Turn Freezer off at Night?

JohnSwift10

One of my neighbours has their upright freezer in their garage and he has bought a plug in timer and set it to switch the freezer off from midnight to 08:00 hours.

Anyone have any idea if he will save any electricity?

I don't think he will.

MakingUpGround

I personally wouldn't be playing about food safely, that's probably the last thing I would be doing to save electricity 

FreeBear

Will save a bit of energy, but... What will the temperature increase be over the 8h period, and will it shorten the life of the food stored in the freezer ?

Ultrasonic

I certainly wouldn't be doing this but is there some supposed logic relating to efficiency of the freezer cooling?

jimexbox

Daft idea, not only is it potentially dangerous as the food temperature will fluctuate. The freezer will use extra energy to lower the temperature when it's turned back on. 

EssexHebridean

I’d hazard a guess that a modern freezer will see almost no temperature drop internally overnight with power removed - certainly at this time of year. Whether it will make any appreciable difference to the energy use is another question, but is he going to kill himself with food poisoning? Almost certainly not! 

If he really wants to save energy then moving the freezer into the house would possibly do so. (Or alternatively, on an Economy 7 rate, turn the thing off for the final 8 hours of the peak rate!)

Benny2020

If you put your microwave in the freezer it will freeze and cook.
One of my workmates used to bring an empty flask to work and take hot water home.
He also used to free wheel down hills in his car and tailgate to get a slipstream, used to get to work on a thimble full of fuel.

Ultrasonic

EssexHebridean said:

If he really wants to save energy then moving the freezer into the house would possibly do so.

Why do you say this? I'd expect the garage to be better as it's colder?

Going back to the original question, freezer manufacturers obviously do their best to optimise efficiency. If it would save electricity to not actively cool overnight they do this already.

Xbigman

The amount of energy to keep a set amount of food at a set temperature for 24 hours is constant.  
All modern freezers will keep food safe for 24 hours with no power so its not a food safety issue. Letting a freezer come up in temperature 3 or 4 degrees and then cooling back down will affect the quality/texture but not by a massive amount. Turning a freezer off at night is therefore pointless and makes no sense.

Now if someone had E7 and they turned their freezer off in the evening and then froze back down on cheap electric that could save money but freezers don't actually run a big percentage of the time so its not a huge saving. Having freezers and even fridges cut out during peak hours on a ToU tariff might be a better idea but I've not tried it personally nor seen any figures from those who have. I'd suggest that's the only way you might make a noticeable saving.


Darren

beefturnmail

This is basically the same as the argument about whether it's cheaper to leave the heating on low all day or turn on and off - as with heating it's cheaper to turn the freezer on and off, but at the risk of ruining food and/or getting food poisoning due to temperature fluctuations

EssexHebridean

Ultrasonic said:

EssexHebridean said:

If he really wants to save energy then moving the freezer into the house would possibly do so.

Why do you say this? I'd expect the garage to be better as it's colder?

Going back to the original question, freezer manufacturers obviously do their best to optimise efficiency. If it would save electricity to not actively cool overnight they do this already.

I believe the theory here is that modern fridges and freezers are optimised to work best at “normal indoor” temperatures and at temperatures above or below those they are less energy efficient. Don’t ask me about the physics behind that though! I know my parents were warned that by having their freezer in the (brick built, insulated but not heated) shed  they would potentially find that it used more energy AND might have a shortened lifespan, though.