CHAPTER 10. NATIONAL IMPACTS ANALYSIS 

TABLE OF CONTENTS 

10.1 INTRODUCTION ............................................................................................................. 10-1
 

10.2 BASE-CASE AND STANDARDS-CASE FORECASTED WALK-IN STOCKS AND 

EFFICIENCY DISTRIBUTIONS..................................................................................... 10-2
 

10.2.1 Installed Walk-in Stock ..................................................................................... 10-2
 

10.2.2 Efficiency Distribution of the Stock .................................................................. 10-4
 

10.3 NATIONAL ENERGY SAVINGS ................................................................................... 10-6
 

10.3.1 National Energy Savings Definition .................................................................. 10-6
 

10.3.2 National Energy Savings Inputs ........................................................................ 10-7
 

10.3.1.1 Unit Energy Consumption (UEC) and Walk-in Stock by Walk-in 

Type .................................................................................................... 10-7
 

10.3.1.2 Site-to-Source Conversion Factors ..................................................... 10-8
 

10.3.1.3 Interactions with Heating, Ventilation, and Air-Conditioning
 

(HVAC) Systems ............................................................................... 10-8
 

10.3.1.4 Rebound Factor................................................................................... 10-8
 

10.3.1.5 Discount Factor................................................................................... 10-8
 

10.4 NET PRESENT VALUE .................................................................................................. 10-9
 

10.4.1 Net Present Value Definition ............................................................................. 10-9
 

10.4.2 Net Present Value Inputs ................................................................................. 10-10
 

10.4.2.1 Total Annual Installed Cost Increases .............................................. 10-10
 

10.4.2.2 Total Annual Operating Cost Savings .............................................. 10-11
 

10.5 NATIONAL ENERGY SAVINGS AND NET PRESENT VALUE RESULTS ........... 10-11
 

10.5.1 National Energy Savings Summary Results .................................................... 10-12
 

10.5.2 Net Present Value Summary Results ............................................................... 10-14
 

REFERENCES ............................................................................................................... 10-17
 

LIST OF TABLES 

Table 10.2.1 Installed Walk-in Stock by Year and Envelope Equipment Class.................. 10-3
 

Table 10.2.2 Installed Walk-in Stock by Year and Refrigeration System Equipment 

Class................................................................................................................ 10-4
 

Table 10.3.1 National Energy Saving Inputs ....................................................................... 10-7
 

Table 10.4.1 Net Present Value Inputs .............................................................................. 10-10
 

Table 10.5.1 National Energy Saving and Net Present Value Inputs ................................ 10-12
 

Table 10.5.2 Maximum Energy Savings for Which Net Present Value of Savings Are 

Greater than Zero at a 7 Percent Discount Rate and Corresponding CSLs 

(2015-2045)................................................................................................... 10-13
 

Table 10.5.3 Maximum Energy Savings for Which Net Present Value of Savings are 

Greater than Zero at a 3 Percent Discount Rate and Corresponding CSLs 

(2015-2045)................................................................................................... 10-14
 

Table 10.5.4 Net Present Value at Maximum Level of Energy Savings for Which Net 

Present Value is Greater than Zero at a 7-Percent Discount Rate and 

Corresponding CSLs..................................................................................... 10-15
 

10-i 
 

 

Table 10.5.5 Net Present Value at Maximum Level of Energy Savings for Which Net 

Present Value is Greater than Zero at a 3-Percent Discount Rate and 

Corresponding CSLs..................................................................................... 10-16
 

LIST OF FIGURES 

Figure 10.2.1 Walk-in Stock by Efficiency Level over Time ............................................... 10-6
 

10-ii 
 

 

CHAPTER 10. NATIONAL IMPACTS ANALYSIS
 

10.1 INTRODUCTION 

This chapter describes the method for estimating the national impacts of candidate 

standard levels (CSLs) for analyzed walk-in cooler and freezer equipment (hereafter “walk-ins” 

or “WICF”). In the national impact analysis (NIA), the U.S. Department of Energy (DOE) 

assesses the cumulative national energy savings (NES) and the cumulative national economic 

impacts of different CSLs. DOE measures energy savings as the cumulative quadrillion British 

thermal units (quads) of energy a CSL is expected to save the Nation. DOE measures economic 

impacts as the net present value (NPV) in 2009 dollars of total customer costs and savings 

expected to result from a CSL. The analysis period over which DOE calculates the NPV and 

NES is from 2015 to 2045. Results of the NIA described in this chapter include (1) national 

energy savings to the Nation as a result of standards; (2) monetary value of operating cost 

savings (primarily from reduced energy consumption) to the Nation as a result of standards; 

(3) increased total installed costs to the Nation as a result of standards; and (4) the NPV of these 

savings (the difference between the present monetary values of operating cost savings and 

increased total installed costs). The main portion of this chapter summarizes the results of these 

estimates. More detailed results are provided in appendices 10A (for NES results) and 10B (for 

NPV results). 

Because a walk-in is designed to work as a single coherent unit, the characteristics of 

complete walk-in systems (e.g., energy consumption, installed cost) must be considered for 

estimating the national impacts of walk-in CSLs. However, each walk-in does consist of two 

distinct parts, the envelope and the refrigeration system. DOE analyzes the two parts of a walk-in 

together for the purpose of calculating the national impacts, but DOE is considering separate 

standards for the two separate WICF components. 

DOE determines both the NPV and NES for each CSL and each equipment class it 

selects in the engineering analysis (preliminary technical support document [TSD] chapter 5). In 

this rulemaking, DOE considers up to 15 CSLs for each of the envelope equipment classes and 

up to 9 CSLs for each of the refrigeration system equipment classes. 

DOE performs all NIA calculations using a Microsoft Excel spreadsheet, available at 

www.eere.energy.gov/buildings/appliance_standards/commercial/wicf.html. Appendix 10A will 

provide instructions for using the spreadsheet. 

The following sections describe in detail the methodology and inputs for the NIA. 

Several NIA inputs, including per-unit costs, per-unit energy consumption, and national 

shipments, are discussed in other analyses. In describing the inputs to the NIA, this chapter 

references those analyses and presents new information on installed stock. Section 10.2 discusses 

DOE’s walk-in shipment forecasts by efficiency, the installed stock of walk-ins, and the mix of 

efficiencies of that stock. Section 10.3 discusses DOE’s calculation of national energy 

consumption in the base and standards cases and the resulting difference in NES between these 

cases. Section 10.4 discusses the NPV calculation. Section 10.5 presents the NES and NPV 

results by equipment class. 

10-1 
 

 

 

10.2	 BASE-CASE AND STANDARDS-CASE FORECASTED WALK-IN STOCKS AND 

EFFICIENCY DISTRIBUTIONS 

The characteristics of DOE’s shipment forecasts (such as equipment costs and operating 

costs) and projected walk-in stocks (such as average efficiency and energy consumption) are key 

aspects of DOE’s NES and NPV estimates. This section describes these key characteristics of 

stock and shipments as they relate to the NES and NPV. 

For example, the projected distribution of walk-in efficiencies shipped and walk-in 

efficiencies in stock are key factors in determining the NPV. Two inputs to the NPV are the perunit total installed cost and per-unit annual operating cost. The per-unit total installed cost often 

varies with the efficiency of walk-ins shipped. When higher efficiency walk-ins are shipped, 

higher or lower installed costs are often incurred. The life-cycle cost analysis (preliminary TSD 

chapter 8) describes how per-unit total installed costs vary as a function of efficiency for each 

walk-in. 

Per-unit annual energy consumption is a key input to the NPV (as an input to the per-unit 

operating cost) and NES. The per-unit annual energy consumption is a function of walk-in 

characteristics in the installed stock. The total installed WICF stock is used to determine total 

annual energy consumption, a key input into the NES and NPV calculations. 

Also important to determining NES and NPV is the average efficiency of the walk-in 

stock. The engineering analysis (preliminary TSD chapter 5) discusses the relationships among 

walk-in system design, system input power, and walk-in efficiency. The energy use 

characterization (preliminary TSD chapter 6) describes how the per-unit energy consumption 

varies as a function of system input power and market sector application for each walk-in design. 

Sections 10.3.2 and 10.4.2 discuss inputs to calculating the NES and NPV in further 

detail. 

The following sections detail the forecasted distribution of efficiencies, installed walk-in 

stocks, and average efficiency of those stocks in the base and standards cases. 

10.2.1 Installed Walk-in Stock 

From the information and the shipment forecasts presented in chapter 9, DOE establishes 

the installed walk-in stock profile for all analyzed walk-in equipment classes. This information is 

an important input to the National Impacts Analysis because the national energy and financial 

impacts are directly related to the size and type of the walk-in stock. The following two tables 

show the installed walk-in stocks, which are the same in the base case and standards case. Table 

10.2.1 presents the stock broken down into 5-year increments by the equipment class of the 

envelope portion of the walk-in. Table 10.2.2 breaks down the stock by refrigeration system 

equipment class instead. Because each walk-in includes both an envelope component and a 

refrigeration system, the total stock is the same in both tables. 

10-2 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 10.2.1 Installed Walk-in Stock by Year and Envelope Equipment Class 

WICF Envelope Systems 

Year and Stock 

2015 2020 2025 2030 2035 2040 2045 

Non-Display Cooler Small 202,025 215,869 231,723 249,314 267,200 286,372 306,924 

Non-Display Cooler 

Medium 752,943 804,539 863,627 929,189 995,846 1,067,301 1,143,898 

Non-Display Cooler Large 337,630 360,767 387,263 416,661 446,552 478,593 512,940 

Display Cooler Small 8,619 9,255 9,980 10,782 11,607 12,496 13,454 

Display Cooler Medium 157,522 169,148 182,392 197,045 212,122 228,367 245,873 

Display Cooler Large 12,929 13,883 14,970 16,173 17,410 18,744 20,180 

Non-Display Freezer 

Small 133,677 142,810 153,401 165,184 177,029 189,723 203,327 

Non-Display Freezer 

Medium 430,401 459,806 493,907 531,845 569,981 610,852 654,654 

Non-Display Freezer 

Large 170,565 182,218 195,732 210,767 225,880 242,077 259,435 

Display Freezer Small 18,270 19,789 21,477 23,331 25,303 27,445 29,771 

Display Freezer Medium 116,520 126,209 136,976 148,797 161,380 175,041 189,873 

Display Freezer Large 9,135 9,894 10,739 11,665 12,652 13,723 14,885 

Total 2,350,236 2,514,186 2,702,186 2,910,753 3,122,962 3,350,732 3,595,214 

10-3 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 10.2.2 Installed Walk-in Stock by Year and Refrigeration System Equipment Class 

WICF Refrigeration 

Systems 

Year and Stock 

2015 2020 2025 2030 2035 2040 2045 

Dedicated Medium 

Temperature Indoor Small 34,546 36,914 39,625 42,633 45,691 48,970 52,484 

Dedicated Medium 

Temperature Indoor Large 62,540 66,834 71,750 77,205 82,753 88,701 95,077 

Dedicated Medium 

Temperature Outdoor 

Small 157,378 168,162 180,512 194,216 208,148 223,084 239,094 

Dedicated Medium 

Temperature Outdoor 

Large 500,411 534,807 574,190 617,882 662,326 709,980 761,075 

Multiplex system 

Medium Temperature 

Small 10,101 10,793 11,586 12,466 13,360 14,319 15,346 

Multiplex system 

Medium Temperature 

Large 706,693 755,951 812,292 874,764 938,458 1,006,819 1,080,192 

Dedicated Low 

Temperature Indoor Small 22,859 24,420 26,232 28,246 30,272 32,443 34,769 

Dedicated Low 

Temperature Indoor Large 34,863 37,244 40,006 43,079 46,168 49,479 53,027 

Dedicated Low 

Temperature Outdoor 

Small 104,134 111,249 119,500 128,678 137,905 147,794 158,392 

Dedicated Low 

Temperature Outdoor 

Large 288,562 308,682 331,906 357,706 383,806 411,819 441,885 

Multiplex system Low 

Temperature Small 6,684 7,140 7,670 8,259 8,851 9,486 10,166 

Multiplex system Low 

Temperature Large 421,467 451,989 486,918 525,619 565,222 607,841 653,707 

Total 2,350,236 2,514,186 2,702,186 2,910,753 3,122,962 3,350,732 3,595,214 

10.2.2 Efficiency Distribution of the Stock 

Besides the size of the stock, the other information necessary to calculate the national 

energy impacts of the walk-in standard is the average energy consumption of the stock in both 

the base case and the standards case. 

DOE calculates the energy consumption separately for each combination of envelope and 

refrigeration system equipment classes, at each possible combination of efficiency levels, for 

each possible combination of standard levels in each year. Because this results in a prohibitively 

large number of possible combinations of factors (24 equipment class combinations with some 

shipments, times 160 possible combinations of efficiency level in the equipment in the market, 

times 160 possible standard levels DOE could set for each equipment class, times 31 years = 

19,000,000 + combinations), DOE does not present these calculations in detail here. However, 

DOE outlines its method below. The calculations themselves are available in the Microsoft Excel 

10-4 
 

 

 

spreadsheet DOE used to conduct the National Impact Analysis. As mentioned above, this 

spreadsheet is available at 

www.eere.energy.gov/buildings/appliance_standards/commercial/wicf.html. 

The method employed in that spreadsheet is as follows. Although, as mentioned above, 

there are many possible combinations of types of shipments, regular patterns in these 

combinations allow for simpler analysis. Based on manufacturer interviews and DOE estimates, 

DOE assumes that the great majority of the WICF market will use equipment roughly 

corresponding to CSL 0 in the baseline. Based on the same sources, DOE also assumes that 

WICF consumers are unlikely to deliberately purchase equipment that exceeds any minimum 

efficiency standards (sometimes called a “shift” effect). Instead, DOE judges that consumers are 

likely to purchase equipment that exactly meets any efficiency standards established (a “roll-up” 

effect). 

Therefore, it is possible to characterize the efficiency implications of any possible 

standard in a fairly concise manner. At any given point in time, all walk-ins will either: 

•	 meet the baseline efficiency level (DOE assumes this for all walk-ins installed before the 

standard goes into effect), 

•	 meet the efficiency standard (DOE assumes these for all new walk-ins installed after the 

standard goes into effect), or 

•	 partially meet the standard (DOE assumes this for all walk-ins in which the refrigeration 

system is replaced after the standard goes into effect, but in which the old, pre-standard, 

envelope is still in use). 

DOE projects that walk-in owners will retire their walk-ins primarily in case of 

mechanical failure, change of business ownership, or for style reasons in the case of some 

display units. Since none of these reasons to retire a walk-in are affected by efficiency standards, 

walk-ins should be replaced at the same rate under any efficiency standard. Therefore, DOE 

concludes that the share of walk-ins that are at the baseline level, at the standard level, or 

partially at the standard level is the same in every scenario. DOE’s projections of how many 

walk-ins are in each of these three categories in any given year (in any scenario) are presented in 

Figure 10.2.1. This information is based on the market growth rates, expected lifetimes of 

envelopes and refrigeration systems, and initial age distribution of the WICF stock, all as 

outlined in the shipments analysis (preliminary TSD chapter 9). 

10-5 
 

     

     

     

     

     

     

 

 

 

 

 

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

2014 2019 2024 2029 2034 2039 2044

Installed Stock by Type (millions)

Both envelope and

refrigeration system meet

standard

Envelope at baseline

efficiency,refrigeration

system meets standard

Both envelope and

refrigeration system at

baseline efficiency

Figure 10.2.1 Walk-in Stock by Efficiency Level over Time 

At each possible standard level, the total energy consumption and average efficiency of 

the stock can be determined by the information in Figure 10.2.1. At each possible combination of 

standard levels, the energy consumption of the WICF stock is the sum of the energy consumption 

of all baseline units, all units that meet the standard, and all units for which only the refrigeration 

system meets the standard. Those energy consumption levels vary by equipment class, but can be 

found in the energy use characterization (preliminary TSD chapter 6). The average efficiency is 

simply the total energy consumption divided by the size of the stock. 

10.3 NATIONAL ENERGY SAVINGS 

10.3.1 National Energy Savings Definition 

DOE calculates annual national energy savings as the difference in annual national 

energy consumption (AEC) between the base case (without standards) and the standards case 

(with standards), adjusted by several factors. These factors are a heating, ventilation, and air 

conditioning (HVAC) factor, rebound factor, site-to-source conversion factor, and a discount 

factor. These are all described in sections 10.3.1.2 through 10.3.1.4. All together, the equation 

for calculating national energy savings takes this form: 

NESt = (AECt,base − AECt,std ) × src _ conv × HVAC × RF × DFt Eq. 10.1 

Where:
 

NESt = national energy savings (in quads of source energy) in the year t,
 

AECt = annual national energy consumption each year (in kilowatt-hours [kWh] of 

electricity consumed onsite), 

src_conv = conversion factor to convert from site energy (kWh) to source energy
 

(quads, Btu/kWh),
 

10-6 
 

 

 

 

 

HVAC = heating, ventilation, air conditioning factor,
 

RF = rebound factor,
 

DFt = discount factor in the year t,
 

t = year in the forecast (e.g., 2020 or 2030),
 

base = base case, and
 

std = standards case.
 

DOE defines the cumulative national energy savings as the sum of the national energy 

savings in each year of the analysis period, i.e., from 2015 to 2045. 

DOE calculated the AEC in any given year by multiplying the annual unit energy 

consumption for each type of walk-in (i.e., each possible equipment class and efficiency level) 

by the number of walk-ins in stock that year of that type. This is shown in the following 

equation: 

AECt = ∑ (UEC , × STOCK PC,CSL t PC CSL ,
 ) Eq. 10.2

PC ,CSL
 

Where:
 

UECPC = unit energy consumption (kWh per year), 

STOCKPC,t = the number of walk-ins of that type in stock in that year,
 

EC = a given combination of equipment classes, e.g., small non-display
 

cooler with small indoor medium-temperature dedicated system, and 

CSL = a given combination of CSLs, e.g., CSL 5 for the envelope and CSL 7 

for the refrigeration system. 

The terms of this equation are explained in the following section. 

10.3.2 National Energy Savings Inputs 

Table 10.3.1 lists the inputs for determining the NES. 

Table 10.3.1 National Energy Saving Inputs 

Input 

Unit Energy Consumption by Walk-in Type and CSL (UECPC,CSL) 

Walk-in Stock by Walk-in Type, CSL, and year (STOCKPC,CSL,t) 

Site-to-Source Conversion Factor (src_conv) 

Heating, Ventilation, Air Conditioning Factor (HVAC) 

Rebound Factor (RF) 

Discount Factor (DF) 

10.3.1.1 Unit Energy Consumption (UEC) and Walk-in Stock by Walk-in Type 

Walk-in UEC and stock by type are inputs to the National Energy Savings calculation 

that are both described elsewhere in this preliminary TSD. UEC is described in the energy use 

characterization (preliminary TSD chapter 6). Stock is described above in section 10.2.1 and in 

the shipments analysis (preliminary TSD chapter 9). 

10-7 
 

 

 

 

10.3.1.2	 Site-to-Source Conversion Factors 

Because walk-ins are powered by electricity, the amount of energy they consume 

indirectly at the point of electricity generation is greater than the amount of energy they use 

directly. To account for this, DOE uses a site-to-source conversion factor to convert its estimates 

of onsite energy consumption (in the form of electricity) into primary or source energy 

consumption (in the form of, e.g., fossil fuels). This conversion factor depends on the generation 

sources used to produce electricity, which can vary over time. For the preliminary analysis, DOE 

used a site-to-source conversion factor of 10,147 Btu/kWh, which is the average site-to-source 

conversion factor of a concurrent rulemaking that applies to the same analysis period. During the 

next phase of the analysis, DOE intends to derive new site-to-source conversion factors specific 

to each year of this analysis using the version of the Building Technologies version of the 

National Energy Modeling Systems (NEMS-BT) that will correspond to the 2010 version of the 

Energy Information Administration’s Annual Energy Outlook (AEO 2010).1 

10.3.1.3	 Interactions with Heating, Ventilation, and Air-Conditioning (HVAC) 

Systems 

The heat output from a walk-in interacts with the functioning of the HVAC systems in its 

building. Walk-ins of greater efficiency may produce slightly less heat, altering that interaction. 

Theoretically, this might change the walk-in’s interaction with the building’s HVAC systems. 

However, the models that can capture this interaction have not been developed to an adequate 

degree. Therefore, DOE assumed that this interaction was not substantial and that estimating its 

precise nature and extent was not feasible. In large part, this is because most walk-ins are cooled 

by outdoor compressors, which reject their waste heat outside the building rather than inside. For 

this analysis, DOE assumed an HVAC factor of 1, or no measurable effect. 

10.3.1.4	 Rebound Factor 

Under economic theory, a “rebound effect” refers to the tendency of a consumer to 

respond to the cost savings associated with more efficient equipment in a manner that actually 

leads to marginally greater equipment usage, thereby diminishing some portion of anticipated 

benefits related to improved efficiency. This typically manifests in the tendency for consumers to 

either make more frequent use of equipment that is highly efficient (e.g., leaving efficient lights 

on more often) or adjusting equipment for greater thermal comfort (e.g., turning the thermostat 

on a more efficient furnace up a degree). However, because walk-ins must cool their contents at 

all times, it is not possible for consumers to operate them more frequently. And because most 

walk-ins operate within a narrow thermal range that is determined by sanitary and other noncomfort reasons, it is unlikely that consumers would significantly decrease the operating 

temperature of their walk-ins simply because the units were more efficient. For this analysis, 

DOE assumed a rebound factor of 1, or no effect. 

10.3.1.5	 Discount Factor 

DOE multiplies the value of energy savings in future years by the discount factor (DF) to 

calculate the present value of these energy savings. The following equation describes how to 

calculate the discount factor for any given year: 

10-8 
 

 

 

 

t−t p ) DF = 1 (1+ r)( Eq. 10.3 

Where: 

r = discount rate,
 

t = year of the monetary value, and
 

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

DOE provides results calculated with both a 3-percent and a 7-percent real discount rate, 

in accordance with the Office of Management and Budget’s (OMB’s) guidance to Federal 

agencies on the development of regulatory analysis (OMB Circular A-4, September 17, 2003),2 

and section E, “Identifying and Measuring Benefits and Costs,” therein. These discount rates are 

based on estimates of the average real rate of return on private investment in the U.S. economy. 

DOE defined the present year as 2010 (the current year) for this preliminary analysis. 

10.4 NET PRESENT VALUE 

10.4.1 Net Present Value Definition 

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

presented here is the value in the present of the total changed in purchase costs and operating 

costs that DOE forecasts WICF consumers would face from energy conservation standards on 

walk-ins. Note that this is not the same as the sum of all costs and benefits from such standards, 

e.g. environment benefits or costs of this rule are not included in the NPV calculation. The NPV 

is calculated as follows: 

NPV = PVS − PVC Eq. 10.4 

Where: 

PVS = present value of the total operating cost savings over time, and 

PVC = present value of the total increase in installed costs over time. 

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

PVS = ∑ (OCSt × DFt ) Eq. 10.5 t 

PVC = ∑ (ICSt × DFt ) Eq. 10.6 t 

Where: 

OCS t = total operating cost savings in year t, 

ICS t = total installed cost increases in year t, 

DFt = discount factor in year t, and 

t = year (PVS and PVC are summed over 2015-2044). 

10-9 
 

 

 

 

DOE determined the contributions to PVC and PVS for each year from the effective date 

of the standard, 2015, to 2045, discounted for the preliminary analysis to the present year (2010). 

DOE calculated costs and savings as the difference between a standards case (i.e., with 

standards) and a base case (i.e., without standards). DOE calculated a discount factor from the 

discount rate and the number of years between the “present” (i.e., 2010, the year to which the 

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

net present value as the sum over time of the discounted net savings (which is equivalent to the 

approach shown in equations 10.4 through 10.6). 

10.4.2 Net Present Value Inputs 

Table 10.4.1 summarizes the inputs to the NPV calculation. 

Table 10.4.1 Net Present Value Inputs 

Input 

Total Installed Cost Increases (ICSt) 

Total Annual Operating Cost Savings (OCSt) 

Discount Factor (DF) 

10.4.2.1 Total Annual Installed Cost Increases 

DOE calculates the increase in total annual installed costs as the difference between the 

total annual installed costs in the standards case minus those in the base case. This is shown in 

the following equation: 

ICSt = (ICt ,base − ICt,std ) Eq. 10.7 

where: 

ICSt = the total installed cost increases in the year t, 

ICt,base = the total installed cost in the year t in the base case, and 

ICt,std = the total installed cost in the year t in the standards case.
 

DOE determines the total installed cost (IC) in each year by adding up the product of 

annual operating cost for each type of walk-in (i.e., each possible equipment class and efficiency 

level) by the number of walk-ins shipped that year of that type. This is shown in the following 

equation: 

ICSt = ∑ (ICPC,CSL × SHIPPC,CSL,t ) Eq. 10.8 

PC,CSL 

where: 

IC PC, CSL = the installed cost for a particular type (equipment class and CSL) of 

walk-in, and 

SHIP PC, CSL = shipments of walk-ins of that type in year t. 

10-10 
 

Installed cost numbers are calculated in the life cycle cost analysis (preliminary TSD 

chapter 8). Shipments are calculated in the shipments analysis (preliminary TSD chapter 9), as 

noted above. 

10.4.2.2 Total Annual Operating Cost Savings 

DOE calculated the total annual operating cost savings in the same manner as the total 

installed cost increase, i.e., as the difference between the total annual installed costs in the 

standards case minus those in the base case. The equation takes the same form as equation 10.7, 

so it is not shown here to avoid redundancy. Similarly, DOE determines the total operating cost 

(TOC) in each year by adding up the product of annual operating cost for each type of walk-in 

(i.e., each possible equipment class and efficiency level) by the number of walk-ins in stock that 

year of that type. This equation takes the same form as equation 10.8, except that operating cost 

savings are calculated based on the size of the walk-in stock in a given year rather than the 

number of walk-in shipments in that year. 

Operating cost numbers are calculated in the life cycle cost analysis (preliminary TSD 

chapter 8). As described in chapter 8, the major component of operating cost is electricity costs, 

though other components, such as maintenance costs, are also included. Stock is calculated in the 

shipments analysis (preliminary TSD chapter 9), as noted above. 

10.5 NATIONAL ENERGY SAVINGS AND NET PRESENT VALUE RESULTS 

The NIA spreadsheet model provides estimates of the NES and NPV due to various 

CSLs. The inputs to the NIA spreadsheet are discussed in sections 10.3.2, National Energy 

Savings Inputs, and 10.4.2, Net Present Value Inputs. 

Table 10.5.1 summarizes the inputs to the spreadsheet model that calculates the NES and 

NPV. A brief description of the data is given for each input. As noted above, the model is freely 

available online at www.eere.energy.gov/buildings/appliance_standards/commercial/wicf.html. 

10-11 
 

 

 

 

 

 

Table 10.5.1 National Energy Saving and Net Present Value Inputs 

Input Data Data Description 

Walk-ins Stock The initial stock is taken from the Shipments Model (preliminary TSD 

chapter 9). This model is based on estimated historical shipments based on 

Commercial Buildings Energy Consumption Survey 20073

 data and U.S. 

Census Bureau Current Industrial Reports data4

, DOE and manufacturer 

estimates of walk-in lifetime, and forecasted growth rates from the Annual 

Energy Outlook 2009 and the U.S. Census of Agriculture5 

. 

Shipments Annual shipments from the walk-in Shipments Model (preliminary TSD 

chapter 9). Sources are the same as for stock estimates. 

Effective Date of Standard 2015 

Analysis Period 2015 to 2045 

Unit Energy Consumption (kWh/yr) Established in the Energy-Use Characterization (preliminary TSD 

chapter 6) by walk-in type and CSL. 

Total Installed Cost Established in the Markups Analysis (preliminary TSD chapter 7) and the 

LCC Analysis (preliminary TSD chapter 8) by walk-in type and CSL. 

Electricity Price Forecast EIA forecasts (to 2030) from the AEO2009 (April version*)6 and 

extrapolation for beyond 2030.7 

Electricity Site-to-Source Conversion Based on a concurrent preliminary TSD, based on AEO20088 forecasts (to 

2030) of electricity generation and electricity-related losses. DOE intends 

to derive new estimates for the notice of proposed rulemaking (NOPR) 

stage.* 

HVAC Interaction Savings Negligible. 

Rebound Effect Negligible. 

Discount Rate 3 and 7 percent real. 

Present Year 2010. 

*While this analysis will rely on the most recent (2010) version of the AEO for the NOPR stage, that version was 

not available in time for the preliminary analysis. 

10.5.1 National Energy Savings Summary Results 

The following section provides summary NES results. Results are cumulative to 2045 

and are shown as primary energy savings measured in quads at particular combinations of 

equipment classes and CSLs. More detailed NES results are provided in appendix 10A. 

Table 10.5.2 and Table 10.5.3 show summary NES results. Results are shown for selected 

CSLs. There is one matched combination of envelope and refrigeration system CSLs per 

matched combination of WICF envelopes and refrigeration equipment classes. The selection 

criteria are as follows. The selected CSLs in the table are those for the highest primary energy 

savings for which the net present value is a positive number (at a 7-percent discount rate). In 

other words, the tables show the maximum possible energy savings for each equipment class that 

would result in a net financial benefit to WICF users. In many cases, this corresponds to the 

highest CSL considered for both the envelope and the refrigeration system. This is because most 

of the CSLs analyzed in this rulemaking are associated with positive net present values. In cases 

where more than one possible combination of CSLs provides the same energy savings at positive 

LCC savings, the lowest possible combination of CSLs that can provide those savings is 

selected. 

10-12 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

The tables are laid out as follows. For conciseness, each table presents three numbers for 

each equipment class. The top number is the maximum energy savings in quads. The lower 

numbers are the CSLs at which these energy savings are achieved—envelope CSL on the left, 

refrigeration system CSL on the right. The first table shows results calculated at a 7-percent 

discount rate, and the second shows results calculated at a 3-percent discount rate. 

Table 10.5.2 Maximum Energy Savings for Which Net Present Value of Savings Are 

Greater than Zero at a 7 Percent Discount Rate and Corresponding CSLs 

(2015-2045) 

Envelope 

Equipment Class 

Maximum Energy Savings (quads) and CSLs for Envelope and Refrigeration Unit (a,b) 

Refrigeration System Equipment Class 

Dedicated 

Indoor 

Small 

Dedicated 

Indoor 

Large 

Dedicated 

Outdoor 

Small 

Dedicated 

Outdoor 

Large 

Multiplex 

System 

Small 

Multiplex 

System 

Large 

Non-Display Cooler 

Small 

0.02 

13,7 

- 0.09

13,8

 - 0.00 

10,3 

-

Non-Display Cooler 

Medium 

- 0.08 

13,7

- 0.36

 13,8 

- 0.24 

10,3 

Non-Display Cooler 

Large 

- - - 0.62

 15,8 

- 0.16

11,3 

Display Cooler 

Small 

- 0.00 

15,7

- 0.02

 15,8 

- -

Display Cooler 

Medium 

- - - - - 0.56 

15,3 

Display Cooler 

Large 

- - - 0.42

 15,8 

- -

Non-Display 

Freezer Small 

0.04 

15,8 

- 0.19

15,9

 - 0.01 

15,4 

-

Non-Display 

Freezer Medium 

- 0.15 

15,8

- 0.64

 15,9 

- 0.44 

15,4 

Non-Display 

Freezer Large 

- - - 0.78

 15,9 

- 0.23

15,4 

Display Freezer 

Small 

- - - 0.10

 15,9 

- -

Display Freezer 

Medium 

- - - - - 0.46 

4,3 

Display Freezer 

Large 

- - - 0.51

 10,8 

- -

10-13 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 10.5.3 Maximum Energy Savings for Which Net Present Value of Savings are 

Greater than Zero at a 3 Percent Discount Rate and Corresponding CSLs 

(2015-2045) 

Envelope 

Equipment Class 

Maximum Energy Savings (quads) and CSLs for Envelope and Refrigeration Unit (a,b) 

Refrigeration System Equipment Class 

Dedicated 

Indoor 

Small 

Dedicated 

Indoor 

Large 

Dedicated 

Outdoor 

Small 

Dedicated 

Outdoor 

Large 

Multiplex 

System 

Small 

Multiplex 

System 

Large 

Non-Display Cooler 

Small 

0.04 

13,7

- 0.18 

13,8

- 0.01

 10,3 

-

Non-Display Cooler 

Medium 

- 0.16

13,7 

- 0.74

13,8

 - 0.51 

10,3 

Non-Display Cooler 

Large 

- - - 1.26

15,8

 - 0.34 

11,3 

Display Cooler 

Small 

- 0.01

15,7 

- 0.04

15,8 

- -

Display Cooler 

Medium 

- - - - - 1.18 

15,3 

Display Cooler 

Large 

- - - 0.87 

15,8 

- -

Non-Display 

Freezer Small 

0.09 

15,8

- 0.40 

15,9

- 0.01

 15,4 

-

Non-Display 

Freezer Medium 

- 0.32

15,8 

- 1.32

15,9

 - 0.94 

15,4 

Non-Display 

Freezer Large 

- - - 1.61

15,9

 - 0.50 

15,4 

Display Freezer 

Small 

- - - 0.21 

15,9 

- -

Display Freezer 

Medium 

- - - - - 1.00 

4,4 

Display Freezer 

Large 

- - - 1.05 

10,7 

- -

10.5.2 Net Present Value Summary Results 

Table 10.5.4 and Table 10.5.5 provide summary NPV results. Results are cumulative to 

2045 and are shown in billion 2009 dollars. The tables are laid out in the same way as Table 

10.5.2 and Table 10.5.3. As in those tables, one CSL combination is shown per equipment class 

combination, and in each case, it is the same CSL combination as was shown for the tables 

above; i.e., net present values are shown for the CSL that generates the maximum energy savings 

at a positive net present value. 

The NPV summary results vary more widely that the NES summary results, from 0.01 

billion $2009 to 7.90 billion 2009$. However, this is not necessarily a reflection of greater 

variation in NPV results than in NES results. Rather, it is simply a result of the way in which 

summary results are presented. As noted above, the CSL combinations used in these summary 

tables are selected on the basis of maximum NES rather than maximum NPV. Therefore, the 

10-14 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NES summary numbers vary less widely than the NPV summary numbers. This does not apply, 

however, to the detailed NPV results. Those are presented in appendix 10B. 

Table 10.5.4 Net Present Value at Maximum Level of Energy Savings for Which Net 

Present Value is Greater than Zero at a 7-Percent Discount Rate and 

Corresponding CSLs 

Envelope Equipment 

Class 

NPV (Billion 2009$) and Corresponding CSLs for Envelope and Refrigeration Unit 

(a,b) 

Refrigeration System Equipment Class 

Dedicated 

Indoor Small 

Dedicated 

Indoor 

Large 

Dedicated 

Outdoor 

Small 

Dedicated 

Outdoor 

Large 

Multiplex 

System 

Small 

Multiplex 

System 

Large 

Non-Display Cooler 

Small 

0.08 - 0.29 - 0.01 -

13,7 13,8 10,3 

Non-Display Cooler 

Medium

- 0.15 - 0.90 - 0.21 

13,7 13,8 10,3 

Non-Display Cooler 

Large 

- - - 0.52 - 0.29 

15,8 11,3 

Display Cooler 

Small 

- 0.05 - 0.24 - -

15,7 15,8 

Display Cooler 

Medium

 - - - - - 3.05

 15,3 

Display Cooler 

Large 

- - - 6.56 - -

15,8 

Non-Display Freezer 

Small 

0.53 - 2.29 - 0.03 -

15,8 15,9 15,4 

Non-Display Freezer 

Medium

- 1.52 - 6.44 - 1.22 

15,8 15,9 15,4 

Non-Display Freezer 

Large 

- - - 7.90 - 0.75 

15,9 15,4 

Display Freezer 

Small 

- - - 0.05 - -

15,9 

Display Freezer 

Medium

 - - - - - 0.08

 4,3 

Display Freezer 

Large 

- - - 0.09 - -

10,8 

10-15 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 10.5.5. Net Present Value at Maximum Level of Energy Savings for Which Net 

Present Value is Greater than Zero at a 3-Percent Discount Rate and 

Corresponding CSLs 

Envelope 

Equipme 

nt Class 

NPV (Billion 2009$) and Corresponding CSLs for Envelope and Refrigeration Unit (a,b) 

Refrigeration System Equipment Class 

Dedicated 

Indoor 

Small 

Dedicated 

Indoor Large 

Dedicated 

Outdoor 

Small 

Dedicated 

Outdoor 

Large 

Multiplex 

System 

Small 

Multiplex 

System 

Large 

NonDisplay 

Cooler 

Small 

0.19 - 0.67 - 0.02 -

13,7 13,8 10,3 

NonDisplay 

Cooler 

Medium

- 0.41 - 2.25 - 0.87 

13,7 13,8 10,3 

NonDisplay 

Cooler 

Large 

- - - 1.91 - 0.85 

15,8 11,3 

Display 

Cooler 

Small 

- 0.10 - 0.47 - -

15,7 15,8 

Display 

Cooler 

Medium

 - - - - - 6.63

 15,3 

Display 

Cooler 

Large 

- - - 13.38 - -

15,8 

NonDisplay 

Freezer 

Small 

1.08 - 4.65 - 0.07 -

15,8 15,9 15,4 

NonDisplay 

Freezer 

Medium

- 3.16 - 13.30 - 3.42 

15,8 15,9 15,4 

NonDisplay 

Freezer 

Large 

- - - 16.33 - 2.06

 15,9 15,4 

Display 

Freezer 

Small 

- - - 0.05 - -

15,9 

Display 

Freezer 

Medium

 - - - - - 0.00

 4,4 

Display 

Freezer 

Large 

- - - 0.06 - -

10,7 

10-16 
 

 

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1

 EIA (U.S. Energy Information Administration). 2010. Annual Energy Outlook 2010. 

DOE/EIA-0383(forthcoming). U.S. Department of Energy, Energy Information Administration, 

Washington D.C. 

2

 Office of Management and Budget. Circular A-4. September 2003. Washington, D.C. 

http://www.whitehouse.gov/omb/circulars/a004/a-4.pdf. 

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 EIA (U.S. Energy Information Administration). Commercial Buildings Energy Consumption 

Survey 2003. Accessed January 2010 at 

http://www.eia.doe.gov/emeu/cbecs/cbecs2003/public_use_2003/cbecs_pudata2003.html. 

4

 U.S. Census Bureau 2007 Economic Census. Accessed March 2010 at 

http://www.census.gov/econ/census07/. 

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 NASS (U.S. National Agricultural Statistics Service.) The 2007 Census of Agriculture. 2007. 

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 EIA (U.S. Energy Information Administration). 2009. Update to the Annual Energy Outlook 

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Washington D.C. 

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 U.S. Census Bureau. 2007 Economic Census. Accessed March 2010 at 

http://www.census.gov/econ/census07/ 

8

 EIA (U.S. Energy Information Administration). 2008. Annual Energy Outlook 2008. 

DOE/EIA-0383(2008). U.S. Department of Energy, Energy Information Administration, 

Washington D.C. 

10-17