8D-i 

APPENDIX 8D. DEVELOPMENT OF BASE CASE EFFICIENCY DISTRIBUTIONS

TABLE OF CONTENTS

8D.1 INTRODUCTION ........................................................................................................ 8D-1

8D.2 INITIAL DISTRIBUTIONS ......................................................................................... 8D-1

8D.3 EFFICIENCY TREND ................................................................................................. 8D-1

8D.4 2019 EFFICIENCY DISTRIBUTIONS ....................................................................... 8D-2

REFERENCES ......................................................................................................................... 8D-3

LIST OF TABLES

Table 8D.2.1 Manufacturer-Provided and DOE-Adjusted Estimates of Efficiency 

Distributions (2012) .......................................................................................... 8D-1

Table 8D.3.1 Base Case Projected Shipment-Weighted Efficiencies for CUAC ≥65 to <135 

kBtu/h ................................................................................................................ 8D-2

Table 8D.4.1 Base Case Efficiency Distribution (2019) for SPVU <65,000 Btu/h ................. 8D-2
8D-1 

APPENDIX 8D. DEVELOPMENT OF BASE CASE EFFICIENCY DISTRIBUTIONS

8D.1 INTRODUCTION

DOE developed base case efficiency distributions for 2019, the year in which amended 

standards would take effect, through a combination of estimates from manufacturer interviews 

and projected trends from a previous air conditioning rulemaking. 

8D.2 INITIAL DISTRIBUTIONS

For each single package vertical unit (SPVU) equipment class considered for amended 

standards, DOE determined the initial distribution of equipment efficiencies in the marketplace 

based on manufacturer-provided information. Table 8D.2.1 shows the manufacturer-provided 

estimates from interviews conducted in 2012, as well as the estimates DOE developed based on 

this information for the two sizes of equipment. For SPVU less than 65,000 Btu/h, DOE made 

two adjustments. The first was to combine the 9 and 9.5 energy efficiency rations (EERs) into 9 

EER, and the second was to reduce the total from 100.1% to 100.0%. For larger SPVUs, because 

there are no units on the market above 10.0 EER, DOE summed the manufacturer-provided 

distribution from 10 to 11.75 EER. 

Table 8D.2.1 Manufacturer-Provided and DOE-Adjusted Estimates of Efficiency 

Distributions (2012) 

Efficiency 

Level

Manufacturer 

Estimate DOE-Adjusted Estimates

SPVUs SPVU <65 

kBtu/h

SPVU ≥65 and 

<135 kBtu/h

9 EER 86.0% 89.4% 89.4%

9.5 EER 3.5% 0.0% 0.0%

10 EER 8.0% 8.0% 10.6%

10.5 EER 1.5% 1.5% -

11 EER 1.0% 1.0% -

11.75 EER 0.1% 0.1% -

12.3 EER N/A 0.0% -

Total 100.1% 100.0% 100.0%

8D.3 EFFICIENCY TREND

To project forward from 2012 to 2019, DOE first “rolled-up” all the 9 EER equipment to 

a 10 EER by 2015, the ASHRAE Standard 90.1-2013 compliance date. The DOE then derived a 

trend based on the same rate of growth in efficiency as it used in the 2004 rulemaking for 

commercial unitary air conditioners (CUAC).

1 Table 8D.3.1 shows the base-case projected 

shipment-weighted efficiencies for CUAC greater than or equal to 65,000 Btu/h and less than 

135,000 Btu/h, which was the smallest equipment class in that rulemaking and therefore used as 

a proxy for SPVU. This efficiency trend shows an increase of 0.69 EER over 24 years, or an 

average of about 1 EER every 35 years.
8D-2 

Table 8D.3.1 Base Case Projected Shipment-Weighted Efficiencies for CUAC ≥65 and <135 

kBtu/h

Year EER Year EER

2012 10.37 2024 10.74

2013 10.40 2025 10.77

2014 10.43 2026 10.80

2015 10.46 2027 10.83

2016 10.49 2028 10.86

2017 10.53 2029 10.89

2018 10.56 2030 10.92

2019 10.59 2031 10.95

2020 10.62 2032 10.97

2021 10.65 2033 11.00

2022 10.68 2034 11.03

2023 10.71 2035 11.06

Source: http://www1.eere.energy.gov/buildings/appliance_standards/commercial/pdfs/

cuac_tsd_app_t.pdf , Table T.2.1.

8D.4 2019 EFFICIENCY DISTRIBUTIONS

Using the 2012 efficiency distribution adjusted to meet the ASHRAE Standard 90.1-2013 

compliance date of 2015 and the trend derived from CUAC (1 EER every 34.8 years), DOE 

projected the base case efficiency distribution to 2019. Projections through 2019 are shown in 

Table 8D.4.1 for equipment classes less than 65,000 Btu/h. 

Table 8D.4.1 Base Case Efficiency Distribution (2019) for SPVU <65,000 Btu/h 

Year Efficiency Level (EER) Avg

9.00 10.00 10.50 11.00 11.75 12.30 EER

2012 89.4% 8.0% 1.5% 1.0% 0.1% 0.0% 9.13

2013 86.5% 10.9% 1.5% 1.0% 0.1% 0.0% 9.15

2014 83.7% 13.7% 1.5% 1.0% 0.1% 0.0% 9.18

2015 0.0% 97.4% 1.5% 1.0% 0.1% 0.0% 10.02

2016 0.0% 91.7% 7.2% 1.0% 0.1% 0.0% 10.05

2017 0.0% 85.9% 13.0% 1.0% 0.1% 0.0% 10.08

2018 0.0% 80.2% 18.7% 1.0% 0.1% 0.0% 10.11

2019 0.0% 74.4% 24.5% 1.0% 0.1% 0.0% 10.13
8D-3 

REFERENCES

1. U.S. Department of Energy. 2004. Technical Support Document: Energy Efficiency Program 

for Commercial and Industrial Equipment: Commercial Unitary Air Conditioners and Heat 

Pumps. Washington, D.C. 

http://www1.eere.energy.gov/buildings/appliance_standards/commercial/cuac_tsd_060904.ht

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