which uses more electricity ? a full or an empty fridge?

Answer 1

Neither. Let's have a given that 1 fridge is empty and at 40 degrees inside. The other fridge is full and at 40 degrees. The room that these 2 fridges are in is at 70 degrees. The difference in temperature is the cause for heat to flow from hot to cold. The fridges have insulation that has a certain resistance to heat flow. The heat will flow through the walls of the fridges the same, so then Q(heat flow)=A(area)x(T1(70 degrees)-T2(40 degrees))/R(resistance). The area of heat loss for both fridges are equal,the resistance of both fridges are equal, the temperature differential for both is equal, so the amount of electricity needed to keep the fridges at 40 degrees is equal.

Answer 2

The First Law of Thermodynamics says:

The increase in the internal energy of a thermodynamic system is equal to the amount of heat energy added to the system minus the work done by the system on the surroundings.

The real issue here is each time you open the door of the fridge, you exchange cold air for room temperature air, which is what causes the fridge to work harder. So if you have your fridge full, there is less cold air to swap out. BUT, if you stock your fridge too much, then the air can't circulate.

This is really a secondary consideration, but it is an interesting question. The empty fridge will use more electricity in general.

Answer 3

That's a complicated question.

If you _just_ filled the fridge with room temperature items the fridge will have to work for awhile to cool them down.

If the fridge is full of already cooled items then it probably doesn't work harder than if it's empty. Unless you're opening and closing the door, in which case the items will help prevent all the cold air from pouring out.

In a static situation, no cooling of items needed, and no door opening and closings, then I think it would be the same either way. The fridge simply has to remove the heat conducted in through its insulation.

Answer 4

To quote "Blunt"...
If you turn on an empty fridge, and a full fridge of room temperature food at the same time, it would take longer for the full fridge to get down to temperature. Once they reach the proper temperature, they both use about the same amount of energy.
He's right for this reason:
When you cool something, you are slowing down the movement of the molecules of the substance. The air in the empty fridge is significantly less dense (has less molecules to be slowed down) than the food in the full fridge. Less molecules to be slowed = less energy used!

Answer 5

Full.

Let me clarify. If you turn on an empty fridge, and a full fridge of room temperature food at the same time, it would take longer for the full fridge to get down to temperature. Once they reach the proper temperature, they both use about the same amount of energy.

Answer 6

Initially, a full fridge. Once temperature has been attained, it then becomes a matter of maintenance. And so the answer is, over the long haul, the empty one. Look at your BTU conversion tables. Which is more costly, to convert or to maintain?

Answer 7

Empty. The cold food in the fridge helps keep it colder in there and the fridge doesn't have to work as hard cooling a big space.

I'm sorry Dukalink, I accidently gave you a thumbs down. Forgive me.

Answer 8

I would think that a full fridge would use more electricity to get to a cold temperature, but once the cold temperature would be reached I would think that it would require less to keep it cold. I dont know its probably such a miniscule amount that it wouldnt matter either way. but still a great question. maybe one for mythbusters.

Answer 9

Empty, as the full fridge can use the Buddy System, when it comes to usage

Answer 10

an empty one: the more you have in the fridge,the less it takes to keep it cold,once everything gets cold