A new energy saving project for me!
I thought the doorbell project was about the last thing I could do around my house to save any more on my electric bill... Until I read your post above!
What a great idea! Actually I have a crawl space and it is quite cold down there in the fall/winter/spring. And I also like fresh air. And my refrigerator uses a fan to blow air over the condenser coil...
So how about a vent from the crawl space attached to an air intake on the bottom of my refrigerator? I imagine one of those 4" flexible dryer hoses would be a large enough vent for this?
Anyway cold air would come in the dryer vent hose from a 4" hole drilled in the floor, then the refrigerator would not need to work as hard.
Then I would get fresh warm air each time the refrigerator ran.
Problems with this are that some refrigerators do not have fans, just a coil on the back. I suppose you could build an insulated chamber which exposed the back to the outside air for this? Better yet would be the back and sides of the refrigerator as well.
Then also some houses are sealed so tight these days, they would not allow any air to be blown into the house because there would be no exit. I suppose you could exhaust the air back into the crawl space.
Or if the exit air vent was on one side of the house, and the wind was blowing toward that vent, there might be positive air pressure coming into the exit vent and this would cause the fan to not be able to blow air over the condenser coils or air might flow backwards.
Anyway something to think about. Maybe new homes could have a refrigerator chamber exposed to the outside via vents or refrigerators could have optional connection(s) for 4" (or whatever) flexible hose to connect to the crawlspace/outside. (Like a dryer does.)
A screen or air filter on the vent openings would be a good idea.