Byggmeister Test Home: Cold 

Climate Multifamily Masonry 

Building Condition Assessment 

and Retrofit Analysis

H. Wytrykowska, K. Ueno, and R. Van Straaten

Building Science Corporation

September 2012
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iii

Byggmeister Test Home: Cold Climate Multifamily Masonry Building 

Condition Assessment and Retrofit Analysis

Prepared for:

The National Renewable Energy Laboratory 

through the U.S. Department of Energy’s Building America Program

15013 Denver West Parkway

Golden, CO 80401

Prepared by: 

H. Wytrykowska, K. Ueno, R. Van Straaten, 

Building Science Corporation

30 Forest Street

Somerville, MA 02143

NREL Technical Monitor: Cheryn Engebrecht

Prepared under Subcontract No. KNDJ-0-40337-00

September 2012
iv

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v 

Contents

List of Figures ............................................................................................................................................ vi

List of Tables ............................................................................................................................................ viii

Definitions ................................................................................................................................................... ix

Executive Summary.................................................................................................................................... x

1 Introduction ........................................................................................................................................... 1

1.1 Context and Relevance to Other Homes.......................................................................................... 1

2 Site Assessment for Jamaica Plain Three-Family............................................................................. 2

2.1 Exterior Masonry Condition Assessment ........................................................................................ 2

2.2 Basement Condition Assessment..................................................................................................... 8

2.3 Roof Assessment............................................................................................................................ 11

2.4 Windows Assessment .................................................................................................................... 13

2.5 Airtightness Testing....................................................................................................................... 13

2.6 Mechanical System and Domestic Hot Water Assessment............................................................ 15

3 Energy Use and Modeling of Upgrade Options for Jamaica Plain Three-Family ........................ 17

3.1 Actual Energy Use (Utility Bills) .................................................................................................. 17

3.2 Energy Modeling of Upgrade Options (EnergyGauge USA Parametric)...................................... 19

3.3 Cost Effectiveness of the Retrofit Measures.................................................................................. 22

4 Retrofit Measure Discussion for Jamaica Plain Three-Family....................................................... 25

4.1 Enclosure System Upgrades .......................................................................................................... 25

4.1.1 Exterior Brick Bulk Water Control................................................................................... 25

4.1.2 Foundation Wall Insulation............................................................................................... 26

4.1.3 Basement Slab Retrofit ..................................................................................................... 28

4.1.4 Hallway Conditions and Skylight ..................................................................................... 30

4.2 Mechanical System Upgrades........................................................................................................ 31

4.2.2 Mini-Split Space Conditioning ......................................................................................... 31

4.2.3 Domestic Hot Water Equipment....................................................................................... 34

5 Masonry Insulation THERM Modeling for Jamaica Plain Three-Family........................................ 35

5.1 Interior Insulation of Tee (Party) Wall .......................................................................................... 35

5.2 Exterior Insulation of Tee (Party) Wall ......................................................................................... 40

6 Brick Freeze-Thaw Analysis for Jamaica Plain Three-Family........................................................ 44

6.1 Material Property Test Results....................................................................................................... 44

6.1.1 Dry Density....................................................................................................................... 44

6.1.2 Water Absorption Coefficient (A-value) .......................................................................... 45

6.1.3 Free Water Saturation ....................................................................................................... 45

6.1.4 Vacuum Saturation ........................................................................................................... 45

6.1.5 Critical Degree of Saturation ............................................................................................ 46

6.2 Hygrothermal Simulations............................................................................................................. 46

6.2.1 Air Leakage....................................................................................................................... 46

6.2.2 Climate Data ..................................................................................................................... 47

6.2.3 Material Properties............................................................................................................ 47

6.2.4 Assessing Freeze-Thaw Performance ............................................................................... 47

6.2.5 Simulation Model ............................................................................................................. 49

6.2.6 Other Considerations ........................................................................................................ 50

6.3 Results and Interpretation .............................................................................................................. 50

6.3.1 Freeze-Thaw Risk Conclusions........................................................................................ 52

7 Conclusions ........................................................................................................................................ 53

References................................................................................................................................................. 55

Appendix: Jamaica Plain Three-Family Heating and Cooling Manual J Results ............................... 57
vi 

List of Figures

Figure 1. Preretrofit Jamaica Plain Three-Family in Boston, Massachusetts....................................... 1

Figure 2. Exterior front and overhead view of masonry townhome project ......................................... 2

Figure 3. Front window sill and head details, showing end dams on solid stone sill ......................... 2

Figure 4. Exterior 1-in. mortar/air space and interior wall (strapping and wood lath with plaster).... 3

Figure 5. Front face brick/side brick transition (left) and brick termination at grade (right) .............. 3

Figure 6. Efflorescence pattern under window sills (left); lack of drip edge at window sill band 

detail (right)........................................................................................................................................... 4

Figure 7. Adjacent building, showing severe mortar erosion under window sills............................... 4

Figure 8. Front parapet brick condition (left) and interior side of parapet showing height (right) .... 5

Figure 9. Brick condition adjacent to front steps (left) and evidence of splashback (right)............... 5

Figure 10. Minor freeze-thaw damage visible adjacent to front doorway ............................................. 6

Figure 11. Freeze-thaw damage at front party wall (left) and doorway arch details above (right) ..... 6

Figure 12. Freeze-thaw damage and mortar erosion next to front steps at two adjacent buildings .. 7

Figure 13. Rear building elevation (left), window detail (center), and light well area (right)............... 7

Figure 14. Residual paint at rear of building (left) and scarification of brick due to abrasive 

cleaning (right)...................................................................................................................................... 8

Figure 15. Brick condition at parapet near light well (left), and chimney condition (right)................. 8

Figure 16. Evidence of capillary rise on north party wall (laundry area) .............................................. 9

Figure 17. Capillary rise on south party wall (near furnaces). Left image shows front of building. .. 9

Figure 18. Severe subfluorescence at window at light well; stone shelf below grade...................... 10

Figure 19. Rear wall near subfluorescence damage visible in basement........................................... 10

Figure 20. Front entryway wood support structure, with embedment in masonry............................ 11

Figure 21. Joists supported at sides of building in brick masonry ..................................................... 11

Figure 22. Rubber single-ply membrane roof and interior view of the third floor ceiling ................. 12

Figure 23. Roof drain (left) and stairway skylight (right) ...................................................................... 12

Figure 24. 10–12-in. parapet at front of building (left) and party walls (right) .................................... 13

Figure 25. Interior view of the windows and visual inspection of the glass....................................... 13

Figure 26. Airtightness testing; leakage at doors to hallway............................................................... 14

Figure 27. Air leakage was evident at electrical receptacles and ductwork registers....................... 14

Figure 28. Multipoint air leakage testing of Unit 2................................................................................. 15

Figure 29. Gas furnaces (left) and DHW tanks (right) ........................................................................... 16

Figure 30. 25 months’ gas usage and HDD base 65°F for Apartment 3 .............................................. 17

Figure 31. Monthly gas use (therms) versus heating degree days (HDD 65°F) .................................. 18

Figure 32. EgUSA parametric energy model, by end use, millions Btu/year source energy............ 19

Figure 33. J.P. Three-Family: BEopt optimization results—cost versus energy savings ................. 23

Figure 34. J.P. Three-Family: BEopt optimization results—source energy use................................. 24

Figure 35. Drip edges and sloped window sills are critical deflection elements (Straube 2011) ..... 26

Figure 36. Parging and mortar erosion due to capillarity (Lstiburek 2007b)...................................... 27

Figure 37. Reglet details to protect embedded beam ends (Lstiburek 2007) ..................................... 28

Figure 38. Storage use basement slab insulation/moisture control retrofit (left); cement board 

surface (right)...................................................................................................................................... 29

Figure 39. Use of air gap membrane and insulation as a “wet slab” retrofit (Lstiburek 2008)......... 30

Figure 40. Front door vestibule, showing double doors and glazing.................................................. 31

Figure 41. Mini-split wall-mounted unit (left) and recessed compact air handler (right) .................. 32

Figure 42. Transformations, Inc. floor plan (2nd floor) and J.P. Three-Family floor plan (Unit 3) ..... 33

Figure 43. Tee wall with 2-in. spray foam depicting materials, temperature, and heat flux.............. 36

Figure 44. Tee wall with 2-in. spray foam and foam at corner depicting materials, temperature, and 

heat flux............................................................................................................................................... 37

Figure 45. Tee wall with 2-in. spray foam and 1-ft. foam at corner depicting materials, temperature, 

and heat flux........................................................................................................................................ 38

Figure 46. Tee wall with 4-in. spray foam depicting materials, temperature, and heat flux.............. 39

Figure 47. Tee wall with exterior insulation (base case) depicting materials, temperature, and heat 

flux ....................................................................................................................................................... 41
vii 

Figure 48. Tee wall with extended exterior insulation depicting materials, temperature, and heat 

flux` ...................................................................................................................................................... 42

Figure 49. Capped party wall at J.P. Three-Family, and roof “wrap” over an exposed party wall ... 43

Figure 50. Confirming existing wall assembly and collecting front (east) face brick sample .......... 44

Figure 51. Confirming existing wall assembly and collecting rear (west) face brick sample........... 44

Figure 52. Freeze-thaw damage potential assessment procedure ...................................................... 49

Figure 53. WUFI 4.1 Pro model of existing wall system........................................................................ 50

Figure 54. Predicted winter conditions at back of rear face brick ....................................................... 51

Figure 55. Predicted winter conditions at back of front face brick...................................................... 52

Unless otherwise noted, all figures were created by Building Science Corporation. 
viii

List of Tables

Table 1. Air Leakage Testing Results for Unit 2 .................................................................................... 15

Table 2. Enclosure and Mechanical Characteristics: Existing Building and Deep Energy Retrofit . 20

Table 3. Manual J Design Heating and Cooling Loads per Unit........................................................... 32

Table 4. Mitsubishi Hyper-Heat Mini-Split Capacity and Rating Tables .............................................. 32

Table 5. Composite R-Values for 1-in. Cavity with Various Levels of Mortar Fill............................... 35

Table 6. Material Properties for Selected Brick ..................................................................................... 47

Unless otherwise noted, all tables were created by Building Science Corporation. 
ix

Definitions

ACH Air changes per hour

ACH50 Air changes per hour at 50 Pascal test pressure

AFUE Annual fuel utilization efficiency

ASHP Air source heat pump

ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers

BA Building America program

BEopt Building Energy Optimization (software)

BSC Building Science Corporation

ccSPF Closed-cell spray polyurethane foam

CFM Cubic feet per minute

CFM50 Cubic feet per minute at 50 Pascal test pressure

CSA Canadian Standards Association

DER Deep energy retrofit

DOE U.S. Department of Energy

DHW Domestic hot water

EgUSA EnergyGauge USA

ERV Energy recovery ventilator

FT Freeze-thaw

HERS Home Energy Rating System developed by the Residential Energy Services Network 

(RESNET).

HRV Heat recovery ventilator

HVAC Heat, ventilation, and air conditioning

ICC International Code Council, Inc.

IRC International Residential Code for One- and Two-Family Dwellings

NREL National Renewable Energy Laboratory

PV Photovoltaic

Scrit Critical degree of saturation for freeze-thaw damage to masonry (expressed as a 

decimal, e.g., 0.8)

SHGC Solar heat gain coefficient

THC Thousand Home Challenge

WUFI Wärme- und Feuchtetransport instationär
x 

Executive Summary

Building Science Corporation (BSC) seeks to further the energy efficiency market for New 

England area retrofit projects by supporting projects that are based on solid building science 

fundamentals and verified implementation. BSC has been working with Byggmeister, a partner 

on the Building America (BA) team, on retrofit projects under the BA program. Byggmeister is a 

local design-build firm that specializes in energy efficient retrofits and new construction. The 

Duclos, Eldrenkamp and Panish Energy Group (DEEP Energy Group), which is associated with 

Byggmeister, conducts design-phase energy analysis and monitors completed projects. 

The Byggmeister multifamily test home located in Jamaica Plain, Massachusetts (Jamaica Plain 

or J.P. Three-Family) is a three-story brick row house. The test home is examined with the goal 

of producing a case study that could be applied to similar New England homes. This report will 

contribute to basic areas of research, including finding the combination of measures that are

feasible, affordable, and suitable for this type of construction and acceptable to homeowners. 

For the J.P. Three-Family retrofit, BSC weighed options for insulating load-bearing masonry 

buildings on the interior while considering unique conditions such as the appearance of the 

exterior, walls and roof shared between multiple housing units, bulk water management, and the 

building’s susceptibility to freeze-thaw (FT) damage.

Energy modeling was performed with BEopt (Christensen and Anderson 2006) and 

EnergyGauge USA (Parker et al. 1999) software packages to determine energy impacts and cost 

effectiveness of various measures. While BEopt calculates estimated cost effectiveness of the 

retrofit measures, several limitations of the software prevent it from accurately modeling certain 

aspects of the building’s energy use. The EgUSA results are shown in a step-by-step parametric 

model to evaluate the impact of individual measures. In addition, utility bill/energy use data were 

examined for trends and to “tune” the energy models to some degree. 

Heat flow simulations were run using THERM 5.2 (LBNL 2003) Two-Dimensional Building 

Heat-Transfer Modeling Software to examine thermal bridging at the masonry walls. Due to the 

existing geometries of the walls, such as the tee or party walls between the units, several 

scenarios were examined for the interior and exterior insulation of the tee party walls.

In order to assess the FT risk to the bricks, material property tests were performed with the 

Wärme- und Feuchtetransport instationär (WUFI) 4.1 Pro hygrothermal simulation program. 

Simulations were conducted for both the west-facing rear wall and east-facing front wall to 

assess the impact of solar radiation and rain on different orientations and to determine the effects 

of adding thermal insulation to the inside of the walls.
1 

1 Introduction

Building Science Corporation (BSC) seeks to further the energy efficiency market for New 

England area retrofit projects by supporting projects based on solid building science 

fundamentals and verified implementation. BSC has been working with Building America (BA) 

partner, Byggmeister, a local design-build firm that specializes in energy efficient retrofits and 

new construction. The Duclos, Eldrenkamp and Panish Energy Group (DEAP Energy Group), 

which is associated with Byggmeister, provides design-phase energy analysis and conducts 

monitoring of completed projects. 

The Byggmeister multifamily test home located in the Jamaica Plain neighborhood of Boston, 

Massachusetts (J.P. Three-Family), is a three-story brick row house. BSC examined the home 

with the goal of producing a case study that could be applied to similar New England homes. 

This study contributes to several basic areas of research that include finding the combination of 

measures that are feasible, affordable, and suitable for this type of construction and that are 

acceptable to homeowners. This report also examines the package of measures considered, initial 

energy use results, material properties test results of the brick, and heat flow simulation results 

for the party walls.

This test home is a candidate to participate in the National Grid Deep Energy Retrofit Pilot 

Program (National Grid 2009), which provides financial incentives and technical support to 

participants. The program’s goal is to achieve at least 50% better energy performance than a 

code-built home. BSC has partnered with National Grid, providing technical guidance and 

support for the program. Through this partnership, BSC began working with the owner of the 

J.P. Three-Family to provide recommendations for retrofitting the building. 

1.1 Context and Relevance to Other Homes 

The J.P. Three-Family test home is a three-story row house with load-bearing mass masonry 

(brick) walls located in the Jamaica Plain neighborhood of Boston. The building and the adjacent 

properties were built circa 1906–1918. The test home is divided into three apartments: a onebedroom first floor unit and two-bedroom units on the second and third floors. All units are 

typically occupied with vacancies between rental terms that provide an opportunity to perform 

retrofit upgrades. 

Figure 1. Preretrofit Jamaica Plain Three-Family in Boston, Massachusetts 

J.P. ThreeFamily - FrontJ.P. ThreeFamily - Rear
2 

2 Site Assessment for Jamaica Plain Three-Family

2.1 Exterior Masonry Condition Assessment

The front and rear of the building are predominantly east and west exposures, respectively, 

although there is some shielded south-facing wall, due to the narrow light well at the side of the 

building. 

Figure 2. Exterior front and overhead view of masonry townhome project

The test building was cleaned and repointed more recently than identical buildings on the street 

were, as depicted in the exterior photos (Figure 2).

Figure 3. Front window sill and head details, showing end dams on solid stone sill

The front face brick is a smooth finish brick (likely chosen for appearance), with fine mortar 

joints; the transition between the front face brick and side/rear utility brick is shown in Figure 5. 

The brick wall at the front and rear of the building is two wythes thick, with a 1-in. space 

between the wythes that is filled with mortar droppings and air space. The interior is finished 
3 

with wood strapping (with an approximately1-in. air space cavity) and wood lath with horsehair 

plaster.

Figure 4. Exterior 1-in. mortar/air space and interior wall (strapping and wood lath with plaster)

The front façade has water shedding details such as stone band courses at the window sills and 

above some window heads. At grade, the brick terminates to a stone (likely granite) base course. 

This base course reduces brick capillary water uptake.

Figure 5. Front face brick/side brick transition (left) and brick termination at grade (right) 

End dams carved into the stone sills (Figure 3 and Figure 7) direct water accumulation from the 

window face out from the surface of the masonry. However, efflorescence and signs of water 

runoff were noticeable below the windows at most floors. The lack of a drip edge detail at the 

window sill band was noted (Figure 6).
4 

Figure 6. Efflorescence pattern under window sills (left); lack of drip edge at window sill band 

detail (right) 

At first, the team suspected that the efflorescence might be caused by the window sill planter 

boxes; however, adjacent identical buildings without planter boxes also showed a pattern of 

water runoff and mortar joint erosion concentrated under window sills (Figure 7).

Figure 7. Adjacent building, showing severe mortar erosion under window sills

An initial assessment of a building for freeze-thaw (FT) vulnerability starts with an examination 

of the most exposed areas, in terms of rainfall deposition and concentration, and cold 

temperatures. Typically, the most exposed and unheated area is a building’s parapet: rainfall 

accumulates at top corners, and flow of heat from the interior is reduced due to the greater 

surface area. The parapet at J.P. Three-Family showed no signs of FT damage (Figure 8). A 

metal cap detail is installed over the parapet, and the brick is detailed to enhance water shedding 

and reduce accumulation on the wall below. This detail tends to reduce risks of wetting, and 

therefore, FT damage.
5 

Figure 8. Front parapet brick condition (left) and interior side of parapet showing height (right) 

However, further assessment of the building showed some FT damage to the brick. For instance, 

there was some minor damage near the front porch, as noted in Figure 9 and Figure 10. 

Figure 9. Brick condition adjacent to front steps (left) and evidence of splashback (right)

This damage did not have a clear cause; potential causes might include water concentrations in 

the past, snow accumulation (and therefore melting) against the brick exterior, or interior versus 

exterior geometries (reduced heat flow at exterior corners). The damage at the front doorway 

(Figure 10) shows the classic face delamination issues typical of FT damage. 
6 

Figure 10. Minor freeze-thaw damage visible adjacent to front doorway

More severe FT damage was noted at the pillar at the front face of the party wall (Figure 11).

Again, an obvious single cause was not noted, but suspected causes include rainfall splashback at 

the front porch, snow accumulation against the front porch, rainwater concentration from the two 

archway details above, and exposure to extreme temperatures (the brick “fin” receives little 

thermal energy from the unheated entryways). 

Figure 11. Freeze-thaw damage at front party wall (left) and doorway arch details above (right) 

Finally, the adjacent buildings were examined, and a consistent pattern of severe FT damage was 

noted next to the front porch at the basement wall level. Potential causes noted previously might 

also apply to the FT damage in this area. 
7 

Figure 12. Freeze-thaw damage and mortar erosion next to front steps at two adjacent buildings

The rear of the J.P. Three-Family building (Figure 13) is constructed similarly to the façade 

although it has substantially less detailing and is constructed of utility-grade brick. Rear-facing

windows are capped with segmental arches and solid stone sills are used. Most of the rear 

elevation, except for the light well section, is shielded by an attached porch. 

Figure 13. Rear building elevation (left), window detail (center), and light well area (right) 

The light well area shows signs of residual exterior whitewash or paint that was at least partially 

removed in the past. The exposed brick shows signs of abrasive cleaning, such as “swirl” marks 

on the face of the brick (see Figure 14). This cleaning might have detrimental effects on the 

durability of this brick (NPS 1979). 
8 

Figure 14. Residual paint at rear of building (left) and scarification of brick due to abrasive 

cleaning (right) 

No FT damage was visible on the exterior condition survey, including at the parapet. However, 

one of the two rear chimneys tilts noticeably inward (toward the north). Both chimneys are 

uncapped and exposed to rainfall.

Figure 15. Brick condition at parapet near light well (left), and chimney condition (right) 

2.2 Basement Condition Assessment

The building is on a full basement foundation; the underground space is used for laundry, 

mechanical equipment, and tenant storage. The side walls of the basement (party walls to 

adjacent units) are full-height brick having an interior cementitious parge coat. The parge coat is 

delaminating, revealing mortar erosion and underlying brick with subfluorescence damage. The 

damage (Figure 16) is in the classic pattern of the damage caused by capillary rise from damp 

soils, as discussed by Lstiburek (2007a).
9 

Figure 16. Evidence of capillary rise on north party wall (laundry area)

The capillary rise is relatively even around the perimeter of the building, and it is anywhere from 

8 to 12 courses in height. Interior brick columns also show similar patterns of mortar and brick 

erosion due to capillary rise.

Figure 17. Capillary rise on south party wall (near furnaces). Left image shows front of building. 

On the exposed portions of the foundation (front, rear, and side light well), the foundation is 

rubble stone (likely granite) below grade and brick above grade (Figure 17). Some interior brick 

spalling was visible on the front elevation of the basement wall. 

At the side of the basement, at the light well, severe subfluorescence and delamination was seen 

near the window (Figure 18). This area had the stone-and-brick foundation noted above. 
10 

Figure 18. Severe subfluorescence at window at light well; stone shelf below grade 

The cause of this damage was apparent on the exterior of the building (Figure 19); the exterior 

grade is higher than the stone courses, resulting in buried brick courses. Moisture from the soil is 

drawn into the brickwork by capillary uptake and, interior spalling results. 

Figure 19. Rear wall near subfluorescence damage visible in basement

These water conditions should be addressed before considering the retrofit of interior insulation 

in the basement walls. Recommended solutions include exterior excavation of the basement wall, 

and possibly adding an air gap membrane at the buried portion of the brick and/or adding damp 

proofing materials to the brick exterior. 

There are several locations where wood members are embedded in the brick masonry. One case 

is at the front of the house, where a wooden beam supports the platform of the front entry of the 

building (Figure 20). Some evidence of water seepage was seen on these wood elements; 

however, when tested with a handheld moisture content meter (Delmhorst BD-10), dry 

conditions were detected (moisture content of approximately 11%). 

Exterior grade level

Grade level
11 

Figure 20. Front entryway wood support structure, with embedment in masonry

Similarly, the floor joists run laterally across the structure and are resting on masonry at the sides 

(most rest on party walls but some rest on exterior walls) of the building (Figure 21).

Figure 21. Joists supported at sides of building in brick masonry

Embedded wood members in the masonry should be addressed before applying impermeable 

interior insulation. Measures should be implemented that reduce the impact of bulk and capillary 

water at the joists ends.

2.3 Roof Assessment

The building’s flat roof was reroofed roughly 10 years ago with black, single-ply membrane. 

After reroofing, the roof leaked on multiple occasions. Leaks were primarily due to improper 

termination of the membrane at the parapet and penetration locations. The owner hired another 

company to fix the construction defects. 
12 

Figure 22. Rubber single-ply membrane roof and interior view of the third floor ceiling

Water accumulates at several low spots in the roof. The drain, located near the chimney, is often 

clogged with leaves and other debris. During the field assessment, the team noticed that the roof 

cover board under the membrane (fiberboard or similar) was “spongy,” providing evidence of 

water leakage into the assembly.

The skylight, which provides light to the building stairway, is original to the building and shows 

substantial weathering. However, it does not show signs of leakage. 

Figure 23. Roof drain (left) and stairway skylight (right)

The height of the roof parapet varies. At the front of the building, it is about 12 in. high, and the 

demising wall parapet is about 11 in. The parapet near the rear of the building is much lower, 

measuring roughly 4 in. If the owner chooses to insulate the roof on the exterior, the parapet at 

the rear of the building may need to be raised to allow for the desired amount of insulation. 
13 

Figure 24. 10–12-in. parapet at front of building (left) and party walls (right)

The ceiling cavity underneath the roof deck is roughly 12 in. deep; extensive intrusive 

disassembly was not done, so it is not clear if this cavity is a single joist height (12 in.) or if it is 

two separate framing systems.

2.4 Windows Assessment

The windows, which are less than 10 years old, appear to be in good condition. Windows are 

double-glass, vinyl-framed, with either a low-e coating or clear glazing (it is unclear from initial 

inspections). The owner is considering replacing the windows or installing storm windows to 

improve the overall thermal performance. 

Figure 25. Interior view of the windows and visual inspection of the glass

2.5 Airtightness Testing

The second-floor unit (middle unit) was tested for airtightness with a blower door and duct 

blaster.
14 

Figure 26. Airtightness testing; leakage at doors to hallway

Air leakage was evident at the hallway doors, which was expected given the lack of gaskets 

around the doors. In addition, air leakage was observed at electrical receptacles and from the 

ductwork grilles. This was not a guarded or nulled test, so results include leakage to the exterior 

and to other units. 

Figure 27. Air leakage was evident at electrical receptacles and ductwork registers

Therefore, multipoint air leakage testing was conducted with the grilles open and sealed with 

duct mask (i.e., subtraction method duct leakage test). The results are shown in Figure 28; note 

that the maximum pressure achieved was 27 Pa, so cubic feet per minute at 50 pascal test 

pressure (cfm50) results are extrapolated using the Q = C × ΔPn relationship.
15 

y = 198.84x0.6058

R2 = 0.9912

y = 171.95x0.5982

R2 = 0.9985

0

200

400

600

800

1000

1200

1400

0 5 10 15 20 25 30

Flow (CFM)

Pressure (Pa)

Ducts Open

Ducts Masked

Power (Ducts Open)

Power (Ducts Masked)

Figure 28. Multipoint air leakage testing of Unit 2

Table 1. Air Leakage Testing Results for Unit 2

cfm50 ACH50 cfm50/ft2enclosure

Unmasked 2,127 13.3 0.62

Masked 1,785 11.2 0.52

Results indicate a large total enclosure air leakage; however, results do not indicate separate air 

leakage to the exterior (which would have impact on energy consumption). However, with 

conservative estimates of two-thirds of the total leakage to the exterior, this is still equivalent to 

9 ACH at 50 pascal test pressure. In addition, 342 cfm50 is attributed to the ductwork system by 

the subtraction test. Assuming an exponent (n) value of 0.65 (in Q = C × ΔPn), this leakage is 

equivalent to 218 cfm25. Note that leakage to the exterior via the ductwork system represents a 

large portion (16%) of total enclosure leakage. However, direct testing of the duct system 

leakage was not conducted due to time constraints; only a subtraction test was done. 

Additional testing, such as guarded/nulled tests to separate interior and exterior leakage and 

whole-building (single zone) test to determine aggregate exterior air leakage, would be useful. 

2.6 Mechanical System and Domestic Hot Water Assessment

The building’s mechanical system consists of three atmospherically vented natural gas furnaces, 

one serving each housing unit. Each 80,000 Btu/h input furnace has a standing pilot light. The 

building owner has reported that the pilot lights require periodic relighting, indicating end of 

service life issues. 

Heat is distributed through the uninsulated sheet metal ductwork that is located in the basement 

and also runs through conditioned space. The ductwork was marginally sealed with cloth/rubber 

duct tape. The ductwork system has not yet been tested for leakage.
16 

Domestic hot water (DHW) is generated for each unit by a gas-fired 40-gal tank of relatively 

recent vintage. Each heater is vented atmospherically through the chimney. 

Figure 29. Gas furnaces (left) and DHW tanks (right)
17 

3 Energy Use and Modeling of Upgrade Options for Jamaica 

Plain Three-Family

3.1 Actual Energy Use (Utility Bills)

The building owner provided energy use data for the three apartment units. Unfortunately, 

electrical use data was limited to average monthly use for the three units. Average usage was 

similar for the three units, at 300, 400, and 370 kWh/month. 

Natural gas data, plotted in Figure 30, was available for 25 months for all apartments. The owner 

noted that the residents of Apartment 3 were from a warm climate and, hence, used an 

exceptionally high setpoint which resulted in the high gas usage for Apartment 3. 

0

100

200

300

400

500

600

5-096-097-098-099-09

10-0911-0912-09

1-102-103-104-105-106-107-108-109-10

10-1011-1012-10

1-112-113-114-115-11

therms/month

0

200

400

600

800

1000

1200

1400

HDD Base 65 F

Apt 1 Apt 2 Apt 3 HDD

Figure 30. 25 months’ gas usage and HDD base 65°F for all three apartments 

Because of the abnormally high usage for Apartment 3, the owner provided gas use data for 

Apartment 3 from 2008 when it was occupied by previous tenants. Instead of plotting this data 

separately, BSC generated an x-y plot of gas use (therms/month) against monthly heating degree 

days for all apartment data, as shown in Figure 31. 
18 

0

50

100

150

200

250

300

350

0 200 400 600 800 1000 1200 1400

HDD (65 F)

Therms (monthly)

Apt 1 Apt 2 Apt 3 High User Apt 3 Low User

Figure 31. Monthly gas use (therms) versus heating degree days (HDD 65°F) 

Comparing the data points for Apartment 3 in Figure 31 clearly shows the effect of occupant 

behavior on natural gas consumption. Except for the high-user in Apartment 3, all data follow 

similar patterns, with wintertime peaks in the 100–150 therms per month range and baseline (gas 

cooking plus DHW) use of approximately 20 to 25 therms per month. Given the potential effects 

of occupancy and setpoint, it is difficult to draw any conclusions on energy use due to exposure 

(i.e., Apartment 2 lower due to less exposed surface area). 

Energy use data was used to roughly calibrate the EnergyGauge USA (EgUSA) model discussed 

below. Note that the model was not extensively tuned due to the lack of knowledge of which 

input should be modified. (For instance, should infiltration, duct leakage, or insulation levels be 

changed when calibrating heating energy use?) 
19 

3.2 Energy Modeling of Upgrade Options (EnergyGauge USA Parametric)

BSC ran a set of parametric energy simulations for the prototype row house using EgUSA 

(Parker et al. 1999). EgUSA is an hourly energy modeling software package running on the U.S. 

Department of Energy’s DOE-2 engine. BSC prefers EgUSA over the Building Energy 

Optimization tool (BEopt, Christensen and Anderson 2006) for its ability to capture attributes 

such as party walls and multifamily features not currently available in BEopt. The impact of 

various upgrade options on end use loads are depicted in Figure 32. 

Characteristics of the preretrofit and postretrofit house are outlined in Table 2. 

Figure 32. EgUSA parametric energy model, by end use, millions Btu/year source energy

Each modeled upgrade is described below. Simulations were cumulative (i.e., non-branching 

simulations) such that each subsequent upgrade is in addition to all of the previous upgrades. In 

parentheses following the upgrade name is the incremental savings in percent of the base case 

and the estimated annual cost savings in dollars, assuming electricity rates of $0.16/kWh and 

natural gas cost of $1.25/therm. 

R-48 ceiling insulation (6.2%/$265): Upgrade from an uninsulated joist space to R-48 

insulation. Note that for moisture-safe performance, the requirements of International Residential 

Code for One- and Two-Family Dwellings R806.4 (International Code Council 2009) must be 

met by using minimum R-20 insulation (this could be accomplished by tapered polyisocyanurate 

to provide drainage, 3.5 in. thick, above the roof deck and under the membrane). The remaining 

R-28 insulation could be added by installing cavity fill insulation in the joist space. In reality, 

some air sealing must be done during the roof retrofit step (e.g., perimeter air seal, removing roof 

sheathing boards), but sealing is modeled as a separate step.

Wall insulation to R-16 (3.2%/$135): Upgrade from an uninsulated assembly to a minimal, 

code-compliant opaque wall insulation level, of roughly 2-in-thick closed-cell spray 

polyurethane foam (ccSPF) (or equivalent) against the interior or exterior of the masonry. 

Interior insulation will require the demolition of interior wall finishes, and reconstruction. The 

moisture impacts of interior masonry insulation are discussed in detail in sections 5 and 6. Again, 

this upgrade would improve airtightness, which is modeled as a separate step.
20 

Table 2. Enclosure and Mechanical Characteristics: Existing Building and Deep Energy Retrofit

Existing Building Proposed Deep Energy Retrofit

Building envelope

Ceiling

No ceiling insulation observed in roof joist space: no venting 

visible at membrane roof

R-20 continuous insulation (tapered polyisocyanurate; R806.4 

requirement) + dense pack cellulose (or similar) cavity 

insulation (~8" estimate; R-28), R-48 total nominal

Walls

Uninsulated: 2 wythe masonry with 1" mortar/air space 

between wythes. 1" wood strapping on interior, with wood lath 

& plaster finish (~1" thick)

Front: R-40 wall insulation: ~6.5" closed cell spray foam on 

interior of masonry wall

Rear: R-40 wall insulation: ~6.5" closed cell spray foam on 

exterior of masonry wall, or 10" EPS EIFS. Code reports 

typically call out 4" maximum for EIFS

Demising Walls

Uninsulated stud frame walls to hallway

Retrofit dense pack cellulose insulation into 2x4 walls to 

hallway (estimated full 4"; ~R-14)

Foundation (Walls) Rubble stone (below grade) and brick (above grade) basement 

walls; no insulation.

R-20 wall insulation: ~3" closed cell spray foam on interior of 

basement wall

Foundation (Slab) Uninsulated slab; varying between earth and poor quality 

concrete observed

R-10 slab insulation; current plan Utica-style retrofit of dimple 

mat, 2" XPS, and loose-laid cement board

Windows Vinyl frame double glazed with low-E coating 

(verify if possible) U=~0.35, SHGC=~0.30

Add low-E storm windows to existing double low E windows; 

U=~0.24, SHGC=~0.35

Skylight

Single glazed, metal frame (assumed) steel

High performance option: Wasco triple glazed skylight

U=~0.27, SHGC=~0.22

Infiltration 10 ACH 50 assumed value (not tested)

7.4 sq in leakage area per 100 sf of envelope area

(0.7 CFM 50 per sf enclosure area)

1.3 ACH 50 target value (tight range)

1.0 sq in leakage area per 100 sf of envelope area 

(0.1 CFM 50 per sf enclosure area)

Mechanical systems

Heat Atmospheric gas furnace located in basement; standing pilot 

light. Assume ~75% AFUE

Mitsubishi Inverter-driven mini splits; two heads (?) per unit; 

MSZ-FE**NA heat pump units

Cooling None See above

DHW 40 or 50 gallon atmospheric gas tank water heaters (one per 

unit); assume ~0.55 EF

0.82 EF instantaneous gas water heater in basement; one per 

unit

Ducts Uninsulated sheet metal in basement and through conditioned 

space (to various units). 

Assume very high leakage (~30% of airflow?) None

Ventilation

None

Fantech SH704 Heat Recovery Ventilator (HRV) 70 

CFM,~60% effective, acting as bathroom exhaust (with 

Ventech VT20M controller), supply to hall or bedroom

Return Pathways None (door undercuts) n/a

Appliances, Lighting, MELs

Appliances n/a Replace refrigerators and clothes washer (basement)

Lighting Assumed 14% fluorescent lighting 100% fluorescent lighting package

Wall insulation to R-40 (1.0%/$43): Raise the wall insulation level to that required for the 

National Grid Deep Energy Retrofit (DER) program. The incremental savings represent the 

change from R-16 to R-40 walls; in the interior insulation example, this would require 4 in. of 

ccSPF. 

Foundation wall insulation to R-20 (1.5%/$65): Add ccSPF insulation to the uninsulated brick 

and rubble stone walls. There are some secondary moisture issues that need to be addressed 

before this retrofit is undertaken. However, as a general solution, this recommended upgrade will 

resolve minor bulk moisture issues and any capillary or vapor drive issues from the soil. 

Foundation slab insulation to R-10 (0%/$0): Add R-10 insulation to the foundation slab. 

Although no energy savings are associated with this upgrade, it is a useful step for mitigating the 

risk of condensation on the basement slab and for allowing storage of porous materials without 

damage. In addition, the existing slab is a low-quality concrete with no vapor retarder. Because 

basement leakage is being reduced and will be part of the conditioned space, BSC recommends 

installing a measure to reduce evaporation due to capillarity. One example would be a slab 

insulation system (described later), which would solve this problem very effectively. Alternately, 

a vapor control layer applied to the slab (e.g., epoxy paint) could be used. 
21 

Windows to U 0.24,solar heat gain coefficient 0.22 (2.4%/$104): Add low e storm windows to 

the exterior of the existing low e double-glazed windows to raise window performance to be on 

par with a triple-glazed window (per National Grid DER program requirements). However, 

recent research suggests that this may be a problematic upgrade: LBNL research (Melton and 

Yost 2011) indicates that in direct sunlight and hot weather, this combination can result in very 

high temperatures (185°F) in the cavity between the glazing and the storm window. Therefore, 

because of the risk of premature deterioration of the existing window, BSC does not recommend 

adding low-e storm windows. 

High performance skylight U 0.27, solar heat gain coefficient 0.22 (0.1%/$4): Replace 

existing skylight with a high performance, triple-glazed, low-solar heat gain coefficient (SHGC) 

unit. The existing skylight is over the stairwell, which accesses the three units. Energy savings 

are minimal in simulations connecting the skylight to the conditioned space. Actual savings will 

likely be lower than modeled because the hallway is not intentionally conditioned. Actual 

savings may be higher, however, due to reduced air leakage through the improved skylight. 

Air leakage reduced to 0.25 cfm50/ft2

 enclosure (11.8%/$502): Conduct air sealing to 

improve air leakage to 0.25 cfm50/ft2 of building enclosure (equivalent to improving leakage to 

3.4 ACH50 from 10 ACH50). If the full set of deep energy retrofit measures is undertaken, it is 

likely (but not certain) that this airtightness level can be achieved. One issue is that the masonry 

party walls are likely to be left untouched; unparged masonry is not an air barrier, although it 

typically has low air leakage. For reference, concrete block is 0.3 l/s·m2 at 75 Pa, versus the 0.02 

l/s·m

2 at 75 Pa requirement for an air barrier material (i.e., concrete block is an order of 

magnitude leakier than the requirement). Air barrier connections between various enclosure 

elements (roof-to-wall, wall-to-foundation, wall-to-window) are critical to successfully 

improving air leakage. 

Infiltration reduced to 0.1 cfm50/ft2 enclosure (5.5%/$232): Conduct further air sealing to 

tighten the building to the equivalent of 1.3 ACH50 (from 3.4 ACH50). Achieving this 

performance level may be difficult, especially in a multifamily retrofit case.

Switch to Mitsubishi mini-split heat pump for heating and cooling (5.2%/$176 without

cooling): Replace existing gas-fired atmospheric furnace with a 23 SEER/10 HSPF mini-split 

heat pump. Savings were realized when examining heating alone; however, assuming that 

cooling is operated (in lieu of ventilation cooling), savings drop to 1.4%. This step includes 

eliminating duct losses to the basement (both leakage and conductive). As expected, gas usage 

decreases while electricity usage increases. Utility costs happen to result in a net reduction of 

source energy but a net increase in cost.

0.82 EF instantaneous gas water heater (2.6%/$110): This replaces each atmospheric gas hot 

water tank with an instantaneous gas-fired water heater. The savings above reflect the total for 

the three units (whole building).

Exhaust only ventilation, 210 cfm (-7.4%/-$375): With the air tightening measures being 

undertaken, it is necessary to add controlled mechanical ventilation to maintain acceptable 

indoor air quality. A basic exhaust-only ventilation system was simulated, at the flow rate above, 

150 W power draw (1.4 cfm/W), 50% run time, and no heat recovery. The American Society of 

Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 62.2 rate for a given unit is 

32 cfm (at 2 bedrooms); the 50% duty cycle is intended to match this rate. As can be seen, 

ventilation without heat recovery adds a substantial penalty to energy consumption. 
22 

Heat recovery, 60% effective (2.8%/$141): Add small, individual unit heat recovery ventilators 

at 70 cfm per unit (Fantech SH704 or equivalent). These systems run at 120 W, 210 cfm (total), 

and 50% run time. There are notable savings associated with reducing the thermal impact of 

controlled mechanical ventilation.

14% fluorescent to 100% fluorescent lights (3.2%/$161): Replace the default level of 

fluorescent lighting with an all-fluorescent package to substantially reduce energy use. Persistent 

savings may be difficult to achieve because occupants may change light bulbs to non-fluorescent 

lamps.

ENERGY STAR® refrigerator and washing machine (2.3%/$101): Replace refrigerators (in 

all three units) and washing machine (central laundry in basement) with ENERGY STAR-rated 

appliances. Savings include the effect of reducing domestic water heating energy use. 

Overall, the proposed package of improvements achieves energy savings of 38.2% ($1,540 per 

year) relative to the base case. 

However, further analysis of the pattern of energy use (Figure 30) reveals other interesting 

results. Multifamily housing (e.g. J.P. Three-Family) has a different energy use profile compared 

to single-family housing. Occupant-related loads (miscellaneous end use loads, DHW) are 

higher, per square foot, than in single-family homes. At the same time, enclosure loads are lower 

due to minimal exposed wall surface area, party walls which are effectively R-∞ (adiabatic 

conditions), and a relatively low glazing-to-floor area ratio. In the base case, heating represented 

42% of the total source energy use; with all upgrades incorporated, only 22% of the total source 

energy use is attributed to heating and cooling. Miscellaneous end use loads, which are 

controlled by the occupant, are greater than space conditioning loads (comprising one-third of 

the total in the benchmark case). Therefore, the effect of enclosure upgrades on energy use is 

limited in typical multifamily housing.

3.3 Cost Effectiveness of the Retrofit Measures

The cost effectiveness of the retrofit measures considered for this project was performed with 

BEopt, the Building America performance analysis tool. BEopt takes user-supplied cost data and 

energy use information for a set of energy-saving measures and optimizes combinations of 

measures for cost effectiveness. On a plot of average source energy savings per year against the 

annualized energy related costs, optimal combinations of measures form the lower bound of the 

data points. 

While BEopt calculates estimated cost effectiveness of the retrofit measures, several limitations 

of the software prevent it from accurately modeling certain aspects of the building’s energy use. 

The primary BEopt limitations relevant to this project are:

• BEopt cannot model party walls (adiabatic surfaces) or more than one wall construction 

in the same building. For the BEopt model, the estimated preretrofit and postretrofit wall 

insulation values (R-4 and R-40, respectively) were applied to all four walls when heat 

transfer at this R-value would only occur at two of the four walls. As a result, BEopt 

overestimates energy use in the preretrofit building and energy savings due to increasing 

the R-value. See “common wall” indications in Figure 42. 

• BEopt lacks the capability to include multifamily building assumptions. Although it 

allows the number of occupants to be specified, it does not factor the increased 
23 

miscellaneous loads of a multifamily home, such as the use of three refrigerators instead 

of one. This inaccuracy is likely to calculate the postretrofit model energy use as less than 

it would be in reality. 

• BEopt cannot model different values for basement wall and slab insulation; only 

basement wall insulation could be modified. This appears to be a software bug. 

• BEopt does not allow modification of heat pump or air conditioner performance ratings. 

While a SEER 23 heat pump is specified for the project, the highest SEER available in 

BEopt is 18. 

The default cost values for the Chicago Retrofit Cost Selection option were used for most of the 

inputs with the exception of wall insulation cost. Those values represent Boston area costs that 

were obtained from RS Means Reed Construction Data, a cost estimating tool that provides the 

cost of materials, installation, overhead, and profit. 

The BEopt optimization of the enclosure compared different amounts of ccSPF insulation 

applied to the interior of the above-grade walls. The two options compared were 2 in. of closed 

cell spray foam with 2 × 4 framing and 1⁄2-in. drywall (R-16) or 6 in. of ccSPF with 2 × 4 framing 

and 1⁄2-in. drywall (R-40). 

For mechanical ventilation, two options were evaluated in the optimization: exhaust-only 

ventilation at the ASHRAE Standard 62.2 rate; and whole-house ventilation at the ASHRAE 

Standard 62.2 rate with a 60% effective heat recovery ventilator. Other preretrofit and 

postretrofit building attribute details included in the BEopt model are outlined in Table 2, with 

the exception of attributes that could not be modeled precisely due to BEopt limitations.

Figure 33. J.P. Three-Family: BEopt optimization results—cost versus energy savings

BEopt simulated combinations of options and found optimal results with R-40 walls and wholehouse ventilation without the Heat Recovery Ventilator. Maximum savings projected by BEopt 

was 55.4%. 
24 

Figure 34. J.P. Three-Family: BEopt optimization results—source energy use
25 

4 Retrofit Measure Discussion for Jamaica Plain Three-Family

There are several obstacles and implementation issues for the proposed changes to the J.P. 

Three-Family building. Minor issues, discussed in the EgUSA energy analysis section, are 

summarized below. A discussion of the major issues, categorized by enclosure and mechanical 

upgrades in section 4.1, follows the brief summary of minor issues in this section. 

Ceiling insulation to R-48: Requires foam above roof deck for condensation control; roof-towall air barrier connections might require opening roof assembly from top or bottom. In addition, 

there may be knob and tube wiring in the ceiling cavities, which would require replacement with 

modern wiring. Field inspectors found non-metallic (NM) cable and metallic-sheathed cable 

(BX) in the ceiling.

Wall insulation to R-16/R-40: Masonry FT risks (see section 6), and recommendations for 

remedial bulk water control measures (see section 4.1.1).

Foundation wall insulation to R-20: Refer to section 4.1.2. 

Foundation slab insulation to R-10: Refer to section 4.1.3. 

Windows to U 0.24, SHGC 0.22: Risks of elevated temperatures and durability risks

High performance skylight U=0.27, SHGC=0.22: Value of high performance skylight in 

unconditioned stairwell 

Switch to mini-split for heating and cooling (23 SEER/10HSPF): Refer to section 4.2.2. 

0.82 EF instantaneous gas water heater: Refer to section 4.2.3. 

4.1 Enclosure System Upgrades

Several enclosure measures require special detailing to control moisture risks associated with 

adding insulation and increasing airtightness.

4.1.1 Exterior Brick Bulk Water Control

The exterior mass masonry shows signs of water accumulation under the windows due to the 

lack of a drip edge. As shown in Figure 35, a lacking or inadequate drip edge can cause bulk 

water to deposit onto the wall below a window (which is a water concentration detail due to the 

non-porous surface of the glass).
26 

Figure 35. Drip edges and sloped window sills are critical deflection elements (Straube 2011)

Therefore, in conjunction with the interior wall insulation, drip edge detailing is required at the 

window sill stone bands. Due to the geometry, the retrofit of a “notch” drip edge is not possible; 

therefore, BSC recommends using a regletted metal drip edge (cut into the masonry).

4.1.2 Foundation Wall Insulation

The foundation wall shows evidence of capillary rise (a.k.a. “rising damp”) as moisture from the 

ground is drawn into the porous brick foundation. This rising moisture results in loss of the 

surface parging, erosion of mortar joints, and damage to exposed brick surfaces, as discussed by 

Lstiburek (2007b). This process is shown graphically in Figure 36. 
27 

Figure 36. Parging and mortar erosion due to capillarity (Lstiburek 2007b)

Adding interior insulation will reduce drying potential to the interior, which will reduce the rate 

of efflorescence, subfluorescence, and mortar erosion. However, it is unknown if this might 

result in subfluorescence damage to the brick. BSC will study this in a future project, Hybrid 

Foundation Insulation Retrofits.

Another potential risk of adding interior insulation is that moisture from the ground will no 

longer dry to the interior of the basement; it is possible that the moisture might continue to rise 

upward, resulting in moisture damage to the ends of the structural wood member embedded in 

the masonry. Regletted metal details to prevent capillary transport are shown in Figure 37. Note 
28 

that the figures show rough guidelines based on the area of exposed above-grade wall; the 

interior is shown with a vapor-impermeable layer (such as spray foam).

Figure 37. Reglet details to protect embedded beam ends (Lstiburek 2007)

Another potential solution is “injectable damp proofing courses” that appear to be commonly 

available in the United Kingdom and Europe. Their installation involves drilling a horizontal 

series of holes in the mortar joint, and injecting a silane/siloxane-based cream into the holes. The 

cream is reported by manufacturers to migrate laterally, resulting in reduced capillary uptake at 

this mortar joint as silanes and siloxanes change surface tension (and therefore capillary 

transport) in porous materials. The holes are then plugged for appearance.

This product is of interest due to the simplicity of the retrofit and may be worth further study. 

However, one caution is that most commercial literature on silanes and siloxanes shows a 

migration distance in the millimeter range, as opposed to inches (the spacing of the holes 

shown), which brings into question the ability of this product to form a complete barrier to 

capillarity.

As mentioned previously, the portion of the basement wall that goes below grade must be 

addressed through excavation and moisture protection of the exterior. 

4.1.3 Basement Slab Retrofit

If the basement is used only for storage, mechanical equipment, and secondary services (e.g., 

laundry), a possible basement retrofit assembly is shown below in Figure 38. The assembly is 

composed of: 

• Existing basement slab: add leveling if required or desired. 

• Air gap membrane (Cosella-Dörken Delta-FL or equivalent): provides air barrier (all 

seams must be sealed; material must be terminated in an airtight manner at perimeter) and 

vapor control from slab/ground. It is critical that this seal is airtight; the air space under 
29 

the membrane will often be at 100% relative humidity (Figure 39) and have poor air 

quality. 

• Rigid foam insulation: Extruded polystyrene (XPS) typical; R-10 (2-in. XPS) required for 

National Grid DER program. 

• Cement tile backer board (USG Durock or equivalent) as a walking surface, loosely laid 

onto assembly, and cut around obstructions. This material is an improvement over 

plywood or OSB subflooring for several reasons. It is non-moisture sensitive, given the 

likelihood of flooring and moisture problems in basements. It also does not have the 

rigidity of plywood, and it therefore mostly conforms to the surface below. Based on our 

experience to date, adhesion of the cement board is not necessary to prevent shifting. In 

addition, leaving the cement board loose-laid allows removal in case of bulk water 

events, or for inspection of conditions under the insulation. 

Figure 38. Storage use basement slab insulation/moisture control retrofit (left); cement board 

surface (right)

As noted above, there were no significant energy savings associated with insulation of the 

basement slab, but it is recommended for moisture control. If National Grid DER program 

requirements are not being followed, it may be permissible to omit the rigid foam insulation. 

This will likely increase the risk of storage of moisture-sensitive materials (e.g., boxes) on the 

surface. However, there is some minimal R-value associated with the air gap membrane, even 

though it is bridged by dimples (roughly R-1), thus providing some thermal break from the 

concrete slab.
30 

Figure 39. Use of air gap membrane and insulation as a “wet slab” retrofit (Lstiburek 2008)

4.1.4 Hallway Conditions and Skylight

The hallway of the building (highlighted in blue in Figure 42) is not an intentionally conditioned 

space. It has limited exposure to the exterior, the front entryway door (double door with 

vestibule; see Figure 38), and the roof and skylight areas. The hallway is currently well 

connected to the basement, in terms of air leakage.

Overall, this presents a conundrum in terms of strategies for this space in a deep energy retrofit. 

It will be costly to add a high-performance skylight to this space, which is not being conditioned 

to interior setpoint. In addition, the exterior front door will be costly to retrofit as a triple 

glazed/high performance system with low air leakage, for instance, due to the arch-top transom. 

However, if the interior door is upgraded to form the thermal boundary of the apartment, the 

ceiling and wall of the vestibule, which are adjacent to conditioned space, need to be insulated. 

Furthermore, this raises the question of whether it might be worthwhile to add insulation to the 

walls between the hallway and the units. There will be a temperature difference across this wall; 

however, an air barrier would be very difficult to retrofit (likely connected through floor 

cavities). Separating the hallway from the units would also include weatherstripping (and 

possibly insulation) of the unit doors to the hallway. 
31 

Overall, the issue might be studied with a more involved multizone energy model that would 

include the effect of air leakage between these multiple spaces.

Figure 40. Front door vestibule, showing double doors and glazing

4.2 Mechanical System Upgrades

Two of the mechanical system options that require further explanation are the use of mini-split 

heat pumps to provide space heating and cooling, and the DHW systems. 

4.2.2 Mini-Split Space Conditioning

Instead of retaining and upgrading the ducted, gas-fired furnaces in the basement, the option of 

conditioning the apartment units using non-ducted (or minimally ducted) air source mini-split 

heat pumps was examined. Given the target of a deep energy retrofit, this approach holds some 

promise. Eliminating ductwork also eliminates duct leakage and conduction losses to the 

basement, not to mention the uncontrolled air exchange (infiltration/exfiltration) induced by duct 

leakage. Duct registers and grilles would be capped within the unit to disconnect them from the 

system and reduce air leakage. An additional benefit is that the chimneys could be capped or 

removed entirely if combined with the upgrade to direct vent appliances with sidewall vents. 

This eliminates a potential location for roof water leakage and reduces air leakage through the 

chimney from the basement.

Previous work with Transformations, Inc. (BSC 2011) used mini-split heat pumps in singlefamily housing (one per floor) in Massachusetts. This work demonstrated that these units could 

maintain interior setpoint using one distribution point per floor, even in a cold climate. During 

winter, the bedrooms were 0°–7°F colder than the hallway (where the mini-split head was 

located; see Figure 42). Results were strongly affected by whether the bedroom door was opened 

or closed. Overall, the consensus among practitioners of low-energy house design indicates that 

single-point (or limited) distribution should only be attempted in a cold climate in houses that are 

highly insulated (i.e., deep energy retrofit levels, with triple-glazed (or better) windows, have 

exceptional airtightness (of approximately1 ACH50 or less). 

Choices for interior mini-split units include ductless wall-mounted units or minimally ducted 

recessed ceiling units (see Figure 41). The recessed units (i.e., compact air handlers) have the 

benefit of being able to distribute conditioned air directly to more rooms (with closed doors), but 

with the downside of having a much higher installed cost per unit. In addition, these recessed 
32 

units are not currently available in combination with the low-temperature mini-split heat pumps 

on the market. 

Figure 41. Mini-split wall-mounted unit (left) and recessed compact air handler (right)

The design loads for heating and cooling were calculated with ACCA Manual J version 8 (using 

Elitesoft/Rhvac), with results shown below.

Table 3. Manual J Design Heating and Cooling Loads per Unit

Unit

Heating Load 

(kBtu/h)

Sensible Load 

(kBtu/h)

Latent Load 

(kBtu/h)

Total Load 

(kBtu/h)

Basement 2,988 1,282 0 1,282

Hallway 171 98 0 98

First (1 BR) 7,307 5,656 1,478 7,134

Second (2 BR) 8,489 6,101 1,678 7,779

Third (2 BR) 9,472 6,383 1,678 8,061

Total Building 28,427 19,520 4,834 24,354

Table 4. Mitsubishi Hyper-Heat Mini-Split Capacity and Rating Tables

MSZ-FE09NA

(0.75 ton nominal)

MSZ-FE12NA 

(1.0 ton nominal)

Rated 9,000 Btu/h 12,000 Btu/h

Capacity Range 2,800–9,000 Btu/h 2,800–12,000 Btu/h

Cooling Efficiency 26.0 SEER 23.0 SEER

47oF HSPF (Region IV) 10.0 Btu/h/W 10.6 Btu/h/W

47oF Rated Capacity 10,900 Btu/h 13,600 Btu/h

17oF Rated Capacity 6,700 Btu/h 8,300 Btu/h

17oF Maximum Capacity 12,500 (10,900 at 5°F) Btu/h 13,600 (12,500 at 5°F) Btu/h

These loads can be compared to equipment capacities for the low-temperature mini-split heat 

pumps used at the Transformations, Inc. work. The 99.6% heating design dry bulb temperature 
33 

for Boston, Massachusetts is 7.4°F. Therefore, using the mini-split unit’s maximum capacity at 

5°F (see the “Maximum Capacity” row),it appears that a single 1- ton unit would provide 

sufficient capacity at design conditions for a given floor. 

The question remains of whether a single point of distribution can be used in these floor plans. A 

comparison between the Transformation, Inc. floor plan (second floor) and the Jamaica Plain 

Three-Family (third floor unit) is shown in Figure 42 below. They are shown roughly at the same 

scale; the sizes can be compared as follows:

• Transformations, Inc. plan: 959 ft2 (including bump out) 

• Jamaica Plain Three-Family: 1,063 ft2 (including hallway; 970 ft2 without).

Figure 42. Transformations, Inc. floor plan (2nd floor) and J.P. Three-Family floor plan (Unit 3)

The J.P. Three-Family building has a more elongated floor plan than the Transformations plan, 

and the heating and cooling loads are concentrated at the front and back (at the exposed wall 

surfaces). Another potential risk is that the party walls may not be completely adiabatic, as 

assumed in the load calculations. Finally, the City of Boston has legal requirements for minimum 

temperature allowed in occupied rental units, per 105 - Code of Massachusetts Regulations 

410.000: Minimum Standards of Fitness for Human Habitation (State Sanitary Code, Chapter II): Common wall Common wall

Mini split head
34 

“410.201: Temperature Requirements. The owner shall provide heat in every habitable 

room and every room containing a toilet, shower, or bathtub to at least 68°F (20° C) 

between 7:00 a.m. and 11:00 p.m. and at least 64°F (17°C) between 11:01 p.m. and 6:59 

a.m. every day other than during the period from June 15th to September 15th, both 

inclusive, in each year except and to the extent the occupant is required to provide the 

fuel under a written letting agreement. The temperature shall at no time exceed 78°F 

(25°C) during the heating season. The temperature may be read and the requirement 

shall be met at a height of five feet above floor level on a wall any point more than five 

feet from the exterior wall. The number of days per year during which heat must be 

provided in accordance with 105 CMR 410.000 may be increased or decreased through a 

variance granted in accordance with the provisions of 105 CMR 410.840 notwithstanding 

the prohibitions of the first clause of the first sentence of 105 CMR 410.840(A).” 

For reference, CMR 410.840 covers a request for a variance. Therefore, the system design might 

require one or more of these options: 

• The use of two smaller (3/4-ton) mini-split heads, front and rear, to match the distribution 

of the heating and cooling loads. However, this will increase the price of the mini-split 

heat pump option significantly. 

• The installation of electric panel radiators (electric resistance heat) in some rooms. This 

was a solution used in some other single-point distribution systems as a backup; the use 

of electric resistance heat varied widely, based on occupant behavior differences.

4.2.3 Domestic Hot Water Equipment

BSC recommends replacing the atmospheric tank water heaters with gas-fired condensing, 

tankless water heaters (one per unit). These units draw combustion air from and exhaust flue 

gases directly to the exterior. However, this raises the issue of cost; retail price for these units is 

in the range of $800 to $1200 each (material cost) plus installation; estimated annual hot water 

savings are $110/yr at current energy prices.

One option to consider, to lower the cost of this upgrade, is to install a high-output gas-fired 

condensing tank water heater, such as an American Water Heater Polaris Commercial unit 

(130,000 to 199,000 Btu/h input; approximately 95% thermal efficiency). The cost of this unit is 

higher than a single tankless water heater, but likely lower than three tankless units installed 

(especially considering that only one set of plumbing connections is required). The unit would 

need to be sized to match the expected DHW draw loads. One caveat is that this system requires 

shared billing of DHW energy use, which may or may not be a feasible option. 
35 

5 Masonry Insulation THERM Modeling for Jamaica Plain ThreeFamily

When retrofitting insulation to mass masonry walls, another factor to address is various thermal 

bridges, which occur due to existing geometries of masonry. One example is a tee wall or party 

wall between two units; commonly, only one side would be insulated, so the party wall has the 

potential to become a thermal bridge. 

Therefore, heat flow simulations were run using THERM 5.2 (LBNL 2003) Two-Dimensional 

Building Heat-Transfer Modeling Software. Note that this is a steady-state software package, so 

it does not capture dynamic effects, thermal mass, or any solar gain effects. The masonry 

material used in this simulation had a conductivity of 0.347 Btu/h∙ft∙°F (R-0.24 per in.), or at the 

8-in. thickness of the exterior wall, R-1.9 (not including R-value of interior air spaces and 

plaster).

Note that these simulations were set up as if the space between the two brick wythes is 

completely filled with masonry; as discussed in the condition survey, in reality, some air spaces 

exist in this gap. The true R-value of the masonry wall is likely to be slightly higher than the 

values used in these simulations. This can be demonstrated with a parallel paths calculation, as 

shown in Table 5. 

Table 5. Composite R-Values for 1-in. Cavity with Various Levels of Mortar Fill

% Cavity Fill Composite R-Value 

0% (air only) R-1.1

25% R-0.58

50% R-0.39

75% R-0.30

100% (fully grouted) R-0.25

An interior temperature of 68°F was modeled; the exterior temperature was a matter of further 

consideration. The 99.6% heating design dry bulb temperature of Boston could be used (7°F); 

however, this might be too extreme, given the thermal mass properties of the masonry. Another 

thought was to use the lowest monthly average temperature, of 29°F; this was considered too 

loose of a boundary condition. Therefore, an exterior temperature of 20°F was chosen for this 

work as an estimate of relatively cold (but not extreme) conditions which accounts for some 

thermal mass effects.

5.1 Interior Insulation of Tee (Party) Wall

BSC examined several scenarios for insulating the interior of the tee party wall. First, a 2-in. 

layer of spray foam was modeled on the exterior wall, while the adjacent unit retained its original 

wood strapping and plaster. The party wall was left undisturbed. 

The resulting temperature distributions (Figure 43) show the expected colder temperatures 

through the insulated wall. In comparison, the uninsulated wall has a temperature gradient across 

the entire wall section. There is a gradual transition between the two conditions at the tee 

intersection.
36 

One common concern in interior retrofits has been the possibility of condensation on uninsulated 

interior surfaces adjacent to the insulation; it is likely that the surfaces will be colder than their 

original condition, increasing condensation risks. However, the temperature distribution on the 

tee wall seems to indicate that temperatures of exposed surfaces (at the corner) are roughly the 

same as they are in the uninsulated case, indicating no increased condensation risk.

Figure 43. Tee wall with 2-in. spray foam depicting materials, temperature, and heat flux

Heat flux measurements show that adding insulation greatly reduces heat flux through the 

insulated wall, as would be expected. The greatest heat flux occurs at the interior corners (area 

Temperature (°F)

Heat Flux (Btu/hr∙ft2)

Uninsulated unit Insulated unit
37 

circled in red). Note that in the insulated case, the high heat flux is “pushed” past the insulated 

corner. Due to this heat flux issue, BSC ran another simulation adding a minimal amount of 

insulation past the corner, as shown in Figure 44. 

Figure 44. Tee wall with 2-in. spray foam and foam at corner depicting materials, temperature, and 

heat flux 

In these simulations, the highest heat flux is reduced, and interstitial condensation risks are 

minimal—in fact, there is less risk than in the base, uninsulated case. However, there are still 

Temperature (°F)

Heat Flux (Btu/hr∙ft2)

Uninsulated unit Insulated unit
38 

“corner effects” at the interior insulated corner. Additional simulations were conducted with the 

length of the party wall insulation increased to 1 ft. (0.3 m) (see Figure 45).

Figure 45. Tee wall with 2-in. spray foam and 1-ft. foam at corner depicting materials, temperature, 

and heat flux

These simulations show that the overall heat flux due to corner effects is strongly reduced by 

extending the tee wall insulation by a ft. However, it is vital to remember that these results are 

specific to the geometry of the building, and the relative thermal characteristics of the masonry 

Temperature (°F)

Heat Flux (Btu/hr∙ft2)

Uninsulated unit Insulated unit
39 

and the insulation material. However, this is likely a reasonable field guideline to use in these 

situations.

Finally, simulations were run with the 4 in. of interior spray foam being considered for a deep 

energy retrofit (approximately R-40 nominal), as shown in Figure 47.

Figure 46. Tee wall with 4-in. spray foam depicting materials, temperature, and heat flux

Uninsulated unit Insulated unit

Temperature (°F)

Heat Flux (Btu/hr∙ft2)
40 

Similar to previous cases, Figure 46 shows that heat flux through the party wall does occur. 

However, surface temperatures do not appear to pose a condensation risk in the postretrofit unit. 

Overall, if the deep energy retrofit insulation option is considered, extending this insulation onto 

the party wall is a reasonable step to limit heat flux.

5.2 Exterior Insulation of Tee (Party) Wall

Another solution being considered for the rear of the building (which has less detailing and 

aesthetic impact) is to insulate on the exterior of the structure; the results for adding 2 in. of 

insulation are shown in Figure 47. The insulation was terminated at the mid-thickness of the 

party wall likely because legal restrictions prevent the retrofit from extending beyond the 

property line between the two buildings. 

One immediately obvious effect is that the wall becomes warmer, which is intrinsic to an exterior 

insulation retrofit. Of course, an exterior retrofit protects the substrate inboard of the insulation 

(both from seasonal temperature extremes and bulk water exposure) resulting in greater 

durability of the structure (Hutcheon 1964; Lstiburek 2007a). The typical objection to an exterior 

retrofit, however, is aesthetics—particularly when the exterior has significant aesthetic value, 

such as a well-detailed mass masonry building does. 
41 

Figure 47. Tee wall with exterior insulation (base case) depicting materials, temperature, and heat 

flux

However, Figure 47 shows noticeable heat flux from thermal bridging through the masonry at 

the tee wall, even with exterior insulation. Therefore, simulations were run extending the exterior 

insulation past the midpoint of the party wall, to the far side of the masonry wall (Figure 48).

Temperature (°F)

Heat Flux (Btu/hr∙ft2)

Insulated unit Uninsulated unit
42 

Figure 48. Tee wall with extended exterior insulation depicting materials, temperature, and heat 

flux

This change significantly reduces the heat flux from the insulated corner. Note that the color key 

in Figure 48 differs from previous runs, so the images should not be compared directly. 

Specifically, the heat flux in the corner is close to 7 Btu/h·ft2

, while in the previous case (nonextended insulation), it was closer to 9 Btu/h·ft2 or higher. If this additional insulation is a 

Temperature (°F)

Heat Flux (Btu/h∙ft2)

Insulated unit Uninsulated unit
43 

measure that can be executed without causing property boundary issues, it is highly 

recommended.

It should be noted that exterior insulation does not address interior air barrier issues, so details to 

transition the air barrier to the exterior will be required.

Another item of interest is the party wall where it penetrates the roof, as shown in Figure 49. The 

effect of this thermal bridge could be simulated to determine the effect of using an exterior 

insulation “cap” over the exposed wall. 

Figure 49. Capped party wall at J.P. Three-Family, and roof “wrap” over an exposed party wall
44

6 Brick Freeze-Thaw Analysis for Jamaica Plain Three-Family

6.1 Material Property Test Results

Sample face bricks were collected from the front (east facing, Figure 50) and rear (west facing, 

Figure 51) facades of the Jamaica Plain Three-Family building. 

Figure 50. Confirming existing wall assembly and collecting front (east) face brick sample

Figure 51. Confirming existing wall assembly and collecting rear (west) face brick sample

The researchers conducted material property tests on the sample bricks to facilitate the 

hygrothermal simulations and inform the assessment of FT risk. The test method, material 

properties, and results are summarized in the sections that follow.

6.1.1 Dry Density

Dry density is a basic characteristic that describes brick. It is used as an input to the Wärme- Und 

Feuchtetransport Instationär (WUFI) 4.1 Pro hygrothermal simulation program. The program 

uses dry density when predicting how much heat and moisture is stored in a material over a 

given time period.

To determine dry density, brick samples are dried in a gravity oven and periodically weighed 

using a precision scale. Drying continues until there is no longer any change in mass. The 
45

volume of each brick sample is then determined using a liquid displacement method. The dry 

mass is simply divided by the volume to calculate the dry density. 

The dry density of front brick was 120 lb/ft3 and the rear brick was 130 lb/ft3

.

6.1.2 Water Absorption Coefficient (A-value)

The water absorption coefficient (Aw or A-value) characterizes the capillary uptake of a brick. It 

is used in WUFI 4.1 Pro to predict the movement of liquid water under capillary suction and 

redistribution.

To obtain A-value, oven-dried bricks are placed so that their exposed face (i.e., the outside face 

of the brick) is just in contact with a pool of distilled water. The samples are periodically 

removed from the water, weighed using a precision scale, and placed back in contact with the 

water surface. The measured mass is plotted against the square root of the time of the 

measurements and normalized for cross-sectional area. The A-value is determined from the slope 

of this graph and has the rather unusual units of lb./in2 √s.

The A-value was 0.000157 lb./in2 √s for the front brick and 0.000115 lb/in.2 √s for the rear brick.

6.1.3 Free Water Saturation

Free water saturation occurs when a material is in contact with a water surface on its bottom face 

and surrounded by air at 100% relative humidity (RH) so that evaporation cannot occur and the 

material reaches an equilibrium moisture content (i.e., its weight will no longer change no matter 

how long it remains in contact with the water surface and is surrounded by 100% RH). Free 

water saturation moisture content is used in WUFI 4.1 Pro to predict the movement and storage 

of moisture in materials. 

Free water saturation can quickly be estimated by placing brick samples in boiling water for 5

hours. The brick samples are then allowed to cool to room temperature while in the water bath. 

The free water saturation mass of each brick sample is determined using a precision scale and the 

free water saturation moisture content is calculated by subtracting each sample’s previously 

determined dry weight and dividing by the volume.

The free water saturation moisture content of the brick samples was found to be 18.4 lb/ft3 or 

15.3% for front brick and 12.6 lb/ft3 or 9.7% for rear brick.

6.1.4 Vacuum Saturation

The vacuum saturation moisture content is used to estimate the amount of moisture that can be 

held in the brick when all of its pores are filled with water. This characteristic value is used to 

determine the degree of saturation when assessing resistance to FT action.

To determine vacuum saturation, carefully cut brick “slices” (approximately 3/8-in. thick) are 

placed in a desiccator and a vacuum pump is used to remove 99.9% of the air. The vacuum pump 

is shut off and water is supplied to the desiccator. Because nearly 100% of the pores of the brick 

slices are filled with water in this process, the brick slices are called “vacuum saturated.” The 

vacuum saturation moisture content is determined by weighing each vacuum saturated slice 

using a precision scale and subtracting its previously determined oven dry weight and dividing 

by the volume.

The average vacuum saturation moisture content of the prepared brick ‘slices’ was 19.5 lb/ft3 or 

16.3% moisture content for front brick and 14.8 lb/ft3 or 11.4% moisture content for rear brick.
46

6.1.5 Critical Degree of Saturation

The critical degree of saturation (Scrit) is used to predict the severity of FT events when assessing 

FT risk. The degree of saturation is the fraction of saturation relative to complete vacuum 

saturation. For example, at 0.5 degrees of saturation, the brick contains 50% of the moisture that 

it would at vacuum saturation. Fagerlund (1977) showed that below some Scrit, no FT damage is 

possible, regardless of the number of temperature excursions below freezing. Similarly, very few 

freezing cycles are needed to cause damage if the moisture content is above Scrit.

Carefully prepared brick slices are outfitted with measurement targets and the pretest length is 

measured using a precision micrometer. The slices are then brought to various degrees of 

saturation (e.g., 0.2, 0.4, 0.6, etc.) and sealed in packaging so that the moisture does not escape. 

The sealed slices are allowed to rest for several days so that internal moisture can distribute 

uniformly throughout each slice. The slices are then immersed in a controlled temperature bath 

and subjected to six FT cycles. The slices are then brought back to room temperature, removed 

from the bath, and the post-test length measured. The change in dimension is used to assess the 

resistance to FT action and estimate the Scrit at which the material becomes susceptible to FT 

damage.

The estimated Scrit for the brick slices tested was between 0.4 and 0.7 for both samples.

6.2 Hygrothermal Simulations

The WUFI 4.1 Pro computer model was used to simulate the effects of insulating the walls on 

the moisture and temperature conditions of the masonry walls. WUFI is one of the most 

advanced commercially available hygrothermal moisture programs in use today. Its accuracy has 

been verified (by the Frauenhofer-Institut für Bauphysik in Germany) against numerous fullscale field studies of enclosure performance (roofs, walls, foundations, parking garage decks, 

etc.) over a number of years. Much of the field verification work supporting the model has been 

solid masonry and stone wall systems.

WUFI is one of the few models in the public domain that can properly account for rain 

absorption and different water absorption/redistribution for arbitrary material data and boundary 

conditions. Given the appropriate material data, WUFI calculates heat and moisture flow every 

hour under the influence of sun, rain, temperature, and humidity (for more information, see 

http://www.wufi.de). The analysis is, however, only as accurate as the assembly data, the 

material properties, and the interior and exterior conditions input.

6.2.1 Air Leakage

The WUFI 4.1 Pro computer model has the capacity to predict air-leakage-induced wetting and 

drying; however, we have not made use of this feature because the leakage path and driving 

forces are unknown, and are generally unique. The time scale of wind-induced air leakage is also 

much shorter than 1 hour. 

In all of the cases studied in this project it has been assumed that air leakage across the enclosure 

has been substantially controlled by standard air sealing techniques. It is not reasonable to 

attempt to design a retrofit with a significant amount of air leakage. However, experience has 

shown that air barrier systems formed by careful taping, caulking, use of spray polyurethane 

products and fully adhered membranes are quite likely to achieve high levels of airtightness 

when properly installed using standard quality control measures. Before and after blower door air 

leakage testing can be carried out to identify air leakage paths and to subsequently confirm if air 

sealing was successful.
47

6.2.2 Climate Data

Climate data for Boston, Massachusetts, available in the WUFI 4.1 Pro database, was used for 

this analysis.

The building is currently not air conditioned; however, the owner is considering air conditioning

as part of the retrofit. Our analysis assumes that the building will be air conditioned after retrofit.

6.2.3 Material Properties

Because it is often not convenient (or even possible) to determine the many material properties 

necessary for hygrothermal simulations, WUFI 4.1 Pro includes a database of several hundred 

common materials. However, hygrothermal computer models are only as reliable as their input 

data, and it is advisable to measure and use key material properties whenever this can easily be 

done.

Table 6 presents several important material properties for selected brick from our WUFI 

materials database. For the purposes of our simulations, BSC has chosen to use a modified 

version of the Solid Historical brick for the brick wythes. The modifications reflect the material 

properties measured in the BSC laboratory.

Table 6. Material Properties for Selected Brick

Name Source* Density 

lb/ft3

Conductivity

BTU/(hr ft·oF)

VDRF

-

Aw

lb./in2 √s

Free Saturation

lb/ft3 %

Brick (old) ASHRA

E 1018

104.3 0.23 16 - 12.2 12%

Dunning Red Fill 

Brick

BSI 114.6 - - 0.00023 17.4 15%

Red Matt Clay 

brick

MEWS 120.8 0.29 137.8 0.00004 3.5 3%

Solid Brick 

Masonry

IBP 118.6 0.35 10 0.00016 11.9 10%

Solid Brick 

Extruded

IBP 103.0 0.35 9.5 0.00057 23.1 22%

Solid Brick Hand 

Formed

IBP 107.7 0.40 17 0.00043 12.5 12%

Solid Brick 

Historical (front 

facade)

IBP 120.1 0.35 15 0.000157 18.4 15.3%

Solid Brick 

Historical (rear 

façade)

IBP 129.6 0.35 15 0.000116 12.5 9.7%

*All values taken from WUFI material database

6.2.4 Assessing Freeze-Thaw Performance

Although FT damage is an age-old problem, it still cannot be accurately predicted. For example, 

physical testing of individual bricks is commonly considered to be the best measure, despite the 

fact that the ASTM and CSA standards often reject bricks found from experience to be durable 
48

and sometimes accept bricks that fail in the field (Vickers 1993; Arnott and Maurenbrecher 

1990; Robinson et al. 1995).

Different materials, such as clay brick, calcium silicate, concrete, and natural stones exhibit 

different susceptibility to FT damage. Hence, the approach taken in this report has been to assess 

the potential for FT damage based on the microclimatic conditions experienced by the material in 

question.

It is well accepted that two factors have the most importance to FT damage: the moisture content 

during freezing and the number of FT cycles. BSC has defined a freeze cycle as occurring when 

the temperature within the material drops below 23°F and a thaw cycle to occur when the 

temperature rises above 32°F. This is based on the observation (Litvan 1988) that FT is not a 

problem at temperatures just below freezing—damage tends to require temperatures much colder 

than 23°F and most test standards require the material to be cooled below 5°F.

The process by which BSC calculates the number of potentially damaging FT cycles from hourly 

data is shown in Figure 52. The critical moisture content for FT damage is defined as the 

moisture content above which FT damage can occur. From BSC’s testing on the brick samples 

collected during our visit to the Jamaica Plain Three-Family building, it has been determined that 

the critical moisture content is between 40% and 70% of the saturation moisture content (0.4 < 

Scrit < 0.7).
49

Figure 52. Freeze-thaw damage potential assessment procedure

6.2.5 Simulation Model

Figure 53 shows the WUFI 4.1 Pro model for the existing wall system. The various materials 

used in the wall assembly are represented by different colors. This image depicts the red face 

brick (represented by the four red rectangles on the far left), followed by a layer of air/mortar 

(light grey), the inner brick (orange), an air/wood strapping layer (light blue), and the interior 

lath and plaster (white rectangle on the far right). The existing wall was modeled to have a 

number of layers of oil-based paint on the interior plaster (dashed line at the interior surface).
50

BSC created similar models for the proposed insulation retrofit options by adding insulation and 

gypsum board layers to the interior of the existing wall system model. Options analyzed include 

2 in. of 2 lb/ft3 ccSPF, 6 in. of 2 lb/ft3 ccSPF, and 6 in of 1 lb/ft3 SPF.

Figure 53. WUFI 4.1 Pro model of existing wall system

Previous simulations or similar constructions have found that a subsurface layer on the exterior 

of the face brick and a layer on interior of the face brick experienced the highest moisture 

concentrations and largest and most frequent temperature swings. BSC has modeled these as a 

10-mm (approximately 3/8-in.) thick volume, which lies 5 mm (approximately 1/4 in.) inside the 

exterior face, and a 5-mm (approximately 1/4-in.) thick volume at the interior face. These two 

layers were used in assessing the potential for damaging FT cycles.

6.2.6 Other Considerations

Simulations were conducted for both the west-facing rear wall and east-facing front wall to 

assess the impact of solar radiation and rain on different orientations. Low, medium, and high 

rain exposures were all considered because a building’s geometry and architectural detailing can 

act to concentrate or minimize the amount of rainwater incident on its wall surfaces.

6.3 Results and Interpretation

Three key variables need to be considered when interpreting the results. One variable is the 

uncertainty in the brick properties, most importantly, the Scrit. Another variable is that buildings 

often have localized areas of rainwater concentration caused by architectural details. Finally, the 

weather data used is from Boston airport which likely has a considerably greater rain exposure 

than the building does.

Postprocessing is used to analyze the hourly predicted temperature and moisture content values 

produced by the hygrothermal simulations. The assessment of damaging FT cycles can also be 

carried out graphically by plotting the predicted temperature and moisture content at any layer 

and checking for instances when the temperature is below 23°F while the moisture content is 

over the critical saturation moisture content. 

It is evident that the temperature frequently travels below the 23°F threshold for FT cycling on 

east and west façades. The moisture content spikes correspond to wetting caused by rain events. 

The simulation shows a low FT risk for the existing building as evident by the good condition of 
51

the current façade. The simulation and the existing conditions of the building suggest that Scrit is 

close to 0.7 and that the building has a low rain exposure.

The addition of thermal insulation to the inside of the wall reduces the temperature of the 

brickwork. The insulation also limits the ability of the wall to dry to the inside of the building 

and limits outward heat flow which assists outward drying. 

On the rear west façade, simulations (see Figure 54) show a low FT risk similar to that of the 

existing enclosure with any of the insulation retrofits modeled where rainwater concentrations 

are avoided. If the actual Scrit of the brick is close to 0.7, FT risk remains low even at locations of 

relatively high rain exposures. If the actual Scrit of the brick is close to 0.4, freeze-thaw risk is 

high at locations of relatively high rain exposures. 

The east façade rain exposure was higher in the model, and the brick had a greater liquid water 

uptake rate. If the actual Scrit of the brick is close to 0.4, the model (see Figure 55) shows 

significant increases for FT degradation risk due to any of the retrofit strategies. If the actual Scrit

of the brick is close to 0.7, the model shows that only the retrofit option of adding 3 in. of 1 lb/ft3

spray foam results in a similarly low FT degradation risk where rainwater concentrations are 

avoided.

-10

-5

0

5

10

15

20

25

30

35

40

01-Nov08-Nov15-Nov22-Nov29-Nov06-Dec13-Dec20-Dec27-Dec03-Jan10-Jan17-Jan24-Jan31-Jan07-Feb14-Feb21-Feb28-Feb07-Mar14-Mar21-Mar28-Mar

Brick Temperature (oC)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Water Saturation

Brick Temperature

Exist Building - rear, light rain, RDF = 0.3

Exist Building - rear, heave rain, RDF = 0.7

2" BASF - rear, light rain, RDF = 0.3

2" BASF - rear, heavy rain, RDF = 0.7

3" 1lb PUR - rear, light rain, RDF = 0.3

3" 1lb PUR - rear, light rain, RDF = 0.7

6" PUR - rear, light rain, RDF = 0.3

6" PUR - rear, light rain, RDF = 0.7

Figure 54. Predicted winter conditions at back of rear face brick
52

-10

-5

0

5

10

15

20

25

30

35

40

01-Nov08-Nov15-Nov22-Nov29-Nov06-Dec13-Dec20-Dec27-Dec03-Jan10-Jan17-Jan24-Jan31-Jan07-Feb14-Feb21-Feb28-Feb07-Mar14-Mar21-Mar28-Mar

Brick Temperature (oC)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Water Saturation

Figure 55. Predicted winter conditions at back of front face brick

6.3.1 Freeze-Thaw Risk Conclusions

Further testing is recommended to more accurately determine the Scrit value of the brick. This can 

be completed with the remaining portion of the brick sample that is available. Testing of more 

sample brick would further reduce the uncertainty of the material properties and the conclusion 

drawn from the work.

Site monitoring of driving rain is also recommended to more accurately determine driving rain 

loading on the façade.

The analysis shows a low risk of FT degradation of the brickwork on the rear west façade with 

any of the proposed insulation retrofits given that rainwater concentrations can be avoided.

The analysis shows a significantly increased risk of FT degradation at the rear of the face bricks 

on the front east façade with the various insulation retrofits assuming that the Scrit value of the 

brick is actually at the lower end of the range found in our testing. If the Scrit value is at the 

higher end of the range found in our testing, then the analysis suggests that the 2 in. of 2 lb/ft3

ccSPF and 6 in. of 1 lb/ft3 SPF retrofits result in a significant increase in FT risk, while the 

retrofit option using 3 in. of 1 lb/ft3 SPF did not significantly raise the FT risk.

Considering the importance of the Scrit value, BSC recommends awaiting further testing results 

before making a decision on insulation retrofit. If a greater amount of insulation than 3 in. of 1 

lb/ft3 SPF is desired, BSC suggests onsite driving rain monitoring and reanalysis to ensure FT 

degradation risk at the front east of the building is minimal. In any case, BSC recommends 

addressing rainwater concentration problems which are causing currently degradation problems 

and may become more problematic with insulation retrofit.
53

7 Conclusions

BSC assessed the Jamaica Plain Three-Family building for exterior masonry conditions (for 

evidence of FT damage), basement conditions (examining efflorescence and capillary action), 

roof conditions, window conditions, airtightness, and mechanical systems. Simulations were 

performed with BEopt and EgUSA software packages to determine energy impacts and costeffectiveness of various retrofit measures. The EgUSA results are shown in a step-by-step 

parametric model, providing impact of individual measures. In addition, utility bill energy use 

data was examined for trends and to “tune” the energy models to some degree.

Enclosure measures under consideration include superinsulation of the masonry walls (either 

interior or exterior), roof retrofit (including air impermeable insulation for condensation control 

and air leakage control), basement wall and slab insulation (with complications due to capillary 

transport and embedded wood members), window upgrades (possibly with low e storm windows 

on the exterior of existing double glazed windows), and air leakage reductions (to various 

tightness levels). Some of the recommended upgrades have issues to their implementation as a 

retrofit strategy, such as moisture-related durability issues (e.g., exterior brick wall interior 

insulation, or capillary rise issues at basement walls). 

Mechanical system upgrades under consideration include the use of mini-split heat pumps for 

space conditioning (abandoning the existing gas furnace and ductwork system), instantaneous 

water heaters, and lighting and appliance upgrades. The mini-split heat pump retrofit is an 

excellent solution to the small heating loads that result from a deep energy retrofit; however, 

there are some concerns about whether single point heating will be sufficient given the 

concentrated loads in the front and back of each apartment unit. In addition, there may be 

restrictions due to Massachusetts rental law requirements. The recommended upgrade for the 

domestic water heating system was a single central high-efficiency water heater (e.g., 

condensing tank), which would likely have a lower installed costs than three instantaneous 

condensing gas water heaters. However, a single water heater would eliminate the ability to 

easily submeter hot water gas use (individual appliances allow for submetering at the gas meter 

level).

One issue that was examined in detail is the effect of thermal bypass or thermal bridging with 

various masonry wall insulation retrofit details. Specifically, BSC modeled a tee wall or party 

wall between two units to determine the effect of the common practice of insulating only one 

side of the party wall. Two-dimensional heat flow simulations showed that the party wall 

provides a thermal bridge; however, adding interior insulation to the party wall roughly 1 ft from 

the exterior wall substantially reduces this effect. In addition, if an exterior insulation approach is 

chosen, insulating only to the property line (mid-thickness of the party wall) results in thermal 

bridging issues; extending this insulation at least to the far side of the party wall reduces the heat 

flux through this system.

The final issue examined in detail was a FT assessment of the building to determine its suitability 

to interior insulation retrofit. Brick samples were collected from the building, and material 

property tests were performed. These results were used as inputs to one-dimensional 

hygrothermal simulations, with various orientations, degrees of rain exposure, and insulation 

thicknesses/materials. The material property testing had a wide range of Scrit values, leaving high 

uncertainty; therefore, additional testing is necessary before making final recommendations. In 

fact, if the lower range of Scrit values is the “true” value, interior insulation is not recommended. 
54

If the Scrit value is at the higher end, moderate levels of insulation (3 in. of 1 lb/ft3 open cell 

urethane spray foam) will not significantly raise FT risks. However, greater insulation and/or less 

vapor permeability to the interior, as would occur with 2 in. of 2 lb/ft3

closed cell urethane spray 

foam, or 6 in. of 1 lb/ft3open cell foam, results in a significant increase in FT damage at the 

exposure levels modeled.

After the preliminary brick testing was completed, the owner decided not to insulate the exterior 

walls at this time. A retrofit including demolition of interior finishes was considered to be too 

intrusive and not feasible. Given the limited exposure of the exterior walls, retrofitting this 

component is lower on the priority list for the owner. However, other retrofit measures that will 

improve the performance of the building are being pursued, such as the installation of insulation 

at the roof and the replacement of the mechanical systems. Retrofit measures at the basement 

walls and slab are next on the priority list for the owner.

Given that the exterior walls will not be receiving any insulation at this time, the project no 

longer qualifies for the comprehensive or full deep energy retrofit through the National Grid 

DER Pilot Program. However, the owner may quality for the partial or staged deep energy 

retrofit.
55

References

Arnott, M.R; Maurenbrecher, A.H.P. (1990), An alternative test for determining the frost 

resistance of bricks. The Masonry Society Journal (9:1) p. 105.

ASHRAE (2010). ASHRAE Standard 62.2-2010: Ventilation and Acceptable Indoor Air Quality 

in Low-Rise Residential Buildings. Atlanta, GA: American Society of Heating, Refrigerating, 

and Air-Conditioning Engineers.

BSC (2011). “Initial New Construction Pilot Community Evaluations – Transformations, Inc., 

Massachusetts – Cold Climate “.

Christensen, C.; Anderson, R. (2006). BEoptTM Software for Building Energy Optimization: 

Features and Capabilities. NREL/TP-550-39929. Golden, CO: National Renewable Energy 

Laboratory. Accessed June 23, 2011: http://www.nrel.gov/buildings/pdfs/39929.pdf. 

ENERGY STAR Performance Ratings Methodology for Incorporating Source Energy Use,

Accessed May 16, 2011: 

http://www.energystar.gov/ia/business/evaluate_performance/site_source.pdf. 

Fagerlund, G. (1977). “The critical degree of saturation method of assessing the freeze/thaw 

resistance of concrete.” Materials and Structures (10:58), pp. 217-230.

Hutcheon, N.B. (1964). NRC-IRC (National Research Council of Canada-Institute for Research 

in Construction) Canadian Building Digest CBD-50. Principles Applied to an Insulated Masonry 

Wall, Ottawa, ON: National Research Council of Canada.

International Code Council (2009), International Residential Code for One- and Two-family 

Dwellings. Country Club Hills, IL: International Code Council. 

THERM 5.2: A PC Program for Analyzing Two-Dimensional Heat Transfer through Building 

Products. (2003). Berkeley, CA: Lawrence Berkeley National Laboratory.

Litvan, G. (1988). “The Mechanism of Frost Action in Concrete – Theory and Practical 

Implications.” Proceedings of Workshop on Low Temperature Effects on Concrete. September 5-

9, 1988, Sapporo, Hokkaido, Japan. Ottawa, Ontario: IRC/NRCC; pp. 116-127. 

Lstiburek, J.W. (2005). “Understanding Air Barriers.” ASHRAE Journal (47); pp. 24–30. 

Atlanta, GA: American Society of Heating, Refrigeration, and Air-Conditioning Engineers, Inc.

Lstiburek, J.W. (2007a). “Building Sciences: The Perfect Wall.” ASHRAE Journal (50); pp. 74–

78. Atlanta, GA: American Society of Heating, Refrigeration, and Air-Conditioning Engineers, 

Inc.

Lstiburek, J.W. (2007b). “Building Sciences: Capillarity-Small Sacrifices.” ASHRAE Journal

(49); pp. 58–61. Atlanta, GA: American Society of Heating, Refrigeration, and Air-Conditioning 

Engineers, Inc.
56 

Lstiburek, J.W. (2008). “Building Sciences: Concrete Floor Problems.” ASHRAE Journal (50); 

pp. 28–32. Atlanta, GA: American Society of Heating, Refrigeration, and Air-Conditioning 

Engineers, Inc.

Lstiburek, J.W. (2010). Attic Air Sealing Guide and Details. Westford, MA: Building Science 

Corporation, Accessed January 7, 2011: http://www.buildingscience.com/documents/guides-andmanuals/gm-attic-air-sealing-guide/view. 

Melton, P.; Yost, P. (2011). “Making Windows Work Better.” Environmental Building News, 

(20:6). 

National Grid (2009). “Deep Energy Retrofit Multifamily and Single-family Pilot Guidelines,” 

National Grid, Accessed May 16, 2011: http://www.powerofaction.com/media/der_desc.pdf. 

National Park Service (1979). Preservation Brief 6: Dangers of Abrasive Cleaning to Historic 

Buildings, Washington, DC: National Park Service. 

Parker, D., Broman, P.; Grant, J.; Gu L.; Anello, M.; Vieira R.; Henderson, H. (1999). 

“EnergyGauge USA: A Residential Building Energy Design Tool.” Proceedings of Building 

Simulation '99, September 1999, Kyoto, Japan. College Station, TX: Texas A&M University. 

Perry, R.H; Chilton, C.H. (1973). Chemical Engineer's Handbook. 5th edition. New York: 

McGraw Hill. pp. 6-14. 

Robinson, G.C.; Butler, D.; Smalley, A., (1995), “Predicting Brick Frost-Resistance Part 1.” 

Proc.of American Ceramic Society Bulletin. (74:8), pp. 57-61.

Straube, J. (2011). Rain Penetration Control for Institutional, Commercial and Industrial 

Buildings. Westford, MA: Building Science Press. 

Vickers, M.A. (1993). “Comparison of Laboratory Freeze-Thaw Procedures,” J.M. Melander and 

L.R. Lauersdorf, Eds., Masonry: Design and Construction, Problems and Repair, ASTM STP 

1180, Philadelphia, PA: American Society for Testing and Materials.
Appendix A 

Jamaica Plain Three-Family Heating and Cooling Manual J Results 

A-1
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Building Science Corporation Buhs II 

Westford, MA 01886 Page 1 

Project Report 

General Project Information 

Project Title: Buhs II 

Designed By: BSC 

Project Date: Thursday, June 16, 2011 

Design Data 

Reference City: Boston, Massachusetts 

Building Orientation: Front door faces Northeast 

Daily Temperature Range: Medium 

Latitude: 42 Degrees 

Elevation: 15 ft. 

Altitude Factor: 0.999 

Elevation Sensible Adj. Factor: 1.000 

Elevation Total Adj. Factor: 1.000 

Elevation Heating Adj. Factor: 1.000 

Elevation Heating Adj. Factor: 1.000 

Outdoor Outdoor Outdoor Indoor Indoor Grains 

Dry Bulb Wet Bulb Rel.Hum Rel.Hum Dry Bulb Difference 

Winter: 7.4 6.5 80% n/a 70 n/a 

Summer: 91 73 43% 50% 75 28 

Check Figures 

Total Building Supply CFM: 791 CFM Per Square ft.: 0.244 

Square ft. of Room Area: 3,248 Square ft. Per Ton: 1,519 

Volume (ft3) of Cond. Space: 27,156 

Building Loads 

Total Heating Required Including Ventilation Air: 28,426 Btuh 28.426 MBH 

Total Sensible Gain: 19,241 Btuh 80 % 

Total Latent Gain: 4,834 Btuh 20 % 

Total Cooling Required Including Ventilation Air: 24,075 Btuh 2.01 Tons (Based On Sensible + Latent) 

2.14 Tons (Based On 75% Sensible 

Capacity) 

Notes 

Rhvac is an ACCA approved Manual J and Manual D computer program.
 

Calculations are performed per ACCA Manual J 8th Edition, Version 2, and ACCA Manual D.
 

All computed results are estimates as building use and weather may vary.
 

Be sure to select a unit that meets both sensible and latent loads according to the manufacturer's performance data at 

your design conditions.
 

A-2

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Sum of room airflows ma y be greater than system airflow because 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II
 

Westford, MA 01886 Page 2
 

Load Preview Report
 

Scope 

Net 

Ton 

ft.2 

/Ton Area 

Sen 

Gain 

Lat 

Gain 

Net 

Gain 

Sen 

Loss 

Sys 

Htg 

CFM 

Sys 

Clg 

CFM 

Sys 

Act 

CFM 

Duct 

Size 

Building 2.01 1,619 3,248 19,241 4,834 24,075 28,426 275 791 791

 System 1 0.69 2,550 1,750 6,758 1,478 8,236 10,466 105 279 279 0* 

Ventilation 616 678 1,294 2,409

 Zone 1 657 5,040 800 5,840 4,898 64 229 229 

3-1st_Floor_Bed_1 171 1,204 400 1,604 1,014 13 55 55 1--4 

4-1st_Floor_Kitchen 146 2,010 0 2,010 1,548 20 91 91 1--6 

5-1st_Floor_Dining_Room 143 266 0 266 307 4 12 12 1--4 

6-1st_Floor_Living 167 1,348 400 1,748 1,637 21 61 61 1--4 

7-1st_Floor_Bathroom 30 212 0 212 392 5 10 10 1--4

 Zone 2 934 1,282 0 1,282 2,988 39 58 58 

1-Basement 934 1,282 0 1,282 2,988 39 58 58 1--4

 Zone 3 159 98 0 98 171 2 4 4 

2-1st_floor_hall 53 26 0 26 34 0 1 1 1--4 

8-2nd_floor_hall 53 26 0 26 34 0 1 1 1--4 

15-3rd_floor_hall 53 46 0 46 103 1 2 2 1--4

 System 2 0.65 1,155 749 6,101 1,678 7,779 8,489 79 249 249 0* 

Ventilation 616 678 1,294 2,409

 Zone 1 749 5,485 1,000 6,485 6,080 79 249 249 

9-2nd_floor_Bed2 92 629 200 829 849 11 29 29 1--4 

10-2nd_Floor_Bed_1 171 1,025 400 1,425 1,086 14 47 47 1--4 

11-2nd_Floor_Kitchen 146 1,822 0 1,822 1,709 22 83 83 1--5 

12-2nd_Floor_Dining_Room 143 257 0 257 319 4 12 12 1--4 

13-2nd_Floor_Living 167 1,549 400 1,949 1,689 22 70 70 1--5 

14-2nd_Floor_Bathroom 30 203 0 203 428 6 9 9 1--4

 System 3 0.67 1,115 749 6,383 1,678 8,061 9,472 92 262 262 0* 

Ventilation 616 678 1,294 2,409

 Zone 1 749 5,767 1,000 6,767 7,063 92 262 262 

16-3rd_Floor_Bed_1 171 1,089 400 1,489 1,310 17 50 50 1--4 

17-3rd_Floor_Kitchen 146 1,877 0 1,877 1,900 25 85 85 1--5 

18-3rd_Floor_Dining_Room 143 311 0 311 507 7 14 14 1--4 

19-3rd_Floor_Living 167 1,612 400 2,012 1,908 25 73 73 1--5 

20-3rd_Floor_Bathroom 30 214 0 214 468 6 10 10 1--4 

21-3rd_floor_Bed2 92 664 200 864 970 13 30 30 1--4 

Sum of room airflows may be greater than system airflow because 

system has multiple zones. 

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Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II
 

Westford, MA 01886 Page 3
 

Duct Size Preview
 

Room or 

Duct Name Source Minimum Velocity 

Maximum 

Velocity 

Rough. 

Factor 

Design 

L/100 

SP 

Loss 

Duct 

Velocity 

Duct 

Length Htg 

Flow 

Clg 

Flow 

Act. 

Flow 

Duct 

Size 

System 1

 Supply Runouts

 Zone 1

 3-1st_Floor_Bed_1 Built-In 450 750 0 0.1 627.5 13 55 55 1--4

 4-1st_Floor_Kitchen Built-In 450 750 0 0.1 465.6 20 91 91 1--6

 5-1st_Floor_Dining_Room Built-In 450 750 0 0.1 138.6 4 12 12 1--4

 6-1st_Floor_Living Built-In 450 750 0 0.1 702.5 21 61 61 1--4

 7-1st_Floor_Bathroom Built-In 450 750 0 0.1 110.5 5 10 10 1--4

 Zone 2

 1-Basement Built-In 450 750 0 0.1 668.1 39 58 58 1--4

 Zone 3

 2-1st_floor_hall Built-In 450 750 0 0.1 13.6 0 1 1 1--4

 8-2nd_floor_hall Built-In 450 750 0 0.1 13.6 0 1 1 1--4

 15-3rd_floor_hall Built-In 450 750 0 0.1 24 1 2 2 1--4

 Other Ducts in System 1

 Supply Main Trunk Built-In 650 900 0 0.1 0 105 279 279 0 

System 2

 Supply Runouts

 Zone 1

 9-2nd_floor_Bed2 Built-In 450 750 0 0.1 327.8 11 29 29 1--4

 10-2nd_Floor_Bed_1 Built-In 450 750 0 0.1 534.2 14 47 47 1--4

 11-2nd_Floor_Kitchen Built-In 450 750 0 0.1 607.7 22 83 83 1--5

 12-2nd_Floor_Dining_Room Built-In 450 750 0 0.1 133.9 4 12 12 1--4

 13-2nd_Floor_Living Built-In 450 750 0 0.1 516.7 22 70 70 1--5

 14-2nd_Floor_Bathroom Built-In 450 750 0 0.1 105.8 6 9 9 1--4

 Other Ducts in System 2

 Supply Main Trunk Built-In 650 900 0 0.1 0 79 249 249 0 

System 3

 Supply Runouts

 Zone 1

 16-3rd_Floor_Bed_1 Built-In 450 750 0 0.1 567.5 17 50 50 1--4

 17-3rd_Floor_Kitchen Built-In 450 750 0 0.1 626.1 25 85 85 1--5

 18-3rd_Floor_Dining_Room Built-In 450 750 0 0.1 162.1 7 14 14 1--4

 19-3rd_Floor_Living Built-In 450 750 0 0.1 537.7 25 73 73 1--5

 20-3rd_Floor_Bathroom Built-In 450 750 0 0.1 111.5 6 10 10 1--4

 21-3rd_floor_Bed2 Built-In 450 750 0 0.1 346.1 13 30 30 1--4

 Other Ducts in System 3

 Supply Main Trunk Built-In 650 900 0 0.1 0 92 262 262 0 

Summary 

System 1 

Heating Flow: 105 

Cooling Flow: 279 

System 2 

Heating Flow: 79 

Cooling Flow: 249 

System 3 

Heating Flow: 92 

Cooling Flow: 262 

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Building Science Corporation Buhs II 

Westford, MA 01886 Page 4 

System 1 - Buhs II Minisplit Apt 1 - Adequate Exposure Diversity Test 

Test For Adequate Exposure Diversity 

Heat Gain, Btuh 

9.8% Diff. from Avg. 

0 

2,000 

4,000 

6,000 

8,000 

10,000 

8 am 9 am 10 am 11 am 12 pm 1 pm 2 pm 3 pm 4 pm 5 pm 6 pm 7 pm 

Average Glass 1.3 x Average Hourly Glass Gain Hourly Total Net 

Sensible Gain Glass Gain Gain 

Over 12 Hours 

AED Calculation Summary 

--- SYSTEM HAS ADEQUATE EXPOSURE DIVERSITY. --­

System is on NE, SE, SW, NW rosette.
 

Peak load exceeds 12-hour average load by 9.8%.
 

AED Excursion (amount by which peak exceeds 1.3 x average): 0 Btuh
 

Definition: A system has adequate exposure diversity if the peak-hour glass load for the entire conditioned space does 

not exceed the average glass load for the entire conditioned space by more than 30 percent. 

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Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 5 

System 2 - Buhs II Minisplit Apt 2 - Adequate Exposure Diversity Test 

Test For Adequate Exposure Diversity 

Heat Gain, Btuh

11.8% Diff. from Avg. 

0 

2,000 

4,000 

6,000 

8,000 

8 am 9 am 10 am 11 am 12 pm 1 pm 2 pm 3 pm 4 pm 5 pm 6 pm 7 pm 

Average Glass 1.3 x Average Hourly Glass Gain Hourly Total Net 

Sensible Gain Glass Gain Gain 

Over 12 Hours 

AED Calculation Summary 

--- SYSTEM HAS ADEQUATE EXPOSURE DIVERSITY. --­

System is on NE, SE, SW, NW rosette.
 

Peak load exceeds 12-hour average load by 11.8%.
 

AED Excursion (amount by which peak exceeds 1.3 x average): 0 Btuh
 

Definition: A system has adequate exposure diversity if the peak-hour glass load for the entire conditioned space does 

not exceed the average glass load for the entire conditioned space by more than 30 percent. 

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Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 6 

System 3 - Buhs II Minisplit Apt 3 - Adequate Exposure Diversity Test 

Test For Adequate Exposure Diversity 

Heat Gain, Btuh 

11.8% Diff. from Avg. 

0 

2,000 

4,000 

6,000 

8,000 

10,000 

8 am 9 am 10 am 11 am 12 pm 1 pm 2 pm 3 pm 4 pm 5 pm 6 pm 7 pm 

Average Glass 1.3 x Average Hourly Glass Gain Hourly Total Net 

Sensible Gain Glass Gain Gain 

Over 12 Hours 

AED Calculation Summary 

--- SYSTEM HAS ADEQUATE EXPOSURE DIVERSITY. --­

System is on NE, SE, SW, NW rosette.
 

Peak load exceeds 12-hour average load by 11.8%.
 

AED Excursion (amount by which peak exceeds 1.3 x average): 0 Btuh
 

Definition: A system has adequate exposure diversity if the peak-hour glass load for the entire conditioned space does 

not exceed the average glass load for the entire conditioned space by more than 30 percent. 

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Building Science Corporation Buhs II 

Westford, MA 01886 Page 7 

Total Building Summary Loads
 

Area 

Quan 

Sen 

Loss 

Lat 

Gain 

Sen 

Gain 

Total 

Gain 

Component 

Description 

Buhs II glass: Glazingbasement: GlazingR-40: WallDemising: Part15B0-20sf-4: Wall-Basement, , R-20 board insulation to 

floor, no interior finish, 4' floor depth 

Buhs II R-48: Roof/Ceiling21B-32: Floor-Basement, Concrete slab, any thickness, 2 

or more feet below grade, R-3 or higher insulation 

installed below floor, any floor cover, shortest side of 

floor slab is 32' wide 

357.4 

17.7 

1310.7 

1121.5 

440.3 

801.3 

933.9 

6,041 

387 

2,055 

1,594 

1,038 

1,052 

819 

0 

0 

0 

0 

0 

0 

0 

7,013 

471 

903 

1,197 

88 

302 

0 

7,013 

471 

903 

1,197 

88 

302 

0 

Subtotals for structure: 

People: 

Equipment: 

Lighting: 

Ductwork: 

Infiltration: Winter CFM: 119, Summer CFM: 0 

Ventilation: Winter CFM: 105, Summer CFM: 105 

14 

0 

12,986 

0 

8,214 

7,226 

0 

2,800 

0 

0 

0 

2,034 

9,974 

3,220 

4,200 

0 

0 

0 

1,847 

9,974 

6,020 

4,200 

0 

0 

0 

3,881 

Total Building Load Totals: 28,426 4,834 19,241 24,075 

Check Figures 

Total Building Supply CFM: 791 CFM Per Square ft.: 0.244 

Square ft. of Room Area: 3,248 Square ft. Per Ton: 1,519 

Volume (ft3) of Cond. Space: 27,156 

Building Loads 

Total Heating Required Including Ventilation Air: 28,426 Btuh 28.426 MBH 

Total Sensible Gain: 19,241 Btuh 80 % 

Total Latent Gain: 4,834 Btuh 20 % 

Total Cooling Required Including Ventilation Air: 24,075 Btuh 2.01 Tons (Based On Sensible + Latent) 

2.14 Tons (Based On 75% Sensible 

Capacity) 

Notes 

Rhvac is an ACCA approved Manual J and Manual D computer program.
 

Calculations are performed per ACCA Manual J 8th Edition, Version 2, and ACCA Manual D.
 

All computed results are estimates as building use and weather may vary.
 

Be sure to select a unit that meets both sensible and latent loads according to the manufacturer's performance data at 

your design conditions.
 

A-8

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Building Science Corporation Buhs II 

Westford, MA 01886 Page 8 

System 1 Buhs II Minisplit Apt 1 Summary Loads
 

Area 

Quan 

Sen 

Loss 

Lat 

Gain 

Sen 

Gain 

Total 

Gain 

Component 

Description 

Buhs II glass: Glazingbasement: GlazingR-40: WallDemising: Part15B0-20sf-4: Wall-Basement, , R-20 board insulation to 

floor, no interior finish, 4' floor depth 

Buhs II R-48: Roof/Ceiling21B-32: Floor-Basement, Concrete slab, any thickness, 2 

or more feet below grade, R-3 or higher insulation 

installed below floor, any floor cover, shortest side of 

floor slab is 32' wide 

109.6 

17.7 

393.6 

377.2 

440.3 

52.8 

933.9 

1,853 

387 

617 

536 

1,038 

69 

819 

0 

0 

0 

0 

0 

0 

0 

2,169 

471 

271 

403 

88 

20 

0 

2,169 

471 

271 

403 

88 

20 

0 

Subtotals for structure: 

People: 

Equipment: 

Lighting: 

Ductwork: 

Infiltration: Winter CFM: 40, Summer CFM: 0 

Ventilation: Winter CFM: 35, Summer CFM: 35 

4 

0 

5,319 

0 

2,738 

2,409 

0 

800 

0 

0 

0 

678 

3,422 

920 

1,800 

0 

0 

0 

616 

3,422 

1,720 

1,800 

0 

0 

0 

1,294 

System 1 Buhs II Minisplit Apt 1 Load Totals: 10,466 1,478 6,758 8,236 

Check Figures 

Supply CFM: 279 CFM Per Square ft.: 0.160 

Square ft. of Room Area: 1,750 Square ft. Per Ton: 2,331 

Volume (ft3) of Cond. Space: 13,682 

System Loads 

Total Heating Required Including Ventilation Air: 10,466 Btuh 10.466 MBH 

Total Sensible Gain: 6,758 Btuh 82 % 

Total Latent Gain: 1,478 Btuh 18 % 

Total Cooling Required Including Ventilation Air: 8,236 Btuh 0.69 Tons (Based On Sensible + Latent) 

0.75 Tons (Based On 75% Sensible 

Capacity) 

Notes 

Rhvac is an ACCA approved Manual J and Manual D computer program.
 

Calculations are performed per ACCA Manual J 8th Edition, Version 2, and ACCA Manual D.
 

All computed results are estimates as building use and weather may vary.
 

Be sure to select a unit that meets both sensible and latent loads according to the manufacturer's performance data at 

your design conditions.
 

A-9

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Building Science Corporation Buhs II 

Westford, MA 01886 Page 9 

System 2 Buhs II Minisplit Apt 2 Summary Loads
 

Area 

Quan 

Sen 

Loss 

Lat 

Gain 

Sen 

Gain 

Total 

Gain 

Component 

Description 

Buhs II glass: Glazing- 123.9 2,094 0 2,422 2,422 

R-40: Wall- 458.5 719 0 316 316 

Demising: Part- 372.1 529 0 397 397 

Subtotals for structure: 

People: 

Equipment: 

Lighting: 

Ductwork: 

Infiltration: Winter CFM: 40, Summer CFM: 0 

Ventilation: Winter CFM: 35, Summer CFM: 35 

5 

0 

3,342 

0 

2,738 

2,409 

0 

1,000 

0 

0 

0 

678 

3,135 

1,150 

1,200 

0 

0 

0 

616 

3,135 

2,150 

1,200 

0 

0 

0 

1,294 

System 2 Buhs II Minisplit Apt 2 Load Totals: 8,489 1,678 6,101 7,779 

Check Figures 

Supply CFM: 249 CFM Per Square ft.: 0.333 

Square ft. of Room Area: 749 Square ft. Per Ton: 1,105 

Volume (ft3) of Cond. Space: 6,737 

System Loads 

Total Heating Required Including Ventilation Air: 8,489 Btuh 8.489 MBH 

Total Sensible Gain: 6,101 Btuh 78 % 

Total Latent Gain: 1,678 Btuh 22 % 

Total Cooling Required Including Ventilation Air: 7,779 Btuh 0.65 Tons (Based On Sensible + Latent) 

0.68 Tons (Based On 75% Sensible 

Capacity) 

Notes 

Rhvac is an ACCA approved Manual J and Manual D computer program.
 

Calculations are performed per ACCA Manual J 8th Edition, Version 2, and ACCA Manual D.
 

All computed results are estimates as building use and weather may vary.
 

Be sure to select a unit that meets both sensible and latent loads according to the manufacturer's performance data at 

your design conditions.
 

A-10

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 10 

System 3 Buhs II Minisplit Apt 3 Summary Loads
 

Area 

Quan 

Sen 

Loss 

Lat 

Gain 

Sen 

Gain 

Total 

Gain 

Component 

Description 

Buhs II glass: Glazing- 123.9 2,094 0 2,422 2,422 

R-40: Wall- 458.5 719 0 316 316 

Demising: Part- 372.1 529 0 397 397 

Buhs II R-48: Roof/Ceiling- 748.5 983 0 282 282 

Subtotals for structure: 

People: 

Equipment: 

Lighting: 

Ductwork: 

Infiltration: Winter CFM: 40, Summer CFM: 0 

Ventilation: Winter CFM: 35, Summer CFM: 35 

5 

0 

4,325 

0 

2,738 

2,409 

0 

1,000 

0 

0 

0 

678 

3,417 

1,150 

1,200 

0 

0 

0 

616 

3,417 

2,150 

1,200 

0 

0 

0 

1,294 

System 3 Buhs II Minisplit Apt 3 Load Totals: 9,472 1,678 6,383 8,061 

Check Figures 

Supply CFM: 262 CFM Per Square ft.: 0.350 

Square ft. of Room Area: 749 Square ft. Per Ton: 1,056 

Volume (ft3) of Cond. Space: 6,737 

System Loads 

Total Heating Required Including Ventilation Air: 9,472 Btuh 9.472 MBH 

Total Sensible Gain: 6,383 Btuh 79 % 

Total Latent Gain: 1,678 Btuh 21 % 

Total Cooling Required Including Ventilation Air: 8,061 Btuh 0.67 Tons (Based On Sensible + Latent) 

0.71 Tons (Based On 75% Sensible 

Capacity) 

Notes 

Rhvac is an ACCA approved Manual J and Manual D computer program.
 

Calculations are performed per ACCA Manual J 8th Edition, Version 2, and ACCA Manual D.
 

All computed results are estimates as building use and weather may vary.
 

Be sure to select a unit that meets both sensible and latent loads according to the manufacturer's performance data at 

your design conditions.
 

A-11

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 11 

System 1, Zone 1 Summary Loads (Peak Load Procedure for Rooms)
 

Area 

Quan 

Sen 

Loss 

Lat 

Gain 

Sen 

Gain 

Total 

Gain 

Component 

Description 

Buhs II glass: Glazing- 109.6 1,853 0 2,169 2,169 

R-40: Wall- 393.6 617 0 271 271 

Demising: Part- 305.1 434 0 325 325 

Subtotals for structure: 

People: 

Equipment: 

Lighting: 

Ductwork: 

Infiltration: Winter CFM: 29, Summer CFM: 0 

4 

0 

2,904 

0 

1,994 

0 

800 

0 

0 

0 

2,920 

920 

1,200 

0 

0 

0 

2,920 

1,720 

1,200 

0 

0 

0 

System 1, Zone 1 Load Totals: 4,898 800 5,040 5,840 

Check Figures 

Supply CFM: 229 CFM Per Square ft.: 0.349 

Square ft. of Room Area: 657 Square ft. Per Ton: 1,250 

Volume (ft3) of Cond. Space: 5,906 

Zone Loads 

Total Heating Required: 4,898 Btuh 4.898 MBH 

Total Sensible Gain: 5,040 Btuh 86 % 

Total Latent Gain: 800 Btuh 14 % 

Total Cooling Required: 5,840 Btuh 0.49 Tons (Based On Sensible + Latent) 

0.53 Tons (Based On 75% Sensible 

Capacity) 

Notes 

Rhvac is an ACCA approved Manual J and Manual D computer program.
 

Calculations are performed per ACCA Manual J 8th Edition, Version 2, and ACCA Manual D.
 

All computed results are estimates as building use and weather may vary.
 

Be sure to select a unit that meets both sensible and latent loads according to the manufacturer's performance data at 

your design conditions.
 

A-12

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 12 

System 1, Zone 2 Summary Loads (Peak Load Procedure for Rooms)
 

Area 

Quan 

Sen 

Loss 

Lat 

Gain 

Sen 

Gain 

Total 

Gain 

Component 

Description 

basement: Glazing- 17.7 387 0 471 471 

15B0-20sf-4: Wall-Basement, , R-20 board insulation to 440.3 1,038 0 88 88 

floor, no interior finish, 4' floor depth 

21B-32: Floor-Basement, Concrete slab, any thickness, 2 933.9 819 0 0 0 

or more feet below grade, R-3 or higher insulation 

installed below floor, any floor cover, shortest side of 

floor slab is 32' wide 

Subtotals for structure: 

People: 

Equipment: 

Lighting: 

Ductwork: 

Infiltration: Winter CFM: 11, Summer CFM: 0 

0 

0 

2,244 

0 

744 

0 

0 

0 

0 

0 

682 

0 

600 

0 

0 

0 

682 

0 

600 

0 

0 

0 

System 1, Zone 2 Load Totals: 2,988 0 1,282 1,282 

Check Figures 

Supply CFM: 58 CFM Per Square ft.: 0.062 

Square ft. of Room Area: 934 Square ft. Per Ton: 8,743 

Volume (ft3) of Cond. Space: 6,351 

Zone Loads 

Total Heating Required: 2,988 Btuh 2.988 MBH 

Total Sensible Gain: 1,282 Btuh 100 % 

Total Latent Gain: 0 Btuh 0 % 

Total Cooling Required: 1,282 Btuh 0.11 Tons (Based On Sensible + Latent) 

0.11 Tons (Based On 75% Sensible 

Capacity) 

Notes 

Rhvac is an ACCA approved Manual J and Manual D computer program.
 

Calculations are performed per ACCA Manual J 8th Edition, Version 2, and ACCA Manual D.
 

All computed results are estimates as building use and weather may vary.
 

Be sure to select a unit that meets both sensible and latent loads according to the manufacturer's performance data at 

your design conditions.
 

A-13

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 13 

System 1, Zone 3 Summary Loads (Peak Load Procedure for Rooms)
 

Component 

Description 

Area 

Quan 

Sen 

Loss 

Lat 

Gain 

Sen 

Gain 

Total 

Gain 

Demising: Part­ 72.1 102 0 78 78 

Buhs II R-48: Roof/CeilingSubtotals for structure: 

People: 

Equipment: 

Lighting: 

Ductwork: 

Infiltration: Winter CFM: 0, Summer CFM: 0 

System 1, Zone 3 Load Totals: 

52.8 

0 

0 

69 

171 

0 

0 

171 

0 

0 

0 

0 

0 

0 

0 

20 

98 

0 

0 

0 

0 

0 

98 

20 

98 

0 

0 

0 

0 

0 

98 

Check Figures 

Supply CFM: 4 CFM Per Square ft.: 0.028 

Square ft. of Room Area: 159 Square ft. Per Ton: 19,469 

Volume (ft3) of Cond. Space: 1,425 

Zone Loads 

Total Heating Required: 171 Btuh 0.171 MBH 

Total Sensible Gain: 98 Btuh 100 % 

Total Latent Gain: 0 Btuh 0 % 

Total Cooling Required: 98 Btuh 0.01 Tons (Based On Sensible + Latent) 

0.01 Tons (Based On 75% Sensible 

Capacity) 

Notes 

Rhvac is an ACCA approved Manual J and Manual D computer program.
 

Calculations are performed per ACCA Manual J 8th Edition, Version 2, and ACCA Manual D.
 

All computed results are estimates as building use and weather may vary.
 

Be sure to select a unit that meets both sensible and latent loads according to the manufacturer's performance data at 

your design conditions.
 

A-14

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 14 

System 2, Zone 1 Summary Loads (Average Load Procedure for Rooms)
 

Area 

Quan 

Sen 

Loss 

Lat 

Gain 

Sen 

Gain 

Total 

Gain 

Component 

Description 

Buhs II glass: Glazing- 123.9 2,094 0 2,422 2,422 

R-40: Wall- 458.5 719 0 316 316 

Demising: Part- 372.1 529 0 397 397 

Subtotals for structure: 

People: 

Equipment: 

Lighting: 

Ductwork: 

Infiltration: Winter CFM: 40, Summer CFM: 0 

5 

0 

3,342 

0 

2,738 

0 

1,000 

0 

0 

0 

3,135 

1,150 

1,200 

0 

0 

0 

3,135 

2,150 

1,200 

0 

0 

0 

System 2, Zone 1 Load Totals: 6,080 1,000 5,485 6,485 

Check Figures 

Supply CFM: 249 CFM Per Square ft.: 0.333 

Square ft. of Room Area: 749 Square ft. Per Ton: 1,342 

Volume (ft3) of Cond. Space: 6,737 

Zone Loads 

Total Heating Required: 6,080 Btuh 6.080 MBH 

Total Sensible Gain: 5,485 Btuh 85 % 

Total Latent Gain: 1,000 Btuh 15 % 

Total Cooling Required: 6,485 Btuh 0.54 Tons (Based On Sensible + Latent) 

0.56 Tons (Based On 75% Sensible 

Capacity) 

Notes 

Rhvac is an ACCA approved Manual J and Manual D computer program.
 

Calculations are performed per ACCA Manual J 8th Edition, Version 2, and ACCA Manual D.
 

All computed results are estimates as building use and weather may vary.
 

Be sure to select a unit that meets both sensible and latent loads according to the manufacturer's performance data at 

your design conditions.
 

A-15

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 15 

System 3, Zone 1 Summary Loads (Average Load Procedure for Rooms)
 

Area 

Quan 

Sen 

Loss 

Lat 

Gain 

Sen 

Gain 

Total 

Gain 

Component 

Description 

Buhs II glass: Glazing- 123.9 2,094 0 2,422 2,422 

R-40: Wall- 458.5 719 0 316 316 

Demising: Part- 372.1 529 0 397 397 

Buhs II R-48: Roof/Ceiling- 748.5 983 0 282 282 

Subtotals for structure: 

People: 

Equipment: 

Lighting: 

Ductwork: 

Infiltration: Winter CFM: 40, Summer CFM: 0 

5 

0 

4,325 

0 

2,738 

0 

1,000 

0 

0 

0 

3,417 

1,150 

1,200 

0 

0 

0 

3,417 

2,150 

1,200 

0 

0 

0 

System 3, Zone 1 Load Totals: 7,063 1,000 5,767 6,767 

Check Figures 

Supply CFM: 262 CFM Per Square ft.: 0.350 

Square ft. of Room Area: 749 Square ft. Per Ton: 1,278 

Volume (ft3) of Cond. Space: 6,737 

Zone Loads 

Total Heating Required: 7,063 Btuh 7.063 MBH 

Total Sensible Gain: 5,767 Btuh 85 % 

Total Latent Gain: 1,000 Btuh 15 % 

Total Cooling Required: 6,767 Btuh 0.56 Tons (Based On Sensible + Latent) 

0.59 Tons (Based On 75% Sensible 

Capacity) 

Notes 

Rhvac is an ACCA approved Manual J and Manual D computer program.
 

Calculations are performed per ACCA Manual J 8th Edition, Version 2, and ACCA Manual D.
 

All computed results are estimates as building use and weather may vary.
 

Be sure to select a unit that meets both sensible and latent loads according to the manufacturer's performance data at 

your design conditions.
 

A-16

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 16 

System 1, Zone 1 Pie Chart
 

Wall 21% 

System
 

1, Zone
 

1
 

Loss
 

4,898
 

Btuh
 

Glass 38% 

Infiltration 41% 

System 

1, Zone 

1 

Gain 

5,840 

Btuh 

Wall 10% 

Equipment 21% 

Glass 40% 

People 29% 

A-17

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 17 

System 1, Zone 2 Pie Chart
 

Infiltration 25% Floor 27% 

System 

1, Zone 

2 

Loss 

2,988 

Btuh 

Wall 35% 

Glass 13% 

Wall 7% 

System
 

1, Zone
 

2
 

Gain
 

1,282
 

Btuh
 Glass 46% 

Equipment 47% 

A-18

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 18 

System 1, Zone 3 Pie Chart
 

Roof 40% 

System 

1, Zone 

3 

Loss 

171 

Btuh Wall 60% 

Roof 20% 

System
 

1, Zone
 

3
 

Gain
 

98
 

Btuh
 

Wall 80% 

A-19

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 19 

System 2, Zone 1 Pie Chart
 

System
 

2, Zone
 

1
 

Loss
 

6,080
 

Btuh
 

Glass 34% 

Wall 21% 

Infiltration 45% 

System 

2, Zone 

1 

Gain 

6,485 

Btuh 

Wall 11% 

Equipment 19% 

Glass 37% 

People 33% 

A-20

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 20 

System 3, Zone 1 Pie Chart
 

System Wall 18% 3, Zone
 

1
 

Loss
 

7,063
 

Btuh
 

Roof 14% 

Glass 30% 

Infiltration 39% 

Roof 4% 

System
 

3, Zone
 

1
 

Gain
 

6,767
 

Btuh
 

Glass 36% 

Wall 11% 

People 32% 

Equipment 18% 

A-21

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 21 

Detailed Room Loads - Room 3 - 1st_Floor_Bed_1 (Peak Fenestration Gain 

Procedure) 

General 

Room is in zone 1, which peaks at 3 pm
 

Calculation Mode: Htg. & clg. Occurrences:
 1 

Room Length: 15.9 ft. System Number: 1 

Room Width: 10.8 ft. Zone Number: 1 

Area: 171.0 sq.ft. Supply Air: 55 CFM 

Ceiling Height: 9.0 ft. Supply Air Changes: 2.1 AC/hr 

Volume: 1,535.0 cu.ft. Req. Vent. Clg: 0 CFM 

Number of Registers: 1 Actual Winter Vent.: 4 CFM 

Runout Air: 55 CFM Percent of Supply.: 8 % 

Runout Duct Size: 4 in. Actual Summer Vent.: 7 CFM 

Runout Air Velocity: 627 ft./min. Percent of Supply: 12 % 

Runout Air Velocity: 627 ft./min. Actual Winter Infil.: 6 CFM 

Actual Loss: 0.443 in.wg./100 ft. Actual Summer Infil.: 0 CFM 

Item Area -U- Htg Sen Clg Lat Sen
 

Description Quantity Value HTM Loss HTM Gain Gain
 

SW-Wall-R-40 10.8 X 9 82.5 0.025 1.6 129 0.7 0 57 

N -Part-15°/20°-Demising 20.4 X 9 183.6 0.071 1.4 261 1.1 0 196 

SW-Gls-Buhs II glass shgc-0.22 14.2 0.270 16.9 241 34.5 0 491 

0%S 

Subtotals for Structure: 631 0 744 

Infil.: Win.: 5.6, Sum.: 0.0 97 3.959 383 0.000 0 0 

People: 200 lat/per, 230 sen/per: 2 400 460 

Room Totals: 1,014 400 1,204 

A-22

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 22 

Detailed Room Loads - Room 4 - 1st_Floor_Kitchen (Peak Fenestration Gain 

Procedure) 

General 

Room is in zone 1, which peaks at 3 pm
 

Calculation Mode: Htg. & clg. Occurrences:
 1 

Room Length: 13.3 ft. System Number: 1 

Room Width: 10.9 ft. Zone Number: 1 

Area: 146.0 sq.ft. Supply Air: 91 CFM 

Ceiling Height: 9.0 ft. Supply Air Changes: 4.2 AC/hr 

Volume: 1,310.0 cu.ft. Req. Vent. Clg: 0 CFM 

Number of Registers: 1 Actual Winter Vent.: 7 CFM 

Runout Air: 91 CFM Percent of Supply.: 7 % 

Runout Duct Size: 6 in. Actual Summer Vent.: 11 CFM 

Runout Air Velocity: 466 ft./min. Percent of Supply: 12 % 

Runout Air Velocity: 466 ft./min. Actual Winter Infil.: 13 CFM 

Actual Loss: 0.139 in.wg./100 ft. Actual Summer Infil.: 0 CFM 

Item Area -U- Htg Sen Clg Lat Sen
 

Description Quantity Value HTM Loss HTM Gain Gain
 

SW-Wall-R-40 10.9 X 9 84 0.025 1.6 132 0.7 0 58 

SE-Wall-R-40 13.3 X 9 112 0.025 1.6 175 0.7 0 77 

SW-Gls-Buhs II glass shgc-0.22 14.2 0.270 16.9 241 34.5 0 491 

0%S 

SE-Gls-Buhs II glass shgc-0.22 8 0.270 16.9 135 23.0 0 184 

0%S 

Subtotals for Structure: 683 0 810 

Infil.: Win.: 12.6, Sum.: 0.0 218 3.963 865 0.000 0 0 

Equipment: 0 1,200 

Room Totals: 1,548 0 2,010 

A-23

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 23 

Detailed Room Loads - Room 5 - 1st_Floor_Dining_Room (Peak Fenestration Gain 

Procedure) 

General 

Room is in zone 1, which peaks at 3 pm
 

Calculation Mode: Htg. & clg. Occurrences:
 1 

Room Length: 10.0 ft. System Number: 1 

Room Width: 14.4 ft. Zone Number: 1 

Area: 143.0 sq.ft. Supply Air: 12 CFM 

Ceiling Height: 9.0 ft. Supply Air Changes: 0.6 AC/hr 

Volume: 1,286.0 cu.ft. Req. Vent. Clg: 0 CFM 

Number of Registers: 1 Actual Winter Vent.: 1 CFM 

Runout Air: 12 CFM Percent of Supply.: 11 % 

Runout Duct Size: 4 in. Actual Summer Vent.: 1 CFM 

Runout Air Velocity: 139 ft./min. Percent of Supply: 12 % 

Runout Air Velocity: 139 ft./min. Actual Winter Infil.: 1 CFM 

Actual Loss: 0.023 in.wg./100 ft. Actual Summer Infil.: 0 CFM 

Item Area -U- Htg Sen Clg Lat Sen
 

Description Quantity Value HTM Loss HTM Gain Gain
 

SE-Wall-R-40 1.8 X 9 7.4 0.025 1.6 12 0.7 0 5 

N -Part-15°/20°-Demising 7.2 X 9 64.8 0.071 1.4 92 1.1 0 69 

SE-Gls-Buhs II glass shgc-0.22 8.3 0.270 16.9 141 23.0 0 192 

0%S 

Subtotals for Structure: 245 0 266
 

Infil.: Win.: 0.9, Sum.: 0.0 16 3.937 62 0.000 0 0
 

Room Totals: 307 0 266 

A-24

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 24 

Detailed Room Loads - Room 6 - 1st_Floor_Living (Peak Fenestration Gain 

Procedure) 

General 

Room is in zone 1, which peaks at 3 pm
 

Calculation Mode: Htg. & clg. Occurrences:
 1 

Room Length: 13.9 ft. System Number: 1 

Room Width: 12.0 ft. Zone Number: 1 

Area: 167.0 sq.ft. Supply Air: 61 CFM 

Ceiling Height: 9.0 ft. Supply Air Changes: 2.5 AC/hr 

Volume: 1,501.0 cu.ft. Req. Vent. Clg: 0 CFM 

Number of Registers: 1 Actual Winter Vent.: 7 CFM 

Runout Air: 61 CFM Percent of Supply.: 12 % 

Runout Duct Size: 4 in. Actual Summer Vent.: 7 CFM 

Runout Air Velocity: 703 ft./min. Percent of Supply: 12 % 

Runout Air Velocity: 703 ft./min. Actual Winter Infil.: 7 CFM 

Actual Loss: 0.554 in.wg./100 ft. Actual Summer Infil.: 0 CFM 

Item Area -U- Htg Sen Clg Lat Sen
 

Description Quantity Value HTM Loss HTM Gain Gain
 

NE-Wall-R-40 13.8 X 9 66.9 0.025 1.6 105 0.7 0 46 

N -Part-15°/20°-Demising 6.3 X 9 56.7 0.071 1.4 81 1.1 0 60 

NE-Gls-Buhs II glass shgc-0.22 56.8 0.270 16.9 960 13.8 0 782 

0%S (2) 

Subtotals for Structure: 1,146 0 888 

Infil.: Win.: 7.1, Sum.: 0.0 124 3.968 491 0.000 0 0 

People: 200 lat/per, 230 sen/per: 2 400 460 

Room Totals: 1,637 400 1,348 

A-25

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 25 

Detailed Room Loads - Room 7 - 1st_Floor_Bathroom (Peak Fenestration Gain 

Procedure) 

General 

Room is in zone 1, which peaks at 3 pm 

Calculation Mode: Htg. & clg. 

Room Length: 5.6 ft. 

Room Width: 5.4 ft. 

Area: 30.0 sq.ft. 

Ceiling Height: 9.0 ft. 

Volume: 274.0 cu.ft. 

Number of Registers: 1 

Runout Air: 10 CFM 

Runout Duct Size: 4 in. 

Runout Air Velocity: 110 ft./min. 

Runout Air Velocity: 110 ft./min. 

Actual Loss: 0.015 in.wg./100 ft. 

Occurrences: 

System Number: 

Zone Number: 

Supply Air: 

Supply Air Changes: 

Req. Vent. Clg: 

Actual Winter Vent.: 

Percent of Supply.: 

Actual Summer Vent.: 

Percent of Supply: 

Actual Winter Infil.: 

Actual Summer Infil.: 

1 

1 

1 

10 CFM 

2.1 AC/hr 

0 CFM 

2 CFM 

18 % 

1 CFM 

12 % 

3 CFM 

0 CFM 

Item 

Description 

SE-Wall-R-40 5.4 X 9 

SE-Gls-Buhs II glass shgc-0.22 

0%S 

Area 

Quantity 

40.8 

8 

-UValue 

0.025 

0.270 

Htg 

HTM 

1.6 

16.9 

Sen 

Loss 

64 

135 

Clg 

HTM 

0.7 

23.0 

Lat 

Gain 

0 

0 

Sen 

Gain 

28 

184 

Subtotals for Structure: 

Infil.: Win.: 2.8, Sum.: 0.0 49 3.957 

199 

193 0.000 

0 

0 

212 

0 

Room Totals: 392 0 212 

A-26

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 26 

Detailed Room Loads - Room 1 - Basement (Peak Fenestration Gain Procedure)
 

General 

Room is in zone 2, which peaks at 10 am
 

Calculation Mode: Htg. & clg. Occurrences:
 1 

Room Length: 42.3 ft. System Number: 1 

Room Width: 22.1 ft. Zone Number: 2 

Area: 934.0 sq.ft. Supply Air: 58 CFM 

Ceiling Height: 6.8 ft. Supply Air Changes: 0.6 AC/hr 

Volume: 6,351.0 cu.ft. Req. Vent. Clg: 0 CFM 

Number of Registers: 1 Actual Winter Vent.: 13 CFM 

Runout Air: 58 CFM Percent of Supply.: 22 % 

Runout Duct Size: 4 in. Actual Summer Vent.: 7 CFM 

Runout Air Velocity: 668 ft./min. Percent of Supply: 12 % 

Runout Air Velocity: 668 ft./min. Actual Winter Infil.: 11 CFM 

Actual Loss: 0.501 in.wg./100 ft. Actual Summer Infil.: 0 CFM 

Item Area -U- Htg Sen Clg Lat Sen
 

Description Quantity Value HTM Loss HTM Gain Gain
 

SW-Wall-15B0-20sf-4 22.1 X 6.8 150.3 0.033 2.4 357 0.2 0 32 

NE-Wall-15B0-20sf-4 23 X 6.8 146.7 0.033 2.3 344 0.2 0 28 

SE-Wall-15B0-20sf-4 22.2 X 6.8 143.3 0.033 2.3 337 0.2 0 28 

NE-Gls-basement shgc-0.3 0%S (2) 9.7 0.350 21.9 212 23.7 0 230 

SE-Gls-basement shgc-0.3 0%S 8 0.350 21.9 175 45.5 0 364 

Floor-21B-32 22.1 X 42.3 933.9 0.014 0.9 819 0.0 0 0 

Subtotals for Structure: 2,244 0 682 

Infil.: Win.: 10.8, Sum.: 0.0 188 3.962 744 0.000 0 0 

Equipment: 0 600 

Room Totals: 2,988 0 1,282 

A-27

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 27 

Detailed Room Loads - Room 2 - 1st_floor_hall (Peak Fenestration Gain Procedure)
 

General 

Room is in zone 3, which peaks at 7 pm
 

Calculation Mode: Htg. & clg. Occurrences:
 1 

Room Length: 8.1 ft. System Number: 1 

Room Width: 6.5 ft. Zone Number: 3 

Area: 53.0 sq.ft. Supply Air: 1 CFM 

Ceiling Height: 9.0 ft. Supply Air Changes: 0.1 AC/hr 

Volume: 475.0 cu.ft. Req. Vent. Clg: 0 CFM 

Number of Registers: 1 Actual Winter Vent.: 0 CFM 

Runout Air: 1 CFM Percent of Supply.: 12 % 

Runout Duct Size: 4 in. Actual Summer Vent.: 0 CFM 

Runout Air Velocity: 14 ft./min. Percent of Supply: 12 % 

Runout Air Velocity: 14 ft./min. Actual Winter Infil.: 0 CFM 

Actual Loss: 0.000 in.wg./100 ft. Actual Summer Infil.: 0 CFM 

Item Area -U- Htg Sen Clg Lat Sen
 

Description Quantity Value HTM Loss HTM Gain Gain
 

N -Part-15°/20°-Demising 2.7 X 9 24 0.071 1.4 34 1.1 0 26 

Subtotals for Structure: 34 0 26
 

Infil.: Win.: 0.0, Sum.: 0.0 0 0 0 0 0 0
 

Room Totals: 34 0 26 

A-28

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 28 

Detailed Room Loads - Room 8 - 2nd_floor_hall (Peak Fenestration Gain 

Procedure) 

General 

Room is in zone 3, which peaks at 7 pm 

Calculation Mode: Htg. & clg. 

Room Length: 8.1 ft. 

Room Width: 6.5 ft. 

Area: 53.0 sq.ft. 

Ceiling Height: 9.0 ft. 

Volume: 475.0 cu.ft. 

Number of Registers: 1 

Runout Air: 1 CFM 

Runout Duct Size: 4 in. 

Runout Air Velocity: 14 ft./min. 

Runout Air Velocity: 14 ft./min. 

Actual Loss: 0.000 in.wg./100 ft. 

Occurrences: 

System Number: 

Zone Number: 

Supply Air: 

Supply Air Changes: 

Req. Vent. Clg: 

Actual Winter Vent.: 

Percent of Supply.: 

Actual Summer Vent.: 

Percent of Supply: 

Actual Winter Infil.: 

Actual Summer Infil.: 

1 

1 

3 

1 CFM 

0.1 AC/hr 

0 CFM 

0 CFM 

12 % 

0 CFM 

12 % 

0 CFM 

0 CFM 

Item 

Description 

N -Part-15°/20°-Demising 2.7 X 9 

Area 

Quantity 

24 

-UValue 

0.071 

Htg 

HTM 

1.4 

Sen 

Loss 

34 

Clg 

HTM 

1.1 

Lat 

Gain 

0 

Sen 

Gain 

26 

Subtotals for Structure: 

Infil.: Win.: 0.0, Sum.: 0.0 0 0 

34 

0 0 

0 

0 

26 

0 

Room Totals: 34 0 26 

A-29

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 29 

Detailed Room Loads - Room 15 - 3rd_floor_hall (Peak Fenestration Gain 

Procedure) 

General 

Room is in zone 3, which peaks at 7 pm 

Calculation Mode: Htg. & clg. 

Room Length: 8.1 ft. 

Room Width: 6.5 ft. 

Area: 53.0 sq.ft. 

Ceiling Height: 9.0 ft. 

Volume: 475.0 cu.ft. 

Number of Registers: 1 

Runout Air: 2 CFM 

Runout Duct Size: 4 in. 

Runout Air Velocity: 24 ft./min. 

Runout Air Velocity: 24 ft./min. 

Actual Loss: 0.001 in.wg./100 ft. 

Occurrences: 

System Number: 

Zone Number: 

Supply Air: 

Supply Air Changes: 

Req. Vent. Clg: 

Actual Winter Vent.: 

Percent of Supply.: 

Actual Summer Vent.: 

Percent of Supply: 

Actual Winter Infil.: 

Actual Summer Infil.: 

1 

1 

3 

2 CFM 

0.3 AC/hr 

0 CFM 

0 CFM 

21 % 

0 CFM 

12 % 

0 CFM 

0 CFM 

Item 

Description 

N -Part-15°/20°-Demising 2.7 X 9 

UP-Roof-Buhs II R-48 8.1 X 6.5 

Area 

Quantity 

24 

52.8 

-UValue 

0.071 

0.021 

Htg 

HTM 

1.4 

1.3 

Sen 

Loss 

34 

69 

Clg 

HTM 

1.1 

0.4 

Lat 

Gain 

0 

0 

Sen 

Gain 

26 

20 

Subtotals for Structure: 

Infil.: Win.: 0.0, Sum.: 0.0 0 0 

103 

0 0 

0 

0 

46 

0 

Room Totals: 103 0 46 

A-30

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 30 

Detailed Room Loads - Room 9 - 2nd_floor_Bed2 (Average Load Procedure) 

General 

Calculation Mode: Htg. & clg. Occurrences: 1 

Room Length: 10.5 ft. System Number: 2 

Room Width: 8.8 ft. Zone Number: 1 

Area: 92.0 sq.ft. Supply Air: 29 CFM 

Ceiling Height: 9.0 ft. Supply Air Changes: 2.1 AC/hr 

Volume: 831.0 cu.ft. Req. Vent. Clg: 0 CFM 

Number of Registers: 1 Actual Winter Vent.: 5 CFM 

Runout Air: 29 CFM Percent of Supply.: 17 % 

Runout Duct Size: 4 in. Actual Summer Vent.: 4 CFM 

Runout Air Velocity: 328 ft./min. Percent of Supply: 14 % 

Runout Air Velocity: 328 ft./min. Actual Winter Infil.: 5 CFM 

Actual Loss: 0.123 in.wg./100 ft. Actual Summer Infil.: 0 CFM 

Item Area -U- Htg Sen Clg Lat Sen 

Description Quantity Value HTM Loss HTM Gain Gain 

NE-Wall-R-40 8.8 X 9 64.9 0.025 1.6 102 0.7 0 45 

N -Part-15°/20°-Demising 10.5 X 9 94.5 0.071 1.4 134 1.1 0 101 

NE-Gls-Buhs II glass shgc-0.22 14.2 0.270 16.9 241 17.8 0 253 

0%S 

Subtotals for Structure: 477 0 399 

Infil.: Win.: 5.4, Sum.: 0.0 79 4.702 372 0.000 0 0 

People: 200 lat/per, 230 sen/per: 1 200 230 

Room Totals: 849 200 629 

A-31

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 31 

Detailed Room Loads - Room 10 - 2nd_Floor_Bed_1 (Average Load Procedure)
 

General 

Calculation Mode: Htg. & clg. Occurrences: 1 

Room Length: 15.9 ft. System Number: 2 

Room Width: 10.8 ft. Zone Number: 1 

Area: 171.0 sq.ft. Supply Air: 47 CFM 

Ceiling Height: 9.0 ft. Supply Air Changes: 1.8 AC/hr 

Volume: 1,535.0 cu.ft. Req. Vent. Clg: 0 CFM 

Number of Registers: 1 Actual Winter Vent.: 6 CFM 

Runout Air: 47 CFM Percent of Supply.: 13 % 

Runout Duct Size: 4 in. Actual Summer Vent.: 7 CFM 

Runout Air Velocity: 534 ft./min. Percent of Supply: 14 % 

Runout Air Velocity: 534 ft./min. Actual Winter Infil.: 7 CFM 

Actual Loss: 0.322 in.wg./100 ft. Actual Summer Infil.: 0 CFM 

Item Area -U- Htg Sen Clg Lat Sen
 

Description Quantity Value HTM Loss HTM Gain Gain
 

SW-Wall-R-40 10.8 X 9 82.5 0.025 1.6 129 0.7 0 57 

N -Part-15°/20°-Demising 20.4 X 9 183.6 0.071 1.4 261 1.1 0 196 

SW-Gls-Buhs II glass shgc-0.22 14.2 0.270 16.9 241 21.9 0 312 

0%S 

Subtotals for Structure: 631 0 565 

Infil.: Win.: 6.6, Sum.: 0.0 97 4.703 455 0.000 0 0 

People: 200 lat/per, 230 sen/per: 2 400 460 

Room Totals: 1,086 400 1,025 

A-32

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 32 

Detailed Room Loads - Room 11 - 2nd_Floor_Kitchen (Average Load Procedure)
 

General 

Calculation Mode: Htg. & clg. Occurrences: 1 

Room Length: 13.3 ft. System Number: 2 

Room Width: 10.9 ft. Zone Number: 1 

Area: 146.0 sq.ft. Supply Air: 83 CFM 

Ceiling Height: 9.0 ft. Supply Air Changes: 3.8 AC/hr 

Volume: 1,310.0 cu.ft. Req. Vent. Clg: 0 CFM 

Number of Registers: 1 Actual Winter Vent.: 10 CFM 

Runout Air: 83 CFM Percent of Supply.: 12 % 

Runout Duct Size: 5 in. Actual Summer Vent.: 12 CFM 

Runout Air Velocity: 608 ft./min. Percent of Supply: 14 % 

Runout Air Velocity: 608 ft./min. Actual Winter Infil.: 15 CFM 

Actual Loss: 0.304 in.wg./100 ft. Actual Summer Infil.: 0 CFM 

Item Area -U- Htg Sen Clg Lat Sen
 

Description Quantity Value HTM Loss HTM Gain Gain
 

SW-Wall-R-40 10.9 X 9 84 0.025 1.6 132 0.7 0 58 

SE-Wall-R-40 13.3 X 9 112 0.025 1.6 175 0.7 0 77 

SW-Gls-Buhs II glass shgc-0.22 14.2 0.270 16.9 241 21.9 0 312 

0%S 

SE-Gls-Buhs II glass shgc-0.22 8 0.270 16.9 135 21.9 0 175 

0%S 

Subtotals for Structure: 683 0 622 

Infil.: Win.: 14.9, Sum.: 0.0 218 4.701 1,026 0.000 0 0 

Equipment: 0 1,200 

Room Totals: 1,709 0 1,822 

A-33

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 33 

Detailed Room Loads - Room 12 - 2nd_Floor_Dining_Room (Average Load 

Procedure) 

General 

Calculation Mode: 

Room Length: 

Room Width: 

Area: 

Ceiling Height: 

Volume: 

Number of Registers: 

Runout Air: 

Runout Duct Size: 

Runout Air Velocity: 

Runout Air Velocity: 

Actual Loss: 

Htg. & clg. 

10.0 ft. 

14.4 ft. 

143.0 sq.ft. 

9.0 ft. 

1,286.0 cu.ft. 

1 

12 CFM 

4 in. 

134 ft./min. 

134 ft./min. 

0.022 in.wg./100 ft. 

Occurrences: 

System Number: 

Zone Number: 

Supply Air: 

Supply Air Changes: 

Req. Vent. Clg: 

Actual Winter Vent.: 

Percent of Supply.: 

Actual Summer Vent.: 

Percent of Supply: 

Actual Winter Infil.: 

Actual Summer Infil.: 

1 

2 

1 

12 CFM 

0.5 AC/hr 

0 CFM 

2 CFM 

16 % 

2 CFM 

14 % 

1 CFM 

0 CFM 

Item 

Description 

SE-Wall-R-40 1.8 X 9 

N -Part-15°/20°-Demising 7.2 X 9 

SE-Gls-Buhs II glass shgc-0.22 

0%S 

Area 

Quantity 

7.4 

64.8 

8.3 

-UValue 

0.025 

0.071 

0.270 

Htg 

HTM 

1.6 

1.4 

16.9 

Sen 

Loss 

12 

92 

141 

Clg 

HTM 

0.7 

1.1 

21.9 

Lat 

Gain 

0 

0 

0 

Sen 

Gain 

5 

69 

183 

Subtotals for Structure: 

Infil.: Win.: 1.1, Sum.: 0.0 16 4.698 

245 

74 0.000 

0 

0 

257 

0 

Room Totals: 319 0 257 

A-34

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 34 

Detailed Room Loads - Room 13 - 2nd_Floor_Living (Average Load Procedure)
 

General 

Calculation Mode: Htg. & clg. Occurrences: 1 

Room Length: 13.9 ft. System Number: 2 

Room Width: 12.0 ft. Zone Number: 1 

Area: 167.0 sq.ft. Supply Air: 70 CFM 

Ceiling Height: 9.0 ft. Supply Air Changes: 2.8 AC/hr 

Volume: 1,501.0 cu.ft. Req. Vent. Clg: 0 CFM 

Number of Registers: 1 Actual Winter Vent.: 10 CFM 

Runout Air: 70 CFM Percent of Supply.: 14 % 

Runout Duct Size: 5 in. Actual Summer Vent.: 10 CFM 

Runout Air Velocity: 517 ft./min. Percent of Supply: 14 % 

Runout Air Velocity: 517 ft./min. Actual Winter Infil.: 8 CFM 

Actual Loss: 0.220 in.wg./100 ft. Actual Summer Infil.: 0 CFM 

Item Area -U- Htg Sen Clg Lat Sen
 

Description Quantity Value HTM Loss HTM Gain Gain
 

NE-Wall-R-40 13.8 X 9 66.9 0.025 1.6 105 0.7 0 46 

N -Part-15°/20°-Demising 3.2 X 9 29.2 0.071 1.4 42 1.1 0 31 

NE-Gls-Buhs II glass shgc-0.22 56.8 0.270 16.9 960 17.8 0 1,012 

0%S (2) 

Subtotals for Structure: 1,107 0 1,089 

Infil.: Win.: 8.5, Sum.: 0.0 124 4.703 582 0.000 0 0 

People: 200 lat/per, 230 sen/per: 2 400 460 

Room Totals: 1,689 400 1,549 

A-35

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 35 

Detailed Room Loads - Room 14 - 2nd_Floor_Bathroom (Average Load Procedure)
 

General 

Calculation Mode: Htg. & clg. Occurrences: 1 

Room Length: 5.6 ft. System Number: 2 

Room Width: 5.4 ft. Zone Number: 1 

Area: 30.0 sq.ft. Supply Air: 9 CFM 

Ceiling Height: 9.0 ft. Supply Air Changes: 2.0 AC/hr 

Volume: 274.0 cu.ft. Req. Vent. Clg: 0 CFM 

Number of Registers: 1 Actual Winter Vent.: 2 CFM 

Runout Air: 9 CFM Percent of Supply.: 27 % 

Runout Duct Size: 4 in. Actual Summer Vent.: 1 CFM 

Runout Air Velocity: 106 ft./min. Percent of Supply: 14 % 

Runout Air Velocity: 106 ft./min. Actual Winter Infil.: 3 CFM 

Actual Loss: 0.014 in.wg./100 ft. Actual Summer Infil.: 0 CFM 

Item Area -U- Htg Sen Clg Lat Sen
 

Description Quantity Value HTM Loss HTM Gain Gain
 

SE-Wall-R-40 5.4 X 9 40.8 0.025 1.6 64 0.7 0 28 

SE-Gls-Buhs II glass shgc-0.22 8 0.270 16.9 135 21.9 0 175 

0%S 

Subtotals for Structure: 199 0 203
 

Infil.: Win.: 3.3, Sum.: 0.0 49 4.695 229 0.000 0 0
 

Room Totals: 428 0 203 

A-36

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 36 

Detailed Room Loads - Room 16 - 3rd_Floor_Bed_1 (Average Load Procedure)
 

General 

Calculation Mode: Htg. & clg. Occurrences: 1 

Room Length: 15.9 ft. System Number: 3 

Room Width: 10.8 ft. Zone Number: 1 

Area: 171.0 sq.ft. Supply Air: 50 CFM 

Ceiling Height: 9.0 ft. Supply Air Changes: 1.9 AC/hr 

Volume: 1,535.0 cu.ft. Req. Vent. Clg: 0 CFM 

Number of Registers: 1 Actual Winter Vent.: 6 CFM 

Runout Air: 50 CFM Percent of Supply.: 13 % 

Runout Duct Size: 4 in. Actual Summer Vent.: 7 CFM 

Runout Air Velocity: 568 ft./min. Percent of Supply: 13 % 

Runout Air Velocity: 568 ft./min. Actual Winter Infil.: 7 CFM 

Actual Loss: 0.363 in.wg./100 ft. Actual Summer Infil.: 0 CFM 

Item Area -U- Htg Sen Clg Lat Sen
 

Description Quantity Value HTM Loss HTM Gain Gain
 

SW-Wall-R-40 10.8 X 9 82.5 0.025 1.6 129 0.7 0 57 

N -Part-15°/20°-Demising 20.4 X 9 183.6 0.071 1.4 261 1.1 0 196 

SW-Gls-Buhs II glass shgc-0.22 14.2 0.270 16.9 241 21.9 0 312 

0%S 

UP-Roof-Buhs II R-48 15.9 X 10.8 170.6 0.021 1.3 224 0.4 0 64 

Subtotals for Structure: 855 0 629 

Infil.: Win.: 6.6, Sum.: 0.0 97 4.703 455 0.000 0 0 

People: 200 lat/per, 230 sen/per: 2 400 460 

Room Totals: 1,310 400 1,089 

A-37

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 37 

Detailed Room Loads - Room 17 - 3rd_Floor_Kitchen (Average Load Procedure)
 

General 

Calculation Mode: Htg. & clg. Occurrences: 1 

Room Length: 13.3 ft. System Number: 3 

Room Width: 10.9 ft. Zone Number: 1 

Area: 146.0 sq.ft. Supply Air: 85 CFM 

Ceiling Height: 9.0 ft. Supply Air Changes: 3.9 AC/hr 

Volume: 1,310.0 cu.ft. Req. Vent. Clg: 0 CFM 

Number of Registers: 1 Actual Winter Vent.: 9 CFM 

Runout Air: 85 CFM Percent of Supply.: 11 % 

Runout Duct Size: 5 in. Actual Summer Vent.: 11 CFM 

Runout Air Velocity: 626 ft./min. Percent of Supply: 13 % 

Runout Air Velocity: 626 ft./min. Actual Winter Infil.: 15 CFM 

Actual Loss: 0.322 in.wg./100 ft. Actual Summer Infil.: 0 CFM 

Item Area -U- Htg Sen Clg Lat Sen
 

Description Quantity Value HTM Loss HTM Gain Gain
 

SW-Wall-R-40 10.9 X 9 84 0.025 1.6 132 0.7 0 58 

SE-Wall-R-40 13.3 X 9 112 0.025 1.6 175 0.7 0 77 

SW-Gls-Buhs II glass shgc-0.22 14.2 0.270 16.9 241 21.9 0 312 

0%S 

SE-Gls-Buhs II glass shgc-0.22 8 0.270 16.9 135 21.9 0 175 

0%S 

UP-Roof-Buhs II R-48 13.3 X 10.9 145.6 0.021 1.3 191 0.4 0 55 

Subtotals for Structure: 874 0 677 

Infil.: Win.: 14.9, Sum.: 0.0 218 4.701 1,026 0.000 0 0 

Equipment: 0 1,200 

Room Totals: 1,900 0 1,877 

A-38

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 38 

Detailed Room Loads - Room 18 - 3rd_Floor_Dining_Room (Average Load 

Procedure) 

General 

Calculation Mode: 

Room Length: 

Room Width: 

Area: 

Ceiling Height: 

Volume: 

Number of Registers: 

Runout Air: 

Runout Duct Size: 

Runout Air Velocity: 

Runout Air Velocity: 

Actual Loss: 

Htg. & clg. 

10.0 ft. 

14.4 ft. 

143.0 sq.ft. 

9.0 ft. 

1,286.0 cu.ft. 

1 

14 CFM 

4 in. 

162 ft./min. 

162 ft./min. 

0.031 in.wg./100 ft. 

Occurrences: 

System Number: 

Zone Number: 

Supply Air: 

Supply Air Changes: 

Req. Vent. Clg: 

Actual Winter Vent.: 

Percent of Supply.: 

Actual Summer Vent.: 

Percent of Supply: 

Actual Winter Infil.: 

Actual Summer Infil.: 

1 

3 

1 

14 CFM 

0.7 AC/hr 

0 CFM 

3 CFM 

18 % 

2 CFM 

13 % 

1 CFM 

0 CFM 

Item 

Description 

SE-Wall-R-40 1.8 X 9 

N -Part-15°/20°-Demising 7.2 X 9 

SE-Gls-Buhs II glass shgc-0.22 

0%S 

UP-Roof-Buhs II R-48 10 X 14.4 

Area 

Quantity 

7.4 

64.8 

8.3 

142.9 

-UValue 

0.025 

0.071 

0.270 

0.021 

Htg 

HTM 

1.6 

1.4 

16.9 

1.3 

Sen 

Loss 

12 

92 

141 

188 

Clg 

HTM 

0.7 

1.1 

21.9 

0.4 

Lat 

Gain 

0 

0 

0 

0 

Sen 

Gain 

5 

69 

183 

54 

Subtotals for Structure: 

Infil.: Win.: 1.1, Sum.: 0.0 16 4.698 

433 

74 0.000 

0 

0 

311 

0 

Room Totals: 507 0 311 

A-39

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 39 

Detailed Room Loads - Room 19 - 3rd_Floor_Living (Average Load Procedure)
 

General 

Calculation Mode: Htg. & clg. Occurrences: 1 

Room Length: 13.9 ft. System Number: 3 

Room Width: 12.0 ft. Zone Number: 1 

Area: 167.0 sq.ft. Supply Air: 73 CFM 

Ceiling Height: 9.0 ft. Supply Air Changes: 2.9 AC/hr 

Volume: 1,501.0 cu.ft. Req. Vent. Clg: 0 CFM 

Number of Registers: 1 Actual Winter Vent.: 9 CFM 

Runout Air: 73 CFM Percent of Supply.: 13 % 

Runout Duct Size: 5 in. Actual Summer Vent.: 10 CFM 

Runout Air Velocity: 538 ft./min. Percent of Supply: 13 % 

Runout Air Velocity: 538 ft./min. Actual Winter Infil.: 8 CFM 

Actual Loss: 0.238 in.wg./100 ft. Actual Summer Infil.: 0 CFM 

Item Area -U- Htg Sen Clg Lat Sen
 

Description Quantity Value HTM Loss HTM Gain Gain
 

NE-Wall-R-40 13.8 X 9 66.9 0.025 1.6 105 0.7 0 46 

N -Part-15°/20°-Demising 3.2 X 9 29.2 0.071 1.4 42 1.1 0 31 

NE-Gls-Buhs II glass shgc-0.22 56.8 0.270 16.9 960 17.8 0 1,012 

0%S (2) 

UP-Roof-Buhs II R-48 13.9 X 12 166.7 0.021 1.3 219 0.4 0 63 

Subtotals for Structure: 1,326 0 1,152 

Infil.: Win.: 8.5, Sum.: 0.0 124 4.703 582 0.000 0 0 

People: 200 lat/per, 230 sen/per: 2 400 460 

Room Totals: 1,908 400 1,612 

A-40

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 40 

Detailed Room Loads - Room 20 - 3rd_Floor_Bathroom (Average Load Procedure)
 

General 

Calculation Mode: Htg. & clg. Occurrences: 1 

Room Length: 5.6 ft. System Number: 3 

Room Width: 5.4 ft. Zone Number: 1 

Area: 30.0 sq.ft. Supply Air: 10 CFM 

Ceiling Height: 9.0 ft. Supply Air Changes: 2.1 AC/hr 

Volume: 274.0 cu.ft. Req. Vent. Clg: 0 CFM 

Number of Registers: 1 Actual Winter Vent.: 2 CFM 

Runout Air: 10 CFM Percent of Supply.: 24 % 

Runout Duct Size: 4 in. Actual Summer Vent.: 1 CFM 

Runout Air Velocity: 112 ft./min. Percent of Supply: 13 % 

Runout Air Velocity: 112 ft./min. Actual Winter Infil.: 3 CFM 

Actual Loss: 0.015 in.wg./100 ft. Actual Summer Infil.: 0 CFM 

Item Area -U- Htg Sen Clg Lat Sen
 

Description Quantity Value HTM Loss HTM Gain Gain
 

SE-Wall-R-40 5.4 X 9 40.8 0.025 1.6 64 0.7 0 28 

SE-Gls-Buhs II glass shgc-0.22 8 0.270 16.9 135 21.9 0 175 

0%S 

UP-Roof-Buhs II R-48 5.6 X 5.4 30.4 0.021 1.3 40 0.4 0 11 

Subtotals for Structure: 239 0 214
 

Infil.: Win.: 3.3, Sum.: 0.0 49 4.695 229 0.000 0 0
 

Room Totals: 468 0 214 

A-41

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 41 

Detailed Room Loads - Room 21 - 3rd_floor_Bed2 (Average Load Procedure) 

General 

Calculation Mode: Htg. & clg. Occurrences: 1 

Room Length: 10.5 ft. System Number: 3 

Room Width: 8.8 ft. Zone Number: 1 

Area: 92.0 sq.ft. Supply Air: 30 CFM 

Ceiling Height: 9.0 ft. Supply Air Changes: 2.2 AC/hr 

Volume: 831.0 cu.ft. Req. Vent. Clg: 0 CFM 

Number of Registers: 1 Actual Winter Vent.: 5 CFM 

Runout Air: 30 CFM Percent of Supply.: 16 % 

Runout Duct Size: 4 in. Actual Summer Vent.: 4 CFM 

Runout Air Velocity: 346 ft./min. Percent of Supply: 13 % 

Runout Air Velocity: 346 ft./min. Actual Winter Infil.: 5 CFM 

Actual Loss: 0.137 in.wg./100 ft. Actual Summer Infil.: 0 CFM 

Item Area -U- Htg Sen Clg Lat Sen 

Description Quantity Value HTM Loss HTM Gain Gain 

NE-Wall-R-40 8.8 X 9 64.9 0.025 1.6 102 0.7 0 45 

N -Part-15°/20°-Demising 10.5 X 9 94.5 0.071 1.4 134 1.1 0 101 

NE-Gls-Buhs II glass shgc-0.22 14.2 0.270 16.9 241 17.8 0 253 

0%S 

UP-Roof-Buhs II R-48 10.5 X 8.8 92.3 0.021 1.3 121 0.4 0 35 

Subtotals for Structure: 598 0 434 

Infil.: Win.: 5.4, Sum.: 0.0 79 4.702 372 0.000 0 0 

People: 200 lat/per, 230 sen/per: 1 200 230 

Room Totals: 970 200 664 

A-42

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 42 

Room Cooling and Heating Loads Bar Graphs
 

1st_Floor_Bed_1
 

1st_Floor_Kitchen
 

1st_Floor_Dining_Room
 

1st_Floor_Living
 

1st_floor_hall 

2nd_floor_hall 

3rd_floor_hall 

Cooling 

1st_Floor_Bathroom 

Basement 

2nd_floor_Bed2 Heating

0 500 1,000 1,500 2,000 2,500 3,000 

Btuh 

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\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 43 

Room Cooling and Heating Loads Bar Graphs
 

2nd_Floor_Bed_1
 

2nd_Floor_Kitchen
 

3rd_Floor_Kitchen 

3rd_Floor_Dining_Room 

3rd_Floor_Living 

2nd_Floor_Dining_Room 

Cooling 

2nd_Floor_Living 

2nd_Floor_Bathroom 

3rd_Floor_Bed_1 

3rd_Floor_Bathroom Heating 

0 500 1,000 1,500 2,000 2,500 

Btuh 

A-44

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 44 

Room Cooling and Heating Loads Bar Graphs
 

3rd_floor_Bed2 

0 200 400 600 800 1,000 

Cooling 

Heating 

Btuh 

A-45

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 45 

Room Cooling Loads Bar Graphs
 

1st_Floor_Bed_1
 

1st_Floor_Kitchen
 

1st_Floor_Dining_Room
 

1st_Floor_Living
 

1st_floor_hall 

2nd_floor_hall 

3rd_floor_hall 

Sensible 

1st_Floor_Bathroom 

Basement 

2nd_floor_Bed2 Latent

0 500 1,000 1,500 2,000 2,500 

Btuh 

A-46

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 46 

Room Cooling Loads Bar Graphs
 

2nd_Floor_Bed_1
 

2nd_Floor_Kitchen
 

3rd_Floor_Kitchen 

3rd_Floor_Dining_Room 

3rd_Floor_Living 

2nd_Floor_Dining_Room 

Sensible 

2nd_Floor_Living 

2nd_Floor_Bathroom 

3rd_Floor_Bed_1 

3rd_Floor_Bathroom Latent 

0 500 1,000 1,500 2,000 

Btuh 

A-47

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 47 

Room Cooling Loads Bar Graphs
 

3rd_floor_Bed2 

0 200 400 600 800 

Sensible 

Latent 

Btuh 

A-48

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Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 48 

System 1 Room Load Summary
 

No 

Room 

Name 

Area 

SF 

Htg 

Sens 

Btuh 

Min 

Htg 

CFM 

Run 

Duct 

Size 

Run 

Duct 

Vel 

Clg 

Sens 

Btuh 

Clg 

Lat 

Btuh 

Min 

Clg 

CFM 

Act 

Sys 

CFM 

---Zone 1--­

3 1st_Floor_Bed_1 171 1,014 13 1-4 627 1,204 400 55 55 

4 1st_Floor_Kitchen 146 1,548 20 1-6 466 2,010 0 91 91 

5 1st_Floor_Dining_ 143 307 4 1-4 139 266 0 12 12 

Room 

6 1st_Floor_Living 167 1,637 21 1-4 703 1,348 400 61 61 

7 1st_Floor_Bathroo 30 392 5 1-4 110 212 0 10 10 

m 

Zone 1 subtotal 657 4,898 64 5,040 800 229 229 

---Zone 2--­

1 Basement 934 2,988 39 1-4 668 1,282 0 58 58 

Zone 2 subtotal 

---Zone 3--­

2 1st_floor_hall 

8 2nd_floor_hall 

15 3rd_floor_hall 

934 

53 

53 

53 

2,988 

34 

34 

103 

39 

0 

0 

1 

1-4 

1-4 

1-4 

14 

14 

24 

1,282 

26 

26 

46 

0 

0 

0 

0 

58 

1 

1 

2 

58 

1 

1 

2 

Zone 3 subtotal 159 171 2 98 0 4 4 

Ventilation 2,409 616 678 

System 1 total 1,750 10,466 105 6,758 1,478 279 279 

Note: Since the system is multizone, the Peak Fenestration Gain Procedure was used to determine glass sensible gains 

at the room and zone levels, so the sums of the zone sensible gains and airflows for cooling shown above are not 

intended to equal the totals at the system level. Room and zone sensible gains and cooling CFM values are for the hour 

in which the glass sensible gain for the zone is at its peak. Sensible gains at the system level are based on the "Average 

Load Procedure + Excursion" method. 

Cooling System Summary 

Cooling Sensible/Latent Sensible Latent Total 

Tons Split Btuh Btuh Btuh 

Net Required: 0.69 82% / 18% 6,758 1,478 8,236
 

Recommended: 0.75 75% / 25% 6,758 2,253 9,010
 

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\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 49 

System 2 Room Load Summary
 

No 

Room 

Name 

Area 

SF 

Htg 

Sens 

Btuh 

Min 

Htg 

CFM 

Run 

Duct 

Size 

Run 

Duct 

Vel 

Clg 

Sens 

Btuh 

Clg 

Lat 

Btuh 

Min 

Clg 

CFM 

Act 

Sys 

CFM 

---Zone 1--­

9 2nd_floor_Bed2 92 849 11 1-4 328 629 200 29 29 

10 2nd_Floor_Bed_1 171 1,086 14 1-4 534 1,025 400 47 47 

11 2nd_Floor_Kitchen 146 1,709 22 1-5 608 1,822 0 83 83 

12 2nd_Floor_Dining 143 319 4 1-4 134 257 0 12 12 

_Room 

13 2nd_Floor_Living 167 1,689 22 1-5 517 1,549 400 70 70 

14 2nd_Floor_Bathro 30 428 6 1-4 106 203 0 9 9 

om 

Ventilation 2,409 616 678 

System 2 total 749 8,489 79 6,101 1,678 249 249 

Cooling System Summary 

Cooling Sensible/Latent Sensible Latent Total 

Tons Split Btuh Btuh Btuh 

Net Required: 0.65 78% / 22% 6,101 1,678 7,779 

Recommended: 0.68 75% / 25% 6,101 2,034 8,134 

Equipment Data 

Heating System Cooling System 

Type: Electric Resistance Standard Air Conditioner 

Model: 

Indoor Model: 

Brand: 

Efficiency: 0% 0 SEER 

Sound: 

Capacity: 0 0 

Sensible Capacity: n/a 0 Btuh 

Latent Capacity: n/a 0 Btuh 

A-50

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
 

 

 

 

 

 

 

Rhvac - Residential & Light Commercial HVAC Loads Elite Software Development, Inc. 

Building Science Corporation Buhs II 

Westford, MA 01886 Page 50 

System 3 Room Load Summary
 

No 

Room 

Name 

Area 

SF 

Htg 

Sens 

Btuh 

Min 

Htg 

CFM 

Run 

Duct 

Size 

Run 

Duct 

Vel 

Clg 

Sens 

Btuh 

Clg 

Lat 

Btuh 

Min 

Clg 

CFM 

Act 

Sys 

CFM 

---Zone 1--­

16 3rd_Floor_Bed_1 171 1,310 17 1-4 568 1,089 400 50 50 

17 3rd_Floor_Kitchen 146 1,900 25 1-5 626 1,877 0 85 85 

18 3rd_Floor_Dining_ 143 507 7 1-4 162 311 0 14 14 

Room 

19 3rd_Floor_Living 167 1,908 25 1-5 538 1,612 400 73 73 

20 3rd_Floor_Bathroo 30 468 6 1-4 112 214 0 10 10 

m 

21 3rd_floor_Bed2 92 970 13 1-4 346 664 200 30 30 

Ventilation 2,409 616 678 

System 3 total 749 9,472 92 6,383 1,678 262 262 

Cooling System Summary 

Cooling Sensible/Latent Sensible Latent Total 

Tons Split Btuh Btuh Btuh 

Net Required: 0.67 79% / 21% 6,383 1,678 8,061 

Recommended: 0.71 75% / 25% 6,383 2,128 8,510 

Equipment Data 

Heating System Cooling System 

Type: Electric Resistance Standard Air Conditioner 

Model: 

Indoor Model: 

Brand: 

Efficiency: 0% 0 SEER 

Sound: 

Capacity: 0 0 

Sensible Capacity: n/a 0 Btuh 

Latent Capacity: n/a 0 Btuh 

A-51

\\Somerserv\somerdata ...\Buhs II load calculations.rhv Monday, June 20, 2011, 5:59 PM 
DOE/GO-102012-3469 ▪ September 2012

Printed with a renewable-source ink on paper containing at 

least 50% wastepaper, including 10% post-consumer waste.