10 ways to make your refrigerator use less energy

by thomas on May 11, 2009 (Feature image by Infrogmation - Artwork by Banksy)

Fridge kite by Banksy

Refrigerators are less energy efficient than most people realize. Their energy efficiency ratings are done under ideal conditions – get a few things wrong and you might end up spending a lot more electricity on cooling your food than necessary.

If you follow the advice in the list below, though, you can be safe in the knowledge that your fridge is a lean, green cooling machine!

Please leave a comment if you know about more ways to improve the energy efficiency of your refrigerator!

  1. Don’t leave the door open
    The longer the door stays open, the more hot air gets inside – making the refrigerator spend energy cooling it down.
  2. Keep food away from the back wall
    If food or anything else touches the back wall inside the refrigerator, the cooling cycle will go haywire and waste energy. Prolonged contact with the back wall will also damage your veggies.
  3. Keep warm leftovers out
    Putting warm food inside your refrigerator will, not surprisingly, make it work harder. It also increases the chances of unpleasant bacteria growth in the food, so it’s better to cool the food to room temperature first.
  4. Thaw frozen food in the fridge
    Are any of tomorrow’s dinner ingredients in the freezer? Put them in the fridge today, and let them thaw slowly. As an added bonus, slowly thawed food will taste better.
  5. Dust or vacuum the cooling coils
    The coils on the back of the refrigerator are what gets rid of heat from its interior. If they get too dusty, they’ll be less efficient at conducting heat, making the refrigerator work harder. The same applies to your freezer. Make sure you don’t damage or bend the coils while you dust them; it’ll make them less efficient.
  6. Defrost the freezing compartment
    Built-up frost and ice will reduce energy efficiency significantly. The same goes for your freezer; defrost it when frost build-up is getting noticeable.
  7. Use an energy efficient light bulb
    The light bulbs in refrigerators are normally incandescent bulbs that will produce more heat than light – kind of counterproductive in a cooling appliance. LED bulbs are especially suitable in a refrigerator.
  8. Place it next to an outside wall
    Walls that are exposed to the elements are generally cooler than walls that are not – unless you live in a very warm climate, of course, in which case it might be better to place the refrigerator as far from outside walls as possible.
  9. Avoid stoves and hot water heaters
    Try to place your refrigerator away from anything that will radiate heat.
  10. Give it some air
    Make a healthy flow of air around the appliance possible; this helps transport heat away. This is especially important for the coils on the back – the air they heat up has to be replaced with cooler air, or your poor fridge will be working hard and wasting energy constantly.

Don’t go yet, there’s more! The follow-up to this post has 13 more ways to fridge energy saving heaven.

{22 comments... read them below or add one }

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{ 19 comments… read them below or add one }

thomas June 1, 2015 at 09:52

@Marius: I haven’t conducted any scientific research into the matter, so I guess I don’t have any absolute proof. However, the idea is that a fridge is designed to get rid of heat through air circulating across its interior walls. Cooling fluids are circulated through these walls and absorb the heat. The walls are designed to transfer this heat easily to the cooling fluid. If frost and ice is built up, this transfer ability is hindered, thereby lowering the efficiency of the whole process.

thomas June 1, 2015 at 09:48

@shubhs_kurosaki: The refrigerator works by transporting heat from its interior to its exterior. Making that job easier (ie. cooling its exterior) should lower the energy consumption of your refrigerator. However: if the side walls of your refrigerator are getting warm, you should check why it’s getting warm first. Most refrigerators are designed to get rid of heat through heat sinks, usually located at the back. They’re made of a lot of thin blades of metal which has a pipe running through them. If these aren’t properly ventilated or very dusty, they won’t be very efficient. Also, if the side walls are getting warm because of sun or heat from an oven or other things, you should relocate the fridge or the heat source.

shubhs_kurosaki May 30, 2015 at 10:04

Can any1 tell me, if i try to cool the side walls of the refrigerator which gets hot, will it save energy, or the ref will have to spend more energy?

Marius Dejess May 26, 2015 at 02:22

Defrost the freezing compartment
Built-up frost and ice will reduce energy efficiency significantly. The same goes for your freezer; defrost it when frost build-up is getting noticeable.

Do you have any proof or explanation why?

thomas June 26, 2012 at 11:22

Thanks, Nwal – that’s a useful tip :-)

Nwal June 26, 2012 at 03:55

I found keeping two liter soda bottles in the freezer help maintain the temperature. To start off the summer , I put two in the freezer at night when everyone goes to bed . This allows them to freeze in less time (no one is opening the freezer every five minutes). Once frozen, I smash the bottles with a hammer and cut it down the side for crushed ice . I store the ice in freezer bags. Also the bottles are still recyclable, only down fall is loosing the deposit return . Use cold water and place the new water bottle next to the second frozen bottle, put the bag of ice on top.

thomas July 27, 2010 at 13:04

@Carlos: Thanks for commenting :)

You need something with high thermal mass that’ll take up space – jugs or bottles of clean water is a good option. Just remember to keep their lids or corks on, to prevent the water from evaporating.

I did read somewhere – I think it was in a make-your-own-fridge tutorial, can’t find the link now – that beer supposedly has better thermal mass than water, so maybe a few sixpacks at the back of your fridge will do the job even better. I haven’t tested this myself, though.

Carlos July 27, 2010 at 05:20

Regarding the tip: “The more food there is in your fridge, the less room there is for warm air to occupy when you open the door. The warm air that does get in is quickly cooled down by the food.”

If I stacked the fridge with all the food I could buy, but still there’s plenty of room, what else can I fill (not overstock) the fridge with?

thomas May 28, 2009 at 09:17

@Banchero Media: Thanks, those are important considerations for when you’re getting a new refrigerator. Properly sizing it might save some space, too :-)

Banchero Media May 28, 2009 at 01:13

Excellent suggestions! Also, if you are looking to replace your old fridge, think of a couple of things: Properly size the unit. No need to buy a large family-size unit if there are only a couple of you in the home. Also, research energy usage ratings and look for a unit that uses what you think you need at a price you can afford.

thomas May 21, 2009 at 12:48

@Debi: It depends on how often you open the freezer.

When you open your freezer (or refrigerator, the same principles apply to both), the cold air will “slide” out of it at the bottom of the opening, while air at room temperature will enter at the top. This room tempered air has to be cooled to keep the freezer at the right temperature.

If the freezer is already full of frozen items, the heat in the room tempered air will be absorbed relatively quickly by these. Which means your freezer has to spend less energy cooling it down.

If the freezer is empty, or nearly so, it won’t get much help cooling the room tempered air down. So it has to spend more energy to maintain the proper temperature.

Plus, if there’s a lot of empty space in your freezer there will be more room for the warmer air to fill.

So putting in stuff to keep the freezer full might be worth it if you open it relatively often.

What you have to take into account, though, is that when you put those milk jugs and soda bottles in there, the freezer has to spend a chunk of energy to cool them down. If you open your freezer kind of rarely, you might not “earn” that chunk back.

Please note that the above applies to freezers that have their door on the front, ie. that open like a refrigerator.

If you have chest freezer with a lid on top, freezing extra stuff almost certainly isn’t worth it.

The reason for this is that due to the fact that warm air rises and cold air doesn’t, a chest style freezer will lose very little of its cold air when it’s opened.

Debi May 21, 2009 at 01:02

Good Tips… thanks. I heard that if you keep the FREEZER as full as possible it uses less energy. We used to put nearly full plastic containers such as old milk jugs or soda bottles in the freezer when it was too empty. Is that a good idea?

thomas May 15, 2009 at 10:36

@Yanic A: Glad you liked it :-)

Yanic A. May 14, 2009 at 22:53

Wonderful list of tips. Did not know about the foods touching the back wall. I have already remedied the situation! Thanks for such a thorough article.


thomas May 13, 2009 at 14:49

@Wodger Wabbit: That’s a great tip, thanks :-)

seanJK May 12, 2009 at 10:42

yeah, that’s waht i meant

Wodger Wabbit May 12, 2009 at 10:16

One thing that you should also keep in mind is to keep your fridge well stocked, but not too well stocked.

If you keep it well stocked, all the cold food and beverages in there will help cool any warm air that gets in. Helps with #1 on your list.

But don’t overstuff your fridge, either. Air circulation helps with the cooling process, too, so you should leave some gaps for the air to flow through.

thomas May 11, 2009 at 18:15

@seanJK: You mean pre-cooling stuff on the porch (for example) that isn’t already cooled when you get it from the store, right?

That’s a good trick; not only does it mean that you get the initial electricity-sucking cooldown period for free, it will probably also cool your food/drink faster (because of the constant supply of cold, circulating air).

Just don’t forget it outside in the winter cold for the whole night, unless you want it frozen!


seanJK May 11, 2009 at 17:10

One thing you can do is if you’ve been shopping stuff that doesn’t really need cooling but is better if it’s cooled (like botteled water or mineral water), is to cool it outside before you put it in your fridge. this only works if you live in a cool climate and it’s winter, of course.

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