CHAPTER 7. ENERGY USE CHARACTERIZATION 

TABLE OF CONTENTS 

7.1 INTRODUCTION ........................................................................................................... 7-1
 

7.2 APPROACH TO ENERGY USE ANALYSIS ............................................................... 7-1
 

7.3 ENERGY USE FOR WALK-IN COOLERS AND FREEZERS .................................... 7-1
 

7.3.1 Sizes and Product Classes Analyzed for Energy Use .......................................... 7-2
 

7.3.2 Direct Energy Consumption ................................................................................ 7-3
 

7.3.3 Product Load........................................................................................................ 7-4
 

7.3.4 Envelope Load ..................................................................................................... 7-4
 

7.3.5 Assumptions for Computing the Product Cooling Load...................................... 7-5
 

7.3.6 Duty Cycle ........................................................................................................... 7-6
 

7.3.7 Matching of the Refrigeration Capacity .............................................................. 7-7
 

7.3.8 Mismatch Factor .................................................................................................. 7-7
 

7.3.9 Normalized Energy Consumption (NEC) for the Refrigeration System ............. 7-9
 

7.4 ENERGY ANALYSIS RESULTS .................................................................................. 7-9
 

7.5 State-by-State Annual Energy Consumption ................................................................. 7-10
 

LIST OF TABLES 

Table 7.3.1 WICF Envelope Classes and Sizes for Energy Use Analysis .................................. 7-2 

Table 7.3.1 Equipment Classes for Refrigeration Equipment .................................................... 7-3 

Table 7.3.2 Combination of WICF Envelopes and Refrigeration Systems Analyzed................ 7-3 

Table 7.3.3 Daily Direct Electrical Energy Consumption of the Envelopes (kWh/Day).......... 7-4 

Table 7.3.4 Envelope Refrigeration Loads (kBtu/Day).............................................................. 7-5 

Table 7.3.5 Assumptions for Estimation of Nominal Product Load........................................... 7-5 

Table 7.3.6 Capacities and Oversize Factors for the Refrigeration Systems.............................. 7-8 

Table 7.4.1 Annual Energy Consumption Estimates for a Medium Non-Display Cooler 

Matched with a Dedicated Medium-Temperature Outdoor System (kWh/ year). 7-10 

Table 7.5.1 State-wise Annual Energy Consumption Estimates for a Baseline Small NonDisplay Cooler Envelope matched with Outdoor medium Temperature 

System (kWh/year) ............................................................................................... 7-11 

LIST OF FIGURES 

Figure 7.3.1 Oversize Factor vs. Required Capacity Plot ........................................................... 7-9 

7-i 
 

 

 

CHAPTER 7. ENERGY USE CHARACTERIZATION
 

7.1 INTRODUCTION 

This chapter presents the U.S. Department of Energy’s (DOE’s) analysis of annual energy 

usage of complete walk-in cooler and freezer (WICF) systems at various efficiency levels of the main 

subsystems, i.e., the envelope and the refrigeration system. These estimated values of annual energy 

usage (kWh/yr) are key inputs to the determination of life-cycle cost (LCC) and payback period (PBP) 

analyses (chapter 8 of the preliminary technical support document [TSD]) as well as national impacts 

analyses (chapter 10 of the preliminary TSD). 

7.2 APPROACH TO ENERGY USE ANALYSIS 

The TSD chapter on engineering analysis (chapter 5) provides estimates of nominal energy 

consumption for the two principal components of the WICFs; i.e., the envelope and the refrigeration 

system at baseline and at several higher efficiency levels ideally matched with a nominally sized 

counterpart system. There are multiple independent design options with varying cost incidences 

available for each of these subsystems for achieving aggregate energy savings for the complete system. 

Thus, many design options are analyzed for a complete WICF system, being the multiplication product 

of the individual separate design options for the envelope and the refrigeration system. The annual 

energy consumption for any given system in the set of complete systems configured with the envelope 

at a specific efficiency level, and a matched refrigeration system, also at a specific efficiency level, is 

ascertained using a set of assumptions for product loading, duty cycle, and other associated conditions. 

WICF systems are often custom built with varying envelope dimensions, they cater to different 

refrigeration loads, and they are configured with different classes of refrigeration systems. Therefore, 

DOE considered three typical sizes in each of the product classes of envelope as analysis points and 

estimated the energy consumption for these sizes. Four envelope classes and six refrigeration system 

classes were analyzed at multiple analysis points in the engineering analysis (chapter 5 of the 

preliminary TSD). Energy usage for the combined walk-in system was estimated by matching each 

analysis point of all the envelope classes to an appropriate refrigeration system class sized to one of the 

possible analysis points. 

7.3 ENERGY USE FOR WALK-IN COOLERS AND FREEZERS 

The aggregate energy consumption of a complete walk-in system comprises the energy 

consumption due to three distinct subsets of components: 

1.	 Energy consumed directly by envelope components, i.e., lights, anti-sweat heaters, powered 

secondary devices for infiltration reduction, etc. (direct energy consumption) 

2.	 Energy consumed by components of the refrigeration systems inside the envelope, i.e.,
 

evaporator fans, defrost energy, etc., and 

3.	 Energy consumed by the refrigeration system components outside the envelope, i.e., the
 

compressor motor and the condenser fan motor. 

Refrigeration or envelope-related components, located inside the cooled space, also generate 

waste heat and add to the refrigeration load of the envelope. The additional heat load must also be 

removed by the refrigeration equipment, thereby adding to the refrigeration system electricity 

consumption. 

7-1 
 

 

 

 

 

7.3.1 Sizes and Product Classes Analyzed for Energy Use 

The sizes and the product classes for the walk-in envelopes for energy use analysis are identical 

to the four primary walk-in envelope classes identified for the engineering analysis. These are (1) nondisplay coolers; (2) non-display freezers; (3) display coolers, and (4) display freezers. Three typical 

sizes were chosen from each envelope equipment class for energy-use analysis as was done for the 

engineering analysis. Table 7.3.1 gives details of the dimensions of the envelopes, the respective 

product classes, and the product class and size code. In later discussions, the envelopes are identified 

by the composite product code that comprises the product class code and the size code, e.g., the product 

code display cooler-small (DCS) refers to the small-sized display cooler. 

Table 7.3.1 WICF Envelope Classes and Sizes for Energy Use Analysis 

Dimensions [length × width × height, ft] 

Class Small Medium Large Class Code 

Non-Display 

Cooler 10’ × 8’ × 7.6’ 12’ × 20’ × 

9.5’ 

25’ × 30’ × 

12’ SC 

Non-Display 

Freezer 8’ × 6’ × 7.6’ 9’ × 20’ × 

9.5’ 

25’ × 20’ × 

12’ SF 

Display Cooler 6’ × 6’ × 6.6’ 10.2’ × 7’ × 

7.6’ 

80’ × 15’ × 

7.6’ DC 

Display Freezer 6’ × 6’ × 6.6’ 10.2’ × 7’ × 

7.6’ 

80’ × 15’ × 

7.6’ DF 

Size Code S M L 

For the refrigeration systems, DOE analyzed the six primary walk-in refrigeration system classes taken up from the 

engineering analysis. These include dedicated indoor systems, dedicated outdoor systems, and unit coolers connected 

to Multiplex Systems for both medium and low temperature applications. DOE chose two representative sizes (small 

and large) from each of the six refrigeration system product classes for energy-use analysis. Each envelope product 

class could be matched with one of the three medium or low-temperature refrigeration equipment classes. The size of 

the refrigeration system matched with the WICF envelope was based on the nominal capacity of the specific size of 

the refrigeration system and the cooling load of the envelope. Table 7.3.3 gives the details of the matched 

refrigeration systems for each WICF analyzed. The class codes for the refrigeration systems are defined in 

Table 7.3.2, and the size descriptions are abbreviated; i.e., Lg. and Sm. stand for the large and 

small sized system, respectively. 

7-2 
 

 

 

 

 

 

 

 

 

 

 

 

Table 7.3.2 Equipment Classes for Refrigeration Equipment 

Condensing Type* 

Operating 

Temperature Condenser Location Class 

Multiplex 

Medium - MC.M 

Low - MC.L 

Dedicated 

Medium 

Indoor 

DC.M.I 

Low DC.L.I 

Medium 

Outdoor 

DC.M.O 

Low DC.L.O 

*Note: For each of the six equipment classes, two analysis points will be used, 

corresponding to small and large representative units. 

Table 7.3.3 Combination of WICF Envelopes and Refrigeration Systems Analyzed 

Class/ Size 

code SCS SCM SCL DCS DCM DCL SFS SFM SFL DFS DFM DFL 

DC.M.I-Sm √

DC.M.I-Lg √ √ √ √ √

DC.M.O-Sm √

DC.M.O-Lg √ √ √ √ √

MC.M-Sm √

MC.M-Lg √ √ √ √ √

DC.L.I-Sm √

DC.L.I-Lg √ √ √ √ √

DC.L.O-Sm √

DC.L.O-Lg √ √ √ √ √

MC.L-Sm √

MC.L-Lg √ √ √ √ √

7.3.2 Direct Energy Consumption 

The methodology for estimating the direct energy consumption under different engineering 

options for the envelope has been explained in detail in chapter 5 of the preliminary TSD (sections 5.5). 

Table 7.3.4 gives details of the daily direct electrical energy consumption of the envelope. 

7-3 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 Table 7.3.4 Daily Direct Electrical Energy Consumption of the Envelopes (kWh/Day) 

Class/ Size 

Code SCS SCM SCL DCS DCM DCL SFS SFM SFL DFS DFM DFL Efficiency 

Levels 

0 0.36 0.36 1.08 12.41 32.17 100.90 4.75 5.30 10.42 20.10 43.95 123.41 

1 0.36 0.36 1.08 7.28 18.48 64.82 4.75 5.30 10.42 12.49 23.68 87.34 

2 0.17 0.17 0.50 3.26 11.64 64.82 4.56 5.11 10.42 12.49 23.68 87.34 

3 0.17 0.17 0.50 3.26 11.64 38.68 4.56 5.11 9.84 8.47 17.53 87.34 

4 0.17 0.17 0.50 1.86 6.61 15.45 4.56 5.11 9.84 8.47 13.01 61.19 

5 0.17 0.17 0.50 1.55 2.90 10.17 4.56 5.11 9.84 6.25 7.10 24.23 

6 0.17 0.17 0.50 1.55 2.05 10.17 4.56 5.11 9.84 5.94 7.10 18.95 

7 0.17 0.17 0.50 0.89 2.05 10.17 4.56 5.11 9.84 5.94 6.25 18.95 

8 0.17 0.17 0.37 0.89 2.05 10.17 4.56 5.11 10.52 5.28 6.25 18.95 

9 0.17 0.17 0.37 0.89 2.05 10.17 4.56 5.56 10.52 5.28 6.25 18.95 

10 0.17 0.17 0.37 0.89 2.05 10.17 4.79 5.56 10.52 5.28 6.25 18.95 

11 0.17 0.17 0.37 0.89 2.05 10.17 4.79 5.56 10.38 5.28 6.25 18.95 

12 0.17 0.17 0.37 0.89 2.05 10.17 4.79 5.56 10.38 5.28 6.25 18.95 

13 0.17 0.17 0.37 0.89 2.05 10.17 4.79 5.56 10.38 5.28 6.25 18.95 

14 0.17 0.17 0.37 0.89 2.05 10.17 4.79 5.56 10.38 5.28 6.25 18.95 

15 0.17 0.17 0.37 0.89 2.05 10.17 4.82 5.60 10.38 5.75 7.12 18.95 

7.3.3 Product Load 

The aggregate refrigeration load in the envelope comprises the product load and the nonproduct load. The product heat load is the load associated with WICF’s essential function of 

maintaining the optimal storage conditions defined by the specified temperature and humidity ranges 

for the products inside, i.e., the load directly related to the products stored in the WICF envelope. This 

generally includes the product “pull-down” load, which is the load associated with reducing the 

temperature of delivered products down to the desired storage temperature of the walk-in. This load 

varies with both the delivered product temperature and specific heat. The product load may 

occasionally include latent loads associated with products required to be frozen and also loads 

associated with the respiration of fresh fruits and vegetables. 

7.3.4 Envelope Load 

The envelope (non-product) refrigeration load is composed of the following: (1) the heat 

transmitted through the envelope via conduction; (2) the air infiltration through the panel and door 

joints and also through open doors; and (3) the heat load due to the operation of the electrical 

components inside the envelope. 

The methodology for computing the heat loads following the DOE test procedure is explained 

in detail in preliminary TSD chapter 5 for the Engineering Analysis. Non-product refrigeration load is 

computed in detail for all the design options of the four classes of envelopes in three different typical 

sizes. The detailed calculations for these are shown in the spreadsheets for engineering analysis for the 

envelope. The envelope heat loads in kBtu/day are shown in Table 7.3.5. 

7-4 
 

 

 

 

 

 

 

 

 

 

 

 

Table 7.3.5 Envelope Refrigeration Loads (kBtu/Day) 

Class/ Size 

Code SCS SCM SCL DCS DCM DCL SFS SFM SFL DFS DFM DFL Efficiency 

levels 

0 60 138 279 283 684 3,851 132 315 596 383 823 4,375 

1 33 71 164 265 638 3,727 53 120 261 357 754 4,252 

2 32 71 162 252 614 3,330 52 120 259 218 515 3,094 

3 22 70 161 204 532 3,241 50 119 257 204 494 3,091 

4 20 52 153 147 515 2,292 48 114 246 203 478 3,002 

5 20 49 145 87 363 1,293 48 107 232 180 416 2,616 

6 19 46 115 80 203 1,291 47 105 224 118 415 1,587 

7 18 44 111 78 193 1,285 44 97 207 117 250 1,574 

8 16 40 110 77 193 1,235 44 95 177 114 250 1,557 

9 15 37 99 77 192 896 42 77 172 114 248 1,539 

10 12 29 91 56 192 888 35 72 160 114 247 1,519 

11 10 24 90 56 137 881 31 62 159 112 245 1,153 

12 9 21 79 56 137 871 29 56 150 90 186 1,141 

13 8 20 73 55 136 864 28 52 150 90 186 1,127 

14 8 20 60 55 135 864 27 50 128 89 184 1,125 

15 8 20 53 54 134 856 26 50 117 76 163 1,110 

7.3.5 Assumptions for Computing the Product Cooling Load 

For the energy-use analysis of the WICF systems, the aggregate refrigeration load for each of 

the twelve WICF envelope sizes is obtained by adding nominal product loads to the envelope nonproduct heat load. The assumptions made for calculating the product load are described below. The key 

parameters that determine the product load are the product pull-down temperature, the product-specific 

heats, and the daily loading ratio of the products in relation to the interior refrigerated space of the 

WICF. Table 7.3.6 gives details of the parameters assumed for different product classes for the typical 

sizes considered for the analysis. 

Table 7.3.6 Assumptions for Estimation of Nominal Product Load 

SC SC SC DC SF SF DF 

Parameter Units S M L DCS M DCL S SFM L DFS DFM L 

Product Pull 

down TD (°F) 10 10 10 10 10 10 10 10 10 10 10 10 

Product specific 

heat 

Btu/lb 

/ °F 0.9 0.9 0.9 0.9 0.9 0.9 

0.4 

5 0.45 0.45 0.45 0.45 0.45 

Daily Loading 

Ratio 

Lbs/cf 

t 4 2 2 4 2 2 1 0.5 0.5 1 0.5 0.5 

From the physical dimensions of the envelope, the gross inside volume was computed. This was 

multiplied by the daily loading ratio (lbs/cft) to obtain the lbs of product that is loaded in the envelope 

on daily basis and generated the daily pull-down load for the envelope. The daily loading ratio is 

different from the actual average loading ratio obtained by dividing the maximum weight of the 

products stored in the WICF by the volume of the refrigerated space. The daily loading ratio is lower 

7-5 
 

 

 

 

 

 

than the actual average loading ratio to reflect the quantity of products delivered on daily basis. The 

assumed daily loading ratios were higher for the coolers than for the freezers and higher for the 

smallest sizes of the envelopes than for the intermediate and higher sizes. The product-specific heats 

were assumed at 0.45 Btu/lb/ °F for the frozen products and 0.9 Btu/lb/ °F for all products stored in the 

WICF coolers. The pull-down temperatures were taken at 10 °F for both the coolers and freezers to 

represent an average loading condition. DOE believes that these conditions represent the typical 

conditions found in the industry, and based on these assumptions, a reasonable nominal product load 

could be estimated that could be used for further analysis. 

7.3.6 Duty Cycle 

The nominal product cooling load was added to the non-product cooling load for obtaining the 

aggregate daily cooling load for the envelope. The aggregate refrigeration load is required to be 

removed from the envelope interior for maintaining the specified temperature condition inside the 

envelope. The refrigeration system to be matched with any given envelope is required to have adequate 

capacity to meet the “high load” condition of the envelope and to also have enough reserve capacity for 

meeting unexpectedly high product-load situations or unusually hot outside weather conditions. DOE 

defined the high-load factor as the ratio of the high hourly load to the average refrigeration load of the 

envelope over a 24-hour period. DOE modeled the “high load” factor to conform to the assumptions 

made in AHRI standard 1250 to calculate the envelope load (section 6). In AHRI Standard 1250, it was 

assumed that for a walk-in system with an indoor condensing unit, the high envelope load (BLH) is 

70 percent of the capacity of the refrigeration system (qss) at the specified temperature of 90 °F), and 

the low envelope load (BLL) is 10 percent of the refrigeration system capacity at (qss). It is further 

assumed in AHRI 1250 (section 6) that the high-load period (BLH) occurs for 8 hours per day. The 

average envelope load (BLA) for the above situation could be derived as follows: 

BLA= (8 BLH + 16 BLL )/24 Eq. 7.1 

BLH = 0.7 qss Eq. 7.2 

BLL = 0.1 qss Eq. 7.3 

Using the above equations, DOE obtained that the high load factor for the walk-in coolers at 

2.33. An identical relationship is obtained for the coolers with external condensers. For the freezers 

with the internally located condensers, the corresponding relationships from AHRI 1250 are: 

BLH = 0.8 qss Eq. 7.4 

BLL = 0.4 qss Eq. 7.5 

The average envelope load (BLA) for freezers is derived with duty cycle condition identical for 

coolers (8 hours of high load operation, and 16 hours of low load operation). DOE used the above 

relationships to obtain the high load factor of 1.5 for the walk-in freezers. 

7-6 
 

 

7.3.7 Matching of the Refrigeration Capacity 

For obtaining a matched refrigeration systems for the given envelope, DOE derived the hourly 

peak refrigeration load (kBtu/hr) for the envelope, and then used the corresponding equations in AHRI 

1250 to arrive at the matched capacity. These equations are as follows 

For WICF cooler systems: 

BLH = 0.7 qss Eq. 7.6 

For WICF freezer systems: 

BLH = 0.8 qss Eq. 7.7 

The refrigeration system capacity in the above equations is the measured net capacity of the 

refrigeration system measured with testing methodology and rating conditions described in AHRI 

1250. For the dedicated systems, qss is the measured value at the outside ambient temperatures of 95 °F 

for the systems with outdoor condensing units and 90 °F for the systems with indoor condensing units. 

For the multiplex systems, qss is the measured capacity of the unit coolers at an adjusted suction dew 

point condition of 19 °F for the cooler and -26 °F for the freezer. Using the above equations, a precise 

capacity (k Btu/hr) required for the refrigeration system to match with a given WICF envelope could be 

calculated. However, DOE recognized that an exact match for this calculated capacity may not be 

available in the refrigeration systems available in the market. Under such a situation, the capacity of the 

best matched refrigeration system is likely to be the nearest higher capacity refrigeration system 

available in the market. To account for this phenomenon, DOE multiplied the refrigeration capacity 

calculated above by a mismatch factor that is greater than one. Multiplying the mismatch factor 

resulted in somewhat higher capacity systems being coupled to a given WICF envelope. 

7.3.8 Mismatch Factor 

For deriving the mismatch factor, a matching table (Table 7.3.7) is constructed to represent the 

actual matching process. DOE assumed an unfavorable mismatch situation where a required capacity of 

9,000 Btu/ hour was matched to the next available size of the refrigeration system having a capacity of 

12,000 Btu/hour (1 ton of refrigeration = 12,000 Btu/ hour) resulting in an oversize factor of 1.33. The 

oversize factors are computed in 0.5-ton intervals, assuming the industry manufacturer and market 

refrigeration systems starting with the smallest capacity at 0.5 ton and at 0.5-ton intervals. The oversize 

factors are plotted against the required capacities, and the resulting plot is presented in Figure 7.3.1. 

7-7 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 7.3.7 Capacities and Oversize Factors for the Refrigeration Systems 

Required Capacity 

('000 Btu/hr) 

Available Capacity 

('000 Btu/hr) 

Oversize 

Factor 

9 6 1.33 

15 12 1.20 

21 18 1.14 

27 24 1.11 

33 30 1.09 

39 36 1.08 

45 42 1.07 

51 48 1.06 

57 54 1.05 

63 60 1.05 

69 66 1.04 

75 72 1.04 

81 78 1.04 

87 84 1.03 

93 90 1.03 

99 96 1.03 

105 102 1.03 

111 108 1.03 

117 114 1.03 

120 

A logarithmic trend line is fitted on the observed points, and a following relationship is 

obtained. 

Oversize Factor = -0.0901 Ln( Required capacity in ‘000 kBtu/ hr) + 1.4257 Eq. 7.8 

DOE used the oversize factor described above to calculate the nearest matched capacity of the 

refrigeration systems. 

7-8 
 

Oversize Factor 

1.35 

1.3 

1.25 

1.2 

1.15 

1.1 

1.05 

1 

0 

y = -0.0901Ln(x) + 1.4257 

R2

 = 0.8984 

50 100 150 

Required Capacity ('000 kBtu/ hr) 

Figure 7.3.1 Oversize Factor vs. Required Capacity Plot 

7.3.9 Normalized Energy Consumption (NEC) for the Refrigeration System 

DOE used the NEC metric for estimating the annual energy consumption of the matched WICF 

system. The normalized energy consumption has been defined as the annual energy consumption of the 

refrigeration system divided by its net capacity under specified conditions as defined in AHRI 1250 for 

determining the key test metric Annual Walk-in Energy Factor (AWEF). The methodology used for 

computing the NEC metric for the refrigeration systems has been described in detail and the NEC 

results reported in chapter 5 (Engineering Analysis). This is based on the procedures described in 

AHRI 1250. The duty cycles, the high load, and the low load factors proposed by DOE essentially 

follow the AHRI methodology. 

In AHRI 1250, the total annual cooling load for the envelope and associated annual energy 

consumption of the refrigeration system are based on the envelope load model that assumed variation 

of the cooling load with the outside ambient temperature. This relationship was based on the variability 

of the conduction heat gain through the three sides of the envelope assumed to be on the exterior 

perimeter of the building and exposed to the outside ambient condition. This resulted in some small 

seasonal variation of the cooling load of the envelope. In the DOE model for energy consumption, the 

variation of the cooling load for the envelope with the outside ambient condition was not modeled 

explicitly. However, because the Normalized Energy Consumption (NEC) metrics used to estimate the 

energy consumption were based on the variation of the duty cycle and load factor on outside ambient 

conditions, the annual energy consumptions derived using NEC results essentially have the same 

conditions implied. 

7.4 ENERGY ANALYSIS RESULTS 

The annual energy consumptions estimated using the methodology described above for all the 

envelope product classes analyzed are presented in appendix 7A. A representative table showing annual 

energy consumption estimates for a medium non-display cooler matched with a dedicated mediumtemperature outdoor system is shown in Table 7.4.1. 

7-9 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 7.4.1 Annual Energy Consumption Estimates for a Medium Non-Display Cooler Matched 

with a Dedicated Medium-Temperature Outdoor System (kWh/ year) 

Type Non-Display Cooler (Medium)/Dedicated Medium-Temperature Outdoor Systems 

Length × Width 

× Height (ft) 12′ ×20′ × 9.5′

Refrigeration 

System 

Efficiency Levels 

0 1 2 3 4 5 6 7 8* 

Envelope 

Efficiency Levels 

0 15,547 14,887 13,341 11,173 8,146 5,979 5,200 5,108 4,882 

1 9,813 9,398 8,428 7,066 5,165 3,804 3,315 3,257 3,115 

2 9,687 9,274 8,309 6,956 5,066 3,713 3,226 3,169 3,028 

3 9,654 9,243 8,281 6,932 5,049 3,700 3,215 3,158 3,017 

4 8,082 7,738 6,934 5,806 4,231 3,104 2,698 2,651 2,533 

5 7,832 7,499 6,719 5,627 4,101 3,009 2,616 2,570 2,456 

6 7,529 7,209 6,460 5,410 3,944 2,894 2,516 2,472 2,363 

7 7,396 7,082 6,346 5,315 3,875 2,844 2,473 2,429 2,322 

8 7,022 6,724 6,026 5,047 3,681 2,702 2,350 2,309 2,207 

9 6,753 6,466 5,795 4,855 3,541 2,600 2,261 2,222 2,124 

10 6,129 5,869 5,260 4,407 3,216 2,363 2,056 2,020 1,931 

11 5,650 5,411 4,850 4,065 2,967 2,181 1,899 1,866 1,784 

12 5,406 5,177 4,641 3,889 2,840 2,089 1,818 1,787 1,708 

13 5,289 5,065 4,541 3,806 2,779 2,044 1,780 1,749 1,672 

14 5,289 5,065 4,541 3,806 2,779 2,044 1,780 1,749 1,672 

15* 5,289 5,065 4,541 3,806 2,779 2,044 1,780 1,749 1,672 

7.5 STATE-BY-STATE ANNUAL ENERGY CONSUMPTION 

DOE calculated the average annual energy use for each WICF envelope class matched with 

outdoor condenser systems for all 237 typical meteorological year (TMY2) stations in the United 

States. DOE mapped each TMY2 station to a certain State, based on its location. Within each State, 

DOE assigned a relative weight to each TMY2 station, based on the total population of identifiable 

population centers (cities, towns, other) that can be shown to be most climatically similar to the TMY2 

location. The detailed methodology for developing the weighting factors is discussed in appendix 7B. 

The annual energy consumption data for the TMY2 locations were then weighted to obtain annual 

energy consumption data for each State. The State-wise energy consumptions for these systems are 

given in appendix 7C for the coolers and in appendix 7D for freezers. A representative table showing 

state-wise annual energy consumption estimates for a medium non-display cooler matched with a 

dedicated medium-temperature outdoor system is shown in Table 7.5.1. 

7-10 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 7.5.1 State-wise Annual Energy Consumption Estimates for a Baseline Small NonDisplay Cooler Envelope matched with Outdoor medium Temperature System (kWh/year) 

Refr. Eff. Level 0 1 2 3 4 5 6 7 8 

AK 6,352 6,056 5,017 3,360 3,116 2,815 2,598 1,876 1,849 

AL 6,833 6,520 5,404 3,952 3,655 3,311 3,088 2,378 2,346 

AR 6,793 6,481 5,372 3,922 3,627 3,283 3,060 2,350 2,318 

AZ 6,951 6,634 5,499 4,328 4,001 3,607 3,378 2,671 2,636 

CA 6,795 6,484 5,374 3,754 3,472 3,141 2,921 2,213 2,182 

CO 6,598 6,294 5,215 3,637 3,367 3,046 2,826 2,111 2,081 

CT 6,625 6,320 5,237 3,642 3,372 3,051 2,831 2,117 2,088 

DE 6,676 6,369 5,278 3,724 3,446 3,120 2,899 2,186 2,156 

FL 6,983 6,665 5,525 4,237 3,916 3,553 3,326 2,618 2,583 

GA 6,812 6,500 5,387 3,908 3,614 3,274 3,051 2,342 2,309 

HI 7,045 6,725 5,575 4,357 4,026 3,659 3,430 2,723 2,687 

IA 6,569 6,266 5,192 3,627 3,359 3,039 2,820 2,103 2,074 

ID 6,582 6,278 5,202 3,617 3,349 3,028 2,809 2,093 2,064 

IL 6,601 6,297 5,218 3,649 3,379 3,058 2,838 2,122 2,092 

IN 6,638 6,332 5,247 3,687 3,413 3,089 2,869 2,155 2,125 

KS 6,682 6,375 5,283 3,794 3,511 3,176 2,955 2,241 2,210 

KY 6,684 6,377 5,284 3,736 3,457 3,130 2,909 2,196 2,165 

LA 6,888 6,574 5,449 4,051 3,745 3,394 3,169 2,461 2,428 

MA 6,605 6,301 5,221 3,602 3,334 3,017 2,797 2,083 2,054 

MD 6,685 6,378 5,285 3,739 3,460 3,132 2,911 2,198 2,167 

ME 6,522 6,220 5,154 3,520 3,260 2,948 2,730 2,013 1,984 

MI 6,567 6,263 5,190 3,584 3,319 3,003 2,784 2,068 2,039 

MN 6,505 6,204 5,140 3,562 3,299 2,986 2,766 2,048 2,019 

MO 6,690 6,382 5,289 3,788 3,505 3,173 2,951 2,238 2,207 

MS 6,834 6,521 5,405 3,972 3,673 3,327 3,103 2,393 2,361 

MT 6,517 6,215 5,150 3,546 3,285 2,970 2,751 2,034 2,005 

NC 6,758 6,448 5,343 3,817 3,531 3,198 2,976 2,265 2,234 

ND 6,465 6,166 5,108 3,536 3,276 2,964 2,745 2,025 1,997 

NE 6,612 6,307 5,226 3,689 3,415 3,090 2,870 2,154 2,124 

NH 6,531 6,229 5,161 3,560 3,298 2,983 2,764 2,047 2,018 

NJ 6,670 6,363 5,273 3,707 3,431 3,106 2,885 2,172 2,142 

NM 6,707 6,399 5,303 3,775 3,493 3,161 2,939 2,227 2,196 

NV 6,787 6,476 5,367 3,991 3,692 3,332 3,108 2,397 2,365 

NY 6,647 6,341 5,255 3,670 3,397 3,075 2,855 2,141 2,111 

OH 6,608 6,303 5,223 3,630 3,361 3,042 2,822 2,107 2,078 

OK 6,764 6,454 5,349 3,898 3,606 3,263 3,040 2,328 2,296 

OR 6,649 6,343 5,256 3,597 3,329 3,009 2,791 2,079 2,049 

PA 6,633 6,327 5,243 3,662 3,390 3,068 2,848 2,134 2,104 

RI 6,612 6,307 5,226 3,615 3,346 3,028 2,808 2,094 2,065 

SC 6,802 6,490 5,379 3,892 3,600 3,260 3,038 2,328 2,296 

SD 6,530 6,228 5,161 3,605 3,339 3,020 2,800 2,082 2,053 

TN 6,770 6,460 5,354 3,874 3,584 3,245 3,022 2,311 2,279 

TX 6,883 6,569 5,445 4,080 3,772 3,416 3,191 2,482 2,448 

7-11 
 

 

 

 

 

 

 

Table 7.5.1 (contd) 

Refr. Eff. Level 0 1 2 3 4 5 6 7 8 

UT 6,642 6,336 5,251 3,713 3,437 3,108 2,887 2,173 2,143 

VA 6,708 6,399 5,303 3,760 3,479 3,150 2,929 2,216 2,186 

VT 6,519 6,218 5,152 3,545 3,284 2,971 2,752 2,034 2,006 

WA 6,616 6,311 5,230 3,545 3,282 2,966 2,748 2,036 2,006 

WI 6,524 6,223 5,156 3,557 3,295 2,981 2,762 2,045 2,016 

WV 6,661 6,355 5,266 3,680 3,406 3,083 2,863 2,150 2,120 

WY 6,516 6,214 5,149 3,533 3,272 2,959 2,741 2,023 1,995 

7-12