1

The title says it all; I'm looking for any qualitative information that can help me.

Freezers: https://www.energystar.gov/productfinder/product/certified-residential-freezers/details/2255167 Refrigerators: https://www.energystar.gov/most-efficient/me-certified-refrigerators/results

Per this question, the testing process for refrigerators costs money.

1 Answer 1

2

Although it seems logical that a refrigerator would be more efficient since it doesn't have to keep things as cold, there are a few different factors affecting real-world performance.

Freezers are simpler to operate. In a freezer there's only a top end on the temperature range. From refrigerator manufacturer LG you can see the range in the refrigerator is narrow, but the freezer range is broad:

Freezer and refrigerator temperature range

For a freezer, the compressor can run for a while to get the compartment well below zero. During start-up and stopping, the compressor is less efficient, so it makes sense to run it for a while.

But in a refrigerator, if you run the compressor too long, you risk freezing things that shouldn't be frozen.

Fridges need a "relief" valve. If a fridge does get too cold, it needs to be able to warm back up again. I suspect this is why the insulation is thinner in the fridge compartment -- if it's too thick and the compartment gets too cold, there's no way to warm it back up. But having thinner insulation means that if the compartment gets a bit too cold, it will naturally warm back up a bit. This allows the thermostat and control system to be simpler (and cheaper).

Freezers aren't opened as often. This part gets to the real-world aspect of Energy Star ratings. It's 11am where I am, and so far I've opened my refrigerator three times: creamer for my coffee, orange juice with breakfast, and an apple for a snack. I've only opened my freezer once to get some frozen fruit for my oatmeal. So the testing criteria likely emulates this real-world usage.

2
  • From my googling, it looks like an important element is that freezers are also just more insulated all around, similar to your "relief" valve point.
    – capet
    Sep 25, 2020 at 23:48
  • 2
    Two further factors are: (1) the fridge linked to is a larger volume than the freezer and (2) it is a top-loading freezer, which means that the heat exchange when the door is open is far less than for the side-opening fridge. If people would buy top-loading fridges, they could be significantly more efficient.
    – M Juckes
    Sep 27, 2020 at 16:42

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.