Naked Science Forum

General Science => General Science => Topic started by: Carolyn on 03/05/2007 04:08:55

Title: A Full Freezer
Post by: Carolyn on 03/05/2007 04:08:55

This week I ordered some frozen foods from one of my former restaurant vendors.  When he delivered it, he noticed that my freezer was nearly empty.  He told me it takes more energy to run my freezer empty or almost empty than it takes to run it full, and that I would save on my electric bill if I filled the freezer with jugs of water. 

Is this true?  And if it is, why?

Title: A Full Freezer
Post by: Karen W. on 03/05/2007 04:16:47

Yes it is, I have done it and it works. you loose all that air that gets out everytime you open the door. insted when you have solid iced jugs inside there is a lot less air to recool so thats what I think the ice holds the cold where as it does not all go out the door when you open it! I may be wrong and not as technical but I believe it is something like that. My bill new the difference!

Title: A Full Freezer
Post by: another_someone on 03/05/2007 05:25:25

That is basically it - air easily escapes from a freezer (and with it, all you past effort to cool it), whereas a jug of water tends to stay put when you open the freezer door (unless you choose to remove the jug of water - in which case, it will take with it more energy than the equivalent loss of air would have).  The only caveat I would have to that is that the water (if it is water you are using to retain the cold) should be in a seeled container, otherwise it may tend to evaporate, which will undermine your intent.

Incidentally, for this reason, chest freezers are supposed to be more efficient than freezers with front opening doors (since opening the door on a freezer will cause the cold air to fall to the ground, but with a chest freezer, there is nowhere to fall to but back into the freezer).

Title: A Full Freezer
Post by: Carolyn on 03/05/2007 14:53:53

Thank you George & Karen!  I will be sure to keep it full in the future.

Title: A Full Freezer
Post by: lightarrow on 03/05/2007 15:00:41

Quote from: Carolyn on 03/05/2007 14:53:53

Thank you George & Karen!  I will be sure to keep it full in the future.

Ok, but not so full to prevent air inside from circulating and so transmitting/absorbing heat from the various things/parts, or you will have some things very cooled and some others not.

Title: A Full Freezer
Post by: Carolyn on 03/05/2007 18:57:48

Quote from: lightarrow on 03/05/2007 15:00:41

Quote from: Carolyn on 03/05/2007 14:53:53

Thank you George & Karen!  I will be sure to keep it full in the future.

Ok, but not so full to prevent air inside from circulating and so transmitting/absorbing heat from the various things/parts, or you will have some things very cooled and some others not.

Thanks Alberto!  I'll remember that too.

Title: A Full Freezer
Post by: BillJx on 03/05/2007 22:33:50

As a bonus,  a full freezer will stay frozen a lot longer when the power goes out.

Title: A Full Freezer
Post by: Carolyn on 04/05/2007 01:18:02

This is true - and next month is the beginning of hurricane season, which generally means lots of power outages. [:(!]