greater than or equal to 135,000 

Btu/h to 10.0 EER and 3.9 COP for systems without heat recovery devices and 9.8 EER and 3.9 

COP for systems with heat recovery devices. From two manufacturers’ websites, DOE found 19 

models with no heat recovery option and 9 models with a heat recovery add­on for a total of 28 

unique units. Manufacturers only reported EER and COP information for 8 of these units. For 

the remaining of the units, DOE contacted the relevant manufacturer but could not obtain EER or 

COP ratings. 

2.2.3.5 Air Conditioners and Condensing Units Serving Computer Rooms

Prior to ASHRAE Standard 90.1­2010, air conditioners and condensing units serving 

computer rooms were not considered covered equipment under EPCA, so there are currently no 

federal energy conservation standards for these equipment. As a result, several manufacturers do 

not report efficiency information. However, the CEC regulates the minimum efficiency of 

2­19
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computer room air conditioners, requiring units installed in the state of California to meet a 

minimum EER rating as listed in Table 2.2.2. 

Table 2.2.2 CEC Computer Room Air Conditioners Minimum Efficiency Levels

CEC Equipment Type Cooling Capacity (Btu/h) Minimum Efficiency Level 

Air­cooled computer room air < 65,000 11.0 EER 

conditioners ≥ 65,000 and < 135,000 10.4 EER 

≥ 135,000 and < 240,000 10.2 EER 

Water­cooled, Glycol­cooled, < 65,000 11.1 EER 

and Evaporatively­cooled ≥ 65,000 and < 135,000 10.5 EER 

Computer Air Conditioners ≥ 135,000 and < 240,000 10.0 EER 

As noted previously, the CEC also maintains a directory of “computer room air 

conditioners” in its appliance efficiency database. DOE searched the CEC database for air 

conditioners and condensing units serving computer rooms and supplemented that data with 

information from literature found on manufacturer websites. In total, DOE found over 1500 

models of air conditioners and condensing units serving computer rooms, many of which were 

derivatives of the same basic unit. For example, a basic unit could have the option of an upflow 

or downflow configuration and the option of adding a fluid economizer; thus from this basic unit, 

4 different models are possible. 

The CEC database includes the rated EER of each model listed. Although this 

information provides a measure of equipment efficiency, DOE notes that ASHRAE Standard 

90.1­2010 adopts an updated version of ASHRAE Standard 127 (i.e., ASHRAE Standard 127­

2007), which changes the efficiency metric from EER to SCOP. CEC requires manufacturers to 

use the 2001 version of ASHRAE 127, which tests for the EER and not SCOP. In addition, the 

standard rating conditions were changed between the 2001 and 2007 editions of the ASHRAE 

127 test procedure, which adds to the difficulty of obtaining information about product efficiency 

as rated using the new SCOP rating metric. A footnote to Table D1 in Appendix D of ASHRAE 

Standard 127­2007 contains a “rule­of­thumb” formula that approximates the SCOP value using 

the old EER rating. Using this simple rule of thumb gives a rough approximation of SCOP and a 

basic idea of how SCOP values compare to EER, but is not a substitute for efficiency data 

obtained from direct application of the test method. As a result, DOE was unable to acquire 

reliable SCOP data for computer rooms and air conditioners serving computer rooms. 

2­20
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REFERENCES
 

1	� Air­Conditioning, Heating, and Refrigeration Institute Website. About Us. 2011. (Last 

accessed April 28, 2011.) <www.ahrinet.org/about+us.aspx> 

2	� Heating, Airconditioning & Refrigeration Distributors International Website. About

HARDI. 2011. (Last accessed April 28, 2011.) 

<www.hardinet.org/aws/HARDI/pt/sp/about> 

3	� Air Conditioning Contractors of America Website. About ACCA. 2011. (Last accessed 

April 28,2011.) <www.acca.org/acca> 

4	� AHRI Directory. Directory of Certified Product Performance. 2011. (Last accessed 

April 28, 2011.) <www.ahridirectory.org> 

5	� California Energy Commission Website. Appliance Efficiency Database. 2011. (Last 

accessed April 28, 2011.) <www.appliances.energy.ca.gov/QuickSearch.aspx> 

2­21
�
 

 

 

 

 

CHAPTER 3 ENERGY USE CHARACTERIZATION 

TABLE OF CONTENTS 

3.1 INTRODUCTION .............................................................................................................. 3-1
 

3.2 ENERGY USE ANALYSIS BY EQUIPMENT TYPE ..................................................... 3-1
 

3.2.1 Water-Cooled Air Conditioners.............................................................................. 3-1
 

3.2.1.1 Water-Cooled Condenser Performance ...................................................... 3-2
 

3.2.1.2 Supply Water Temperature ......................................................................... 3-4
 

3.2.1.3 Supply Fan Power....................................................................................... 3-5
 

3.2.1.4 Water-Cooled Condenser-Only Cooling Coefficient of Performance vs. 

Energy Efficiency Ratio Relationship .................................................................... 3-6
 

3.2.1.5 Baseline Annual Energy Use/Ton for Climates—Water-Cooled ............... 3-7
 

3.2.1.6 Energy Use Estimates for Baseline and Higher-Efficiency Water-Cooled Air 

Conditioner Equipment by Equipment Class.......................................................... 3-8
 

3.2.2 Evaporatively Cooled Air Conditioners................................................................ 3-10
 

3.2.2.1 Baseline Annual Energy Use/Ton for Climates—Evaporatively Cooled. 3-11
 

3.2.2.2 Energy Use Estimates for Baseline and Higher Efficiency Evaporatively
 

Cooled Air Conditioners by Equipment Class...................................................... 3-12
 

3.2.3 Single-Package Vertical Air Conditioners and Heat Pumps................................. 3-12
 

3.2.3.1 Fan and Condenser Power Assumptions: Single-Package Vertical Air
 

Conditioners.......................................................................................................... 3-13
 

3.2.3.2 Single-Package Vertical Heat Pump Analysis.......................................... 3-16
 

LIST OF TABLES 

Table 3.2.1 Normalized Energy Use Ton by Climate for Water-Cooled Air Conditioners, 11.0 

EER...................................................................................................................... 3-8
 

Table 3.2.2 Water-Cooled Air Conditioner Representative Capacities by Product Class........... 3-9
 

Table 3.2.3 Normalized Energy Use Ton by Climate for Evaporatively-Cooled Air Conditioners, 

11.0 EER............................................................................................................ 3-11
 

Table 3.2.4 Evaporatively Cooled Air Conditioner Representative Capacities by Product Class..
 

Table 3.2.7 Normalized Energy Use Ton by Climate for SPVHP, Baseline (9.0 EER/3.0 COP)..
 

............................................................................................................................ 3-12
 

Table 3.2.5 Normalized Energy Use Ton by Climate for SPVAC, Baseline (9.0 EER) ........... 3-14
 

Table 3.2.6 Blower Power Adjustments for ECM Motor.......................................................... 3-15
 

............................................................................................................................ 3-17
 

LIST OF FIGURES 

Figure 3.2.1 Comparison of Floor-Space Weighting Factors by Region. Small and Medium
 

Office Buildings versus All Buildings................................................................. 3-7
 

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CHAPTER 3. ENERGY USE CHARACTERIZATION
 

3.1 INTRODUCTION
 

The national energy savings analysis described in chapter 4 of the technical support 

document (TSD) requires determination of the energy savings consumers would realize from the 

establishment of standards at the levels set forth in American Society of Heating, Refrigerating 

and Air-Conditioning Engineers (ASHRAE) Standard 90.1-2010 for specific classes of 

equipment analyzed as well as for more energy efficient standards. 

This chapter describes the energy use analysis for both water-cooled and evaporatively 

cooled commercial packaged air conditioners as well as single package vertical air conditioners 

and heat pumps. These equipment types are described in separate subsections of this chapter that 

detail the analysis and the determination of baseline annual per unit energy consumption (UEC) 

estimates for specific product classes within each of the three product types examined. This 

chapter also describes the development of UEC estimates for more efficient equipment, up to the 

max-tech levels defined in chapter 4 of this TSD. 

For each of these equipment types, the Federal standard is expressed in terms of an 

efficiency metric or metrics: energy efficiency ratio (EER) for cooling efficiency, coefficient of 

performance (COP) for heating efficiency. For each equipment class, this chapter describes how 

an estimate of the UEC is developed corresponding to different rated efficiencies. 

3.2 ENERGY USE ANALYSIS BY EQUIPMENT TYPE 

3.2.1 Water-Cooled Air Conditioners 

The analysis to assess the per unit energy savings of water-cooled air conditioners began 

with a review of the existing market as well as the review of historical shipments data provided 

by the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) and discussed in chapter 4 

of the TSD. The review of the market suggested that most water-cooled air conditioner units on 

the market are designed for installation inside of commercial buildings (as opposed to on 

building rooftops), and the shipments data suggested that in recent years shipments were 

dominated by larger equipment (greater than 240,000 British thermal units per hour (Btu/h) 

capacity), with a trend toward relatively few shipments of smaller capacity units. Because of 

this, the U.S. Department of Energy (DOE) analysis of energy savings focused on typical 

applications for equipment in the 240,000 Btu/h or greater class. Review of manufacturer’s 

literature suggested that a common application is floor-by-floor cooling in a multi-story 

building.1 

To estimate the energy use of water-cooled air conditioners in this application, DOE used 

annual hourly simulation data developed from computer simulations of a prototypical 

commercial office building. The prototype building model was a 3-story, 53,600 ft2 commercial 

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office building developed as part of DOE’s commercial reference building models.a This 

building model, referred to as a “medium office,” has each floor served by a separate packaged 

air conditioning unit. The hourly data used for this analysis was previously developed from 

simulations using this model and the DOE EnergyPlus building simulation software, and 

reflected building simulations in 15 climate locations in the United States.

b Each climate 

location used is representative of climate in 1 of 15 climate regions that have been developed in 

DOE’s Building Energy Codes Program and subsequently used in the development of the 

commercial reference building models. Characteristics of the DOE reference medium office 

building model used in this analysis are provided in appendix 7A. 

The medium office reference building model used packaged variable air volume (VAV) 

rooftop cooling units, one unit serving each floor of the building, and the hourly thermal load and 

supply fan air volume data used for this analysis reflects this. DOE determined that the hourly 

cooling thermal loads from modeling of this type of equipment would be representative of hourly 

loads for systems served by larger water-cooled equipment also providing floor-by-floor cooling 

and serving multiple building thermal zones with a VAV air distribution network. Thus, these 

loads would be accurate for the analysis of water-cooled air conditioners in this application. 

EnergyPlus does not have an equipment component model developed around a water-cooled air 

conditioner used in this application. EnergyPlus does have equipment models of water-source 

heat pumps, but these equipment models do not appear to provide for variable volume air flow. 

For this reason, DOE used the previously developed hourly cooling thermal load, hourly air 

flow, and hourly air temperature data for the air-cooled packaged rooftop equipment used in the 

medium office reference building model as a starting point for its analysis. 

To process the hourly data into annual equipment energy consumption for water-cooled 

air conditioners for baseline level equipment, DOE developed a spreadsheet model of the 

equipment performance of a water-cooled air conditioner using actual manufacturer’s 

performance data for an existing 25-ton water-cooled air conditioner.2 Cooling capacity and 

condenser power consumption curve fits to this data were developed using polynomial 

relationships and the independent variables recommended for modeling of cooling efficiency for 

water-source heat pumps in EnergyPlus with minor variations. Discussion of the modeling of 

the water-cooled condenser and supply fan power follows. 

3.2.1.1 Water-Cooled Condenser Performance 

EnergyPlus provides two methods of modeling equipment performance of water-source 

heat pumps. The method used for this work is referred to as the “equation-fit model.” The 

equation-fit model uses non-dimensional equations developed from curve-fits to manufacturer’s 

a The commercial reference building models are available on DOE’s Office of Energy Efficiency and Renewable 

Energy website as Energy Plus input files at: 

<http://www1.eere.energy.gov/buildings/commercial_initiative/new_construction.html>. Documentation of the 

model development is provided in Deru, M., et al..U.S. Department of Energy Commercial Reference Building 

Models of the National Building Stock. (NREL/TP-5500-46861) (2011). 

b Hourly simulations results for medium office reference building model were developed at Pacific Northwest 

National Laboratory and provided for support of the ASHRAE 90.1 Mechanical Subcommittee in April 2009. 

Simulation results used reflect code requirements for buildings designed to ANSI/ASHRAE/IESNA 90.1-2004. 

3-2 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

performance data to predict the condenser performance in cooling (and heating mode). Least 

squares regression is used to generate a set of performance coefficients from catalog 

performance data at various conditions for the particular equipment modeled. Then the 

respective coefficients from the least squares regressions are used in the model to simulate the 

heat pump performance in the EnergyPlus software. The variables EnergyPlus uses to describe 

the water-cooled condenser performance are the entering air wet bulb and dry bulb temperature, 

the condenser water inlet temperature, the entering air volumetric flow rate, and the condenser 

water flow rate. Each of these variables is made non-dimensional by first dividing by 

corresponding values for each variable at a defined reference condition. Two minor variations 

from the implementation in EnergyPlus included the use of inch-pound (IP) units in developing 

the DOE performance curves and the selection of reference temperature conditions that 

correspond precisely to the DOE rating conditions. The governing equations for the cooling 

performance are as follows: 

Q ̇ ̇ total Twb Tw,in Vair Vw = A1 + A2 × ൬ ൰ + A3 × ൬ ൰ + A4 × ൬ ̇ ൰ + A5 × ൬ ̇ ൰ Eq. 3.2.1 Qtotal_ref Twb_ref Tw,in_ref Vair_ref Vw_ref

Q V̇ V̇ sen Tdb Twb Tw,in air w = B1 + +B2 × ൬ ൰ + B3 × ൬ ൰ + B4 × ൬ ൰ + B5 × ൬ ̇ ൰ + B6 × ൬ ̇ ൰ Eq. 3.2.2 Qsens_ref Tdb_ref Twb_ref Tw,in_ref Vair_ref Vw_ref

Power T V̇ V̇ wb Tw air w = C1 + C2 × ൬ ൰ + C3 × ൬ ൰ + C4 × ൬ ൰ + C5 × ൬ ൰ Eq. 3.2.3 Powerref Twb_ref Tw−ref V̇

air_ref V̇w_ref

Where:
 

A1 – C5 = equation fit coefficients for the cooling mode,
 

Qtotal = cooling capacity (Btu/h),
 

Qtotal_ref = cooling capacity at reference condition (Btu/h),
 

Qsens = sensible cooling capacity (Btu/h),
 

Qsens_ref = sensible cooling capacity at reference condition (Btu/h),
 

Power = condenser power (W),
 

Powerref = condenser power at reference condition (W),
 

Twb = entering air wet bulb temperature (Rankine (°R)),
 

Twb-ref = entering air wet bulb temperature at reference temperature (°R),
 

Tdb = entering air dry bulb temperature (°R),
 

Tdb-ref = entering air dry bulb temperature at reference temperature (°R),
 

Tw = entering water temperature (°R),
 

Tw-ref = entering water temperature at reference temperature (°R),
 

Vair = volumetric air flow rate (cubic feet per minute (cfm)),
 

Vair-ref = volumetric air flow rate at reference (gallons per minute (gpm)),
 

Vw = volumetric water flow rate (cfm), and
 

Vw-ref = volumetric water flow rate at reference (gpm).
 

The equations above are based on steady state full-load operation at the rating (reference) 

conditions and off-rating conditions. To account for operation at part-load and non-steady-state 

operation, part-load performance modifier curves for air-source air conditioners—and that were 

used in the EnergyPlus medium office reference building model—were also used for this 

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analysis. Because these part-load modifier curves reflect the effects of compressor cycling at 

part-load for air-cooled systems, it was determined that they should be representative of the 

compressor cycling impacts for water-cooled air conditioners as well. 

The part-load modifier curves are of the following equation form: 

CoolPLFFPLR = C1 + C2 × PLR Eq. 3.2.4 

Where:
 

CoolPLFFPLR = cooling power part-load factor modifier, 

PLR = ratio of cooling load to cooling capacity under the conditions of interest, and
 

C1 and C2 = equation fit coefficients for the part-load performance curves.
 

C1 and C2 values of 0.771 and 0.229, respectively, were used based on the part-load 

modifier curves in the reference building simulations and for this analysis. 

The steady state power input is then adjusted according to the following equation: 

PLR PowerHourly = Power × Eq. 3.2.5 CoolPLFFPLR

Where: 

PowerHourly = hourly average power in response to hourly cooling load, 

Power = steady state power at conditions as defined in equation 3.2.3, 

PLR = part-load ratio as defined in equation 3.2.4, and 

CoolPLFFPLR = part-load modifier as defined in equation 3.2.4. 

For each climate zone, the original system air volumes were sized based on design day 

runs and the maximum hourly supply air for each system was used as the basis for the system air 

volumes and reference volumetric flow rate. The peak cooling loads were adjusted for rated 

conditions and used to determine the equipment nominal capacity for each system. This is also 

the cooling capacity at reference condition. No hourly condenser-water flow rates were 

available, and for the modeling purpose the condenser water flow rate at all hours was assumed 

to be at the reference (rated) condition. Thus, the condenser water flow rate did not affect the 

performance curves in the analysis. 

3.2.1.2 Supply Water Temperature 

The performance equations developed in this spreadsheet model separately account for 

the water-cooled gross cooling capacity and power consumption as a function of entering air 

conditions and supply water temperature and flow rate. To function, the spreadsheet model 

requires an hourly entering water temperature and entering water flow rate. For this analysis, a 

simple cooling tower supply water temperature model was developed based on a defined control 

profile with minimum 70 °F return water temperature and using a 7 °F approach temperature. 

Thus, the return water temperature from the cooling tower is calculated as 

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Tw = minൣTwb,o + 7 , 70൧ + 459.67 Eq. 3.2.6 

Where: 

Tw = Building supply water temperature from cooling tower (°R), and 

Twb,o = Outdoor air wet bulb temperature (°F). 

The supply water temperature from the cooling tower is thus estimated at 7 °F above the 

current wet bulb temperature during most cooling hours. Condenser water flow rates were 

assumed to be equivalent to the nominal rating condition water flow rates for all cooling hours. 

Using these inputs and performance curves, it was possible to calculate the hourly 

condenser energy consumption of each of the three water-cooled air conditioner units for this 

building model. 

3.2.1.3 Supply Fan Power 

In addition, DOE’s spreadsheet model calculated the fan energy consumption for the 

equipment. Fan energy for each system at design conditions (peak fan capacity) was estimated 

using the following assumptions. 

∆P×Q Powerfan,max = Eq. 3.2.7 6350×nf×nm×0.746

Where: 

Powerfan,max = design fan power (kW), 

ΔP = total fan static pressure (in. H20), 

Q = design supply air flow rate (cfm), 

nf = fan efficiency, and 

nm = motor and drive efficiency. 

A design total fan static pressure of 4.35 in. H2O, fan efficiency of 0.65, and motor 

efficiency of 0.9 were used, providing for a design fan system power of 0.87 W/cfm at design 

conditions. The total fan static pressure was judged likely to be less than that used in the 

reference building design (4.35 in. H2O versus 5.35 in. H2O) based on the determination that the 

total supply and return path pressure drop would be less with water cooled units installed inside 

the building as compared to packaged units installed on rooftops due to the length of the duct 

runs. 

Because this was a VAV system with varying hourly air flow rate, the fan power was 

adjusted hourly using a fan power part-load curve used for the DOE reference building VAV 

system. The fan power curve provides the relationship between fan system power and system air 

flow rate, which varied hourly for the VAV system. The fan power versus flow rate relationship 

is of the form used in EnergyPlus: 

PLFfan = C1 + C2 × FF + C3 × FF2 + C4 × FF3

+C5 × FF3 Eq. 3.2.8 

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Where: 

PLFfan = a part-load factor multiplier equal to the ratio of system fan power to design fan 

power, 

FF = fraction of system design air flow rate, and 

C1 – C5 = equation coefficients for the VAV fan power curve. 

The coefficients C1 through C5 used for this curve are those from the reference building 

model and are shown below. 

C1 = 0.040759894 

C2 = 0.08804497 

C3 = -0.07292612 

C4 =0.943739823 

C5 = 0 

3.2.1.4	 Water-Cooled Condenser-Only Cooling Coefficient of Performance vs. 

Energy Efficiency Ratio Relationship 

For analysis of energy use at the base efficiency (EER) level, DOE developed estimates 

for the condenser-only efficiency (condenser-only cooling COP) for the water-cooled air 

conditioner based on the nominal rating conditions for an 11 EER unit. Condenser-only cooling 

COP at rating conditions is an input to the EnergyPlus simulation model. This parameter can be 

calculated by backing out the estimated fan power at nominal rating conditions from the rated 

energy consumption while accounting for the effect of fan heat. This is done by calculating the 

condenser-only cooling COP according the equation below: 

EER
 

3.413+R
 

COPCU_Cool = 

1−R	 Eq. 3.2.9 

Where: 

EER = EER rating of the equipment being modeled, 

R = ratio of supply fan power to total equipment power at the AHRI rating 

condition, and 

COPCU_Cool = condensing-only cooling COP at rated conditions. 

The parameter R can be estimated from available manufacturer fan power data at the 

external static rating condition and a known air flow rate. Generally, however, the air flow rate 

at rating is not provided in the manufacturer’s literature. DOE used an R of 0.164 based on 

review of available data for a large evaporatively cooled air conditioner and assuming a supply 

air flow rate of 350 cfm/ton.2 For an 11.0 EER unit that DOE modeled directly, the calculated 

condenser-only COP corresponding to an 11.0 EER unit was 4.052. 

3-6 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

3.2.1.5 Baseline Annual Energy Use/Ton for Climates—Water-Cooled 

For each of the 15 climates, DOE used the spreadsheet model to calculate the hourly 

condenser energy use and supply fan energy use for each of the three water-cooled air 

conditioner units in the reference medium office building model and summed the results to 

provide annual energy use estimates for condenser and for supply fan separately. DOE also 

calculated the cooling capacity for each unit and summed these for the whole building. Dividing 

the energy use figures for both condenser and supply fan by the rated cooling capacity provides a 

normalized energy-use-per-ton figure for each end use at the baseline efficiency level. These 

climate-specific results, along with the climate weighting factors used are shown in Table 3.2.1. 

The climate weighting factors are developed from construction statistics for commercial office 

floor space for small and for medium sized office buildings (likely to use commercial packaged 

air conditioning equipment regardless of system size) for the period from 2003 to 2007.3 For 

each building type weights were first calculated for the building class and then averaged. Figure 

3.2.1 shows the floor space weighting factors for this analysis compared with that of all 16 DOE 

reference buildings types with construction floor space tallied in the study. 

25% 

20% 

15% 

10% 

5% 

0% 

1A 2B 2A 3B 3C 3A 

Relative Fraction of Construction by Climate Region 

4B 4C 4A 

DOE Climate Region 

All Buildings 

Office Buildings 

5B 5A 6B 6A 7 8 

Figure 3.2.1 Comparison of Floor-Space Weighting Factors by Region. Small and Medium 

Office Buildings versus All Buildings. 

In addition, Table 3.2.1 shows a parameter called the “full load equivalent operating 

hours” (FLEOH), which is calculated as the annual cooling load served divided by the system 

cooling capacity. In this case the FLEOH shown is the result from weighting of the FLEOH 

calculated for each individual air conditioning unit by the relative capacity of that equipment to 

the total capacity of all equipment serving the reference building model. While not used in 

DOE’s energy calculation, FLEOH values provide a useful reference point to compare with other 

energy calculations methods. 

3-7 
 

 

 

 

 

 

 

 

 

 

 

Table 3.2.1 Normalized Energy Use Ton by Climate for Water-Cooled Air Conditioners, 

11.0 EER 

Climate 

Zone 

Representative 

Climate Location 

Construction 

Wt. 

Annual 

Condenser 

Energy 

kWh/ton 

Annual Fan 

Energy 

kWh/ton 

Annual 

System 

Energy 

kWh/Ton 

FLEOH 

1A Miami, Fl 1.82% 1999 257 2256 2718 

2A Houston, TX 16.20% 1440 215 1654 1966 

2B Phoenix, AZ 4.99% 1446 354 1800 2052 

3A Memphis, TN 14.91% 1051 204 1255 1440 

3B El Paso, TX 10.15% 973 284 1258 1413 

3C San Francisco, CA 1.82% 497 273 770 736 

4A Baltimore, MD 18.18% 824 216 1040 1135 

4B Albuquerque, NM 0.72% 776 357 1133 1154 

4C Salem, OR 2.71% 517 247 764 736 

5A Chicago, IL 16.96% 674 215 889 926 

5B Boise, ID 5.70% 542 283 825 807 

6A Burlington, VT 0.56% 545 230 775 759 

6B Helena, MT 4.62% 446 360 807 682 

7 Duluth, MN 0.56% 352 249 600 496 

8 Fairbanks, AK 0.10% 259 436 696 398 

National 100.00% 947 242 1189 1319 

kWh = kilowatt-hours 

3.2.1.6	 Energy Use Estimates for Baseline and Higher-Efficiency Water-Cooled 

Air Conditioner Equipment by Equipment Class. 

National average estimates of the energy use for efficiencies other than those directly 

modeled in the spreadsheet tool were developed based by first scaling the national average 

condenser energy use per ton from the spreadsheet simulation of 11.0 EER equipment shown in 

Table 3.2.1 by the condenser-only cooling COP corresponding to the higher EER equipment. 

The condenser-only cooling COP is developed based on equation 3.2.9 for higher EER values. 

To that result is added the baseline fan energy consumption/ton values, and the sum is then 

multiplied by the selected representative tonnage for each equipment class; or in equation form, 

UECEER = CAP × [CondUECn × 

COPCU_Cool_Modeled + FanUECn] Eq. 3.2.10 COPCU_Cool_EER

Where:
 

CAP = nominal equipment capacity in cooling tons,
 

UECEER = unit energy consumption at the specific EER level being evaluated,
 

CondUECn = normalized condenser energy consumption from the modeling, kWh/ton –
 

national basis, 

COPCU_Cool_Modeled = the cooling condenser-only COP used in the spreadsheet equipment 

model, 

3-8 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

COPCU_Cooled EER = the cooling condenser-only COP corresponding to the specific EER level 

being evaluated, and 

FanUECn = normalized condenser energy consumption from the modeling, kWh/ton – 

national. 

Thus, for example, to estimate the annual energy consumption of a 35 ton water-cooled 

air conditioner at an EER of 12.4, the initial step is to calculate a condenser-only COPEER using 

equation 3.2.9. For an EER of 12.4, the ASHRAE 90.1-2010 level for this product class, this 

corresponds to a COP of 4.543. UEC is then calculated as 

UEC12.4 EER = 35 tons × [947 kWh/ton × 

4.052 + 242 kWh/ton] Eq. 3.2.11 4.543

A representative capacity for each product class was selected as shown in Table 3.2.2 

based on the approximate average capacity of the units available in the market as identified in 

DOE’s market analysis. 

Table 3.2.2 Water-Cooled Air Conditioner Representative Capacities by Product Class 

Product Class Representative Cooling Capacity 

Water-Cooled Air Conditioner, ≥65,000 and <135,000 Btu/h, Electric

Resistance Heating or No Heating 

8 tons 

Water-Cooled Air Conditioner, ≥65,000 and <135,000 Btu/h, All Other

Heating 

8 tons 

Water-Cooled Air Conditioner, ≥135,000 and <240,000 Btu/h, Electric

Resistance Heating or No Heating 

15 tons 

Water-Cooled Air Conditioner, ≥135,000 and <240,000 Btu/h, All Other

Heating 

15 tons 

Water-Cooled Air Conditioner, ≥240,000 Btu/h, Electric Resistance

Heating or No Heating 

35 tons 

Water-Cooled Air Conditioner, ≥240,000 Btu/h, All Other Heating 35 tons 

For this analysis, the annual supply fan power was not adjusted for different efficiency 

levels. A more detailed analysis of the engineering of higher efficiency water-cooled air 

conditioners might show that some improvement can come from the reduction of supply fan 

power. One path to reducing fan power in rooftop equipment is believed to have been through 

larger case designs and consequently lower internal fan pressure drop. However, based on the 

assumption that these units are typically installed in mechanical rooms as opposed to rooftops, 

increased size may come at the expense of installation cost and available (rentable) floor space. It 

is noted that for a given EER level, assuming that improvements to the fan efficiency are used to 

reach that level, there would be less improvement to the condenser performance and less energy 

savings from the condenser portion of the packaged air conditioning system. 

The resulting UEC values for each class of water-cooled air conditioner are provided in 

chapter 4 of the TSD based on selected efficiency levels analyzed for the national energy savings 

analysis. 

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3.2.2 Evaporatively Cooled Air Conditioners 

The analysis to assess the per unit energy use of evaporatively cooled air conditioners 

began with review of the existing market (see chapter 2 of the TSD). DOE did not identify any 

current models of evaporatively cooled air conditioners less than 240,000 Btu/h cooling capacity. 

The review of the market suggested that the evaporatively-cooled equipment models currently 

available appear to be designed as packaged rooftop cooling units. Based on the available 

models identified, DOE estimated that the average capacity was 40 tons. Because of this, DOE’s 

analysis of energy savings focused on typical applications for this very large equipment class. 

Because of the large size, DOE believes that a common application would also be packaged 

VAV system serving a building. To assess energy use for evaporatively cooled equipment, DOE 

modified the 3-story office reference building model used for the water-cooled equipment 

discussed previously to serve as the simulation model for the very large evaporatively cooled air 

conditioner equipment class. 

The EnergyPlus simulation tool can model evaporatively cooled unitary air conditioners 

directly, with only minor modifications from the air-cooled unitary air conditioner equipment 

models that were used in the original DOE medium office reference building model. EnergyPlus 

offers two alternatives for modeling evaporatively cooled air conditioners. One is to use 

performance curves that characterize the steady state efficiency as a function of ambient wet bulb 

temperature and coil entering air dry bulb temperature (in contrast to the performance curves for 

air-cooled equipment, which use ambient dry bulb temperature and coil entering air dry bulb 

temperature). DOE was not able to derive separate performance curves for evaporatively cooled 

equipment as neither compressor nor overall condenser power data at different operating 

conditions was available in the manufacturer literature reviewed. Therefore, DOE utilized the 

second approach provided for in EnergyPlus, which is to use performance curves for air-cooled 

equipment that are a function of condenser entering air dry bulb conditions, but provide for a 

evaporative condenser using a evaporative condenser effectiveness parameter that reduces the 

condenser coil entering air conditions to below the ambient air temperature according to the 

equation below: 

TC,i = (Twb,o + (1 − Eff) × (Tdb,o − Twb,o) Eq. 3.2.12 

Where:
 

Tc,i = temperature of the air entering the condenser coil (°F),
 

Twb,o = wet-bulb temperature of the outdoor air (°F),
 

Tdb,o = dry-bulb temperature of the outdoor air (°F), and
 

Eff = evaporative condenser effectiveness.
 

DOE modified the medium office reference building model to use this latter modeling 

approach and defined an evaporatively cooled condenser for each of the three packaged VAV 

systems in the model. An evaporative condenser with an effectiveness of 0.9, equivalent to the 

default value in EnergyPlus, was used. 

3-10 
 

 

 

 

 

 

DOE developed estimates for the condenser-only cooling COP based on the nominal 

rating conditions. This was done by backing out the estimated fan power at nominal rating 

conditions and separately accounting for the impact of fan heat using equation 3.2.9 as discussed 

for water-cooled equipment. The fan power ratio parameter R was estimated from review of 

available manufacturer fan power data for an evaporatively-cooled rooftop air conditioner. DOE 

estimated an R of 0.137 based on review of available data for a large evaporatively cooled air 

conditioner and assuming a supply air flow rate of 350 cfm/ton of net cooling capacity.4 For an 

11.0 EER unit that DOE modeled directly, the calculated condenser-only COP was then 

estimated at 3.893. DOE used the fan power performance curves and peak fan power 

assumptions from the original reference medium office building model. 

3.2.2.1 Baseline Annual Energy Use/Ton for Climates—Evaporatively Cooled 

DOE performed simulations in the 15 climates identified previously using the 11.0 EER 

evaporatively cooled air conditioners. Equipment was sized using design day sizing. DOE 

extracted the cooling capacity, annual equipment condenser energy consumption, and blower 

energy consumption for each evaporatively cooled air conditioner equipment simulated. The 

annual energy consumption values were then normalized by dividing by the equipment capacity 

in cooling tons. The sum of the resulting condenser energy per cooling ton and blower energy 

per cooling ton represents the annual energy consumption per cooling ton for equipment at that 

11 EER efficiency level. These climate-specific results, along with the climate weights are 

shown in Table 3.2.3. 

Table 3.2.3 Normalized Energy Use Ton by Climate for Evaporatively-Cooled Air 

Conditioners, 11.0 EER 

Climate 

Zone 

Representative Climate 

Location 

Construction 

Wt. 

Annual 

Condenser 

Energy 

kWh/ton 

Annual 

Fan 

Energy 

kWh/ton 

Annual System 

Energy kWh/Ton 

1A Miami, Fl 1.82% 1683 380 2068 

2A Houston, TX 16.20% 1293 329 1626 

2B Phoenix, AZ 4.99% 1117 431 1551 

3A Memphis, TN 14.91% 979 305 1287 

3B El Paso, TX 10.15% 873 420 1295 

3C San Francisco, CA 1.82% 420 343 764 

4A Baltimore, MD 18.18% 782 318 1101 

4B Albuquerque, NM 0.72% 620 405 1027 

4C Salem, OR 2.71% 426 332 759 

5A Chicago, IL 16.96% 569 313 883 

5B Boise, ID 5.70% 448 374 823 

6A Burlington, VT 0.56% 473 340 814 

6B Helena, MT 4.62% 335 356 692 

7 Duluth, MN 0.56% 318 374 693 

8 Fairbanks, AK 0.10% 186 383 569 

Nat 100.00% 838 341 1189 

3-11 
 

 

 

 

 

 

 

 

 

 

 

 

 

3.2.2.2	 Energy Use Estimates for Baseline and Higher Efficiency Evaporatively 

Cooled Air Conditioners by Equipment Class. 

Energy use energy consumptions for representative evaporatively cooled equipment sizes 

corresponding to each product class were developed as was done for water-cooled air 

conditioners. A representative capacity for each product class was selected, as shown in Table 

3.2.4, based on the approximate average capacity of the units available in the market as identified 

in DOE’s market analysis. 

Table 3.2.4 Evaporatively Cooled Air Conditioner Representative Capacities by Product 

Class 

Product Class Representative Cooling Capacity 

Evaporatively Cooled Air Conditioner, ≥240,000 Btu/h, Electric 

Resistance Heating or No Heating 

40 tons 

Evaporatively Cooled Air Conditioner, ≥240,000 Btu/h, All Other

Heating 

40 tons 

The national average energy consumption per ton figures from Table 3.2.3 were then 

multiplied by the selected equipment capacities for the evaporatively cooled equipment class 

analyzed to establish the UEC values for the evaporatively cooled equipment classes at an 11 

EER level. 

To assess the annual energy consumption at the other efficiency levels analyzed, DOE 

developed estimates of the condenser-only cooling COP for each other efficiency level using 

equation 3.2.9. To establish annual energy consumption metrics for the higher efficiency levels, 

DOE used equation 3.2.10, adjusting the baseline annual condenser energy consumption for each 

climate by the ratio of the baseline condenser-only cooling COP at 11 EER to the condenser-only 

cooling COP at the efficiency levels analyzed. The annual fan energy consumption estimates 

were held constant at the baseline level for all higher standards. The UEC for each efficiency 

level analyzed is the sum of the annual condenser energy consumption and the annual fan energy 

consumption. 

The resulting UEC values for each class of water-cooled air conditioner are provided in 

chapter 4 of the TSD based on selected efficiency levels analyzed for the national energy savings 

analysis. 

3.2.3 Single-Package Vertical Air Conditioners and Heat Pumps 

Based on previous discussions with industry, it is estimated that approximately 60 

percent of the SPVU market goes to educational facilities, the majority of which is for space 

conditioning of modular classroom buildings. Another approximately 20 percent of the market 

may go to providing cooling for telecommunications and electronic enclosures. The remainder is 

used in a wide variety of commercial buildings including office and lodging, and is expected to 

serve more niche applications, such as modular offices buildings, within those market segments. 

For its initial estimate of energy savings for single-package vertical air conditioners 

(SPVACs) and single-package vertical heat pumps (SPVHPs), DOE focused its analysis on the 

education market and in particular modular classrooms. To estimate the energy use of SPVACs 

3-12 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

and SPVHPs in educational facilities, DOE developed a modular classroom building model for 

use with the EnergyPlus software. Characteristics of the modular classroom building model used 

in this analysis are provided in appendix 7A. 

The modular classroom was based on a double-wide modular building design with 1,568 

ft2 of floor area (56 by 28 ft). Wood-frame construction, consistent with known modular 

classroom design, was used. Envelope performance characteristics were established using the 

requirements in ANSI/ASHRAE/IESNA 90.1-2004 to approximate a mix of existing stock and 

new construction.5 Schedules and load profiles were taken from classroom space building zones 

in the DOE primary school reference building models.

c Internal loads were based on direct 

equipment power (watts per square foot) and occupancy figures for the DOE primary school 

reference building model. Lighting power requirements were based on ASHRAE 90.1-2004, 

which was selected to be representative of a mix of existing classroom lighting power in the 

building stock and in recent construction. Because of the small size of the SPVAC equipment, 

an economizer was not assumed in the model, consistent with current and historical requirements 

found in ASHRAE 90.1. DOE notes that local jurisdictions may have building codes for 

education buildings that differ from ASHRAE 90.1 in this respect, but it has not examined this at 

the state or local code level for this analysis. 

DOE simulated this building in each of the 15 climates discussed for water-cooled air 

conditioners and evaporatively cooled air conditioners. Simulations were done for the buildings 

with SPVAC equipment and electric resistance heating, and then separately for the same 

buildings with SPVHP equipment. DOE used the current Federal standard efficiencies of 9.0 

EER for SPVAC equipment and 9.0 EER and 3.0 COP for SPVHP equipment in the less than 

65,000 Btu/h size range. 

3.2.3.1	 Fan and Condenser Power Assumptions: Single-Package Vertical Air 

Conditioners 

Fan power at the baseline efficiency levels was based on manufacturer’s reported fan 

power consumption data for a 3.5 ton SPVAC.

6 From the manufacturer’s literature, at 208/230 

Volts, the reported motor current draw was 3.3 amps. From this, DOE estimated the fan power 

to be 686 watts or 0.49 watts/cfm at the manufacturer’s defined external static pressure of 0.3 in. 

H2O. Based on DOE’s market analysis, all SPVAC and SPVHP equipment at the baseline 

efficiency levels used permanent split capacitor (PSC) blower motors. From the data reviewed, 

DOE established the baseline fan power ratio (R), as used in equation 3.2.9, was 0.15 for this 

equipment. Using equation 3.2.9 to develop the condenser-only cooling COP from this value of 

R for a baseline 9.0 COP unit yields a condenser-only cooling COP of 3.279. 

For modeling the supply fan energy consumption, DOE used a combined fan and fan 

motor efficiency of 0.313, corresponding to a fan motor efficiency of 0.54 and a fan efficiency of 

0.58. Rearranging the variables in equation 3.2.7 for fan power, DOE estimated that the total fan 

static pressure corresponding to the 0.49 watts/cfm identified from the product literature would 

be 1.3 inches. DOE used these supply fan and fan motor efficiencies and total static pressure 

c The commercial reference building models are available on DOE’s website as EnergyPlus input files at: 

<http://www1.eere.energy.gov/buildings/commercial_initiative/new_construction.html>. 

3-13 
 

 

 

 

 

 

 

 

 

 

 

 

estimate as inputs to the EnergyPlus modeling of the baseline unit. For modeling of baseline 

equipment fan power, these values provide for the estimate of total supply fan power for units 

installed in the field. 

DOE first performed simulations for SPVAC equipment at a baseline 9.0 EER. From the 

annual simulation results for SPVAC equipment, DOE extracted the condenser energy use for 

cooling, the blower energy use, and equipment capacity. From these, DOE developed the annual 

cooling energy per ton and annual blower energy per ton for the baseline efficiency simulated. 

These per-ton values were then added together and then multiplied by the average cooling 

capacity estimated for SPVU in the less than 65,000 Btu/h capacity range to arrive at the baseline 

UEC for SPVAC. This average unit capacity was estimated at 3 tons. Table 3.2.5 shows the 

annual energy use per ton data for the baseline SPVAC equipment by climate region and at a 

national levels based on construction wts. Weighting factors for each climate are based on 

average of overall weighting factors for primary and for secondary school buildings by climate 

zone based on square feet of construction of these building types from 2003–2007.3 

Table 3.2.5 Normalized Energy Use Ton by Climate for SPVAC, Baseline (9.0 EER) 

Zone Construction 

Wt. 

Annual 

Condenser 

Cooling 

Energy 

kWh/ton 

Annual 

Fan 

Energy 

kWh/ton 

Annual System Energy 

kWh/ton 

1A 1.46% 2868 761 3630 

2A 15.99% 2088 729 2817 

2B 2.56% 2351 893 3244 

3A 18.48% 1557 740 2297 

3B 8.24% 2000 1074 3074 

3C 1.02% 986 878 1865 

4A 18.94% 1085 757 1842 

4B 0.61% 1597 1102 2699 

4C 2.19% 967 849 1817 

5A 20.85% 802 788 1590 

5B 4.31% 1166 1135 2301 

6A 0.80% 740 781 1521 

6B 3.80% 940 1153 2094 

7 0.64% 301 849 1151 

8 0.10% 372 1241 1613 

Nat 100.00% 1397 823 2220 

To estimate the UEC for higher efficiency SPVAC levels, DOE recognized that the 

available market data indicated that higher EER equipment were much more likely to use 

electronically commutated motor (ECM) blower motors and have resulting lower blower motor 

power. DOE analyzed available products on the market and classified them into units with PSC 

and units with ECM motors. Based on examination of SPVAC and SPVHP models less than 

65,000 Btu/h, DOE developed estimates of the likelihood of an SPVAC or SPVHP unit having 

an ECM motor at each efficiency level. Based on the data available, DOE estimated the fraction 

of units with ECM motor at selected efficiency levels as shown in Table 3.2.6 based on review of 

manufacturer’s literature for equipment at various efficiency levels. 

3-14 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DOE estimated the blower motor power for units using ECM motors at 0.37 W/cfm 

based on a 71 percent efficiency ECM blower motor, or 75.8 percent of the fan power estimated 

for the baseline unit with a PSC blower motor. Using the estimated fraction of units at each 

efficiency levels with ECM and PSC motors, DOE developed an adjustment factor for the fan 

energy/ton (kfan) which it applied to the fan energy/ton figures from the baseline simulations. In 

this estimate of national energy savings potential, DOE did not analyze the potential for fan 

energy savings from variable speed operation with ECM blower motors. 

For the analysis of UEC at higher efficiency levels, DOE scaled the baseline condenser 

cooling energy/ton by the condenser-only cooling COP calculated for higher efficiency levels 

using equation 3.2.9. DOE scaled the fan energy/ton by the kfan factors for SPVAC as shown in 

Table 3.2.6. 

Table 3.2.6 Blower Power Adjustments for ECM Motor 

EER Estimated Fraction 

of SPVAC Market 

with ECM Blower 

Estimated Fraction 

of SPVHP Market 

with ECM Blower 

Relative Blower 

Power Compared 

to Modeled 9.0 

EER Unit 

SPVAC (kfan) 

Relative Blower 

Power Compared 

to Modeled 9.0 

EER Unit 

SPVAC (kfan) 

9.0 (Baseline)* 0 0 1.000 1.000 

9.5 0.25 0.25 0.939 0.939 

10 0.5 0.5 0.879 0.879 

11 0.66 1 0.840 0.758 

12 1 1 0.758 0.758 

*PSC motor assumed in baseline simulation. 

The condenser energy per ton and blower energy per ton at each efficiency level analyzed 

were then added together and the result multiplied by the 3-ton average capacity to develop 

SPVAC UEC for each higher efficiency level analyzed, or in equation form, 

UECEER = CAP × [CondUECn × 

COPCU_Cool_Modeled + kfan_EER × FanUECn] Eq. 3.2.13 COPCU_Cool_EER

Where:
 

CAP = nominal equipment capacity in cooling tons,
 

UECEER = unit energy consumption at the specific EER level being evaluated,
 

CondUECn = normalized condenser energy consumption from the modeling, kWh/ton –
 

national basis, 

COPCU_Cool_Modeled = the cooling condenser-only COP used in the simulation model, 

COPCU_Cool_EER = the cooling condenser-only COP corresponding to the specific EER level 

being evaluated, 

kfan_eer = fan power multiplier (kfan) for each efficiency level for SPVAC, and 

FanUECn = normalized condenser energy consumption from the modeling, kWh/ton – 

national basis. 

3-15 
 

 

 

 

 

 

 

 

 

 

3.2.3.2 Single-Package Vertical Heat Pump Analysis 

The analysis method for SPVHP was carried out in a similar fashion as was done for 

SPVAC; however, the analysis for SPVHP also included the heating energy from the simulation 

results. As with most heat pumps, SPVHP equipment uses electric resistance backup heat to 

supplement the compressor heating capability as needed. For SPVHP analysis, DOE modified 

the modular classroom building model to use a heat pump with electric resistance backup 

heating. In addition to the annual condenser energy for cooling and fan energy that were 

extracted from the simulation results for SPVAC, DOE extracted the condenser heating energy 

and the backup electric resistance heating energy. Each of these energy consumption values was 

normalized on a per-cooling ton basis as was done for SPVAC analysis. 

For each SPVHP heating efficiency analyzed, the condenser heating energy use per ton 

was adjusted using an estimate of the heating-only condenser COP at the rating condition for that 

efficiency level. The calculation of the heating-only condenser COP is based on the fan power 

ratio parameter (R) and the rated high temperature heating COP at 47 °F. The equation relating 

these parameters is 

COPHeat−R COPCUHeat = 

1−R Eq. 3.2.14 

Where:
 

COPHeat = Heating COP rating of the equipment being modeled,
 

R = ratio of supply fan power to total equipment power at the AHRI rating
 

condition, and 

COPCU_Heat = condensing-only heating COP at rated conditions. 

From the SPVHP simulation results at the baseline 9.0 EER and 3.0 COP levels, DOE 

extracted the compressor cooling energy, blower energy, compressor heating energy, backup 

electric resistance heating energy, and the cooling capacity and from these developed per ton 

energy consumption figures for each of these four electric loads. The results by climate and for 

the nation are shown in Table 3.2.7. These per-ton energy figures summed and multiplied by the 

nominal capacity provide the UEC for SPVHP at the modeled EER and COP assuming the fan 

power levels modeled for baseline equipment. 

3-16 
 

 

 

 

 

 

 

 

 

 

 

Table 3.2.7 Normalized Energy Use Ton by Climate for SPVHP, Baseline (9.0 EER/3.0 

COP) 

Zone Construction 

Wt. 

Annual 

Condenser 

Cooling 

Energy 

kWh/ton 

Annual 

Condenser 

Heating 

Energy 

kWh/ton 

Annual 

Supplemental 

Heating 

Energy 

kWh/ton 

Annual 

Fan 

Energy 

kWh/ton 

Annual System Energy 

kWh/ton 

1A 1.46% 2871 16 3 761 3650 

2A 15.99% 2090 306 100 727 3222 

2B 2.56% 2352 90 11 889 3342 

3A 18.48% 1557 672 385 737 3350 

3B 8.24% 2002 410 118 1070 3600 

3C 1.02% 989 663 196 869 2717 

4A 18.94% 1084 1275 1223 752 4334 

4B 0.61% 1597 1007 709 1095 4409 

4C 2.19% 969 1101 319 840 3229 

5A 20.85% 802 1664 2509 783 5757 

5B 4.31% 1166 1574 1826 1129 5695 

6A 0.80% 738 1502 5179 775 8193 

6B 3.80% 941 1469 4773 1147 8329 

7 0.64% 303 1450 5769 845 8367 

8 0.10% 372 857 13595 1238 16062 

Nat. 100.00% 1397 981 1218 819 4414 

To estimate the annual energy consumption for SPVHP at higher efficiency levels and 

different combinations of EER and COP, DOE modified the approach used for SPVAC to 

incorporate changes in the annual condenser heating energy for higher COP equipment. In 

addition to the adjustments for cooling and fan energy discussed for SPVAC, DOE scaled the 

annual condenser heating energy by the condenser-only heating COP calculated for each higher 

efficiency level in accordance with equation 3.2.14. DOE did not adjust the supplemental 

heating energy as it would not be affected by changes in heating COP rating. The equation for 

calculating annual energy consumption at efficiency levels other than those modeled is shown 

below. 

UECEER,COP = CAP × [CondUECcool,n × 

COPCU_Cool_Modeled + CondUECheat,n ×

COPCU_Cool_EER

COPCU_Heat_Modeled + UECHeat_Supp,n + kfan_EER × FanUECn] Eq. 3.2.15 COPCU_Heat_COP

Where: 

CAP = nominal equipment capacity in cooling tons, 

UECEER,COP = unit energy consumption at the specific EER and COP level being 

evaluated, 

CondUECCool,n = normalized condenser cooling energy consumption from the modeling, 

kWh/ton – national basis, 

CondUECHeat,n = normalized condenser heating energy consumption from the modeling, 

kWh/ton – national basis, 

3-17 
 

 

 

 

 

 

 

 

 

 

COPCU_Cool_Modeled =	 the cooling condenser-only COP used in the spreadsheet equipment 

model, 

COPCU_Cool,EER =	 the cooling condenser-only COP corresponding to the specific EER level 

being evaluated, 

COPCU_Heat_Modeled =	 the heating condenser-only COP used in the spreadsheet equipment model, 

COPCU_Heat_COP =	 the heating condenser-only COP corresponding to the specific COP level 

being evaluated, 

UECHeat_Supp,n = normalized condenser energy consumption from the modeling, kWh/ton – 

national, 

kfan_eer = fan power multiplier (kfan) for each higher EER level from Table 3.2.6 for 

SPVHP, and 

FanUECn = normalized condenser energy consumption from the modeling, kWh/ton – 

national. 

The resulting UEC values for each class of SPVHP are provided in chapter 4 of the TSD 

based on selected EER and COP efficiency levels analyzed for the national energy savings 

analysis. 

3-18 
 

 

 

 

 

 

 

 

 

 

REFERENCES
 

1.	 Carrier Corporation. OMNIZONETM Indoor Self-Contained Systems. Farmington, CT. 

(Last accessed April 2011.) 

<http://xpedio.carrier.com/idc/groups/public/documents/marketing/04-850275-25.pdf> 

2. Carrier Corporation. Carrier Product Data Remote Air-Cooled and Water-Cooled Indoor 

Self- contained Systems and Water Source Heat Pumps. 50BV-4PD.pdf. (Last accessed 

March 2011.) 

<http://www.commercial.carrier.com/commercial/hvac/carrier/0,3068,CLI1_DIV12_ETI12 

690_MID4412,00.html> 

3. Jarnagin RE, and GK Bandyopadhyay. 2010. Weighting Factors for the Commercial 

Building Prototypes Used in the Development of ANSI/ASHRAE/IESNA Standard 90.1-

2010. Pacific Northwest National Laboratory: Richland, WA. PNNL-19116. 

<http://www.pnl.gov/main/publications/external/technical_reports/PNNL-19116.pdf> 

4. Trane. Packaged IntelliPakTM Rooftop Systems 20 to 130 tons. Product catalog for 

Packaged Rooftop Air Conditioners IntellipakTM – S*HL,S*HK. (Last accessed April 

2011.) <http://www.trane.com/COMMERCIAL/DNA/View.aspx?i=1102> 

5. ASHRAE. 2004. ANSI/ASHRAE/IESNA Standard 90.1-2004, Energy Standard for 

Buildings Except Low-Rise Residential Buildings. American Society of Heating, 

Refrigerating and Air-Conditioning Engineers, Atlanta, Georgia. 

6. Bard Manufacturing Company, Inc. Bard Product Specifications. BARD WA-Series 

Product Data. S3208.pdf (Last accessed January 2011.) 

<http://www.bardhvac.com/tech_cntr_specs.shtml> 

3-19 
 

 

 

 

 

 

 

CHAPTER 4. NATIONAL ENERGY SAVINGS ANALYSIS 

TABLE OF CONTENTS 

4.1 INTRODUCTION .............................................................................................................. 4-1
 

4.2 NATIONAL ENERGY SAVINGS CALCULATION....................................................... 4-2
 

4.3 INPUTS TO THE NES CALCULATION ......................................................................... 4-5
 

4.3.1 Shipments................................................................................................................ 4-5
 

4.3.2 Unit Electricity Consumption ............................................................................... 4-12
 

4.3.3 Product Lifetime ................................................................................................... 4-22
 

4.3.4 Site-to-Source Energy Conversion Factors........................................................... 4-22
 

4.3.5 Effective Dates and Analysis Period..................................................................... 4-24
 

4.4 NES RESULTS................................................................................................................. 4-25
 

LIST OF TABLES 

Table 4.3.1 Historical Water-Cooled Commercial Air Conditioner Shipments......................... 4-6
 

Table 4.3.6 UECs: Small Water Cooled Equipment with Electric Resistance or No Heat (8 ton 

Table 4.3.7 UECs: Small Water Cooled Equipment with Other Heat (8 ton representative
 

Table 4.3.8 UECs: Large Water Cooled Equipment with Electric Resistance or No Heat (15 ton 

Table 4.3.9 UECs: Large Water Cooled Equipment with Other Heat (15 ton representative
 

Table 4.3.10 UECs: Very Large Water Cooled Equipment with Electric Resistance or No Heat
 

Table 4.3.11 UECs: Very Large Water Cooled Equipment with Other Heat (35 ton 

Table 4.3.12 UECs: Very Large Evaporatively Cooled Equipment with Electric Resistance or
 

Table 4.3.13 UECs: Very Large Evaporatively Cooled Equipment with Other Heat (40 ton 

Table 4.3.18 Efficiency Distributions and Market Weighted-Average UECs: Small Water
 

Table 4.3.19 Efficiency Distributions and Market Weighted-Average UECs: Small Water
 

Table 4.3.2 Historical Water-Cooled Commercial Air Conditioner Shipments......................... 4-7
 

Table 4.3.3 Projected Commercial Water-Cooled Air Conditioner Shipments.......................... 4-8
 

Table 4.3.4 Projected SPVU Shipments ..................................................................................... 4-9
 

Table 4.3.5 Shipments Used in the Analysis: Historical Trend Scenario................................. 4-11
 

representative capacity) ..................................................................................................... 4-12
 

capacity)............................................................................................................................. 4-12
 

representative capacity) ..................................................................................................... 4-13
 

capacity)............................................................................................................................. 4-13
 

(35 ton representative capacity) ......................................................................................... 4-13
 

representative capacity) ..................................................................................................... 4-13
 

No Heat (40 ton representative capacity)........................................................................... 4-14
 

representative capacity) ..................................................................................................... 4-14
 

Table 4.3.14 UECs: SPVAC 1-Phase <65,000 Btu/h (3 ton representative capacity) ............ 4-15
 

Table 4.3.15 UECs: SPVAC 3-Phase <65,000 Btu/h (3 ton representative capacity) ............ 4-15
 

Table 4.3.16 UECs: SPVHP 1-Phase <65,000 Btu/h (3 ton representative capacity).............. 4-15
 

Table 4.3.17 UECs: SPVHP 3-Phase <65,000 Btu/h (3 ton representative capacity)............. 4-15
 

Cooled Equipment with Electric Resistance or No Heat................................................... 4-18
 

Cooled Equipment with Other Heat................................................................................... 4-18
 

4-i 
 

Table 4.3.20 Efficiency Distributions and Market Weighted-Average UECs: Large Water
 

Cooled Equipment with Electric Resistance or No Heat................................................... 4-18
 

Table 4.3.21 Efficiency Distributions and Market Weighted-Average UECs: Large Water
 

Table 4.3.22 Efficiency Distributions and Market Weighted-Average UECs: Very Large Water
 

Table 4.3.23 Efficiency Distributions and Market Weighted-Average UECs: Very Large Water
 

Table 4.3.24 Efficiency Distributions and Market Weighted-Average UECs: Very Large 

Table 4.3.25 Efficiency Distributions and Market Weighted-Average UECs: Very Large 

Table 4.3.26 Efficiency Distributions and Market Weighted-Average UECs: Small Single-Phase 

Table 4.3.27 Efficiency Distributions and Market Weighted-Average UECs: Small Three-Phase 

Table 4.3.28 Efficiency Distributions and Market Weighted-Average UECs: Small Single-Phase 

Table 4.3.29 Efficiency Distributions and Market Weighted-Average UECs: Small Three-Phase 

Table 4.4.1 National Energy Savings for Water and Evaporatively Cooled Products (Quads, 

Table 4.4.2 National Energy Savings for Water and Evaporatively Cooled Products (Quads, 

Cooled Equipment with Other Heat................................................................................... 4-19
 

Cooled Equipment with Electric Resistance or No Heat................................................... 4-19
 

Cooled Equipment with Other Heat................................................................................... 4-19
 

Evaporatively Cooled Equipment with Electric Resistance or No Heat............................ 4-20
 

Evaporatively Cooled Equipment with Other Heat ........................................................... 4-20
 

SPVAC............................................................................................................................... 4-21
 

SPVAC............................................................................................................................... 4-21
 

SPVHP ............................................................................................................................... 4-21
 

SPVHP ............................................................................................................................... 4-22
 

Table 4.3.30 Site-to-Source Conversion Factors ...................................................................... 4-23
 

2013–2042 or 2014-2043): Based on Historical Trends.................................................... 4-25
 

2013–2042 or 2014-2043): Shipments Fixed to 2009 ....................................................... 4-25
 

Table 4.4.3 National Energy Savings for SPVUs (Quads, 2017-2046).................................... 4-27
 

LIST OF FIGURES 

Figure 4.2.1 Flow Diagram of National Energy Savings Calculation ........................................ 4-3
 

Figure 4.4.1 National Energy Savings for Water and Evaporatively Cooled Products by Product
 

Figure 4.4.2 National Energy Savings for Water and Evaporatively Cooled Products by Product
 

Figure 4.3.1 Projection of Commercial Water-Cooled AC Shipments ...................................... 4-7
 

Figure 4.3.2 Relationship between EER and COP for 1-Phase SPVHPs ................................. 4-16
 

Figure 4.3.3 Relationship between EER and COP for 3-Phase SPVHPs ................................. 4-16
 

Class: Historical Trends..................................................................................................... 4-26
 

Class: Shipments Fixed to 2009......................................................................................... 4-26
 

Figure 4.4.3 National Energy Savings for SPVUs by Product Class ....................................... 4-27
 

4-ii 
 

 

 

 

 

4.1 INTRODUCTION 

This chapter describes the national energy savings (NES) analysis for water- and 

evaporatively-cooled products as well as SPVUs. Each subsection of this chapter discusses each 

of these product categories in separate sections. 

Water and Evaporatively Cooled Products 

The NES for water- and evaporatively-cooled products considers the ASHRAE standard 

level as well as several higher efficiency standard levels. The effective date of a standard 

depends upon the standard selected and the product class. For purposes of this analysis, the 

Department assumed the effective date of such a standard would be 2013 (for small products 

under the ASHRAE standard), 2014 (for large and very large products under the ASHRAE 

standard), or 2017 (for all products under standards higher than ASHRAE). 

The Department analyzed the National Energy Savings (NES) of amended energy 

conservation standards for the following eight product classes of commercial water and 

evaporatively cooled air conditioning equipment: (1) small water-cooled with electric resistance 

or no heating (65-135 kBtu/h), (2) small water-cooled with other heating (65-135 kBtu/h), (3) 

large water-cooled with electric resistance or no heating (135-240 kBtu/h), (4) large watercooled with other heating (135-240 kBtu/h), (5) very large water-cooled with electric resistance 

or no heating (240-760 kBtu/h), (6) very large water-cooled with other heating (240-760 kBtu/h), 

(7) very large evaporatively cooled with electric resistance or no heating (240-760 kBtu/h), and 

(8) very large evaporatively cooled with other heating (240-760 kBtu/h). 

The Department examined various standard levels for each class of equipment, including 

the ASHRAE Standard 90.1 2010 efficiency level, the maxtech level (the highest efficiency level 

of equipment currently on the market), and several levels between. The baseline for each level is 

the current federal energy conservation standard. 

SPVUs 

The NES for SPVUs considers several levels of efficiency standards higher than the 

existing federal conservation standard, and up to the maxtech level. For the purposes of this 

analysis, the Department assumed the effective date of such a standard would be 2017 (all 

efficiency levels are higher than ASHRAE standards). 

The Department analyzed the NES of amended energy conservation standards for the 

following four classes of commercial SPVUs: (1) single phase SPVACs under 65,000 Btu/h, (2) 

three phase SPVACs under 65,000 Btu/h, (3) single phase SPVHPs under 65,000 Btu/h, and (4) 

three phase SPVHPs under 65,000 Btu/h. 

4-1 
 

 

4.2 NATIONAL ENERGY SAVINGS CALCULATION 

Water and Evaporatively Cooled Products 

Figure 4.2.1 illustrates the inputs, intermediate values, and outputs of the NES 

calculation. The NES is the difference between the national energy consumption in the base case 

(i.e., the case without amended energy conservation standards) and the standards case (i.e., the 

case with amended energy conservation standards). The Department developed a spreadsheet 

model to calculate the NES from air conditioning equipment standards for eight product classes 

of interest to this analysis. 

4-2
 
 

 

 

NES Inputs 

Calculated Values 

NES Output 

Historical 

Shipments 

Product Class 

Market Shares 

Product Lifetime 

Baseline Unit 

Electricity 

Consumption 

Unit Electricity 

Consumption (at 

each EER under 

consideration) 

Site-to-Source 

Energy 

Conversion 

Analysis Period 

Base Case UEC 

Market Shares 

Standards Case 

UEC Market 

Shares 

Projected 

Shipments 

Projected 

Shipments 

by Product 

Class 

Base Case 

Unit 

Electricity 

Consumption 

Standards 

Case Unit 

Electricity 

Consumption 

Annual 

Electricity 

Savings 

National 

Energy 

Savings 

Figure 4.2.1 Flow Diagram of National Energy Savings Calculation 

For each product class and standards case, DOE calculated the total energy savings using 

a stock accounting method. Using historical shipments provided by AHRI, DOE forecasted 

shipments into the future using two scenarios: (1) based on historical trend, and (2) fixed to 2009 

levels. The number of new shipments in any given year is assumed to remain in the commercial 

building stock for a total of 15 years (the assumed lifetime of the product), at which point that 

entire year’s shipments disappears from existing stock. In this way, the total stock, or number of 

surviving units, in any given year is the sum of that year’s shipments plus the shipments from the 

previous 14 years. 

4-3
 
 

 

 

 

 

 

 

 

 

 

 

 

 

The annual base total energy use in any given year is the sum product of the shipments 

for that year and the previous 14 years and the market weighted average base UECa in each 

relevant year (multiplied by a site to source conversion factor). 

n

Annual Base Total Energy Useyear=n = ෍ Shipmentsyear × Base UECyear

year=n−14

As currently modeled, the base UEC remains constant throughout time. As a result, in the 

calculation above, Base UECyearcould be moved outside the summation terms as Base UEC. 

The annual standards case total energy use in any given year is the sum product of the 

shipments for that year and the previous 14 years and the market weighted average standards 

case UECb in each relevant year (multiplied by a site to source conversion factor). 

Annual Standards Case Total Energy Useyear=n n

= ෍ Shipmentsyear × Standards UECyear

year=n−14

Prior to the analysis period, the standards case UEC is equal to the Base UEC, as 

standards have not yet become effective. Therefore, in the earlier part of the analysis period, 

energy savings accrue from only the newer units in the building stock. Later in the analysis 

period, all units in the building stock will have the lower standards UEC (as they were all 

shipped within the analysis period) and will be providing energy savings. 

The annual energy savings is the difference between the base case total energy use and 

the standards case total energy use. 

Annual Energy Savingsyear=n

= Annual Base Total Energy Useyear=n

− Annual Standards Case Total Energy Useyear=n

DOE calculated the cumulative energy savings over the analysis period by summing the 

annual energy savings for each year in the analysis period. The analysis period differs by 

product, as discussed in the next section. 

a As will be discussed later, the market weighted average base UEC is based on the distribution of efficiencies under 

the current federal standards (base case). It includes products both meeting and exceeding the current federal 

minimum efficiency. It is not the UEC for a product at a specified EER. 

b The market weighted average standards UEC is based on the distribution of efficiencies under a given amended 

federal standards scenario. It may include products both meeting and exceeding the given amended federal standards 

level (with the exception of the Max Tech scenario, in which it is assumed that no product exceeds the amended 

federal standards level). It is not the UEC for a product at a specified EER. 

4-4
 
 

 

 

 

 

 

 

 

 

 

 

 

x+29

Cumulative Energy Savings = ෍ Annual Energy Savingsyear

year=x

For the ASHRAE standard, the cumulative energy savings are presented as above. For 

higher efficiency levels, the Department calculates cumulative energy savings as net of 

ASHRAE standard energy savings, as that is the presumed default. 

Net Cumulative Energy Savingshigher efficiency standard

= Cumulative Energy Savingshigher efficiency standard

− Cumulative Energy SavingsASHRAE standard

SPVUs 

The NES calculation for the four classes of SPVUs of interest to this rulemaking follows 

the same method described above for water- and evaporatively-cooled equipment, with two 

exceptions. The first is that because this analysis is not based on the ASHRAE standard, the 

cumulative energy savings for all efficiency levels are presented as gross energy savings (not net 

of any standard such as ASHRAE). The second is that for SPVHPs, energy saving for heating 

based on COP are taken into account: 

Annual Base Total Energy Useyear=n n

= ෍ Shipmentsyear × (Base UECyear + Base UEC_heatyear) 

year=n−14

Annual Standards Case Total Energy Useyear=n n

= ෍ Shipmentsyear × (Standards UECyear + Standards UEC_heatyear) 

year=n−14

4.3 INPUTS TO THE NES CALCULATION 

The following sections discuss and document the inputs to the calculation of the NES. 

4.3.1 Shipments 

4.3.1.1 Historical Shipments 

Water and Evaporatively Cooled Products 

The Department obtained historical water-cooled commercial air conditioner shipment 

data from AHRI. While AHRI provided shipments in the categories small, large, and very large, 

it is important to note that AHRI tracks large up to 249 kBtu/h, while the federal standards limit 

4-5
 
 

 

 

 

the large category to 240 kBtu/h. Throughout this analysis, DOE used AHRI data to represent the 

large category. Table 4.3.1 shows historical shipments from 1989 through 2009. 

Table 4.3.1 Historical Water-Cooled Commercial Air Conditioner Shipments 

Year 

Small AC 

(65-134.9 kBtu/h) 

Large AC 

(135-249 kBtu/h) 

Very Large AC 

(250 & Over kBtu/h) 

1989 1,437 793 1,622 

1990 1,503 779 1,211 

1991 1,107 621 908 

1992 1,068 537 720 

1993 985 520 668 

1994 922 504 815 

1995 1,121 493 805 

1996 1,217 652 1,020 

1997 989 522 1,216 

1998 795 623 1,886 

1999 874 477 898 

2000 1,478 1,621 1,170 

2001 606 409 762 

2002 502 355 1,227 

2003 390 287 740 

2004 447 291 711 

2005 177 188 861 

2006 316 278 1,231 

2007 359 317 1,231 

2008 282 311 1,390 

2009 152 182 585 

Source: AHRI. 

SPVUs 

The Department relied upon SPVU shipment data from the Energy Efficiency Standards for 

Certain Commercial and Industrial Equipment: Efficiency Standards for Commercial Heating, 

Air Conditioning, and Water Heating Equipment Technical Support Document, Including: 

Packaged Terminal Air Conditioners and Packaged Terminal Heat Pumps, Small Commercial 

Packaged Boilers, Three-Phase Air Conditioners and Heat Pumps <65,000 Btu/h, SinglePackage Vertical Air Conditioners and Single-Package Vertical Heat Pumps<65,000 Btu/h, 

March 2, 2006. In this document, the Department provided 2005 shipments based on ARI 

estimates, as shown in Table 4.3.2. 

4-6
 
 

 

 

 

 

 

 

 

 

 

 

Table 4.3.2 Historical Water-Cooled Commercial Air Conditioner Shipments 

Year 

SPVAC < 

65,000 Btu/h, 

single-phase 

SPVHP < 

65,000 Btu/h, 

single-phase 

SPVAC < 

65,000 Btu/h, 

three-phase 

SPVHP < 

65,000 Btu/h, 

three-phase 

2005 31,976 13,125 14,301 6,129 

Source: ARI Estimate. 

4.3.1.2 Projected Shipments 

Water and Evaporatively Cooled Products 

The Department estimated future shipments using the historical data provided by AHRI. 

The small and large AC categories show an exponential trend, yielding very few shipments in the 

future. (Note that the data points for year 2000 were removed as outliers to facilitate identifying 

historical trends.) The very large AC shipments show no trend, although a linear fit shows a 

slowly decreasing forecast. Figure 4.3.1 shows the extrapolations, and Table 4.3.3 shows 

projected shipments for 2010 through 2043. 

Ship = 6.42E+89e-1.00E-01 * Year 

R2 = 8.60E-01 

Ship = 2.16E+55e-6.07E-02 * Year 

R2 = 8.08E-01 

Ship = -4.19 * Year + 9,399.48 

R2 = 0.01 

0 

200 

400 

600 

800 

1000 

1200 

1400 

1600 

1800 

2000 

1988 1992 1996 2000 2004 2008 2012 2016 2020 2024 2028 2032 2036 2040 

Shipments 

Year 

Small AC (65-134.9) 

Large AC (135-249) 

Very Large AC (250 & Over) 

Expon. (Small AC (65-134.9)) 

Expon. (Large AC (135-249)) 

Linear (Very Large AC (250 & Over)) 

Figure 4.3.1 Projection of Commercial Water-Cooled AC Shipments 

4-7
 
 

 

 

 

Table 4.3.3 Projected Commercial Water-Cooled Air Conditioner Shipments 

Year 

Small AC 

(65-134.9 kBtu/h) 

Large AC 

(135-249 kBtu/h) 

Very Large AC 

(350 & Over kBtu/h) 

2010 208 215 986 

2011 189 203 982 

2012 171 191 978 

2013 154 179 974 

2014 140 169 970 

2015 126 159 965 

2016 114 150 961 

2017 103 141 957 

2018 93 132 953 

2019 85 125 949 

2020 76 117 944 

2021 69 110 940 

2022 63 104 936 

2023 57 98 932 

2024 51 92 928 

2025 46 87 923 

2026 42 81 919 

2027 38 77 915 

2028 34 72 911 

2029 31 68 907 

2030 28 64 903 

2031 25 60 898 

2032 23 57 894 

2033 21 53 890 

2034 19 50 886 

2035 17 47 882 

2036 15 44 877 

2037 14 42 873 

2038 13 39 869 

2039 11 37 865 

2040 10 35 861 

2041 9 33 856 

2042 8 31 852 

2043 8 29 848 

SPVUs 

The Department projected shipments of SPVUs according to the average growth rate of 

2.18 percent noted in the 2006 TSD. This was based on analysis of ARI data for commercial 

unitary AC products 65,000 Btu/h to 240,000 Btu/h for DOE’s commercial unitary AC and HP 

rulemaking. Table 4.3.4 shows the projected SPVU shipments. 

4-8 
Table 4.3.4 Projected SPVU Shipments 

Year 

SPVAC < 

65,000 Btu/h, 

single-phase 

SPVHP < 

65,000 Btu/h, 

single-phase 

SPVAC < 

65,000 Btu/h, 

three-phase 

SPVHP < 

65,000 Btu/h, 

three-phase 

2006 32,673 13,411 14,613 6,263 

2007 33,385 13,703 14,931 6,399 

2008 34,113 14,002 15,257 6,539 

2009 34,857 14,307 15,589 6,681 

2010 35,617 14,619 15,929 6,827 

2011 36,393 14,938 16,277 6,976 

2012 37,187 15,264 16,631 7,128 

2013 37,997 15,596 16,994 7,283 

2014 38,826 15,936 17,364 7,442 

2015 39,672 16,284 17,743 7,604 

2016 40,537 16,639 18,130 7,770 

2017 41,420 17,002 18,525 7,939 

2018 42,323 17,372 18,929 8,112 

2019 43,246 17,751 19,341 8,289 

2020 44,189 18,138 19,763 8,470 

2021 45,152 18,533 20,194 8,655 

2022 46,136 18,937 20,634 8,843 

2023 47,142 19,350 21,084 9,036 

2024 48,170 19,772 21,544 9,233 

2025 49,220 20,203 22,013 9,434 

2026 50,293 20,643 22,493 9,640 

2027 51,389 21,094 22,984 9,850 

2028 52,510 21,553 23,485 10,065 

2029 53,654 22,023 23,997 10,284 

2030 54,824 22,503 24,520 10,508 

2031 56,019 22,994 25,054 10,737 

2032 57,240 23,495 25,600 10,972 

2033 58,488 24,007 26,158 11,211 

2034 59,763 24,531 26,729 11,455 

2035 61,066 25,065 27,311 11,705 

2036 62,397 25,612 27,907 11,960 

2037 63,758 26,170 28,515 12,221 

2038 65,148 26,741 29,137 12,487 

2039 66,568 27,324 29,772 12,759 

2040 68,019 27,919 30,421 13,038 

2041 69,502 28,528 31,084 13,322 

2042 71,017 29,150 31,762 13,612 

2043 72,565 29,785 32,454 13,909 

2044 74,147 30,435 33,162 14,212 

2045 75,764 31,098 33,885 14,522 

2046 77,415 31,776 34,623 14,839 

4-9
 
 

 

 

 

The Department also used the 2.18 percent growth rate to project backwards from 2005 

to estimate shipments that would still be in the product stock during the NES analysis period. 

4.3.1.3 Product Class Market Shares and Projected Shipments by Product Class 

Water and Evaporatively Cooled Products 

The Department could not identify data that would allow the shipments provided by 

AHRI to be separated into products with electrical resistance or no heating, and those with other 

types of heating. However, the Department believes that most small and large water-cooled 

equipment do not provide heating, and as a result assigned 90% of shipments in those categories 

to the no-heating class, and 10% to the other heating class. For very large equipment, the 

Department believes that most equipment are roof-top units that are combined with gas furnaces, 

and as a result assigned 10% of very large shipments to the no-heating class and 10% to the other 

heating class. 

The Department identified nine models of very large evaporatively-cooled equipment, 

but no shipment data were available. For this product class, the Department used the ratio of very 

large evaporative to water cooled models on the market (9:35) and applied this to the water 

cooled shipments to estimate evaporatively cooled shipments. The same fraction as for very large 

water cooled equipment was used to separate units into the heating categories. 

DOE used two shipment scenarios in the analysis: one using the trends identified from 

historical data, and another with future shipments fixed to the 2009 value. Table 4.3.5 shows the 

shipments used for all the product classes in this analysis using the historical shipment scenario. 

This is based on the AHRI historical data, the forecasted shipments, and the attribution of the 

shipments to the specific product classes. No table is provided for the shipment scenario in which 

future shipments are fixed to the 2009 level. 

4-10
 
Table 4.3.5 Shipments Used in the Analysis: Historical Trend Scenario 

Year 

Small 

Water 

E/N 

65-135 

Small 

Water 

O 

65-135 

Large 

Water 

E/N 

135-240 

Large 

Water 

O 

135-240 

VL 

Water 

E/N 

240-760 

VL Water 

O 

240-760 

VL Evap 

E/N 

240-760 

VL Evap 

O 

240-760 

1999 787 87 429 48 90 808 23 208 

2000 1,330 148 1,459 162 117 1,053 30 271 

2001 545 61 368 41 76 686 20 176 

2002 452 50 320 35 123 1,104 32 284 

2003 351 39 258 29 74 666 19 171 

2004 402 45 262 29 71 640 18 165 

2005 159 18 169 19 86 775 22 199 

2006 284 32 250 28 123 1,108 32 285 

2007 323 36 285 32 123 1,108 32 285 

2008 254 28 280 31 139 1,251 36 322 

2009 137 15 164 18 59 526 15 135 

2010 187 21 194 21 99 887 25 228 

2011 170 19 183 20 98 884 25 227 

2012 154 17 172 19 98 880 25 226 

2013 139 15 161 18 97 877 25 226 

2014 126 14 152 17 97 873 25 224 

2015 113 13 143 16 97 868 25 223 

2016 103 11 135 15 96 865 25 222 

2017 93 10 127 14 96 861 25 221 

2018 84 9 119 13 95 858 24 221 

2019 77 8 113 12 95 854 24 220 

2020 68 8 105 12 94 850 24 219 

2021 62 7 99 11 94 846 24 218 

2022 57 6 94 10 94 842 24 217 

2023 51 6 88 10 93 839 24 216 

2024 46 5 83 9 93 835 24 215 

2025 41 5 78 9 92 831 24 214 

2026 38 4 73 8 92 827 24 213 

2027 34 4 69 8 92 823 24 212 

2028 31 3 65 7 91 820 23 211 

2029 28 3 61 7 91 816 23 210 

2030 25 3 58 6 90 813 23 209 

2031 23 2 54 6 90 808 23 208 

2032 21 2 51 6 89 805 23 207 

2033 19 2 48 5 89 801 23 206 

2034 17 2 45 5 89 797 23 205 

2035 15 2 42 5 88 794 23 204 

2036 14 1 40 4 88 789 23 203 

2037 13 1 38 4 87 786 22 202 

2038 12 1 35 4 87 782 22 201 

2039 10 1 33 4 87 778 22 200 

2040 9 1 32 3 86 775 22 199 

2041 8 1 30 3 86 770 22 198 

2042 7 1 28 3 85 767 22 197 

2043 7 1 26 3 85 763 22 196 

4-11
 
 

 

 

 

SPVUs 

For SPVUs, the projected shipments shown in the previous section represent the extent of 

disaggregation necessary for the product classes of interest to this rulemaking. 

4.3.2 Unit Electricity Consumption 

4.3.2.1 Unit Electricity Consumption per EER 

Water and Evaporatively Cooled Products 

For each of the eight product classes, the Department identified a single representative 

capacity based on the approximate average capacity of models identified in the AHRI directory 

and through reviews of manufacturer websites. The UEC data are shown in Table 4.3.6 through 

Table 4.3.13. The UECs are from the energy use analysis (Chapter 3) and represent the energy 

use of a product at a specified EER. 

Table 4.3.6 UECs: Small Water Cooled Equipment with Electric Resistance or No Heat (8 

ton representative capacity) 

Efficiency Level EER UEC 

Baseline 11.5 9,199 

ASHRAE Standard 12.1 8,855 

13 EER 13.0 8,396 

14 EER 14.0 7,953 

15 EER 15.0 7,566 

Max Tech 16.4 7,101 

Table 4.3.7 UECs: Small Water Cooled Equipment with Other Heat (8 ton representative 

capacity) 

Efficiency Level EER UEC 

Baseline 11.3 9,322 

ASHRAE Standard 11.9 8,966 

13 EER 13.0 8,396 

14 EER 14.0 7,953 

15 EER 15.0 7,566 

Max Tech 16.4 7,101 

4-12
 
 

 

 

 

 

Table 4.3.8 UECs: Large Water Cooled Equipment with Electric Resistance or No Heat 

(15 ton representative capacity) 

Efficiency Level EER UEC 

Baseline 11.0 17,838 

ASHRAE Standard 12.5 16,206 

13 EER 13.0 15,743 

14 EER 14.0 14,911 

15 EER 15.0 14,186 

Max Tech 16.1 13,490 

Table 4.3.9 UECs: Large Water Cooled Equipment with Other Heat (15 ton 

representative capacity) 

Efficiency Level EER UEC 

Baseline 11.0 17,838 

ASHRAE Standard 12.3 16,402 

13 EER 13.0 15,743 

14 EER 14.0 14,911 

15 EER 15.0 14,186 

Max Tech 16.1 13,490 

Table 4.3.10 UECs: Very Large Water Cooled Equipment with Electric Resistance or No
 

Heat (35 ton representative capacity)
 

Efficiency Level EER UEC 

Baseline 11.0 41,621 

ASHRAE Standard 12.4 38,041 

13 EER 13.0 36,733 

14 EER 14.0 34,793 

Max Tech 14.8 33,422 

Table 4.3.11 UECs: Very Large Water Cooled Equipment with Other Heat (35 ton 

representative capacity) 

Efficiency Level EER UEC 

Baseline 10.8 42,205 

ASHRAE Standard 12.2 38,504 

13 EER 13.0 36,733 

14 EER 14.0 34,793 

Max Tech 14.8 33,422 

4-13
 
 

 

 

 

Table 4.3.12 UECs: Very Large Evaporatively Cooled Equipment with Electric Resistance 

or No Heat (40 ton representative capacity) 

Efficiency Level EER UEC 

Baseline 11.0 47,171 

ASHRAE Standard 11.9 44,732 

12.5 EER 12.5 43,294 

Max Tech 13.1 41,983 

Table 4.3.13 UECs: Very Large Evaporatively Cooled Equipment with Other Heat (40 ton 

representative capacity) 

Efficiency Level EER UEC 

Baseline 10.8 47,766 

ASHRAE Standard 11.7 45,243 

12.5 EER 12.5 43,294 

Max Tech 13.1 41,983 

SPVUs 

For each of the four SPVU product classes, the Department identified a single 

representative capacity (3 ton) based on the approximate average capacity of models identified in 

the AHRI directory. The UEC data are shown in Table 4.3.14 through Table 4.3.17. The UECs 

are from the energy use analysis and represent the energy use of a product at a specified EER. 

For SPVHPs, the Department determined heating UECs for the heating COPs that 

correspond to the EER of each efficiency level examined. Heating COPs in the AHRI directory 

range from 3.0 to 3.5. However, the relationship between EER and COP is not exceptionally 

clear. Using the linear relationships shown in Figure 4.3.2 and Figure 4.3.3, the heating COPs 

used in this analysis range from 3.00 to 3.36. 

4-14
 
 

 

 

 

Table 4.3.14 UECs: SPVAC 1-Phase <65,000 Btu/h (3 ton representative capacity) 

Efficiency Level EER UEC 

Baseline 9.0 6,660 

9.5 EER 9.5 6,301 

10 EER 10.0 5,962 

11 EER 11.0 5,537 

12 EER 12.0 5,057 

Max Tech 12.6 4,911 

Table 4.3.15 UECs: SPVAC 3-Phase <65,000 Btu/h (3 ton representative capacity) 

Efficiency Level EER UEC 

Baseline 9.0 6,660 

9.5 EER 9.5 6,301 

10 EER 10.0 5,962 

11 EER 11.0 5,537 

12 EER 12.0 5,057 

Max Tech 12.6 4,911 

Table 4.3.16 UECs: SPVHP 1-Phase <65,000 Btu/h (3 ton representative capacity) 

Efficiency Level EER UEC 

Heating 

COP 

Heating 

UEC 

Baseline 

9.5 EER 

10 EER 

11 EER 

12 EER 

Max Tech 

9.0 

9.5 

10.0 

11.0 

12.0 

12.5 

6,648 

6,290 

5,952 

5,325 

5,048 

4,925 

3.01 

3.06 

3.11 

3.21 

3.31 

3.36 

6,280 

6,234 

6,189 

6,105 

6,026 

5,988 

Table 4.3.17 UECs: SPVHP 3-Phase <65,000 Btu/h (3 ton representative capacity) 

Efficiency Level EER UEC 

Heating 

COP 

Heating 

UEC 

Baseline 

9.5 EER 

10 EER 

11 EER 

12 EER 

Max Tech 

9.0 

9.5 

10.0 

11.0 

12.0 

12.5 

6,648 

6,290 

5,952 

5,325 

5,048 

4,925 

3.00 

3.05 

3.09 

3.18 

3.27 

3.32 

6,281 

6,240 

6,201 

6,126 

6,055 

6,021 

4-15
 
 

 

 

 

COP COP 

3.6 

3.5 

3.4 

3.3 

3.2 

3.1 

3 

2.9 

y = 0.1018x + 2.0895 

R2 = 0.4561 

9 9.5 10 10.5 11 11.5 12 12.5 

EER 

Figure 4.3.2 Relationship between EER and COP for 1-Phase SPVHPs 

3.6 

3.5 

3.4 

3.3 

3.2 

3.1 

3 

2.9 

y = 0.0896x + 2.1978 

R2 = 0.3534 

9 9.5 10 10.5 11 11.5 12 12.5 

EER 

Figure 4.3.3 Relationship between EER and COP for 3-Phase SPVHPs 

4-16
 

13 

13 
 

 

 

 

 

 

 

 

4.3.2.2	 Base Case and Standards Case Market Shares and Market Weighted 

Average UEC 

The UECs associated with the base case and standards case scenarios – or market 

weighted average UECs – are dependent on the market shares of products at each efficiency 

level and the UECs for products at each efficiency level (shown in the previous section). In the 

NES, the market shares are based on model distributions as a proxy for shipment distributions. 

Water and Evaporatively Cooled Products 

The Department did not have available data on shipments by efficiency level, so it relied 

on the AHRI certified products directory as well as reviews of manufacturer websites to identify 

models of water-cooled commercial AC products. The Department then created base case 

efficiency distributions based on these models. The AHRI certified directory does not list 

evaporatively-cooled equipment, and the models found on manufacturer websites had limited 

efficiency information. As a result, the Department created base case efficiency distributions 

based on very large air-cooled equipment in the AHRI directory. These distributions were 

bumped up 1.0 EER based on the approximate difference between the federal standards for these 

equipment categories. 

When creating base case efficiency distributions for both water and evaporatively cooled 

products, the Department binned models into efficiency levels in a manner that created a market 

weighted-average EER approximately equal to the full distribution EER. The Department 

assumed that this base case market share remained the same throughout the analysis period. 

For each of the efficiency levels or standards cases analyzed within a given equipment 

class, the Department used a “rollup” scenario to establish the market shares by efficiency level 

for the year that standards become effective (as well as subsequent years). Information available 

to DOE suggests that the efficiencies of equipment in the base case that did not meet the standard 

level under consideration would roll up to meet the standard level. In addition, available 

information suggests that all equipment efficiencies in the base case that were above the standard 

level under consideration would not be affected. 

DOE calculated the market-weighted average UEC values for each standards scenario 

using the distribution of efficiencies as well as the capacity-weighted average UECs for each 

EER being analyzed. The market-weighted average UEC value represents the average energy use 

of the total units shipped under a specified amended standard level. DOE used the market 

weighted average UEC values to calculate the annual energy use of the equipment class at a 

given amended standard level. For each standards case scenario: 

Max Tech

Mkt Wtd Avg UEC = ෍ Market ShareLevel × Capacity Wtd Avg UECLevel

Level=Baseline

Table 4.3.18 through Table 4.3.25 shows the distribution of efficiencies within the base 

case and the rollup scenarios to establish the distribution of efficiencies in the standards cases for 

each equipment class. In addition, the market weighted average UEC (based on the rollup 

4-17
 
 

 

 

 

distribution) is shown for each standard case under consideration. Efficiency distributions do not 

change over time except from base case to standards case on the relevant effective date. 

Table 4.3.18 Efficiency Distributions and Market Weighted-Average UECs: Small Water 

Cooled Equipment with Electric Resistance or No Heat 

Standard 

Scenario 

EER 

Market 

Weighted 

Average 

UEC 

11.5 

(11.5-11.8) 

12.1 

(11.9-12.5) 

13 

(12.6-13.4) 

14 

(13.5-14.4) 

15 

(14.5-15.6) 

16.4 

(15.7-16.4) 

Base Case 7% 27% 13% 13% 20% 20% 8,088 

ASHRAE 

Standard 34% 13% 13% 20% 20% 8,065 

13 EER 47% 13% 20% 20% 7,912 

14 EER 60% 20% 20% 7,705 

15 EER 80% 20% 7,473 

Max Tech 100% 7,101 

Table 4.3.19 Efficiency Distributions and Market Weighted-Average UECs: Small Water
 

Cooled Equipment with Other Heat
 

Standard 

Scenario 

EER 

Market 

Weighted 

Average 

UEC 

11.3 

(11.3-11.7) 

11.9 

(11.8-12.5) 

13 

(12.6-13.4) 

14 

(13.5-14.4) 

15 

(14.5-15.6) 

16.4 

(15.7-16.4) 

Base Case 7% 27% 13% 13% 20% 20% 8,126 

ASHRAE 

Standard 34% 13% 13% 20% 20% 8,102 

13 EER 47% 13% 20% 20% 7,912 

14 EER 60% 20% 20% 7,705 

15 EER 80% 20% 7,473 

Max Tech 100% 7,101 

Table 4.3.20 Efficiency Distributions and Market Weighted-Average UECs: Large Water
 

Cooled Equipment with Electric Resistance or No Heat
 

Standard 

Scenario 

EER 

Market 

Weighted 

Average 

UEC 

11.0 

(11.0-11.5) 

12.5 

(11.6-12.7) 

13 

(12.8-13.4) 

14 

(13.5-14.4) 

15 

(14.5-15.5) 

16.1 

(15.6-16.1) 

Base Case 29% 21% 7% 7% 29% 7% 15,776 

ASHRAE 

Standard 50% 7% 7% 29% 7% 15,309 

13 EER 57% 7% 29% 7% 15,078 

14 EER 64% 29% 7% 14,602 

15 EER 93% 7% 14,137 

Max Tech 100% 13,490 

4-18
 
 

 

 

Table 4.3.21 Efficiency Distributions and Market Weighted-Average UECs: Large Water
 

Cooled Equipment with Other Heat
 

Standard 

Scenario 

EER 

Market 

Weighted 

Average 

UEC 

11.0 

(11.0-11.4) 

12.3 

(11.5-12.6) 

13 

(12.7-13.4) 

14 

(13.5-14.4) 

15 

(14.5-15.5) 

16.1 

(15.6-16.1) 

Base Case 29% 21% 7% 7% 29% 7% 15,818 

ASHRAE 

Standard 50% 7% 7% 29% 7% 15,407 

13 EER 57% 7% 29% 7% 15,078 

14 EER 64% 29% 7% 14,602 

15 EER 93% 7% 14,137 

Max Tech 100% 13,490 

Table 4.3.22 Efficiency Distributions and Market Weighted-Average UECs: Very Large 

Water Cooled Equipment with Electric Resistance or No Heat
 

Standard 

Scenario 

EER Market 

Weighted 

Average 

UEC 

11.0 

(11-11.69) 

12.4 

(11.7-

12.69) 

13 

(12.7-

13.49) 

14 

(13.5-

14.39) 

14.8 

(14.4-14.89) 

Base Case 17% 20% 29% 14% 20% 36,893 

ASHRAE 

Standard 37% 29% 14% 20% 36,279 

13 EER 66% 14% 20% 35,794 

14 EER 80% 20% 34,518 

Max Tech 100% 33,422 

Table 4.3.23 Efficiency Distributions and Market Weighted-Average UECs: Very Large 

Water Cooled Equipment with Other Heat
 

Standard 

Scenario 

EER Market 

Weighted 

Average 

UEC 

10.8 

(10.8-

11.59) 

12.2 

(11.6-

12.69) 

13 

(12.7-

13.49) 

14 

(13.5-

14.39) 

14.8 

(14.4-14.89) 

Base Case 14% 23% 29% 14% 20% 36,980 

ASHRAE 

Standard 37% 29% 14% 20% 36,452 

13 EER 66% 14% 20% 35,794 

14 EER 80% 20% 34,518 

Max Tech 100% 33,422 

4-19
 
 

 

 

 

 

Table 4.3.24 Efficiency Distributions and Market Weighted-Average UECs: Very Large 

Evaporatively Cooled Equipment with Electric Resistance or No Heat
 

Standard 

Scenario 

EER 

Market 

Weighted 

Average 

UEC 

11.0 

(11.0-11.3) 

11.9 

(11.4-12.1) 

12.5 

(12.2-12.7) 

13.1 

(12.8-13.1) 

Base Case 65% 27% 6% 2% 46,166 

ASHRAE 

Standard 92% 6% 2% 44,584 

12.5 EER 98% 2% 43,265 

Max Tech 100% 41,983 

Table 4.3.25 Efficiency Distributions and Market Weighted-Average UECs: Very Large 

Evaporatively Cooled Equipment with Other Heat
 

Standard 

Scenario 

EER 

Market 

Weighted 

Average 

UEC 

10.8 

(10.8-11.2) 

11.7 

(11.3-12.0) 

12.5 

(12.1-12.7) 

13.1 

(12.8-13.1) 

Base Case 56% 35% 7% 2% 46,436 

ASHRAE 

Standard 91% 7% 2% 45,033 

12.5 EER 98% 2% 43,265 

Max Tech 100% 41,983 

SPVUs 

The Department did not have data on shipments of SPVUs by efficiency level, so it relied 

on the AHRI certified products directory to identify models of SPVUs and develop efficiency 

distributions for the base case based on these models. The Department assumed that this base 

case market share remained the same throughout the analysis period. 

For each of the efficiency levels or standards cases analyzed, the Department used a 

“rollup” scenario as described for Water and Evaporatively Cooled Equipment. The Department 

also calculated the market weighted-average UEC in the same way as shown above. 

Table 4.3.26 through Table 4.3.29 shows the distribution of efficiencies within the base 

case and the rollup scenarios to establish the distribution of efficiencies in the standards cases for 

each equipment class. In addition, the market weighted average UEC (based on the rollup 

distribution) is shown for each standard case under consideration. Efficiency distributions do not 

change over time except from base case to standards case on the relevant effective date. 

4-20
 
 

 

 

Table 4.3.26 Efficiency Distributions and Market Weighted-Average UECs: Small SinglePhase SPVAC
 

Standard 

Scenario 

EER Market 

Weighted 

Average 

UEC 

9.0 

(9.0-9.29) 

9.5 

(9.3-9.79) 

10 

(9.8-10.49) 

11 

(10.5-

11.49) 

12 

(11.5-

12.29) 

12.6 

(12.3-12.6) 

Base Case 52% 11% 15% 17% 4% 1% 6,239 

9.5 EER 63% 15% 17% 4% 1% 6,054 

10 EER 78% 17% 4% 1% 5,842 

11 EER 95% 4% 1% 5,511 

12 EER 99% 1% 5,055 

Max Tech 100% 4,911 

Table 4.3.27 Efficiency Distributions and Market Weighted-Average UECs: Small ThreePhase SPVAC
 

Standard 

Scenario 

EER Market 

Weighted 

Average 

UEC 

9.0 

(9.0-9.29) 

9.5 

(9.3-9.79) 

10 

(9.8-10.49) 

11 

(10.5-

11.49) 

12 

(11.5-

12.29) 

12.6 

(12.3-12.6) 

Base Case 34% 10% 21% 24% 9% 2% 6,023 

9.5 EER 44% 21% 24% 9% 2% 5,901 

10 EER 65% 24% 9% 2% 5,753 

11 EER 89% 9% 2% 5,479 

12 EER 98% 2% 5,053 

Max Tech 100% 4,911 

Table 4.3.28 Efficiency Distributions and Market Weighted-Average UECs: Small SinglePhase SPVHP
 

Standard 

Scenario 

EER Market 

Weighted 

Average 

Cooling 

UEC 

Market 

Weighted 

Average 

Heating 

UEC 

9.0 

(9.0-9.29) 

9.5 

(9.3-9.79) 

10 

(9.8-10.49) 

11 

(10.5-

11.49) 

12 

(11.5-

12.29) 

12.5 

(12.3-12.5) 

Base Case 37% 10% 21% 21% 9% 1% 6,017 6,192 

9.5 EER 47% 21% 21% 9% 1% 5,885 6,175 

10 EER 69% 21% 9% 1% 5,725 6,154 

11 EER 90% 9% 1% 5,295 6,096 

12 EER 99% 1% 5,047 6,025 

Max Tech 100% 4,925 5,988 

4-21
 
 

 

 

 

 

 

Table 4.3.29 Efficiency Distributions and Market Weighted-Average UECs: Small ThreePhase SPVHP
 

Standard 

Scenario 

EER 

Market 

Weighted 

Average 

Cooling 

UEC 

Market 

Weighted 

Average 

Heating 

UEC 

9.0 

(9.0-9.29) 

9.5 

(9.3-9.79) 

10 

(9.8-10.49) 

11 

(10.5-

11.49) 

12 

(11.5-

12.29) 

12.5 

(12.3-12.5) 

Base Case 26% 10% 28% 28% 7% 1% 5,909 6,191 

9.5 EER 36% 28% 28% 7% 1% 5,818 6,181 

10 EER 64% 28% 7% 1% 5,697 6,167 

11 EER 92% 7% 1% 5,299 6,119 

12 EER 99% 1% 5,046 6,054 

Max Tech 100% 4,925 6,021 

4.3.3 Product Lifetime 

For both water-cooled and evaporatively-cooled products and SPVUs, DOE estimated the 

product lifetime from the advanced notice of proposed rulemaking on Energy Conservation 

Standards for Commercial Unitary Air Conditioners and Heat Pumps published in the Federal 

Register on July 29, 2004. 69 FR 45460. The product lifetime from the prior TSD was 

estimated to be a mean of 15.4 years. More recent sources confirm this estimate including the 

2008 California Database for Energy Efficient Resources (15 years). For this preliminary 

analysis, DOE used a single-value lifetime of 15 years. 

4.3.4 Site-to-Source Energy Conversion Factors 

For both water and evaporatively cooled products and SPVUs, the Department calculated 

energy savings as site energy, which it then converted to source energy— the energy that electric 

power plants consume. As shown in Table 4.3.30, the Department used site-to-source energy 

conversion factors from the AEO 2010. The Department extrapolated the values in later years 

(after 2035) from their relative sources because the AEO does not forecast beyond 2035. To 

arrive at values for these later years, the Department used the forecast’s trend from 2025 to 2035 

to establish conversion factors in the years 2036 to 2045. 

4-22
 
Table 4.3.30 Site-to-Source Conversion Factors 

Site-to-Source Conversion Factor 

Year (Btu/kWh) 

2008 10,805 

2009 10,876 

2010 10,918 

2011 10,877 

2012 10,818 

2013 10,812 

2014 10,786 

2015 10,727 

2016 10,715 

2017 10,694 

2018 10,683 

2019 10,666 

2020 10,650 

2021 10,643 

2022 10,619 

2023 10,599 

2024 10,556 

2025 10,543 

2026 10,499 

2027 10,475 

2028 10,446 

2029 10,422 

2030 10,409 

2031 10,390 

2032 10,374 

2033 10,354 

2034 10,338 

2035 10,318 

2036 10,296 

2037 10,274 

2038 10,251 

2039 10,229 

2040 10,207 

2041 10,185 

2042 10,163 

2043 10,141 

2044 10,119 

2045 10,098 

2046 10,076 

Source: EIA, AEO 2010. 

4-23
 
 

 

 

 

 

4.3.5 Effective Dates and Analysis Period 

Water and Evaporatively Cooled Products 

For purposes of calculating the NES, the Department used an analysis period of 2013 (the 

assumed effective date of ASHRAE level standards for small products) or 2014 (the assumed 

effective date of ASHRAE level standards for large and very large products) through 2042 and 

2043, respectively. This is the standard analysis period of 30 years. While the analysis period 

remains the same for standards higher than ASHRAE, energy savings do not begin accumulating 

until 2017 (the assumed effective date of higher than ASHRAE standards). 

Generally, covered equipment to which a new or amended energy conservation standard 

applies must comply with the standard if such equipment is manufactured or imported on or after 

a specified date. 

If DOE were to propose a rule prescribing energy conservation standards at the efficiency 

levels contained in ASHRAE Standard 90.1 2010, EPCA states that any such standards shall 

become effective on or after a date which is two or three years (depending on equipment size) 

after the effective date of the applicable minimum energy efficiency requirement in the amended 

ASHRAE standard (i.e., ASHRAE Standard 90.1 2010). (42 U.S.C. 6313(a)(6)(D)) For all water 

and evaporatively cooled equipment in this rulemaking, the effective date in ASHRAE Standard 

90.1 2010 is June 1, 2011. Thus, if DOE decides to adopt the levels in ASHRAE Standard 90.1 

2010, the rule would apply to small equipment (two product classes) manufactured on or after 

June 1, 2013, which is two years from the effective date specified in ASHRAE Standard 90.1 

2010, and to large and very large equipment (six product classes) manufactured on or after June 

1, 2014, which is three years from the effective date specified in ASHRAE Standard 90.1 2010. 

If DOE were to propose a rule prescribing energy conservation standards higher than the 

efficiency levels contained in ASHRAE Standard 90.1 2010, EPCA states that any such 

standards “shall become effective for products manufactured on or after a date which is four 

years after the date such rule is published in the Federal Register.” (42 U.S.C. 6313(a)(6)(D)) 

Thus, for products which DOE might adopt a level more stringent than the ASHRAE efficiency 

levels, the rule would apply to products manufactured on or after April 29, 2017, which is four 

years from the date of publication of the final rule that DOE must meet for higher than ASHRAE 

efficiency levels (30 months after publication of ASHRAE, which was October 29, 2010). 

SPVUs 

For purposes of calculating the NES for SPVUs, DOE used a 30-year analysis period of 

2017-2046. As all efficiency levels being considered for SPVUs are higher than the ASHRAE 

efficiency levels, any rule adopted would apply to products manufactured on or after a date 

which is four years from the date of publication of the final rule adopting standards higher than 

the ASHRAE efficiency levels (30 months after publication of the revised ASHRAE Standard 

90.1, which was October 29, 2010). Under this timeline, compliance with such more-stringent 

standards would be required no later than April 29, 2017. 

4-24
 
 

 

 

 

 

4.4 NES RESULTS 

Water and Evaporatively Cooled Products 

Table 4.4.1, Table 4.4.2, Figure 4.4.1, and Figure 4.4.2 summarize the NES due to new 

energy conservation standards for the eight product classes examined. Results of the national 

energy savings analysis are provided for the two shipment case scenarios, Historical Trends and 

Fixed to 2009. Recall that all levels higher than ASHRAE are shown as net of ASHRAE 

savings. 

Table 4.4.1 National Energy Savings for Water and Evaporatively Cooled Products 

(Quads, 2013–2042 or 2014-2043): Based on Historical Trends 

Efficiency 

Level 

Small 

Water 

E/N 

65-135 

Small 

Water 

O 

65-135 

Large 

Water 

E/N 

135-240 

Large 

Water 

O 

135-240 

VL 

Water 

E/N 

240-

760 

VL Water 

O 

240-760 

VL Evap 

E/N 

240-760 

VL Evap 

O 

240-760 

ASHRAE 

Standard 0.000005 0.0000005 0.0001 0.00001 0.0002 0.002 0.0001 0.001 

13/12.5 EER 0.00002 0.000002 0.00002 0.00001 0.0001 0.001 0.00008 0.001 

14 EER 0.00004 0.000005 0.00013 0.00002 0.0005 0.005 - -

15 EER 0.00007 0.000009 0.00024 0.00003 - - - -

Max Tech 0.00012 0.000014 0.00039 0.00005 0.0008 0.008 0.00017 0.002 

Table 4.4.2 National Energy Savings for Water and Evaporatively Cooled Products 

(Quads, 2013–2042 or 2014-2043): Shipments Fixed to 2009 

Efficiency 

Level 

Small 

Water 

E/N 

65-135 

Small 

Water 

O 

65-135 

Large 

Water 

E/N 

135-240 

Large 

Water 

O 

135-240 

VL 

Water 

E/N 

240-

760 

VL Water 

O 

240-760 

VL Evap 

E/N 

240-760 

VL Evap 

O 

240-760 

ASHRAE 

Standard 0.000011 0.0000013 0.0003 0.00003 0.0001 0.001 0.0001 0.001 

13/12.5 EER 0.00006 0.000008 0.00008 0.00001 0.0001 0.001 0.00005 0.001 

14 EER 0.00014 0.000017 0.00032 0.00004 0.0003 0.003 - -

15 EER 0.00024 0.000028 0.00056 0.00007 - - - -

Max Tech 0.00039 0.000044 0.00089 0.00010 0.0005 0.005 0.00011 0.001 

4-25
 
 

 

NES (Quads) 

0.014 

0.012 

0.010 

0.008 

0.006 

0.004 

0.002 

0.000 

ASHRAE 13/12.5 14 EER 15 EER Max Tech 

VL Evap O 240-760 

VL Evap E/N 240-760 

VL Water O 240-760 

VL Water E/N 240-760 

Large Water O 135-240 

Large Water E/N 135-240 

Small Water O 65-135 

Small Water E/N 65-135 

Standard EER 

Figure 4.4.1 National Energy Savings for Water and Evaporatively Cooled Products by 

Product Class: Historical Trends 

0.009 

0.008 

0.007
 

VL Evap O 240-760
 

0.006 

ASHRAE 

Standard 

13/12.5 EER 14 EER 15 EER Max Tech 

NES (Quads) 

0.005 

0.004 

0.003 

0.002 

0.001 

0 

VL Evap E/N 240-760 

VL Water O 240-760 

VL Water E/N 240-760 

Large Water O 135-240 

Large Water E/N 135-240 

Small Water O 65-135 

Small Water E/N 65-135 

Figure 4.4.2 National Energy Savings for Water and Evaporatively Cooled Products by 

Product Class: Shipments Fixed to 2009
 

4-26 
 

 

 

SPVUs 

Table 4.4.3 and Figure 4.4.3 summarize the NES due to new energy conservation 

standards for the four product classes examined. 

Table 4.4.3 National Energy Savings for SPVUs (Quads, 2017-2046) 

Efficiency 

Level 

SPVAC 

1-phase 

< 65 

SPVAC 

3-phase 

< 65 

SPVHP 

1-phase 

< 65 

SPVHP 

3-phase 

< 65 

9.5 EER 

10 EER 

11 EER 

12 EER 

Max Tech 

0.031 

0.076 

0.139 

0.226 

0.253 

0.010 

0.023 

0.046 

0.083 

0.095 

0.012 

0.026 

0.064 

0.089 

0.101 

0.004 

0.009 

0.025 

0.037 

0.042 

NES (Quads)

0.6 

0.5 

0.4 

0.3 

0.2 

0.1 

0 

SPVHP 3 Phase 

SPVHP 1 Phase 

SPVAC 3 Phase 

SPVAC 1 phase 

9.5 EER 10 EER 11 EER 12 EER Max Tech 

Figure 4.4.3 National Energy Savings for SPVUs by Product Class 

4-27
 
 

 

 

 

REFERENCES
 

1	 Air-Conditioning, Heating, and Refrigeration Institute, Historical Shipment Data 

Commercial Air Conditioners Water Cooled, 2011. Information provided by the AirConditioning, Heating, and Refrigeration Institute (AHRI) to the U.S. Department of 

Energy, March 4, 2011. 

2	 U.S. Department of Energy, Technical Support Document: Energy Efficiency Program 

for Commercial and Industrial Equipment: Efficiency Standards for Commercial 

Heating, Air-Conditioning, and Water Heating Equipment Including Packaged Terminal 

Air-Conditioners and Packaged Terminal Heat Pumps, Small Commercial Packaged 

Boiler, Three-Phase Air-Conditioners and Heat Pumps <65,000 Btu/h, and SinglePackage Vertical Air Conditioners and Single-Package Vertical Heat Pumps < 65,000 

Btu/h, March 2006. Washington, DC. 

3	 California Public Utility Commission 2008. Database for Energy Efficient Resources. 

(Last accessed April 20, 2011.) <www.deeresources.com> 

4-28
 
           

       

   

           

       

     

                   

                     

               

                 

APPENDIX 3A. CHARACTERISTICS OF MEDIUM OFFICE REFERENCE BUILDING

MODEL AND MODULAR CLASSROOM MODEL

TABLE OF CONTENTS
 

3A.1 Introduction............................................................................................................................ 1
 

3A.2 Medium Office Reference Building Model Description ....................................................... 1
 

3A.3 Modular Classroom Building Model Description.................................................................. 9
 

LIST OF TABLES

Table 3A.2.1. Description of DOE Reference Medium Office Building Model.............................2
 

Table 3A.2.2. Key Schedules for DOE Reference Medium Office Building Model ......................8
 

Table 3A.3.1. Description of Modular Classroom Building Model ................................................9
 

Table 3A.3.2. Key Schedules for Modular Classroom Building Model........................................13
 

3A­i
 
           

       

                       

                           

                          

                              

                               

                          

                     

       

                         

   

APPENDIX 3A. CHARACTERISTICS OF MEDIUM OFFICE REFERENCE BUILDING

MODEL AND MODULAR CLASSROOM MODEL

3A.1 INTRODUCTION

The analysis of baseline energy consumption for both water­cooled air conditioners and

evaporatively cooled air conditioners discussed in chapter 3 were based on simulation data for

DOE’s medium office reference building model. This appendix provides key characteristics of the

DOE medium office reference building model which formed the basis of this data. Further details

and background may be found in the documentation and through review of the input files available

at <http://www1.eere.energy.gov/buildings/commercial_initiative/new_construction.html>.

In addition, this appendix provides key characteristics for the modular classroom model

used in the analysis of SPVAC and SPVHP energy usage.

3A.2 MEDIUM OFFICE REFERENCE BUILDING MODEL DESCRIPTION

Table 3A.2.2 provides a high level description of the DOE medium office reference

building model.

3A­1
 
Table 3A.2.1. Description of DOE Reference Medium Office Building Model

Item Description

Program

Vintage NEW CONSTRUCTION

Location(Representing 8 Climate Zones)

Zone 1A: Miami (very hot, humid)Zone 2A: Houston (hot, humid)

Zone 2B: Phoenix (hot, dry)Zone 3A: Memphis (warm, humid)

Zone 3B: El Paso (warm, dry)

Zone 3C: San Francisco(warm,marine)

Zone 4A: Baltimore (mild, humid)

Zone 4B: Albuquerque (mild, dry)

Zone 4C: Salem (mild, marine)

Zone 5A: Chicago (cold, humid)

Zone 5B: Boise (cold, dry)

Zone 6A: Burlin

Zone 6B: Helen

Zone 7: Duluth 

Zone 8: Fairba

Available fuel types gas, electricity

Building Type (Principal Building

Function)

OFFICE

Building Prototype Medium Office

Form

Total Floor Area (sq feet) 53,600

(163.8 ft x 109.2 ft)

3A­2
Item Description

Building shape

Aspect Ratio 1.5

Number of Floors 3Window Fraction(Window­to­Wall Ratio) 33%

Window Locations even distribution among all four sidesShading Geometry noneAzimuth non­directional

3A­3
eter zone depth: 15 ft.

has four perimeter zones and

ore zone.

Perimeter 40%, Core 60%

Periflooronearea

k

Frame

Nonresidential; Roofs, Insulation entirely above de

Item

Thermal Zoning Perim floor

one carea:

Floor to floor height (feet)Floor to ceiling height (feet)

Architecture

Exterior walls

ConstructionU­factor (Btu / h * ft2 * °F) and/or

R­value (h * ft2 * °F / Btu)

Roof

ConstructionU­factor (Btu / h * ft2 * °F) and/or

R­value (h * ft2 * °F / Btu)

Window

Description

meter zone depth: 15 ft. Each

has four perimeter zones and

core zone.Percentages of floor

: Perimeter 40%, Core 60%

13

9

(4 ft above­ceiling plenum)

Steel­Frame Walls

ASHRAE 90.1­1997 Requirements

Nonresidential; Walls, Above­Grade, Steel­Framed

Built­up Roof:

Roof membrane+Roof insulation+metal decking

ASHRAE 90.1 Requirements

Nonresidential; Roofs, Insulation entirely above dec

d

ck

3A­4
Item Description

U­factor (Btu / h * ft2 * °F) ASHRAE 90.1 Requirements

Nonresidential; Vertical Glazing, 31.1­40%, U_fixed

SHGC (all)Operable area 0

Foundation

Foundation Type Slab­on­grade floors (unheated)

Construction 8" concrete slab poured directly on to the earth

Thermal properties for ground level

floor

U­factor (Btu / h * ft2 * °F)

and/orR­value (h * ft2 * °F / Btu)

ASHRAE 90.1 Requirements

Nonresidential; Slab­on­Grade Floors, unheated

Infiltration

Infiltration Peak: 0.2016 cfm/sf of above grade exterior wall surface area (when fans tu

Off Peak: 25% of peak infiltration rate (when fans turn on)

HVAC

System Type

Heating type Gas furnace inside the packaged air conditioning unitCooling type Packaged air conditioning unit

Distribution and terminal units VAV terminal box with damper and electric reheating coil

Zone control type: minimum supply air at 30% of the zone design peak 

HVAC Sizing

Air Conditioning autosized to design day

Heating autosized to design day

HVAC Control

Thermostat Setpoint 75°F Cooling/70°F Heating

Thermostat Setback 80°F Cooling/60°F Heating

Economizers Various by climate location and cooling capacity

Control type: differential dry bulb

3A­5
Item Description

Ventilation ASHRAE Ventilation Standard 62.1­1999

0.10 cfm/sf.

Supply Fan

Fan schedules See under HVAC Operation Schedules, Below

Supply Fan Total Efficiency (%) 60% to 62% depending on the fan motor size

Supply Fan Pressure Drop Varies depending on the Equipment Type

Internal Loads & Schedules

Lighting

Average power density (W/ft2) ASHRAE 90.1­2004 Lighting Power Densities Using the Building Area Method

Schedule See under Schedules, Below

Daylighting Controls ASHRAE 90.1 Requirements

Occupancy Sensors ASHRAE 90.1 Requirements

Plug load

Average power density (W/ft2) 0.75

Schedule

See under Schedules, Below

Occupancy

Average people 268 Total (5 persons/1000 sf)

Schedule

See under Schedules, Below

Misc.

Elevator

Quantity 2Motor type hydraulic

Peak Motor Power

(W/elevator) 16,055

3A­6
Item Description

Heat Gain to Building Interior

Peak Fan/lights Power(W/elevator) 161.9

Exterior Lighting

Peak Power (W) 2,740Schedule See under Schedules, Below

3A­7
Table 3A.2.2. Key Schedules for DOE Reference Medium Office Building Model

Schedule Type Through Day of Week

1

am

2

am

3

am

4

am

5

am

6

am

7

am

8

am

Internal Loads Schedules

WD,

BLDG_LIGHT_SCH Fraction Through 12/31 SummerDesign 0.05 0.05 0.05 0.05 0.05 0.1 0.1 0.3 

Sat, WinterDesign 0.05 0.05 0.05 0.05 0.05 0.05 0.1 0.1 Sun, Hol, Other 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 

WD,

BLDG_EQUIP_SCH Fraction Through 12/31 SummerDesign 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 

Sat, WinterDesign 0.3 0.3 0.3 0.3 0.3 0.3 0.4 0.4 

Sun, Hol, Other 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 

BLDG_OCC_SCH Fraction Through 12/31 WD 0 0 0 0 0 0 0.1 0.2 

SummerDesign 0 0 0 0 0 0 1 1 

Sat, WinterDesign 0 0 0 0 0 0 0.1 0.1 

Sun, Hol, Other 0 0 0 0 0 0 0.05 0.05 

HVAC Schedules

WD,

HVACOperationSchd on/off Through 12/31 SummerDesign 0 0 0 0 0 0 1 1 

(Fan Schedule) Sat, WinterDesign 0 0 0 0 0 0 1 1 

Sun, Hol, Other 0 0 0 0 0 0 0 0 

Schedule Type Through Day of Week

1

pm

2

pm

3

pm

4

pm

5

pm

6

pm

7

pm

8

pm

Internal Loads Schedules

WD,

BLDG_LIGHT_SCH Fraction Through 12/31 SummerDesign 0.8 0.9 0.9 0.9 0.9 0.5 0.3 0.3 

Sat, WinterDesign 0.15 0.15 0.15 0.15 0.15 0.05 0.05 0.05 

Sun, Hol, Other 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 

WD,

BLDG_EQUIP_SCH Fraction Through 12/31 SummerDesign 0.8 0.9 0.9 0.9 0.9 0.5 0.4 0.4 

Sat, WinterDesign 0.35 0.35 0.35 0.35 0.35 0.3 0.3 0.3 Sun, Hol, Other 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 

BLDG_OCC_SCH Fraction Through 12/31 WD 0.5 0.95 0.95 0.95 0.95 0.3 0.1 0.1 

SummerDesign 1 1 1 1 1 1 1 1 Sat, WinterDesign 0.1 0.1 0.1 0.1 0.1 0.05 0.05 0 

Sun, Hol, Other 0.05 0.05 0.05 0.05 0.05 0.05 0 0 

HVAC Schedules

WD,

HVACOperationSchd on/off Through 12/31 SummerDesign 1 1 1 1 1 1 1 1 

(Fan Schedule) Sat, WinterDesign 1 1 1 1 1 1 0 0 

Sun, Hol, Other 0 0 0 0 0 0 0 0 

3A­8
3A.3 MODULAR CLASSROOM BUILDING MODEL DESCRIPTION

Table 3A.3.1. Description of Modular Classroom Building Model

Item Descriptions

Program

Vintage RECENT CONSTRUCTION

Location(Representing 8 Climate Zones)

Zone 1A: Miami (very hot, humid)Zone 2A: Houston (hot, humid)

Zone 2B: Phoenix (hot, dry)Zone 3A: Memphis (warm, humid)

Zone 3B: El Paso (warm, dry)

Zone 3C: San Francisco(warm,marine)

Zone 4A: Baltimore (mild, humid)

Zone 4B: Albuquerque (mild, dry)

Zone 4C: Salem (mild, marine)

Zone 5A: Chicago (cold, humid)

Zone 5B: Boise (cold, dry)

Zone 6A: Burlin

Zone 6B: Helen

Zone 7: Duluth 

Zone 8: Fairba

Available fuel types electricity

Building Type (Principal Building

Function)

Education

Building Prototype Modular Classroom

Form

Total Floor Area (sq feet) 1568

(56 ft x 28 ft)

3A­9
Item Descriptions

Building shape

Aspect Ratio 2

Number of Floors 1

Window Fraction(Window­to­Wall Ratio) 9.4%

Window Locations equal window area among all four sidesShading Geometry noneAzimuth Long Axis E­W

Thermal Zoning Single ZoneFloor to ceiling height (feet) 7.5

(Low Slope Attic)

Architecture

Exterior walls

Construction Wood­Frame WallsU­factor (Btu / h * ft2 * °F) and/or

R­value (h * ft2 * °F / Btu)

ASHRAE 90.1­2004 Requirements

Nonresidential; Walls, Above­Grade, Wood­Framed

Roof

3A­10
Item Descriptions

Construction

Low Attic: Insulation Layer on Ceiling, Attic Space, Wood Decking, Asph

U­factor (Btu / h * ft2 * °F) and/or

R­value (h * ft2 * °F / Btu) ASHRAE 90.1­1994 Requirements Nonresidential; Roofs, Attic

Window

U­factor (Btu / h * ft2 * °F) ASHRAE 90.1­1994 Requirements

Nonresidential; Vertical Glazing, 0­10%, U_fixed

w/Blinds

SHGC (all)Operable area 0

Foundation

Foundation Type Crawlspace

Infiltration

Infiltration Infiltration based on Airflow Net Model. 7 ACH at 50 PA . Adapted from 

Manufactured Housing Model

HVAC

System Type

Heating type Forced Air Electric Resistance or Single Package Vertical Heat P

Cooling type Single Package Vertical Air Conditioner or Heat Pump UnitDistribution and terminal units Single Zone

HVAC Sizing

Air Conditioning autosized to design day (0.4% Conditions)

Heating autosized to design day (99.6% Conditions)

HVAC Control

Thermostat Setpoint 75°F Cooling/70°F Heating

Thermostat Setback 80°F Cooling/60°F Heating

Economizers None

3A­11
Item Descriptions

Ventilation ASHRAE Ventilation Standard 62.1

20 CFM/Occupant

Supply Fan

Fan schedules See under HVAC Schedules, BelowSupply Fan Total Efficiency (%) 31% for SPVU Baseline (9.0 EER)

Supply Fan Pressure Drop (in H20) 1.3

Internal Loads & Schedules

Lighting

Average power density (W/ft2)

1.4

Based on DOE Primary School Reference Building Model and ASHR

Requirements

Schedule See under Schedules, Below

Daylighting Controls None

Occupancy Sensors None

Plug load

Average power density (W/ft2) 1.4

Based on DOE Primary School Reference Building Model and ASHR

Requirements

Schedule See under Schedules, Below

Occupancy

Average people 40 Total (25 persons/1000 sf)

Schedule See under Schedules, Below

3A­12
Table 3A.3.2. Key Schedules for Modular Classroom Building Model

Schedule Type Through Day of Week

1

am

2

am

3

am

4

am

5

am

6

am

7

am

8

am

Internal LoadsSchedules

1/1 ­ 6/30 and 9/1­

BLDG_LIGHT_SCH Fraction 12/31 WD, SummerDesign 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.9 

Sat, Sun, Hol, WinterDesign,

(Study Periods) Other 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 

BLDG_LIGHT_SCH Fraction 6/30 ­ 9/1 WD, SummerDesign 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 

Sat, Sun, Hol, WinterDesign,

(Summer Holiday) Other 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 

1/1 ­ 6/30 and 9/1­

BLDG_EQUIP_SCH Fraction 12/31 WD, SummerDesign 0.35 0.35 0.35 0.35 0.35 0.35 0.35 0.35 

Sat, Sun, Hol, WinterDesign,

(Study Periods) Other 0.35 0.35 0.35 0.35 0.35 0.35 0.35 0.35 

BLDG_EQUIP_SCH Fraction 6/30 ­ 9/1 WD, SummerDesign 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 

Sat, Sun, Hol, WinterDesign,

(Summer Holiday) Other 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 

1/1 ­ 6/15 and 9/15­

BLDG_OCC_SCH Fraction 12/31 WD, SummerDesign 0 0 0 0 0 0 0 0 

Sat, Sun, Hol, WinterDesign,

(Study Periods) Other 0 0 0 0 0 0 0 0 

BLDG_OCC_SCH Fraction 6/15 ­ 9/15 WD, SummerDesign 0 0 0 0 0 0 0 0 

Sat, Sun, Hol, WinterDesign,

(Summer Holiday) Other 0 0 0 0 0 0 0 0 

HVAC Schedules

WD, SummerDesign,

HVACOperationSchd on/off Through 12/31 WinterDesign 0 0 0 0 0 0 0 1 

Sat, Sun, Hol, Other 0 0 0 0 0 0 0 0 

Schedule Type Through Day of Week

1

pm

2

pm

3

pm

4

pm

5

pm

6

pm

7

pm

8

pm

Internal LoadsSchedules

1/1 ­ 6/30 and 9/1­

BLDG_LIGHT_SCH Fraction 12/31 WD, SummerDesign 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9 

Sat, Sun, Hol, WinterDesign,

(Study Periods) Other 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 

BLDG_LIGHT_SCH Fraction 6/30 ­ 9/1 WD, SummerDesign 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 

Sat, Sun, Hol, WinterDesign,

(Summer Holiday) Other 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 

1/1 ­ 6/30 and 9/1­

BLDG_EQUIP_SCH Fraction 12/31 WD, SummerDesign 0.95 0.95 0.95 0.95 0.95 0.35 0.35 0.35 

Sat, Sun, Hol, WinterDesign,

(Study Periods) Other 0.35 0.35 0.35 0.35 0.35 0.35 0.35 0.35 

BLDG_EQUIP_SCH Fraction 6/30 ­ 9/1 WD, SummerDesign 0.5 0.5 0.5 0.5 0.5 0.25 0.25 0.25 

(Summer Holiday) Sat, Sun, Hol, WinterDesign, 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 

3A­13
Schedule Type Through Day of Week

1

pm

2

pm

3

pm

4

pm

5

pm

6

pm

7

pm

8

pm

Other

1/1 ­ 6/15 and 9/15­

BLDG_OCC_SCH Fraction 12/31 WD, SummerDesign 0.95 0.95 0.95 0.95 0.15 0.15 0.15 0.15 

Sat, Sun, Hol, WinterDesign,

(Study Periods) Other 0 0 0 0 0 0 0 0 

BLDG_OCC_SCH Fraction 6/15 ­ 9/15 WD, SummerDesign 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 

Sat, Sun, Hol, WinterDesign,

(Summer Holiday) Other 0 0 0 0 0 0 0 0 

HVAC Schedules

WD, SummerDesign,

HVACOperationSchd on/off Through 12/31 WinterDesign 1 1 1 1 1 1 1 1 

Sat, Sun, Hol, Other 0 0 0 0 0 0 0 0 

3A­14