The cartoon at the top of this article is from a 1986 Mother Earth News article in a similar topic worth reading, found here.
Part 1: Maintenance
If you are reading this, chances are you are probably human. And that being a fact, you probably neglect things (sometimes). I must encourage all human beings to occasionally clean their poor refrigerator’s heat exchanging coils for the sake of our environment.
Our “older” refrigerator/freezer unit, a pretty standard household type, has a coil underneath and a coil at the back. In our house we have pets. We also get lots of pet visitors. Our dog sheds at an alarming rate, our doggie visitors do too, and our cats are very fluffy and love to shed. Never mind what we shed ourselves, it takes very little time to accumulate some of the world’s largest recorded fur-balls.
How the fridge works
Because the fridge actively moves air through its coils to exchange heat from its interior to the exterior, it is a prime candidate to move low-weight material such as pet hair onto or even through these coils. If you are not routinely cleaning your refrigerator grills, Fluffy is then costing you electricity (on top of vet bills and cat food) because the coils are now essentially insulated with pet fluff and therefore they cannot dissipate heat as originally designed. This adds greatly to inefficiency.
The Solution: Clean, clean, clean.
By the way, you should also be pro-active in making sure that your door seal has not changed either by corrosion (ie., spilled juices by children) or natural degradation over time (ie., recently in my case, spousal manhandling while trying to access the electrical outlet, which subsequently involved a great deal of realignment of the freezer door).
A little time can save a lot.