Efficiency Impact of Adjusting Freezer Temperature

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by Tim Fulton on October 7, 2009

Last time, we talked about the efficiency impact of defrosting a freezer. Defrosting gave us around a 5% reduction in energy usage. This time, we will be seeing what reducing the freezer temperature can do for us.


The temperature adjustment for my freezer is on the front end of the left side of the freezer. You can see it in the first picture. As the freezer sat, the dial was set to 4 out of 7. At the end of our last article, this setting was using 1.15 kWh per day.

At setting number 4, the freezer stayed right around -15°F (-26°C) at the very bottom. People that are off the grid tend to keep their freezers around 0°F (-18C) to save energy yet not compromise the length of time food will keep in the freezer.


So, as you can probably imagine, I simply turned the freezer all the way down to the 1 setting. I was a bit afraid about the temperature increasing too much, but it really didn’t rise all that much. I took temperature readings after a few days and the freezer at the bottom was now around -12°F (-24°C) and roughly 0°F (-18°C) at the top. I was kind of surprised that it didn’t increase the temperature more than that. However, I was even more surprised when I saw that the freezer was now only using 1.06 kWh per day. That is a solid 8% decrease from the 1.15 kWh per day it had been using at the end of our last article. So, to date we have decreased the power consumption of the freezer by 12.5% from the original 1.21 kWh per day.

For as simple as this is to do, everyone should really take the 5 minutes to go to their freezer and just turn the dial down. Double checking the actual temperature a few days later is a good idea. If you get too far above 0°F (-18°C), you start to see a drop off in how long the food will stay good. Organizing commonly used food to the top and longer term storage food items to the bottom is a great idea if you want to start increasing temperatures further. However, it would be my guess that most freezers out there are probably running much colder than they need to be.

{ 1 comment }

1 paul October 7, 2009 at 4:03 pm

last week i purcasted a 5 cuft frezzer used & a 7 cuft frezzer used for $110 & 3 days ago i started useing a kill a watt p3 my 7 cuft fridg after 4 days at 39 deg it did 0.74 kwh in 24 hours & the 5cuft frezzer is almost new compared to the 7cuft it used in 8 hours 0.27 its on 1 on the dial , in the middle to the top temp is plus 5 deg at the bottem its rock dard im happy i use up the food every week i was even thinking of no frezzer at oll & maybee next week ill try the small one as refrig & see if a smaller one & newer can use less i can tell now im sold on chest refrig oh yea at over 15 cents per kwh & unemployed im forced to conserve paulclassa@gmail.com

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