Operating Costs for WalkIn Coolers and Freezers
September 6th, 2012Before purchasing your walkin, you may be wondering how much it will cost to operate your walkin.
Estimates for Standard Sized Walkins
To give you a rough estimate of how much it cost to operate a walkin cooler or freezer, using the national average of $0.1022 per kilowatt, look at the chart below.
Cooler Average Cost per month Freezer Average Cost per month 6×6 $67.50 6×6 $232.96 6×8 $67.50 6×8 $232.96 8×8 $120.70 8×8 $232.96 8×10 $113.84 8×10 $355.24 8×12 $113.84 8×12 $355.24 10×10 $144.15 10×10 $355.24 10×12 $144.15 10×12 $415.73 Note: The above figures are estimates in a controlled environment; your exact numbers will vary. *These numbers were figured using the 12month rolling average of $0.1022 kilowatt hour cost. According to the Energy Information Administration this is the average cost in the United States for commercial electricity.
This chart was created using several assumptions that can affect your actual operating cost.
 The type of insulation in the walkin.
 Efficiency of the refrigeration system.
 Inside and outside temperature of walkin.
 Where the walkin is located.
 The temperature and the weight of the product entering the walkin.
 How often the door is opened.
 The age of the walkin.
 Cost of electricity.
This is just to name a few. If you would like to be more accurate using your electric rate, follow the instructions below.
Most walkin refrigeration systems are designed to run 80% of the time or between 16 and 18 hours per day. For a quick estimate of the cost to run your walkin use the chart and formula below.
For standard sized walkins, we have estimated the average kilowatt hours used to run the selected sized walkins. To figure out your monthly cost, select the walkin you want to calculate and multiply the associated AKWH (Average kilowatt hours) by your cost per kilowatt.
AKWH * C = Average Monthly cost
Cooler Avg. KW hours per month (AKWH) Freezer Avg. KW hours per month (AKWH) 6×6 660.48 6×6 2,279.49 6×8 660.48 6×8 2,279.49 8×8 1,181.03 8×8 2,279.49 8×10 1,113.86 8×10 3,475.91 8×12 1,113.86 8×12 3,475.91 10×10 1,410.51 10×10 3,475.91 10×12 1,410.51 10×12 4,067.82 Note: The above figures are estimates; your exact numbers may vary. For example, an 8×10 cooler would be figured by multiplying 1,113.86 by your monthly kilowatt rater per hour. In this example we used our AKWH of 11.89 cents per KWH.
1,113.86 (AKWH) * $.1189 = $132.44 per month
Estimate for a Custom Sized Walkin
If you would like to calculate an estimate on a different sized walkin, follow the provided formula below. You will need to get a BTU (British Thermal Unit) requirement for the walkin you would like to calculate. You can get this information from calling your dealer, U.S. Cooler Company at 8005212665 or go to U.S. Cooler’s refrigeration sizing program to size your walkin. If you have your dealer or U.S. Cooler on the phone you will also need to get the voltage and amperage of the refrigeration system that will match your BTU requirement. When you have the amperage and volts of your refrigeration unit, follow the equation below for your average monthly electricity cost. Make sure you have the amperage and volts for both the condensing unit and evaporator coil.
Cooler: (((TW *16)/1000)*30.42)*C = Monthly Energy Cost
Freezer: (((TW)*18)/1000)*30.42)*C = Monthly Energy Cost
16 = Design run time for a Cooler per day
18 = Design run time for a Freezer per day
30.42 = Average days in a month
A = Amperage
V = Total Voltage of refrigeration unit
C = Your cost per kilowatt in dollars (This could be found on your electricity invoice.)
TW = (A*V) for condensing unit + (A*V) for evaporator coil
This takes the amperage (A) times the voltage (V) of the condensing unit plus the amperage (A) times the voltage (V) of the evaporator coil to get the total watts (TW) of the refrigeration system. The amount of watts used is then multiplied by the number of hours the system will run per day. For coolers the average is 16 hours and freezers average 18 hours per day. This will give you the daily amount of kilowatts required daily. Multiply the daily required kilowatts by 30.42 which is the average days per month to get the monthly required kilowatts. Multiply that number by the Kilowatt cost of electricity in your area to get your cost per month. This will give you an estimate of what the walkin will cost to run per day in your area.
Example: 8×10 cooler, Condensing Unit A = 9.5, V = 230, Evaporator Coil A = .9, V = 115
C = $.1189
9.5*230 = 2,185 condensing unit watts
.9*115 = 103.5 evaporator unit watts
TW = 2,185 + 103.5 = 2,288.50
((((2,288.50)*16)/1,000)*30.42)*$.1189 = $132.44
As discussed above these formulas will give you an idea of the cost to run your walkin and are not to be considered exact figures. If you would like more accurate figures you need to contact a licensed mechanical engineer to design and calculate your system.
6 responses to “Operating Costs for WalkIn Coolers and Freezers”

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Hashem Althor 
The energy numers you have posted have to be without product in a constant environment and without door openings? The numbers you are showing are similar to the controled study we did up to MMCC and much lower than what we have found when doing energy testing at actual resturants. Please let me know if my assumptions are correct, because it would be helpful for class.
Thanks
Mike

Mike,
These are rough estimations and aren’t taking into account the eight variables listed in the article like door openings (since these will vary greatly in specific situations). Did you have numbers you could share for specific cases? 
Why is the average kWh for the 8×8 cooler higher than for the 8×10 and 8×12 coolers?

It has to do with the refrigeration system used in the tests. The 8X8 utilized a 3/4 hp unit while the 8X10 used a 1 hp unit which performed more efficiently in this instance (the 6X6 and 6X8 boxes used a 1/2 hp unit). These were calculated in controlled settings, so they’re to be taken as rough estimations. In realworld conditions the 8X8 may infact cost less to run.

Do you know of any studies that tested the energy consumption of walkins at different temperatures? For instance, a 10×10 freezer at 10 degrees vs. 5.
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