Efficiency Impact of Defrosting a Chest Freezer

Post image for Efficiency Impact of Defrosting a Chest Freezer

by Tim Fulton on September 16, 2009

This entry is part 1 of 2 in the series Freezer Efficiency

About a year ago when I bought my house, the previous owners offered the chest freezer that was downstairs for a reasonable price. We gladly accepted. Ever since, it has been chugging away eating up whatever amount of electricity it needs to keep itself cool. Only recently have I begun to examine it and look into what can be done to increase its efficiency. Throughout the next few weeks and months I’ll be doing what I can to get it running a bit more efficiently.

The first thing I noticed when we started using it was that it was obviously a manual defrost freezer. This was quite apparent from the 1-2 inches of ice/snow on the side of the freezer. This pleased me as I know manual defrost freezers are generally more efficient. However, at the time we moved in, it probably needed to be defrosted. Now, a year later, it really needed to be defrosted.

Before defrosting, I hooked up my Kill A Watt and monitored the energy consumption for just over 9 days. The readings came to 11.17 kWh over 222 hours. This translates to 1.21 kWh a day. With the baseline established for the freezer, I could go ahead and defrost it.

chest freezer

This was the delightful image you saw every time you opened up the freezer.  As you can see, there is a bit of build up on the inside.

chest freezer ice build up

As I started to remove the food to defrost the freezer, I figured I better measure how thick this stuff actually was. As it turns out, it was almost three inches thick!

chest freezer ice build up

With all the food out, you can see how much of the freezer wall was actually covered in ice. Thankfully, the amount of ice didn’t cover the entire inside wall.

After the freezer was defrosted and all the food was back in, I let it run for a few days to get back down to temperature. I then hooked the kill a watt back up to it and let it run for another 216 hours. This time around, it only used 10.41 kWh. A little math shows us that this is 1.15 kWh per day. So, the defrosting looks to have drop the energy usage roughly 5%.

This simple task will save a hair under 22 kWh a year or 1.83 kWh per month. I was honestly hoping for a bit more than that. But, I do have a few more things planned.

{ 1 trackback }

What's going on over at EcoRenovator - Page 2 - Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com
September 30, 2009 at 2:18 pm

{ 1 comment }

1 Ed October 19, 2009 at 8:29 pm

clean the condensor

Comments on this entry are closed.