Real Fridge and Freezer Energy Savings

Hey Mr. Green,
What is the correct temperature for my refrigerator and freezer? --Phil in University Place, Washington

Set the fridge between 35 and 38 degrees Fahrenheit and the freezer at 0*F. Keep both filled--if necessary, with jugs of water or ice. It's an urban myth that cleaning the fridge's coils periodically with a brush or a vacuum cleaner will save energy, but standing there with the door open pondering what to eat is an indisputable juice drain. For bigger savings, visit energystar.gov to find Energy Star models.

Comments

[Richard Holloway]

I don't believe that cleaning the coils saves energy is an "urban myth," implying that the cleaning is not beneficial. The efficiency of the entire refrigeration cycle depends on its ability to transfer heat from the interior of the box to the environment. Dust accumulation on the coils impedes heat transfer to the environment. The compressor motor keeps running until enough heat has been transferred to lower the temperature to the setting of the thermostat inside the box. Running the motor longer consumes energy.

[David Martin]

After 30 years buying, selling, and servicing refrigerators I strongly disagree with your urban myth assessment.
Cleaning rear-mounted condenser coils doesn't make much difference, but coils mounted under the refrigerator with a cooling fan, particularly those in the front, get VERY clogged, especially if cats or dogs are around. The compressor not only might have to run continuously trying to reach proper temperature (a real waste of energy) but will, in extreme cases, overheat to the point of failing, requiring replacement of the refrigerator--another major waste of energy to mine the metal, build the appliance, and transport it to the end user--as well as costing several hundred dollars. Cleaning the coils is about the only preventive maintenance that CAN be done on refrigerators--but it actually is vital, and easily done with no special equipment.

[Marc]

Has anyone done a careful study of the energy benefits of keeping a refrigerator full? It doesn’t take much energy to chill air relative to glass or water (air's volumetric specific heat is about 1500 times lower than glass, about 3000 times lower than water), whereas the liquid or solid water in the refrigerator or freezers “wants” to be at the temperature of the surroundings, and so the refrigerator mechanism needs to keep working against this “want” to keep the water cold or frozen.

I agree with the commenters above that dust on a refrigerator coil could be an energy bandit. The dust acts as an insulator between the air (where you want to send the heat) and the warm coils (which you want to cool down), thus increasing the amount of time the compressor must circulate fluid through the system (and use electricity). It’s too bad that the LBL website to which Mr. Green linked doesn’t list the studies or data.

[M. Federspiel]

Add my comments to those who believe that a clean machine works better than a dirty machine. Clean refrigerator and freezer coils will more efficiently transfer heat to the air. The site you reference, http://hes.lbl.gov/hes/myths.html, indicates "very small savings may indeed arise" but also that "few efforts to actually measure this effect have typically come up empty-handed." Time for a study!

[M. Federspiel]

The other end of the outside coils are the inside coils. Defrosting your freezer will help transfer the cold from the coils to the contents without the insulating effect of a layer of frost. This is for the old frostless freezers, if there are any still around.

[Robert Anthony]

I have a 1954 GE Fridge for 18 years never died
still runs good. in a 12x60 mobile home.
Gotta defrost it. but is really CHEAP on electricity.

[ronald]

it does work i cleaned my coils this morning and felt the fan and wind blowing after it all got cleared and the electric meter barely moved so big savings there

[ge refrigerator parts]

It's a pain fixing up an old refrigerator,but it's possible if you take the time to read up on it.

[lift chair]

Saving the energy is somewhat others crave to perform, not just we are saving this for the future use. We are also decreasing the amount of our bill, which really strikes a lot in our budget. This saving is in two purpose, just like hitting two birds by one stone.

[scottsdale periodontist]

Now i won't have any problem whenever my fridge go crazy.