8-i

CHAPTER 8. NATIONAL IMPACT ANALYSIS

TABLE OF CONTENTS

8.1 INTRODUCTION .............................................................................................................. 8-1

8.2 NATIONAL ENERGY SAVINGS .................................................................................... 8-2

8.2.1 National Energy Savings Definition ....................................................................... 8-2

8.3 INPUTS TO THE NES CALCULATION ......................................................................... 8-4

8.3.1 Shipments................................................................................................................ 8-4

8.3.2 National Annual Energy Consumption................................................................... 8-4

8.3.3 Product Lifetime ..................................................................................................... 8-9

8.3.4 Site-to-Source Energy Conversion Factors............................................................. 8-9

8.3.5 Compliance Dates and Analysis Period.................................................................. 8-9

8.4 INPUTS TO NET PRESENT VALUE CALCULATION (Computer Room Air 

Conditioners)..................................................................................................................... 8-11

8.4.1 Net Present Value Definition................................................................................ 8-11

8.4.2 Net Present Value Inputs ...................................................................................... 8-12

8.4.2.1 Total Annual Installed Cost ................................................................... 8-12

8.4.2.2 Annual Installed Cost–Weighted by Efficiency Distribution ................ 8-13

8.4.2.1 Price Forecast......................................................................................... 8-14

8.4.2.2 Total Annual Operating Cost Savings ................................................... 8-14

8.4.2.3 Discount Factor...................................................................................... 8-15

8.4.2.4 Present Value of Costs........................................................................... 8-15

8.4.2.5 Present Value of Savings....................................................................... 8-16

8.5 NES AND NPV RESULTS.............................................................................................. 8-16

8.5.1 National Energy Savings and Net Present Value Input Summary........................ 8-16

8.5.2 National Energy Savings Results.......................................................................... 8-17

8.5.2.1 Water-cooled and Evaporatively-cooled Products................................. 8-17

8.5.2.2 VRF Water-source Heat Pumps............................................................. 8-18

8.5.2.3 Computer Room Air Conditioners......................................................... 8-18

8.5.3 Annual Costs and Savings .................................................................................... 8-19

8.5.4 Net Present Value Results..................................................................................... 8-20

LIST OF TABLES

Table 8.3.1 National Energy Saving Inputs............................................................................ 8-4

Table 8.3.2 Efficiency Distributions and Market Weighted-Average UECs: Water-Cooled 

Equipment ≥65 and <240 kBtu/h with Electric Resistance/No Heating.............. 8-5

Table 8.3.3 Water-Cooled and Evaporatively-Cooled Equipment Market Shares by Efficiency 

Level, Base Case Used for NIA Analysis............................................................ 8-5

Table 8.3.4 VRF Water-Source Heat Pump Market Shares by Efficiency Level, Base Case 

Used for NIA Analysis......................................................................................... 8-6

Table 8.3.5 Computer Room Air Conditioner Market Shares by Efficiency Level, Base Case 

Used for NIA Analysis......................................................................................... 8-6
8-ii

Table 8.3.6 Water-Cooled and Evaporatively-Cooled Equipment Market-Weighted Annual 

Average Energy Consumption by Standard Level (kwh/year)............................ 8-7

Table 8.3.7 VRF Water-Source Heat Pump Market-Weighted Annual Average Energy 

Consumption by Standard Level (kwh/year)....................................................... 8-8

Table 8.3.8 Computer Room Air Conditioner Shipment-Weighted Annual Average Energy 

Consumption by Standard Level (kwh/year)....................................................... 8-8

Table 8.4.1 Net Present Value Inputs ................................................................................... 8-12

Table 8.4.2 Total Installed Cost per Unit by Efficiency Level from Life-Cycle Cost 

(2011$)............................................................................................................... 8-12

Table 8.4.3 Shipment-Weighted Average Total Installed Cost by Standard Level (2011$) 8-13

Table 8.5.1 Inputs to the NES Spreadsheet Model ............................................................... 8-16

Table 8.5.2 National Energy Savings for Water-Cooled and Evaporatively-Cooled Products: 

Based on Historical Trends (Quads, 2013–2042 or 2014-2043) ....................... 8-17

Table 8.5.3 National Energy Savings for Water-Cooled and Evaporatively-Cooled Products: 

Shipments Fixed to 2009 (Quads, 2013–2042 or 2014-2043)........................... 8-18

Table 8.5.4 National Energy Savings for VRF Water-Source Heat Pumps >135,000 Btu/h 

(Quads, 2013-2042) ........................................................................................... 8-18

Table 8.5.5 National Energy Savings for Computer Room Air Conditioners (Quads, 2012-

2041 or 2013-2042)............................................................................................ 8-19

Table 8.5.6 Summary of Cumulative Net Present Value for Computer Room Air Conditioners 

(Seven Percent Discount Rate) .......................................................................... 8-22

Table 8.5.7 Summary of Cumulative Net Present Value for Computer Room Air Conditioners 

(Three Percent Discount Rate)........................................................................... 8-22

LIST OF FIGURES

Figure 8.5.1 National Annual Costs and Savings for Efficiency Level 1 (Small Air-Cooled 

Computer Room Air Conditioners) ................................................................... 8-20

Figure 8.5.2 Cumulative NES and NPV Results for Small Air-Cooled Computer Room Air 

Conditioners Based on a Seven-Percent Discount Rate .................................... 8-21
8-1

CHAPTER 8. NATIONAL IMPACT ANALYSIS

8.1 INTRODUCTION

This chapter describes the method for estimating the future national energy savings 

(NES) to customers from possible efficiency levels for water-cooled and evaporatively-cooled 

products, variable refrigerant flow (VRF) water-source heat pumps, and computer room air 

conditioners. This chapter also describes the method for estimating the magnitude and net 

present value (NPV) of the future NES for computer room air conditioners. Results of the 

national impact analysis (NIA) described here may include, depending on equipment, national 

energy consumption and savings, monetary value of energy savings to the Nation as a result of 

standards, increased total installed costs to the Nation as a result of standards, and the NPV of 

energy savings (the difference between the present monetary values of energy savings and the 

increased total installed costs). 

The NES for water-cooled and evaporatively-cooled products considers the American 

Society of Heating, Refrigerating and Air-Conditioning (ASHRAE) standard level as well as 

several higher efficiency standard levels for the eight equipment classes of commercial watercooled and evaporatively-cooled air-conditioning equipment that were analyzed. The U.S. 

Department of Energy (DOE) examined various standard levels for each class of equipment, 

including the ASHRAE Standard 90.1-2010 efficiency level, the max-tech level (the highest 

efficiency level of equipment currently on the market), and several levels between. The baseline 

for each level is the current federal energy conservation standard.However, for levels higher than 

ASHRAE Standard 90.1-2010, DOE presents the energy savings as net of the savings from 

ASHRAE. The NES for VRF water-source heat pumps follows the same method and analyzes

two equipment classes of VRF water-source heat pumps. However, DOE did not find any model 

on the market whose efficiency was less than the ASHRAE Standard 90.1-2010 levels. 

DOE determined both the NPV and the NES for each potential efficiency level it 

considered for each of the 15 equipment classes of computer room air conditioners it examined. 

DOE considered four efficiency levels that were higher than the baseline efficiency level defined 

by the ASHRAE Standard 90.1-2010 for each of the 15 equipment classes. DOE also included a 

market baseline level in the analysis spreadsheet. Because of the timing difference between DOE 

adopting standards at ASHRAE Standard 90.1-2010 levels as opposed to the adoption of 

standards of a higher efficiency level, DOE must address the potential energy savings that could 

occur in the time between the dates at which compliance would be required. DOE calculates the 

benefits for adopting standards that are more efficient than ASHRAE by analyzing the energy 

savings from the adoption of standards at the ASHRAE Standard 90.1-2010 level compared with 

the market baseline and then calculating the savings from the adoption of more stringent 

standards compared with the ASHRAE Standard 90.1-2010 as baseline. Because DOE by statute 

may not adopt standards at efficiency levels less stringent than those specified in ASHRAE 

Standard 90.1-2010, it reports all energy and economic impacts in this analysis as potential 

impacts compared with adoption of the ASHRAE Standard 90.1-2010 baseline levels. 

DOE performed all calculations using a Microsoft Excel spreadsheet, which is accessible 

on the Internet at 
8-2

http://www1.eere.energy.gov/buildings/appliance_standards/commercial/ashrae_products_docs_ 

meeting.html.

The important factors in the calculation of national energy consumption for each class of 

equipment include shipments, stock or inventory, national average electricity consumption, and 

the site-to-source conversion factor used to convert the annual site energy savings into the annual 

amount of energy saved at the source of electric generation (the source energy). This chapter 

discusses how these factors are used in the calculation of national energy and economic impacts. 

Chapter 7, Shipments Analysis, provides a detailed description of the shipments analysis that 

DOE used to forecast future purchases of equipment.

DOE was not able to obtain information that quantified how voluntary energy efficiency 

programs affect equipment efficiencies on a national basis, but voluntary programs may increase 

the share of energy-efficient equipment prior to the implementation date of any new standards. 

Consequently, DOE did not explicitly incorporate the impact of market-based initiatives into the 

shipment forecasts detailed in chapter 7 of this technical support document (TSD).

8.2 NATIONAL ENERGY SAVINGS 

8.2.1 National Energy Savings Definition

DOE calculates annual NES as the difference between two scenarios: a base case 

(without new standards) and a standards case (with new standards). DOE develops NES 

estimates for each product class independently. Positive values of NES correspond to net energy 

savings; i.e., national annual energy consumption (AEC) with standards is less than the AEC in 

the base case. For each product class and standards case, DOE calculated the total energy savings 

using a stock accounting method. The number of new shipments in any given year is assumed to 

remain in the commercial building stock for the assumed lifetime of the product, at which point 

that entire year’s shipments disappear from existing stock. In this way, the total stock, or number 

of surviving units, in any given year is the sum of that year’s shipments plus the shipments from 

the previous product lifetime minus one year’s worth.

The annual base total energy use in any given year is the summed product of the 

shipments for that year and the previous product life minus one year’s worth and the marketweighted average base unit energy consumption (UEC)

a

Annual Base Total Energy Useyear=n = � Shipmentsyear × Base UECyear

n

year=n−(Life−1)

in each relevant year (multiplied by a 

site to source conversion factor). 

 a The market weighted average base UEC is based on the distribution of efficiencies under the current federal 

standards (base case). It includes products both meeting and exceeding the current federal minimum efficiency. It is 

not the UEC for a product at a specified energy efficiency ratio (EER).
8-3

As currently modeled, the base UEC remains constant throughout time. As a result, in the 

previous calculation, Base UECyearcould be moved outside the summation terms as Base UEC.

The annual standards case total energy use in any given year is the summed product of 

the shipments for that year and the previous product life minus one year’s worth and the market 

weighted average standards case UECb

Annual Standards Case Total Energy Useyear=n

= � Shipmentsyear × Standards UECyear

n

year=n−(Life−1)

in each relevant year (multiplied by a site-to-source 

conversion factor). 

Prior to the analysis period, the standards case UEC is equal to the Base UEC, as 

standards have not yet become effective. Therefore, in the earlier part of the analysis period, 

energy savings accrue only from the newer units in the building stock. Later in the analysis

period, all units in the building stock will have met the lower standards UEC (as they were all 

shipped within the analysis period) and will be providing energy savings.

For VRF water source heat pumps, energy savings for heating based on the coefficient of 

performance (COP) are also taken into account: 

Annual Base Total Energy Useyear=n

= � Shipmentsyear × (Base UECyear

n

year=n−(Life−1)

+ Base UEC_heatyear)

Annual Standards Case Total Energy Useyear=n

= � Shipmentsyear × (Standards UECyear + Standards UEC_heatyear)

n

year=n−(Life−1)

For all products, the annual energy savings is the difference between the base case total 

energy use and the standards case total energy use.

Annual Energy Savingsyear=n

= Annual Base Total Energy Useyear=n

− Annual Standards Case Total Energy Useyear=n

DOE calculated the cumulative energy savings over the analysis period by summing the 

annual energy savings for each year in the analysis period. The analysis period differs by 

product, as discussed in the next section.

 b The market weighted average standards UEC is based on the distribution of efficiencies under a given amended 

federal standards scenario. It may include products both meeting and exceeding the given amended federal standards 

level (with the exception of the Max Tech scenario, in which it is assumed that no product exceeds the amended 

federal standards level). It is not the UEC for a product at a specified EER.
8-4

Cumulative Energy Savings = � Annual Energy Savingsyear

x+29

year=x

For the ASHRAE standard case, the cumulative energy savings are presented as in the 

previous equation. For higher efficiency levels, the Department calculates cumulative energy 

savings as net of ASHRAE standard energy savings (water-cooled and evaporatively-cooled 

equipment and VRF-water source heat pumps) or uses the ASHRAE standard as the base case in 

the equations shown previously (computer room air conditioners). 

8.3 INPUTS TO THE NES CALCULATION

Table 8.3.1 lists the inputs for the determination of NES. Each of the inputs is discussed in 

more detail. 

Table 8.3.1 National Energy Saving Inputs

Input

Shipments

Annual Unit Energy Consumption (UEC) (quads)

Product Lifetime

Site-to-Source Conversion Factor (quads) (Btu/kwh)

8.3.1 Shipments

DOE forecasted shipments for the base case and all standards cases (see chapter 7, 

Shipments Analysis). DOE thinks that the shipment projections under the standards cases could 

be lower than those in the base-case projection because the higher installed costs would cause 

some customers to forego new equipment purchases. However, DOE has no information that 

would allow a calculation of this effect. The projections of total shipments are the same in both 

the base case and standards cases.

8.3.2 National Annual Energy Consumption

The national AEC is the product of the annual UEC and the stocks of units of each 

vintage. This approach accounts for differences in UEC from year to year. DOE initially 

calculated the AEC at the site (i.e., electricity in kilowatt hours [kWh] consumed by the units). 

DOE then calculated primary energy consumption from site energy consumption by applying a 

conversion factor to account for losses associated with the generation, transmission, and 

distribution of electricity.

DOE uses a market- or shipment-weighted average annual UEC in its calculation of the 

national AEC. This takes into account that the equipment markets reflect shipments with a 

distribution of efficiencies as was shown in chapter 2. To assess the impacts on the market from 

the introduction of higher standards, DOE calculates impacts based on efficiency-distribution 
8-5

weighted annual UEC. Because DOE only developed energy use for explicit efficiency levels, 

the distribution of efficiencies used in the calculation is based on the data outlined in chapter 2 to 

describe the current market, but is “compressed” to fit into the range of efficiency levels selected 

for analysis. To do this, each DOE-analyzed efficiency level was examined. The fraction of the 

current market distribution that surrounds a given analyzed efficiency level is allocated to that

efficiency level. 

For each standard level analyzed, DOE assumed that all equipment shipped in the base 

case with efficiencies that are less than the standard level become shipments at that standard 

level in the standard-level shipment distributions. Shipments in the base-case distribution that are 

more efficient than the efficiency defined by the standard level are assumed to be unaffected. 

DOE terms this a “rollup” scenario, because base-case efficiency shipments that are less than the 

proposed standard level “roll up” to meet the standard.

Table 8.3.2 is an example of how DOE compresses the market distribution into efficiency 

levels by binning as well as the use of the roll-up scenario and resultant market-weighted average 

UECs..

Table 8.3.2 Efficiency Distributions and Market Weighted-Average UECs: WaterCooled Equipment ≥65 and <240 kBtu/h with Electric Resistance/No Heating

Standard 

Scenario

EER Market 

Weighted 

Average 

UEC

11.5

(11.5-

11.8)

12.1

(11.9-

12.5)

13

(12.6-

13.4)

14

(13.5-

14.4)

15

(14.5-

15.6)

16.4

(15.7-16.4) Total

Base Case 7% 27% 13% 13% 20% 20% 100% 8,088

ASHRAE 

Standard 34% 13% 13% 20% 20% 100% 8,065

13 EER 47% 13% 20% 20% 100% 7,912

14 EER 60% 20% 20% 100% 7,705

15 EER 80% 20% 100% 7,473

Max Tech 100% 100% 7,101

The compressed market baseline distributions, used for the NES analyses (and NPV 

analyses in the case of computer room air conditioners), are shown in Table 8.3.3 through Table 

8.3.5, followed by the market- or shipment-weighted average annual UECs for each product 

class and analyzed efficiency level (Table 8.3.6 through Table 8.3.8).

Table 8.3.3 Water-Cooled and Evaporatively-Cooled Equipment Market Shares by 

Efficiency Level, Base Case Used for NIA Analysis

Equipment Class

Market 

Baseline ASHRAE Level 1 Level 2 Level 3 Level 4

Water-cooled, ≥65 and <135 

kBtu/h, Electric Resistance/No 

Heating

7% 27% 13% 13% 20% 20%

Water-cooled, ≥65 and <135 

kBtu/h, Other Heating 7% 27% 13% 13% 20% 20%
8-6

Equipment Class

Market 

Baseline ASHRAE Level 1 Level 2 Level 3 Level 4

Water-cooled, ≥135 and <240 

kBtu/h, Electric Resistance/No 

Heating

29% 21% 7% 7% 29% 7%

Water-cooled, ≥135 and <240 

kBtu/h, Other Heating 29% 21% 7% 7% 29% 7%

Water-cooled, ≥240 and <760 

kBtu/h, Electric Resistance/No 

Heating

17% 20% 29% 14% 20% -

Water-cooled, ≥240 and <760 

kBtu/h, Other Heating 14% 23% 29% 14% 20% -

Evap-cooled, ≥240 and <760 

kBtu/h, Electric Resistance/No 

Heating

65% 27% 6% 2% - -

Evap-cooled, ≥240 and <760 

kBtu/h, Other Heating 56% 35% 7% 2% - -

Table 8.3.4 VRF Water-Source Heat Pump Market Shares by Efficiency Level, Base 

Case Used for NIA Analysis

Equipment Class

Market 

Baseline ASHRAE Level 1 Level 2 Level 3 Level 4

≥135 and <760 kBtu/h without 

Heat Recovery - 3% 73% 15% 3% 5%

≥135 and <760 kBtu/h with 

Heat Recovery - 5% 64% 18% 5% 8%

Table 8.3.5 Computer Room Air Conditioner Market Shares by Efficiency Level, Base 

Case Used for NIA Analysis

Equipment Class

Market 

Baseline ASHRAE Level 1 Level 2 Level 3 Level 4

Air-cooled, <65, kBtu/h 2% 9% 20% 45% 18% 5%

Air-cooled, ≥65and <240

kBtu/h - 2% 20% 45% 31% 2%

Air-cooled, ≥240 and <760

kBtu/h - 2% 20% 45% 31% 2%

Water-cooled, <65 kBtu/h 5% 23% 23% 36% 10% 3%

Water-cooled, ≥65and <240

kBtu/h 2% 26% 30% 22% 16% 4%

Water-cooled, ≥240 and <760

kBtu/h 2% 26% 30% 22% 16% 4%

Water-cooled with fluid 

economizers, <65 kBtu/h 5% 23% 23% 36% 10% 3%

Water-cooled with fluid 

economizers, ≥65and <240

kBtu/h

2% 26% 30% 22% 16% 4%
8-7

Equipment Class

Market 

Baseline ASHRAE Level 1 Level 2 Level 3 Level 4

Water-cooled with fluid 

economizers, ≥240 and <760

kBtu/h

2% 26% 30% 22% 16% 4%

Glycol-cooled, <65 kBtu/h 5% 23% 23% 36% 10% 3%

Glycol-cooled, ≥65 and <240

kBtu/h 2% 26% 30% 22% 16% 4%

Glycol-cooled, ≥240 and <760

kBtu/h 2% 26% 30% 22% 16% 4%

Glycol-cooled with fluid 

economizers, <65 kBtu/h 5% 23% 23% 36% 10% 3%

Glycol-cooled with fluid 

economizers, ≥65 and <240

kBtu/h

2% 26% 30% 22% 16% 4%

Glycol-cooled with fluid 

economizers, ≥240 and <760

kBtu/h

2% 26% 30% 22% 16% 4%

Table 8.3.6 Water-Cooled and Evaporatively-Cooled Equipment Market-Weighted 

Annual Average Energy Consumption by Standard Level (kwh/year)

Equipment Class

Market 

Baseline ASHRAE Level 1 Level 2 Level 3 Level 4

Water-cooled, ≥65 and <135 

kBtu/h, Electric Resistance/No 

Heating

8,088 8,065 7,912 7,705 7,473 7,101

Water-cooled, ≥65 and <135 

kBtu/h, Other Heating 8,126 8,102 7,912 7,705 7,473 7,101

Water-cooled, ≥135 and <240 

kBtu/h, Electric Resistance/No 

Heating

15,776 15,309 15,078 14,602 14,137 13,490

Water-cooled, ≥135 and <240 

kBtu/h, Other Heating 15,818 15,407 15,078 14,602 14,137 13,490

Water-cooled, ≥240 and <760 

kBtu/h, Electric Resistance/No 

Heating

36,893 36,279 35,794 34,518 33,422 -

Water-cooled, ≥240 and <760 

kBtu/h, Other Heating 36,980 36,452 35,794 34,518 33,422 -

Evap-cooled, ≥240 and <760 

kBtu/h, Electric Resistance/No 

Heating

46,166 44,584 43,265 41,983 - -

Evap-cooled, ≥240 and <760 

kBtu/h, Other Heating 46,436 45,033 43,265 41,983 - -
8-8

Table 8.3.7 VRF Water-Source Heat Pump Market-Weighted Annual Average Energy 

Consumption by Standard Level (kwh/year)

Equipment Class

Market 

Baseline ASHRAE Level 1 Level 2 Level 3 Level 4

≥135 and <760 kBtu/h without 

Heat Recovery (Cooling) 18,641 18,641 18,598 17,797 17,011 15,872

≥135 and <760 kBtu/h without 

Heat Recovery (Heating) 7,385 7,385 7,379 7,253 7,117 6,893

≥135 and <760 kBtu/h with 

Heat Recovery (Cooling) 18,176 18,176 18,094 17,343 16,568 15,421

≥135 and <760 kBtu/h with 

Heat Recovery (Heating) 4,799 4,799 4,788 4,680 4,558 4,355

Table 8.3.8 Computer Room Air Conditioner Shipment-Weighted Annual Average 

Energy Consumption by Standard Level (kwh/year)

Equipment Class

Market 

Baseline ASHRAE Level 1 Level 2 Level 3 Level 4

Air-cooled, <65, kBtu/h 23,968 23,910 23,670 23,101 21,917 20,649

Air-cooled, ≥65and <240 

kBtu/h 84,109 84,109 83,911 82,152 77,667 72,137

Air-cooled, ≥240 and <760 

kBtu/h 197,405 197,405 196,883 192,338 180,939 167,066

Water-cooled, <65 kBtu/h 22,774 22,676 22,215 21,489 20,408 19,343

Water-cooled, ≥65and <240 

kBtu/h 84,342 84,195 82,431 79,281 75,497 71,507

Water-cooled, ≥240 and <760 

kBtu/h 190,426 190,075 185,912 178,521 169,685 160,408

Water-cooled with fluid 

economizers, <65 kBtu/h 14,441 14,391 14,154 13,781 13,229 12,685

Water-cooled with fluid 

economizers, ≥65and <240 

kBtu/h

53,536 53,459 52,551 50,932 48,993 46,953

Water-cooled with fluid 

economizers, ≥240 and <760 

kBtu/h

120,357 120,175 118,027 114,223 109,688 104,937

Glycol-cooled, <65 kBtu/h 22,672 22,571 22,097 21,355 20,256 19,177

Glycol-cooled, ≥65 and <240 

kBtu/h 92,071 91,878 89,633 85,713 81,092 76,299

Glycol-cooled, ≥240 and <760 

kBtu/h 204,842 204,399 199,276 190,362 179,888 169,053

Glycol-cooled with fluid 

economizers, <65 kBtu/h 18,324 18,249 17,896 17,344 16,528 15,729

Glycol-cooled with fluid 

economizers, ≥65 and <240 

kBtu/h

74,341 74,195 72,508 69,573 66,125 62,557
8-9

Equipment Class

Market 

Baseline ASHRAE Level 1 Level 2 Level 3 Level 4

Glycol-cooled with fluid 

economizers, ≥240 and <760 

kBtu/h

165,328 164,993 161,138 154,458 146,634 138,563

8.3.3 Product Lifetime

The source for lifetime of water-cooled and evaporatively-cooled products was the 

advanced notice of proposed rulemaking on Energy Conservation Standards for Commercial 

Unitary Air Conditioners and Heat Pumps, which was published in the Federal Register on July 

29, 2004. 69 FR 45460. The mean product lifetime from the prior TSD was estimated to be 15.4 

years. More recent sources confirm this estimate including the 2008 California Database for 

Energy Efficient Resources, which lists15 years. For this analysis, DOE used a single-value 

lifetime of 15 years. 

For VRF water-source heat pumps, DOE used a product lifetime of 19 years based on the 

ASHRAE 2011 HVAC Applications Handbook.

c

8.3.4 Site-to-Source Energy Conversion Factors 

For computer room air conditioners, DOE used 

a product lifetime of 15 years, based on information discussed in chapter 6.

For all products the Department calculated energy savings as site energy, which it then 

converted to source energy— the energy that electric power plants consume. The Department 

used site-to-source energy conversion factors from the Annual Energy Outlook 2010 (AEO 2010) 

(water and evaporatively cooled products – not updated from the notice of data availability 

(NODA)) or AEO 2011 (computer room air conditioners and VRF water-source heat pumps). 

The Department extrapolated the values for years after 2035 from their relative sources because 

the AEO does not forecast beyond 2035. To arrive at values for these later years, the Department 

used the forecast’s trend from 2025 to 2035 to establish conversion factors in the years 2036 to 

2043. 

8.3.5 Compliance Dates and Analysis Period

If DOE were to propose a rule prescribing energy conservation standards at the efficiency 

levels contained in ASHRAE Standard 90.1 2010, the Energy Policy and Conservation Act 

(EPCA) states that compliance with amended standards is required on or after a date that is two 

or three years (depending on equipment size) after the effective date of the applicable minimum 

 c ASHRAE’s handbook does not list a service life for VRF equipment specifically, but it does provide service life 

estimates for water-source heat pumps generally. In this regard, ASHRAE cites two different studies for equipment 

service life. The first study of this type of equipment reported a service life of 19 years. The second, more-recent 

study cited suggests a service life of 24 years for all classes of direct expansion cooling systems. This second study 

relies heavily on extrapolation of a survival curve based on a sample of 1907 DX equipment observations from 

various equipment classes from which 284 units had actually been replaced and most were still in service. 

(ASHRAE Research Project 1237-TRP Interactive Web-based Owning and Operating Cost Database Final Report, 

July 2005. Available at www.ashrae.org ) However, as VRF products are new to the U.S. with relatively little data 

on lifetime, DOE has relied on the older, more conservative, 19-year service life estimate for its analysis.
8-10

energy efficiency requirement in the amended ASHRAE standard (i.e., ASHRAE Standard 90.1 

2010). (42 U.S.C. 6313(a)(6)(D)) 

For all water-cooled and evaporatively-cooled equipment in this rulemaking, the effective 

date in ASHRAE Standard 90.1 2010 is June 1, 2011. Thus, if DOE decides to adopt the levels in 

ASHRAE Standard 90.1 2010, the rule would apply to small equipment (two product classes) 

manufactured on or after June 1, 2013, which is two years from the effective date specified in 

ASHRAE Standard 90.1 2010, and to large and very large equipment (six product classes) 

manufactured on or after June 1, 2014, which is three years from the effective date specified in 

ASHRAE Standard 90.1 2010. 

For VRF water-source heat pumps in this rulemaking, ASHRAE Standard 90.1–2010 

does not specify an effective date; therefore the effective date is assumed to be the publication 

date of ASHRAE Standard 90.1-2010, or October 29, 2010. Thus, if DOE decides to adopt the 

levels in ASHRAE Standard 90.1–2010, the rule would apply to large and very large equipment 

(the product class analyzed here) manufactured on or after October 29, 2013, which is three 

years from the effective date specified in ASHRAE Standard 90.1–2010. 

For computer room air conditioners, the rule would apply to equipment <65,000 Btu/h 

(10 product classes combined into five for analysis purposes) manufactured on or after October 

29, 2012, which is two years after the publication date of ASHRAE Standard 90.1-2010, and to 

equipment ≥65,000 Btu/h (20 product classes combined into 10 for analysis purposes) 

manufactured on or after October 29, 2013, which is three years after the publication date of 

ASHRAE Standard 90.1-2010. Typically equipment at or above 65,000 Btu/h and less than 

135,000 Btu/h would have a compliance date two years after the publication of ASHRAE 

Standard 90.1. However, because ASHRAE Standard 90.1-2010 established a product class for 

computer room air conditioners that combines traditional small and large categories, DOE has 

decided to assign the later compliance date of three years after the publication of ASHRAE 90.1-

2010 to all computer room air conditioner product classes that cover products between 65,000 

Btu/h and 240,000 Btu/h.

If DOE were to propose a rule prescribing energy conservation standards higher than the 

efficiency levels contained in ASHRAE Standard 90.1-2010, EPCA states that any such 

standards “shall become effective for products manufactured on or after a date which is four 

years after the date such rule is published in the Federal Register.” (42 U.S.C. 6313(a)(6)(D)) 

Thus, for products for which DOE might adopt a level more stringent than the ASHRAE 

efficiency levels, the rule would apply to products manufactured on or after April 29, 2017, 

which is four years from the date of publication of the final rule that DOE must meet for 

efficiency levels that are higher than ASHRAE (30 months after publication of ASHRAE, which 

was October 29, 2010).

A 30-year analysis period is used for the NES, extending from the compliance date based 

on adoption of the levels in ASHRAE Standard 90.1-2010. For small computer room air 

conditioners, the analysis period extends from 2012 to 2041; for large and very large computer 

room air conditioners, small water-cooled and evaporatively-cooled equipment, and VRF watersource heat pumps, the analysis period extends from 2013 to 2042; for large and very large 

water-cooled and evaporatively-cooled equipment the analysis period extends from 2014 to 
8-11

2043. The time period for energy savings for standards that are higher than ASHRAE Standard 

90.1-2010 is from 2017 to 2041, 2042, or 2043, based on the product classes as previously 

described. This approach accounts for any lost energy savings from a delay incurred by DOE’s 

not adopting ASHRAE efficiency levels, but instead adopting standards at efficiency levels 

higher than those specified in ASHRAE Standard 90.1-2010.

8.4 INPUTS TO NET PRESENT VALUE CALCULATION (Computer Room Air 

Conditioners)

8.4.1 Net Present Value Definition

The NPV is the value in the present of a time series of costs and savings. The NPV is 

given by the following equation: 

NPV = PVS – PVC

Where: 

PVS = present value of operating cost savings (including electricity, repair, and 

maintenance costs) ($), and

PVC = present value of increased total installed costs (including equipment and 

installation) ($). 

The PVS and PVC are determined according to the following expressions: 

PVS = � OCSt ∗ DFt

t

PVC = � TICt ∗ DFt

t

Where: 

OCS = total annual operating cost savings ($), 

TIC = total annual installed cost increases ($), 

DF = discount factor, and

t = year (PVS is summed over 2012 to 2055 or 2013 to 2056, and PVC is summed over 

2012 to 2041 or 2013 to 2042). 

DOE determined the contribution to PVC for each year, from the effective date of the 

standard (2012 or 2013) to the year 2041 or 2042, discounted for the analysis to the year 2012. 

The contribution to PVS was determined for each year, from the effective date of the standard 

(2012 or 2013) to the year when the last units purchased in 2041 or 2042 have retired (assumed 

to be 2055 or 2056). DOE first calculated costs and savings as the difference between a standards 

case and a base case represented as adoption of the ASHRAE standard. DOE calculated a 
8-12

discount factor from the discount rate and the number of years between the “present” (i.e., year 

to which the sum is being discounted) and the year in which the costs and savings occur. DOE 

calculated the NPV as the sum over time of the discounted net savings. 

8.4.2 Net Present Value Inputs 

Table 8.4.1 lists the inputs to the NPV calculation. Each of the inputs is then discussed 

in detail. 

Table 8.4.1 Net Present Value Inputs

Input

Total Annual Installed Cost (TICt) ($)

Total Annual Operating Cost Savings (OCSt) ($)

Discount Factor

Present Value of Costs (PVC) ($)

Present Value of Savings (PVS) ($)

8.4.2.1 Total Annual Installed Cost 

The increase in the total annual installed cost is equal to the annual change in the per-unit 

total installed cost (difference between base case and standards case) multiplied by the shipments 

forecasted in the standards case. The total installed cost includes both the equipment cost and the 

installation price. DOE based average equipment costs on average manufacturer prices (see 

chapter 6, LifeCycle Cost and Payback Period Analysis) multiplied by average overall markup 

values shown in chapter 5). DOE based average installation prices on nationally representative 

values for each equipment class and efficiency level (see chapter 6) and developed base-case and 

standards-case energy-efficiency shipment scenarios as discussed in chapter 7. For both the basecase and standards-case energy-efficiency scenarios, DOE calculated annual market- or 

shipment-weighted-average efficiencies. Associated with each annual shipment-weightedaverage efficiency, DOE assigned a total installed cost, based on shipment-weighted total 

installed cost for all efficiency levels shipped under that standards-case scenario. 

DOE determined the relationship between efficiency level and total installed cost for each 

computer room air conditioner class as shown in Table 8.4.2. DOE considers the ASHRAE level 

as the base minimum standard that it could set under Federal law. In the NIA, DOE establishes 

the NPV for adopting standards higher than the ASHRAE base case, but does not need to 

determine the NPV of adoption of that minimum base case. DOE only looked at subsequent 

higher standard levels to determine whether each higher level, when examined independently, 

has a positive NPV compared with the ASHRAE base case. 

Table 8.4.2 Total Installed Cost per Unit by Efficiency Level from Life-Cycle Cost 

(2011$)

Equipment Class ASHRAE Level 1 Level 2 Level 3 Level 4

Air-cooled, <65, kBtu/h $ 12,003 $ 13,491 $ 15,239 $ 17,295 $ 19,711

Air-cooled, ≥65and <240 

kBtu/h $ 38,943 $ 41,179 $ 43,588 $ 46,185 $ 48,984

Air-cooled, ≥240 and 

<760 kBtu/h $ 56,633 $ 59,852 $ 63,322 $ 67,061 $ 71,092
8-13

Equipment Class ASHRAE Level 1 Level 2 Level 3 Level 4

Water-cooled, <65 kBtu/h $ 23,716 $ 20,284 $ 17,504 $ 15,253 $ 13,429

Water-cooled, ≥65and 

<240 kBtu/h $ 22,767 $ 28,390 $ 35,948 $ 46,106 $ 59,759

Water-cooled, ≥240 and 

<760 kBtu/h $ 42,240 $ 52,910 $ 67,250 $ 86,522 $ 112,423

Water-cooled with fluid 

economizers, <65 kBtu/h $ 25,025 $ 21,393 $ 18,451 $ 16,069 $ 14,139

Water-cooled with fluid 

economizers, ≥65and 

<240 kBtu/h

$ 23,952 $ 29,903 $ 37,901 $ 48,651 $ 63,099

Water-cooled with fluid 

economizers, ≥240 and 

<760 kBtu/h

$ 44,489 $ 55,781 $ 70,956 $ 91,351 $ 118,760

Glycol-cooled, <65 kBtu/h $ 23,764 $ 20,332 $ 17,552 $ 15,301 $ 13,477

Glycol-cooled, ≥65 and 

<240 kBtu/h $ 22,857 $ 28,473 $ 36,020 $ 46,164 $ 59,795

Glycol-cooled, ≥240 and 

<760 kBtu/h $ 42,419 $ 53,089 $ 67,430 $ 86,702 $ 112,602

Glycol-cooled with fluid 

economizers, <65 kBtu/h $ 25,073 $ 21,441 $ 18,500 $ 16,117 $ 14,187

Glycol-cooled with fluid 

economizers, ≥65 and 

<240 kBtu/h

$ 24,041 $ 29,984 $ 37,971 $ 48,705 $ 63,131

Glycol-cooled with fluid 

economizers, ≥240 and 

<760 kBtu/h

$ 44,668 $ 55,960 $ 71,136 $ 91,530 $ 118,939

8.4.2.2 Annual Installed Cost–Weighted by Efficiency Distribution 

Using the base-case market distribution and the calculated distributions at each possible 

standard level, as discussed in the NES section, DOE developed an average shipment-weighted 

total installed cost for all shipments for each proposed standard level. The shipment-weighted 

total installed costs for each possible standard level are listed in Table 8.4.3. 

Table 8.4.3 Shipment-Weighted Average Total Installed Cost by Standard Level (2011$)

Equipment Class ASHRAE Level 1 Level 2 Level 3 Level 4

Air-cooled, <65, kBtu/h $ 15,091 $ 15,260 $ 15,816 $ 17,404 $ 19,711 

Air-cooled, ≥65and <240 

kBtu/h $ 43,945 $ 43,989 $ 44,509 $ 46,240 $ 48,984 

Air-cooled, ≥240 and <760 

kBtu/h $ 63,836 $ 63,899 $ 64,647 $ 67,140 $ 71,092 

Water-cooled, <65 kBtu/h $ 19,562 $ 18,594 $ 17,169 $ 15,206 $ 13,429 

Water-cooled, ≥65and 

<240 kBtu/h $ 32,568 $ 34,142 $ 38,526 $ 46,652 $ 59,759 

Water-cooled, ≥240 and 

<760 kBtu/h $ 60,836 $ 63,823 $ 72,141 $ 87,559 $ 112,423 
8-14

Equipment Class ASHRAE Level 1 Level 2 Level 3 Level 4

Water-cooled with fluid 

economizers, <65 kBtu/h $ 20,629 $ 19,605 $ 18,096 $ 16,019 $ 14,139 

Water-cooled with fluid 

economizers, ≥65and <240 

kBtu/h $ 34,324 $ 35,990 $ 40,629 $ 49,229 $ 63,099 

Water-cooled with fluid 

economizers, ≥240 and 

<760 kBtu/h $ 64,168 $ 67,330 $ 76,132 $ 92,447 $ 118,760 

Glycol-cooled, <65 kBtu/h $ 19,610 $ 18,642 $ 17,217 $ 15,254 $ 13,477 

Glycol-cooled, ≥65 and 

<240 kBtu/h $ 32,644 $ 34,217 $ 38,594 $ 46,709 $ 59,795 

Glycol-cooled, ≥240 and 

<760 kBtu/h $ 61,015 $ 64,003 $ 72,320 $ 87,738 $ 112,602 

Glycol-cooled with fluid 

economizers, <65 kBtu/h $ 20,678 $ 19,653 $ 18,145 $ 16,068 $ 14,187 

Glycol-cooled with fluid 

economizers, ≥65 and 

<240 kBtu/h $ 34,398 $ 36,062 $ 40,695 $ 49,282 $ 63,131 

Glycol-cooled with fluid 

economizers, ≥240 and 

<760 kBtu/h $ 64,347 $ 67,509 $ 76,311 $ 92,627 $ 118,939 

8.4.2.1 Price Forecast

As discussed in chapter 6, DOE used a constant equipment price assumption for the 

default forecast in the NIA. In order to investigate the impact of different product price forecasts 

on the consumer net present value (NPV) for the considered efficiency levels for computer room 

air conditioners, DOE also considered two alternative price trends. One of these used an 

exponential fit on the deflated Producer Price Index for all other miscellaneous refrigeration and 

air-conditioning equipment, and the other is based on the “deflator— other durables excluding 

medical” that was forecasted for AEO2011. Details on how these alternative price trends were 

developed are in appendix 8-A, which also presents the results of the sensitivity analysis.

8.4.2.2 Total Annual Operating Cost Savings 

The annual operating cost savings to the nation are equal to the change in the average 

annual operating costs (difference between base case and standards case) per unit in the stock for 

each year multiplied by the total number of units in the stock forecasted in the standards case. 

Calculations are done separately for each equipment class. 

The annual operating cost includes electricity, repair, and maintenance costs. 

Annual Energy Cost Savings. DOE calculated annual energy costs based on national 

average commercial electricity prices shown in AEO 2011. To calculate annual energy cost 

savings for a particular equipment class in a given year, DOE first calculated the annual energy 

costs in each forecast year at each efficiency level by multiplying the U.S. average energy 

consumption at each efficiency level by the stock at each efficiency level and in each equipment 
8-15

class, as appropriate, in each year. This total is then multiplied by the national average 

commercial electricity prices. To determine energy savings, the national energy costs at each 

efficiency level (Levels 1–4) were then subtracted from the national energy costs at the 

ASHRAE level. Commercial prices for electricity are derived from the reference case AEO 2011

forecasts through 2035. DOE extrapolated the trend in values from 2025 to 2035 of the forecast 

to establish fuel prices from 2035 to 2056, through the end of the NPV analysis period. This 

method of extrapolation is in line with methods the Energy Information Administration (EIA)

uses to forecast fuel prices for the Federal Energy Management Program. 

Annual Repair Costs. DOE based average annual repair costs on a base repair cost, 

which increased with the value of the computer room air conditioner equipment in 2011$ (see 

chapter 5). Using the efficiency distribution of the stock at each standard level analyzed, DOE 

developed a weighted average repair cost for the stock based on the distribution at each 

standard level. 

Annual Maintenance Costs. DOE determined average annual maintenance costs for 

computer room air conditioners from the life-cycle cost analysis (see chapter 6). DOE used a 

value of $298 per year. These values were applied to all computer room air conditoiners in the 

stock at each year. 

8.4.2.3 Discount Factor 

DOE multiplied monetary values in future years by the discount factor to determine the 

present value. The discount factor (DF) is described by the following equation: 

DF = 1

(1 + r)t−tp

Where:

r = discount rate (percent), 

t = year of the monetary value, 

tp = year in which the present value is being determined. 

DOE estimated national impacts with both a 3 percent and a 7 percent real discount 

rate. These discount rates are used in accordance with the Office of Management and Budget’s 

(OMB) guidance to Federal agencies on the development of regulatory analysis (OMB Circular 

A4, September 17, 2003), and section E, “Identifying and Measuring Benefits and Costs,” 

therein. DOE defined the present year as 2012 for the analysis. 

8.4.2.4 Present Value of Costs 

The present value of increased installed costs is the annual installed cost increase in each 

year (i.e., the difference between the standards case and the base case), discounted to the present, 

and summed for the time period that DOE is considering for the installation of computer room 

air conditioners (i.e., from the earliest effective date of standards, 2012 or 2013, to the year 2041 

or 2042). 
8-16

The increase in total installed cost refers to the equipment cost and installation cost 

associated with the higher efficiency computer room air conditioners purchased in the 

standards case compared to the base case. DOE calculated annual installed costs as the 

difference in total installed cost for new equipment purchased each year, multiplied by the 

shipments in the standards case. 

8.4.2.5 Present Value of Savings 

The present value of operating cost savings is the annual operating cost savings (i.e., the 

difference between the base case and standards case) discounted to the year 2012, and summed 

over the period from the effective date of the standard, 2012 or 2013, to the time when the last 

unit installed in 2041 or 2042 is retired from service (assumed to be 2055 or 2056). Operating 

cost savings represent decreases in operating costs (including electricity, repair, and 

maintenance) associated with the higher efficiency of computer room air conditioners purchased 

in the standards case compared to the base case. Total annual operating cost savings is the 

savings multiplied by the number of computer room air conditioners of each vintage surviving in 

a particular year. Equipment consumes energy over its entire lifetime, and thus, for units 

purchased in 2041 or 2042, the PVS includes energy consumed until the last unit is retired from 

service at the end of 2055 or 2056.

8.5 NES AND NPV RESULTS

The NES spreadsheet model provides estimates of the NES and NPV for various 

efficiency levels. The inputs to the NES spreadsheet are discussed earlier in sections 7.2.2 

(National Energy Savings Inputs) and 7.3.2 (Net Present Value Inputs).

8.5.1 National Energy Savings and Net Present Value Input Summary 

Table 8.5.1 summarizes the inputs to the NES spreadsheet model. For each input, a brief 

description of the data source is given.

Table 8.5.1 Inputs to the NES Spreadsheet Model

Input Data Description

Effective Date of Standard 2012 or 2013 depending on product class.

Shipments Annual shipments from shipments model (see chapter 7, Shipments 

Analysis).

Base-Case Effiicencies Distribution of base-case shipments by efficiency level.

Standards-Case Efficiencies Distribution of shipments by efficiency level for each standards 

case. Standards-case annual market shares by efficiency level 

remain constant over time for the base case and each standards case.

Annual Energy Consumption Annual weighted-average values are a function of efficiency level. 

(Established from the Energy Use Characterization, chapter 4).

Site-to-Source Conversion Site-to-source conversion determined from EIA’s AEO2011 for 

electricity and varies over the analysis period.

Below inputs are for Computer Room Air Conditioners only

Total Installed Cost Annual weighted-average values are a function of efficiency level 

(see chapter 6, LifeCycle Cost and Payback Period Analysis).
8-17

Repair Cost Annualized repair cost for baseline efficiency computer room air 

conditioners based on cost data from RS Means CostWorks 2012. 

DOE assumed that the materials portion of the repair costs would 

vary in direct proportion with the MSP at higher efficiency levels 

(see chapter 6).

Maintenance Cost Annual maintenance costs were $298 based on data on annual 

maintenance costs for computer room air conditioners based on RS 

Means CostWorks 2012 (see chapter 6). Annual maintenance cost 

did not vary as a function of efficiency.

Escalation of Electricity Prices 2011 EIA Annual Energy Outlook forecasts (to 2035) with 

extrapolation for beyond 2035.

Discount Rate 3 and 7 percent real.

Present Year Future costs are discounted to year 2012.

8.5.2 National Energy Savings Results

The following section provides NES results for each efficiency level considered for the 

equipment analyzed. The results are cumulative to 2041, 2042, or 2043, depending on product 

class and are shown as primary energy savings in quads. Inputs to the NES spreadsheet model 

are based on weighted-average values, yielding results that are discrete point values, rather than a 

distribution of values as in the lifecycle cost (LCC) analysis. 

8.5.2.1 Water-cooled and Evaporatively-cooled Products

Table 8.5.2 and Table 8.5.3 at considered standard levels for the eight product classes of 

water-cooled and evaporatively-cooled equipment examined. Results of the NES analysis are 

provided for the two shipment case scenarios, Historical Trends and Fixed to 2009. Recall that 

all levels higher than the ASHRAE standard are shown as net of ASHRAE savings.

Table 8.5.2 National Energy Savings for Water-Cooled and Evaporatively-Cooled 

Products: Based on Historical Trends (Quads, 2013–2042 or 2014-2043)

Efficiency 

Level

Water-cooled, 

≥65 and 

<135 kBtu/h, Electric 

Resistance/No Heating

Water-cooled, 

≥65 and 

<135 kBtu/h, Other 

Heating

Water-cooled, 

≥135 and 

<240 kBtu/h, Electric 

Resistance/No Heating

Water-cooled, 

≥135 and 

<240 kBtu/h, Other 

Heating

Water-cooled, 

≥240 and 

<760 kBtu/h, Electric 

Resistance/No Heating

Water-cooled, 

≥240 and 

<760 kBtu/h, Other 

Heating

Evap-cooled, 

≥240 and 

<760 kBtu/h, Electric 

Resistance/No Heating

Evap-cooled, 

≥240 and 

<760 kBtu/h, Other 

Heating

ASHRAE 

Standard 0.000005 0.0000005 0.0001 0.00001 0.0002 0.002 0.0001 0.001

13/12.5 EER 0.00002 0.000002 0.00002 0.00001 0.0001 0.001 0.00008 0.001

14 EER 0.00004 0.000005 0.00013 0.00002 0.0005 0.005 - -

15 EER 0.00007 0.000009 0.00024 0.00003 - - - -

Max Tech 0.00012 0.000014 0.00039 0.00005 0.0008 0.008 0.00017 0.002
8-18

Table 8.5.3 National Energy Savings for Water-Cooled and Evaporatively-Cooled 

Products: Shipments Fixed to 2009 (Quads, 2013–2042 or 2014-2043)

Efficiency 

Level

Water-cooled, 

≥65 and 

<135 kBtu/h, Electric 

Resistance/No Heating

Water-cooled, 

≥65 and 

<135 kBtu/h, Other 

Heating

Water-cooled, 

≥135 and 

<240 kBtu/h, Electric 

Resistance/No Heating

Water-cooled, 

≥135 and 

<240 kBtu/h, Other 

Heating

Water-cooled, 

≥240 and 

<760 kBtu/h, Electric 

Resistance/No Heating

Water-cooled, 

≥240 and 

<760 kBtu/h, Other 

Heating

Evap-cooled, 

≥240 and 

<760 kBtu/h, Electric 

Resistance/No Heating

Evap-cooled, 

≥240 and 

<760 kBtu/h, Other 

Heating

ASHRAE 

Standard 0.000011 0.0000013 0.0003 0.00003 0.0001 0.001 0.0001 0.001

13/12.5 EER 0.00006 0.000008 0.00008 0.00001 0.0001 0.001 0.00005 0.001

14 EER 0.00014 0.000017 0.00032 0.00004 0.0003 0.003 - -

15 EER 0.00024 0.000028 0.00056 0.00007 - - - -

Max Tech 0.00039 0.000044 0.00089 0.00010 0.0005 0.005 0.00011 0.001

8.5.2.2 VRF Water-source Heat Pumps

Table 8.5.4 summarizes the NES at considered standard levels for the two VRF watersource heat pump product classes examined. Recall that all levels higher than the ASHRAE 

standard are shown as net of ASHRAE savings.

Table 8.5.4 National Energy Savings for VRF Water-Source Heat Pumps >135,000 Btu/h 

(Quads, 2013-2042)

Efficiency Level

≥135 and <760 kBtu/h 

Without Heat Recovery

≥135 and <760 kBtu/h 

With Heat Recovery

Level 1 – ASHRAE – 10.0/9.8 EER - -

Level 2 – 11 EER 0.0009 0.0008

Level 3 – 12 EER 0.0174 0.0083

Level 4 – 13 EER 0.0416 0.0195

Level 5 – “Max-Tech” – 14.5 EER 0.0761 0.0358

* The potential energy savings for efficiency levels more stringent than those specified by ASHRAE 

Standard 90.1-2010 were calculated relative to the efficiency levels that would result if ASHRAE Standard 

90.1-2010 standards were adopted.

8.5.2.3 Computer Room Air Conditioners

Table 8.5.5 summarizes the NES at considered standard levels for the 15 computer room 

air conditioner product classes examined. Recall that all levels higher than the ASHRAE

standard are based on ASHRAE as the baseline.
8-19

Table 8.5.5 National Energy Savings for Computer Room Air Conditioners (Quads, 

2012-2041 or 2013-2042)

Equipment Class

ASHRAE 

Level

Efficiency 

Level 1

Efficiency 

Level 2

Efficiency 

Level 3

Efficiency 

Level 4

Air-cooled, <65, kBtu/h 0.00018 0.0006 0.0021 0.0052 0.0086

Air-cooled, ≥65and <240 kBtu/h - 0.006 0.059 0.196 0.364

Air-cooled, ≥240 and <760 

kBtu/h - 0.004 0.034 0.112 0.206

Water-cooled, <65 kBtu/h 0.00003 0.0001 0.0003 0.0007 0.0010

Water-cooled, ≥65and <240 

kBtu/h 0.0009 0.0088 0.0246 0.0435 0.0634

Water-cooled, ≥240 and <760 

kBtu/h 0.0008 0.0079 0.0220 0.0388 0.0565

Water-cooled with fluid 

economizers, <65 kBtu/h 0.00001 0.00004 0.00011 0.00021 0.00031

Water-cooled with fluid 

economizers, ≥65and <240 

kBtu/h 0.0004 0.0038 0.0106 0.0188 0.0273

Water-cooled with fluid 

economizers, ≥240 and <760 

kBtu/h 0.0002 0.0016 0.0043 0.0076 0.0111

Glycol-cooled, <65 kBtu/h 0.00003 0.00013 0.00033 0.00063 0.00092

Glycol-cooled, ≥65 and <240 

kBtu/h 0.001 0.011 0.031 0.054 0.078

Glycol-cooled, ≥240 and <760 

kBtu/h 0.0008 0.0080 0.0220 0.0384 0.0554

Glycol-cooled with fluid 

economizers, <65 kBtu/h 0.00002 0.0001 0.0002 0.0005 0.0007

Glycol-cooled with fluid 

economizers, ≥65 and <240 

kBtu/h 0.001 0.010 0.027 0.047 0.067

Glycol-cooled with fluid 

economizers, ≥240 and <760 

kBtu/h 0.0005 0.0054 0.0147 0.0257 0.0370

* All energy savings from efficiency levels higher than the ASHRAE standard are calculated with 

ASHRAE levels as a baseline.

8.5.3 Annual Costs and Savings

As a prelude to providing the NPVs for each efficiency level in each equipment class, this 

section presents the annual equipment cost (or total installed cost) increases and annual operating 

cost savings at the national level. 

Figure 8.5.1 shows the changes over time of the non-discounted annual equipment price 

increases and the non-discounted operating cost savings for efficiency level 1 for the small aircooled equipment class, as an example. The total net annual impact is the discounted value of the 

difference between annual equipment purchases and annual operating costs at a 7-percent 

discount rate. The annual equipment price change is the increase in equipment price for 
8-20

equipment purchased each year over the 30-year period from 2012 or 2013 to 2041 or 2042. The 

annual operating savings is the savings in operating costs for equipment purchased, and which 

has not been retired, for each year over the time period from 2012 or 2013 to 2055 or 2056. The 

NPV (the discounted total net annual impact) is the difference between the cumulative annual 

discounted savings and the cumulative annual discounted costs.

Figure 8.5.1 National Annual Costs and Savings for Efficiency Level 1 (Small Air-Cooled 

Computer Room Air Conditioners)

Figure 8.5.1 shows smaller annual operating cost savings compared to the increased 

equipment price costs through 2024, after which annual operating cost savings begin to eclipse 

increased equipment price costs. After 2041, no additional computer room air conditioner sales 

are included in the analysis; however the annual energy savings continues to accrue until the last 

of the computer room air conditioners installed in 2041 are removed from the stock after 2055.

8.5.4 Net Present Value Results

DOE developed NPV results for the efficiency levels considered for 15 computer room 

air conditioner equipment classes. Results are cumulative and are shown as the discounted value 

of these savings in dollar terms. The inputs to the NES spreadsheet model are based on 

-$0.0080

-$0.0060

-$0.0040

-$0.0020

$0.0000

$0.0020

$0.0040

$0.0060

2017 2022 2027 2032 2037 2042 2047 2052

Billion 2011$

Net Savings

Undiscounted Total Annual Operating Savings

Annual Total Incremental Equip. Cost

Discounted Total Net Annual Impact
8-21

weighted-average values yielding results that are discrete point values, rather than a distribution 

of values as in the LCC analysis. The present value of increased total installed costs is the total 

installed cost increase (i.e., the difference between the standards case and base case), discounted 

to 2012, and summed over the time period in which DOE evaluates the impact of standards (i.e., 

from the effective date of the standards, 2012 or 2013, to the year 2041 or 2042). 

Savings are decreases in operating costs (including fuel costs, repair, and maintenance) 

associated with the higher energy efficiency of computer room air conditioners purchased in the 

standards case compared to the base case. Total operating cost savings are the average savings 

per unit multiplied by the number of units of each vintage (i.e., the year of manufacture) 

surviving in a particular year. Computer room air conditioner equipment consumes energy and 

must be maintained over its entire lifetime. For units purchased in 2041 or 2042, the operating 

cost includes energy consumed and maintenance and repair costs incurred until the last unit is 

retired from service in 2055 or 2056. 

As an example, Figure 8.5.2 shows the NPV and NES results for the four efficiency 

levels analyzed for the small air-cooled equipment class, with NPVs calculated using a 7-percent 

discount rate. Both NES and NPV are calculated as benefits of the analyzed standard levels 

compared with adoption of the ASHRAE 90.1-2010 standard level. 

Figure 8.5.2 Cumulative NES and NPV Results for Small Air-Cooled Computer Room 

Air Conditioners Based on a Seven-Percent Discount Rate

$(0.018)

$(0.016)

$(0.014)

$(0.012)

$(0.010)

$(0.008)

$(0.006)

$(0.004)

$(0.002)

$-

$0.002 

0.0000

0.0010

0.0020

0.0030

0.0040

0.0050

0.0060

0.0070

0.0080

0.0090

0.0100

Level 1 Level 2 Level 3 Max Tech

NPV (Billioin 2011$)

Cumulative Energy Savings (Quads)

Efficiency Level

Air-Cooled <65 kBtu/h

Energy Savings NPV
8-22

Table 8.5.6 shows the NPV results for the efficiency levels considered for computer room 

air conditioner equipment based on a 7-percent discount rate. Table 8.5.7 provides the NPV 

results based on the 3-percent discount rate. 

Table 8.5.6 Summary of Cumulative Net Present Value for Computer Room Air 

Conditioners (Seven Percent Discount Rate) 

Equipment Class

Net Present Value (Billion 2011$)

Efficiency 

Level 1

Efficiency 

Level 2

Efficiency 

Level 3

Efficiency 

Level 4

Air-cooled, <65, kBtu/h $ 0.0004 $ (0.0000) $ (0.0048) $ (0.0154)

Air-cooled, ≥65and <240 kBtu/h $ 0.01 $ 0.12 $ 0.34 $ 0.54 

Air-cooled, ≥240 and <760 kBtu/h $ 0.01 $ 0.08 $ 0.24 $ 0.40 

Water-cooled, <65 kBtu/h $ 0.001 $ 0.003 $ 0.006 $ 0.009 

Water-cooled, ≥65and <240 kBtu/h $ (0.004) $ (0.041) $ (0.140) $ (0.332)

Water-cooled, ≥240 and <760 

kBtu/h $ (0.001) $ (0.026) $ (0.102) $ (0.251)

Water-cooled with fluid 

economizers, <65 kBtu/h $ 0.001 $ 0.002 $ 0.003 $ 0.005 

Water-cooled with fluid 

economizers, ≥65and <240 kBtu/h $ (0.02) $ (0.07) $ (0.18) $ (0.38)

Water-cooled with fluid 

economizers, ≥240 and <760 kBtu/h $ (0.005) $ (0.024) $ (0.064) $ (0.134)

Glycol-cooled, <65 kBtu/h $ 0.001 $ 0.003 $ 0.006 $ 0.008 

Glycol-cooled, ≥65 and <240 

kBtu/h $ 0.002 $ (0.028) $ (0.123) $ (0.316)

Glycol-cooled, ≥240 and <760 

kBtu/h $ 0.002 $ (0.018) $ (0.083) $ (0.215)

Glycol-cooled with fluid 

economizers, <65 kBtu/h $ 0.001 $ 0.003 $ 0.006 $ 0.008 

Glycol-cooled with fluid 

economizers, ≥65 and <240 kBtu/h $ (0.01) $ (0.07) $ (0.20) $ (0.46)

Glycol-cooled with fluid 

economizers, ≥240 and <760 kBtu/h $ (0.004) $ (0.033) $ (0.106) $ (0.242)

* Numbers in parentheses indicate negative NPV.

Table 8.5.7 Summary of Cumulative Net Present Value for Computer Room Air 

Conditioners (Three Percent Discount Rate) 

Equipment Class

Net Present Value (Billion 2011$)

Efficiency 

Level 1

Efficiency 

Level 2

Efficiency 

Level 3

Efficiency 

Level 4

Air-cooled, <65, kBtu/h $ 0.002 $ 0.003 $ (0.002) $ (0.017)

Air-cooled, ≥65and <240 kBtu/h $ 0.03 $ 0.29 $ 0.88 $ 1.48 

Air-cooled, ≥240 and <760 kBtu/h $ 0.02 $ 0.19 $ 0.58 $ 1.00 

Water-cooled, <65 kBtu/h $ 0.003 $ 0.007 $ 0.012 $ 0.018 

Water-cooled, ≥65and <240 kBtu/h $ 0.003 $ (0.051) $ (0.220) $ (0.566)

Water-cooled, ≥240 and <760 

kBtu/h $ 0.007 $ (0.029) $ (0.160) $ (0.435)
8-23

Equipment Class

Net Present Value (Billion 2011$)

Efficiency 

Level 1

Efficiency 

Level 2

Efficiency 

Level 3

Efficiency 

Level 4

Water-cooled with fluid 

economizers, <65 kBtu/h $ 0.001 $ 0.004 $ 0.006 $ 0.009 

Water-cooled with fluid 

economizers, ≥65and <240 kBtu/h $ (0.02) $ (0.12) $ (0.33) $ (0.69)

Water-cooled with fluid 

economizers, ≥240 and <760 kBtu/h $ (0.008) $ (0.042) $ (0.117) $ (0.251)

Glycol-cooled, <65 kBtu/h $ 0.003 $ 0.006 $ 0.012 $ 0.017 

Glycol-cooled, ≥65 and <240 

kBtu/h $ 0.02 $ (0.02) $ (0.18) $ (0.53)

Glycol-cooled, ≥240 and <760 

kBtu/h $ 0.01 $ (0.02) $ (0.13) $ (0.38)

Glycol-cooled with fluid 

economizers, <65 kBtu/h $ 0.002 $ 0.006 $ 0.011 $ 0.015 

Glycol-cooled with fluid 

economizers, ≥65 and <240 kBtu/h $ (0.01) $ (0.10) $ (0.34) $ (0.82)

Glycol-cooled with fluid 

economizers, ≥240 and <760 kBtu/h $ (0.004) $ (0.052) $ (0.187) $ (0.447)

* Numbers in parentheses indicate negative NPV.
8-24

REFERENCES

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

for Commercial and Industrial Equipment: Efficiency Standards for Commercial 

Heating, Air-Conditioning, and Water Heating Equipment Including Packaged Terminal 

Air-Conditioners and Packaged Terminal Heat Pumps, Small Commercial Packaged 

Boiler, Three-Phase Air-Conditioners and Heat Pumps <65,000 Btu/h, and SinglePackage Vertical Air Conditioners and Single-Package Vertical Heat Pumps < 65,000 

Btu/h, March 2006. Washington, DC.

2. California Public Utility Commission 2008. Database for Energy Efficient Resources. 

(Last accessed April 20, 2011.) <www.deeresources.com>

3. 2011 ASHRAE Handbook HVAC Applications. ASHRAE, 2011. Atlanta GA (Available 

at www.ashrae.org).

4. U.S. Department of Energy/Energy Information Administration. 2010. Annual Energy 

Outlook 2010. DOE/EIA0383(2010), DOE/EIA, Washington, D.C.

5. U.S. Department of Energy/Energy Information Administration. 2011. Annual Energy 

Outlook 2011. DOE/EIA0383(2011), DOE/EIA, Washington, D.C.