CHAPTER 4. ENERGY USE ANALYSIS

TABLE OF CONTENTS 

4.1 INTRODUCTION ........................................................................................................... 4-1

4.2 BASE NATIONAL AVERAGE UEC DATA ................................................................ 4-1

4.2.1 Air-Cooled Air Conditioners ............................................................................... 4-1

4.2.1.1 Cooling UEC .............................................................................................. 4-1

4.2.1.2 Heating UEC .............................................................................................. 4-3

4.2.2 Water Source Heat Pumps ................................................................................... 4-4

4.2.2.1 Cooling UEC .............................................................................................. 4-4

4.2.2.2 Heating UEC .............................................................................................. 4-5

4.2.2.3 UEC Adjustment ........................................................................................ 4-7

4.3 VARIABILITY BY BUILDING TYPE AND CENSUS DIVISION ............................. 4-8

4.4 RESULTS ...................................................................................................................... 4-10

REFERENCES .......................................................................................................................... 4-12

LIST OF TABLES 

Table 4.2.1 UECs for Air-Cooled Single-Phase Air Conditioners <65,000 Btu/h ........... 4-2

Table 4.2.2 Cooling UECs for Air-Cooled Single-Phase Heat Pumps <65,000 

Btu/h ............................................................................................................... 4-3

Table 4.2.3 Heating UECs for Air-Cooled Single-Phase Heat Pumps <65,000 

Btu/h ............................................................................................................... 4-4

Table 4.2.4 2000 Cooling UECs for Water Source Heat Pumps ...................................... 4-5

Table 4.2.5 Commercial Unitary Heat Pump (≥65,000 - <135,000 Btu/h) Heating 

Energy Use Parameters .................................................................................. 4-6

Table 4.2.6 Water-Source Heat Pump COP to EER Relationship .................................... 4-6

Table 4.2.7 Heating UECs for Water Source Heat Pumps ............................................... 4-7

Table 4.2.8 Factors Used to Represent Relative Changes in Required Cooling 

Energy ............................................................................................................ 4-7

Table 4.2.9 Factors Used to Represent Relative Changes in Required Heating 

Energy ............................................................................................................ 4-8

Table 4.3.1 Distribution of Small Commercial Air-Cooled Air-Conditioning and 

Heating Equipment by Building Type ........................................................... 4-8

Table 4.3.2 Distribution of Water-Source Heat Pumps by Building Type ....................... 4-8

Table 4.3.3 Distribution of Building Types by Census Division: Small Commercial 

Air-Cooled Air-Conditioning and Heating Equipment.................................. 4-9

Table 4.3.4 Distribution of Building Types by Census Division: Water-Source 

Heat Pumps .................................................................................................... 4-9

Table 4.4.1 Cooling UECs (kWh/year) for Small, Air-Cooled, 3-Phase AirConditioning and Heating Equipment less than 65,000 Btu/h ..................... 4-10

Table 4.4.2 Cooling UECs for Water -Source Heat Pumps ............................................ 4-11

4-i 
Table 4.4.3 Heating UECs for Water-Source Heat Pumps ............................................. 4-11

4-ii
CHAPTER 4. ENERGY USE ANALYSIS

4.1 INTRODUCTION

This chapter describes the energy use analysis for small, air-cooled, 3-phase airconditioning and heat pump equipment less than 65,000 Btu/h and water source heat pumps with 

cooling capacities less than 17,000 Btu/h, between 17,000 and 65,000 Btu/h, and between 65,000 

and 135,000 Btu/h. DOE analyzed the energy savings consumers would realize from the 

standards set forth by the American Society of Heating, Refrigeration, and Air-Conditioning 

Engineers (AHRAE) Standard 90.1-2013 for specific equipment classes, as well as for higher 

energy efficiency levels. 

4.2 BASE NATIONAL AVERAGE UEC DATA

4.2.1 Air-Cooled Air Conditioners

4.2.1.1 Cooling UEC 

To estimate the UEC for each class of small commercial packaged air-conditioning and 

heating equipment less than 65,000 Btu/h (air-cooled, three-phase), DOE began with the cooling 

UECs for single-phase equipment installed in commercial buildings as presented in the national 

impact analysis associated with the 2011 direct final rule (DFR) for residential central air 

conditioners and heat pumps.1 Table 4.2.1 and Table 4.2.2 show these cooling UECs for the 

United States. In the 2011 DFR analysis, the cooling UECs for split and single package systems 

were very similar, but UECs were available for higher efficiency levels for split systems than for 

single package equipment. As a result, DOE used the 2011 UECs for split systems for all 

equipment classes analyzed for the current notice of proposed rulemaking (NOPR), including 

both split and single package systems. UECs were directly available for each of the air 

conditioner and heat pump efficiency levels analyzed for this NOPR.

 

4-1 
Table 4.2.1 UECs for Air-Cooled Single-Phase Air Conditioners <65,000 Btu/h 

Electric Commercial

Cooling U.S. (kWh/yr)

SEER Split Packaged

13.0 2702.7 2716.0

13.5 2658.8 2669.1

14.0 2614.9 2622.2

14.5 2529.9 2539.3

15.0 2445.0 2456.4

15.5 2360.0 2373.5

16.0 2275.1 2290.6

16.5 2246.6 2260.5

17.0 2218.1 -

18.0 2161.2 -

19.0 2119.3 -

20.0 2077.5 -

21.0 2035.6 -

22.0 1993.7 -

23.0 1978.3 -

24.5 1955.1 -

Source: U.S. Department of Energy – Office of Energy Efficiency and Renewable Energy. 

Central Air Conditioners National Impact Analysis.1

 

Note: UECs for new units were used, and these values were very similar to the UECs for 

replacement units.

4-2 
Table 4.2.2 Cooling UECs for Air-Cooled Single-Phase Heat Pumps <65,000 Btu/h 

Electric Commercial Cooling 

U.S. (kWh/yr)

SEER Split Packaged

13.0 2741.4 2710.6

13.5 2701.4 2670.1

14.0 2661.3 2629.5

14.5 2582.1 2552.1

15.0 2502.8 2474.7

15.5 2423.5 2397.3

16.0 2344.2 2319.8

16.5 2310.8 2286.3

17.0 2277.4 -

18.0 2210.5 -

19.0 2161.5 -

20.0 2112.5 -

21.0 2063.5 -

22.0 2045.3 -

Source: U.S. Department of Energy – Office of Energy Efficiency and Renewable Energy. 

Central Air Conditioners National Impact Analysis.1

 

4.2.1.2 Heating UEC 

 Although ASHRAE 90.1-2013 increased the HSPF levels for this equipment, DOE did 

not include heating UECs in this analysis. Table 4.2.3 shows that for commercial installations in 

the 2011 analysis, the heating UECs did not scale proportionally with HSPF. Based on these 

data, DOE has determined that increasing HSPF for small commercial air conditioners will likely 

not result in significant energy savings. 

4-3 
Table 4.2.3 Heating UECs for Air-Cooled Single-Phase Heat Pumps <65,000 Btu/h 

SEER

HSPF

Electric

Commercial

Heating U.S. 

(kWh/yr)

Split Packaged Split Packaged

13.0 8.0 7.7 509.5 359.7

13.5 8.1 7.9 508.5 359.0

14.0 8.3 8.1 507.5 358.3

14.5 8.4 8.3 510.4 359.9

15.0 8.5 8.4 513.3 361.6

15.5 8.6 8.6 516.2 363.2

16.0 8.7 8.8 519.0 364.8

16.5 8.8 9.0 515.5 361.9

17.0 9.0 - 512.0 -

18.0 9.2 - 505.0 -

19.0 9.4 - 499.8 -

20.0 9.7 - 494.6 -

21.0 9.9 - 489.5 -

22.0 9.9 - 487.5 -

Source: U.S. Department of Energy – Office of Energy Efficiency and Renewable Energy. 

Central Air Conditioners National Impact Analysis.1 

4.2.2 Water Source Heat Pumps

4.2.2.1 Cooling UEC 

To estimate the cooling UEC for each class of water source heat pump, DOE began with 

the data provided for water source heat pumps published in Appendix D of the 2000 Screening 

Analysis for the Energy Policy Act of 2005 (EPACT).2 Table 4.2.4 shows the input capacity and 

national average full load equivalent operating hours (FLEOH) for each equipment class and 

efficiency level. The UEC equals the input capacity times the FLEOH.

4-4 
Table 4.2.4 2000 Cooling UECs for Water Source Heat Pumps

WSHP 

<17,000 

Btu/h

EER 9.3 11.2 12.5 13.1 14 15.8

Input Capacity (kW) 1.29 1.071 0.96 0.916 0.857 0.759

National Avg FLEOH 1,622.5 1,622.5 1,622.5 1,622.5 1,622.5 1,622.5

UEC (kwh/year) 2,093 1,738 1,558 1,486 1,390 1,231

WSHP 

≥17,000 - 

<65,000 

Btu/h 

EER 9.3 12 12.5 13.1 14 15.2

Input Capacity (kW) 3.871 3 2.88 2.748 2.571 2.368

National Avg FLEOH 1,622.5 1,622.5 1,622.5 1,622.5 1,622.5 1,622.5

UEC (kwh/year) 6,281 4,868 4,673 4,459 4,171 3,842 

WSHP 

≥65,000 - 

<135,000 

Btu/h

 

EER 10.5 12 12.5 13 14

Input Capacity (kW) 8.571 7.5 7.2 6.923 6.429

National Avg FLEOH 1,537.1 1,537.1 1,537.1 1,537.1 1,537.1

UEC (kwh/year) 13,174 11,528 11,067 10,641 9,882 

Source: U.S. Department of Energy – Office of Energy Efficiency and Renewable Energy. 

Screening Analysis for EPACT-Covered Commercial HVAC and Water-Heating Equipment. 

Volume 1 – Main Report. 2000. 

Where identical efficiency levels were available, DOE used the input capacity and 

FLEOH directly from the screening analysis. For additional efficiency levels, DOE used the 

same FLEOH (as it does not differ by efficiency level) and scaled the input capacities based on 

the ratio of EER, as was done in the original analysis and shown in the following equation: 

IIIIIIIIIIIIIIIIIIIIIIIIIIBB = 

EEEEEEAA

EEEEEEBB

xx IIIIIIIIIIIIIIIIIIIIIIIIIIAA

DOE then multiplied the FLEOH by the scaled input capacity to calculate the UEC for each 

additional efficiency level. 

4.2.2.2 Heating UEC 

The 2000 screening analysis did not estimate heating UECs for water source heat pumps. 

DOE requested data on this in the April 2014 Notice of Data Availability (NODA) (79 FR 

20114) but did not receive any. In order to characterize heating-side performance, DOE relied on 

an analysis of the Commercial Buildings Energy Consumption Survey (CBECS) 2003 data for 

air source heat pumps at larger capacities than two of the water source heat pump equipment 

classes in this rulemaking.3 DOE assumed that this estimate was sufficiently representative of the 

heating energy use for all three classes of water source heat pumps.

In the air-source heat pump analysis, DOE identified a representative building set 

consisting of 117 CBECS 2003 records. From this sub-sample of buildings, DOE determined a 

weighted-average annual heating energy consumption of 1.37 kWh/sq.ft. Because CBECS 

provides no information on equipment efficiency, DOE assumed that this energy use value 

4-5 
pertained to heat pumps with a heating efficiency, or coefficient of performance (COP), of 2.9. A 

heating efficiency of 2.9 COP corresponds to the minimum heating efficiency standard for airsource heat pumps in 2003, a value which DOE feels is representative of the heat pump stock 

characterized by CBECS. 

DOE used the energy consumption per square foot value derived from CBECS and the 

tons per square foot value developed for commercial unitary air conditioners greater than or 

equal to 65,000 Btu/h and less than 135,000 Btu/h to calculate an annual energy use per ton 

value for a 2.9 COP unit (Table 4.2.5). Because equipment energy use is a function of 

efficiency, DOE assumed that the annual heating energy consumption of a unit scales in direct 

proportion to the COP. Therefore, DOE multiplied the annual energy use per ton values by the 

representative tons for a given equipment class (1 ton, 3 tons, and 7.5 tons), and adjusted it by 

the ratio of 2.9 COP to the COP for that efficiency level. The COPs for each efficiency level 

were developed based on a relationship between EER and COP of units in the AHRI databasea

(Table 4.2.6). Table 4.2.7 shows the heating-side UEC values for water source heat pumps. 

Table 4.2.5 Commercial Unitary Heat Pump (≥65,000 - <135,000 Btu/h) Heating Energy 

Use Parameters 

Tons/SF 0.00260

Annual Energy Use/ SF 

(2.9 COP) 1.37 

Annual Energy Use per Ton 

(2.9 COP) 527 

Representative Tons 7.5

Table 4.2.6 Water-Source Heat Pump COP to EER Relationship 

Equipment Class Slope Intercept

WSHP <17,000 

Btu/h 0.2136 1.781 

WSHP ≥17,000 -

<65,000 Btu/h 0.2354 1.368 

WSHP ≥65,000 -

<135,000 Btu/h 0.1434 2.667 

a

 http://www.ahridirectory.org/ahridirectory/pages/homeM.aspx

4-6 

 
Table 4.2.7 Heating UECs for Water Source Heat Pumps

WSHP 

<17,000 

Btu/h

EER N/A 11.2 12.2 13.0 14.0 15.7 16.5 18.1

COP 2.9 4.2 4.3 4.6 4.8 5.1 5.3 5.6

Heating UEC

(kWh/year) 527 364 355 335 320 298 288 271 

WSHP 

≥17,000 - 

<65,000 

Btu/h 

EER N/A 12.0 13.0 14.6 16.6 18.0 19.2 21.6

COP 2.9 4.2 4.3 4.8 5.3 5.6 5.9 6.5

Heating UEC

(kWh/year) 1581 1092 1066 954 869 818 779 711 

WSHP 

≥65,000 - 

<135,000 

Btu/h

EER N/A 12.0 13.0 14.0 15.0 16.0 17.2 N/A

COP 2.9 4.2 4.3 4.7 4.8 5.0 5.1 N/A

Heating UEC

(kWh/year) 3953 2729 2666 2452 2379 2310 2233 N/A

4.2.2.3 UEC Adjustment

The cooling UECs for water source heat pumps are based on a study from 2000 and the 

heating UECs from the building stock in 2003. Over time, changes in building shell 

characteristics and internal loads can lead to a change in the energy required to meet a given 

cooling or heating load. The National Energy Modeling System (NEMS) commercial demand 

module accounts for these trends by adjusting the cooling and heating energy use by factors that 

are a function of region and building activity. These factors can be either less than one indicating 

a relative decrease in energy consumption, or positive, indicating an increase. DOE used the 

factors from the version of NEMS underlying AEO 20144

 to adjust the cooling and heating 

energy use from the values developed in 2000 and 2003, respectively, to the start of the analysis 

period, 2020. To do this, DOE took the ratio of the factors in 2020 and 2004. Factors prior to 

2004 were not available, so DOE assumed the 2004 factor was representative of earlier years as 

well. Ideally, DOE would have applied scalars based on building vintages but because DOE did 

not have a breakdown of the buildings by vintage represented by the available UECs, DOE 

applied the ratio of the 2020 and 2004 factors to the average UEC. The resulting factors make 

relatively modest adjustments to the UEC, as shown in Table 4.2.8 and Table 4.2.9. 

Table 4.2.8 Factors Used to Represent Relative Changes in Required Cooling Energy 

Building Type

Census Division

1 2 3 4 5 6 7 8 9

Office 0.96 0.95 0.96 0.96 0.93 0.94 0.92 0.94 0.90

Education 0.96 0.85 0.96 0.94 0.92 0.88 0.9 0.94 0.89

Lodging 0.97 0.96 0.98 0.98 0.94 0.93 0.93 0.95 0.96

Residential 0.97 0.96 0.98 0.98 0.94 0.93 0.93 0.95 0.96

Healthcare 0.96 0.95 0.96 0.95 0.94 0.95 0.95 0.97 0.91

Source: NEMS commercial demand module. 

4-7 
Table 4.2.9 Factors Used to Represent Relative Changes in Required Heating Energy 

Building Type

Census Division

1 2 3 4 5 6 7 8 9

Office 0.96 0.94 0.96 0.96 0.93 0.92 0.90 0.95 0.80

Education 0.95 0.92 0.94 0.92 0.92 0.87 0.91 0.93 0.84

Lodging 0.95 0.94 0.95 0.95 0.95 0.93 0.94 0.97 0.94

Residential 0.96 0.94 0.95 0.95 0.95 0.92 0.93 0.96 0.83

Healthcare 0.95 0.94 0.95 0.94 0.94 0.93 0.94 0.98 0.86

Source: NEMS commercial demand module. 

4.3 VARIABILITY BY BUILDING TYPE AND CENSUS DIVISION

DOE incorporates uncertainty and variability considerations in certain of the key 

parameters for the LCC analysis. In order to reflect variability of the base national average UEC 

estimates, DOE created distributions of UECs by building type and Census Division. 

DOE determined that small, air-cooled, 3-phase air-conditioning and heat pump 

equipment less than 65,000 Btu/h are used in the office and retail sectors and that water-source 

heat pumps are used in the office, lodging, education, multi-family housing, and healthcare 

sectors. Table 4.3.1 and Table 4.3.2 show the distributions of small, air-cooled air conditioning 

and heating equipment and water source heat pumps by building type.3.5 Table 4.3.3 and Table 

4.3.4 show the distributions of building types by census division.3

Table 4.3.1 Distribution of Small Commercial Air-Cooled Air-Conditioning and Heating 

Equipment by Building Type

Building Type Market Share

Office 47%

Retail 53%

Source: CBECS 2003. 

Table 4.3.2 Distribution of Water-Source Heat Pumps by Building Type

Building Type Market Share

Offices 26%

Public 30%

Lodging 5%

Property owners 29%

Medical services 10%

Source: Adjusted from market shares for a 

broader set of building types identified in the 

2014 CUAC NOPR. 

4-8 
Table 4.3.3 Distribution of Building Types by Census Division: Small Commercial AirCooled Air-Conditioning and Heating Equipment

Census Division

Building Type

Office Retail

New England 4% 5%

Middle Atlantic 19% 11%

East North Central 18% 14%

West North Central 7% 7%

South Atlantic 17% 22%

East South Central 4% 6%

West South Central 11% 14%

Mountain 6% 7%

Pacific 14% 13%

Source: CBECS 2003. 

Table 4.3.4 Distribution of Building Types by Census Division: Water-Source Heat 

Pumps

Census Division

Building Type

Office Education Lodging Multifamily Healthcare

New England 4% 3% 7% 7% 3%

Middle Atlantic 19% 14% 16% 20% 16%

East North Central 18% 20% 11% 15% 17%

West North Central 7% 6% 12% 5% 6%

South Atlantic 17% 25% 18% 17% 25%

East South Central 4% 3% 7% 3% 7%

West South Central 11% 12% 8% 10% 12%

Mountain 6% 6% 9% 4% 5%

Pacific 14% 10% 13% 19% 9%

Source: CBECS 2003. 

In order to develop the distribution of UECs, DOE used estimates of Full Load 

Equivalent Operating Hours (FLEOH) provided in the 2000 Screening Analysis for commercial 

air conditioners and heat pumps in 7 building types and 11 cities across the United States.2

 

The Screening Analysis had FLEOHs for five of the building types but did not have 

FLEOHs for multi-family and healthcare. DOE determined that the lodging FLEOHs would be 

representative for multi-family and the office FLEOHs would be representative for healthcare. 

DOE used the total floor space by Census Division from the 2003 Commercial Building Energy 

Consumption Survey (CBECS) to determine the distribution of building types.3 DOE then 

mapped the 11 cities to their respective Census Divisions. The Mountain and Pacific Census 

Divisions had multiple cities which represented different climate zones within the Census 

Division. DOE weighted the FLEOHs by the population of that Census Division which lives in 

the climate zone represented by each city.6,7 The mid-Atlantic Census Division did not have a 

4-9 
representative city in the screening analysis, so DOE used the same FLEOHs from New England 

(whose representative city is Providence) for the Middle Atlantic. 

DOE normalized the distributions of FLEOHs to the national average UECs used in this 

analysis to create distributions of UECs by building type and Census Division. 

4.4 RESULTS

Table 4.4.1 through Table 4.4.3 show the national average UECs by equipment class and 

efficiency level that were used as inputs to the LCC analysis. These include the UEC adjustments 

made to the data for water-source heat pumps to account for changes in cooling and heating 

loads over time. These UECs do not include the effects of random sampling that takes into 

account variability by building type and Census Division. This variability is accounted for in the 

LCC outputs, which are used as inputs to the NIA. As a result, the UECs used in the NIA are not 

exactly the same as those shown here.

Table 4.4.1 Cooling UECs (kWh/year) for Small, Air-Cooled, 3-Phase Air-Conditioning 

and Heating Equipment less than 65,000 Btu/h 

SEER Split AC Package AC Split HP Package HP

13 2,703 2,703 2,741 2,741

14 2,615 2,615 2,661 2,661

15 2,445 2,445 2,503 2,503

16 2,275 2,275 2,344 2,344

17 2,218 2,218 2,277 2,277

18 2,161 2,161 2,211 2,211

19 2,119 2,119 N/A N/A

4-10 
Table 4.4.2 Cooling UECs for Water -Source Heat Pumps

<17,000 Btu/h ≥17,000 and <65,000 Btu/h ≥65,000 and <135,000 Btu/h 

EER UEC 

(kWh/year) EER UEC (kWh/year) EER UEC (kWh/year)

11.2 1,631 12.0 4,568 12.0 10,819

12.2 1,497 13.0 4,217 13.0 9,987

13.0 1,405 14.6 3,755 14.0 9,274

14.0 1,305 16.6 3,302 15.0 8,655

15.7 1,163 18.0 3,045 16.0 8,114

16.5 1,107 19.2 2,855 17.2 7,548

18.1 1,009 21.6 2,538 N/A N/A

Table 4.4.3 Heating UECs for Water-Source Heat Pumps

<17,000 Btu/h ≥17,000 and <65,000 Btu/h ≥65,000 and <135,000 Btu/h

COP UEC 

(kWh/year) COP UEC (kWh/year) COP UEC (kWh/year)

4.2 336 4.2 1,007 4.2 2,517

4.3 328 4.3 983 4.3 2,458

4.5 309 4.8 880 4.7 2,261

4.8 295 5.4 801 4.8 2,194

5.3 274 5.8 754 5.0 2,130

5.5 266 6.1 718 5.1 2,059

6.0 250 6.8 655 N/A N/A

4-11 
REFERENCES

1

 U.S. Department of Energy – Office of Energy Efficiency and Renewable Energy. 2011-10-31 

Energy Conservation Program: Energy Conservation Standards for Residential Furnaces and 

Residential Central Air Conditioners and Heat Pumps

<http://www.regulations.gov/#!documentDetail;D=EERE-2011-BT-STD-0029-0021> 

2

 U.S. Department of Energy – Office of Energy Efficiency and Renewable Energy. Screening 

Analysis for EPACT-Covered Commercial HVAC and Water-Heating Equipment. Volume 1 

– Main Report. 2000. <http://www.regulations.gov/#!documentDetail;D=EERE-2006-STD0098-0015> 

3

 U.S. Department of Energy-Energy Information Administration, Commercial Buildings Energy 

Consumption Survey. 2003. <http://www.eia.gov/consumption/commercial/index.cfm>

4

 U.S. Energy Information Administration, Commercial Demand Module of the National Energy 

Modeling System: Model Documentation 2014. 2014. 

<http://www.eia.gov/forecasts/aeo/nems/documentation/commercial/pdf/m066(2014).pdf> 

5

 U.S. Department of Energy. 2014. Technical Support Document: Energy Efficiency Program 

for Commercial and Industrial Equipment: Small, Large, and Very Large Commercial 

Package Air Conditioning and Heating Equipment. Washington, D.C. 

<www1.eere.energy.gov/buildings/appliance_standards/rulemaking.aspx/ruleid/59>

6

 U.S. Department of Energy–Energy Information Administration, Commercial Buildings Energy 

Consumption Survey – Maps. 2003. <www.eia.gov/consumption/commercial/censusmaps.cfm> 

7

 U.S. Census Bureau – American Fact Finder. Annual Estimates of the Resident Population by 

Sex, Race, and Hispanic Origin: April 1, 2010 to July 1, 2013. 

<www.census.gov/popest/data/counties/asrh/2013/index.html> 

4-12