For those who have a dorm-type refrigerator in a cold hangar, here’s a way to make it useful in the sub-freezing weather.
I went to Lowe’s and purchased a small lamp bulb holder, attached it to a box, wired it with a short cord, and hung it from the upper shelf in the refrigerator. (Alternatively, a small lamp would do.) Put in a 40 watt long-life bulb.
To the end of the cord, I attached a “thermo-cube” (available from Sporty’s at $15 or so). The thermo cube is normally used to turn a Tannis-type heater on and off, and goes on at 35 degrees and off at 45 degrees. (Perfect!)
From the thermo cube, ran an ordinary outlet, with the thermo cube inside the refrigerator.
At 35 degrees, the lightbulb (aka heater) goes on, and it goes off at 45 degrees. Perfect for a Coke, bottled water, or cleaning fluids and polishes that can’t freeze.
To be safe, I installed one of those indoor/outdoor termometers, with minimum and maximum temperature, and put the “outside” probe inside the refrigerator. This not only helps make sure all is doing what it’s supposed to, but can be used to figure out the right size bulb for an individual situation.
My contribution to aviation science. If it burns your hangar down, you’re on your own.
And if you plug in the refrigerator, you can use the whole setup to heat your hangar (leave the coke sitting outside the fridge.) Rube Goldberg would be proud.
Could you use a similar setup as a poor man’s preheater
?. Put a hundred watt (or smaller) buld inside of each engine cowl opening that automatically comes on at a certain temp…
Yep, the idea is that the heat pumped out of the fridge by the compressor would heat the room. The light bulb’s thermostat would be the primary control loop, thus limiting the heat production (after all, the hangar could get so hot as to delaminate the composites, if it were sufficiently insulated and the compressor ran continously.) The interaction between the two thermostats and the optimal settings thereof are left as an exercise for the student.
This is about as good a design as much of the software I’ve written.
Even a small bulb gets pretty hot to the touch. One thing to risk a refrigerator, with a fixture to keep the hot bulb away from “meltable” surfaces. Another thing to put it close to the airplane’s composite surface.
Hey Dave, I don’t know about you, but it’s griping me a little bit that Mike Radomsky is getting all these accolades just for move volume out of the audio panel, while we’ve heated up the hangar while keeping drinks cool, and we get no respect. It’s not a fair world.
“…it’s griping me a little bit that Mike Radomsky is getting all these accolades just for move volume out of the audio panel, while we’ve heated up the hangar while keeping drinks cool, and we get no respect.”
Andy, Dave,
I agree! I’m going to use your idea in my hangar, even though it’s going to cost me (I don’t have a refrigerator…)
Seems my son, Max, and I have just started a new Entrepreneurial Venture… Surplus Designs (see post on the Garmin mod). We’re looking for design engineers. Rube G’s not answering his phone (I tugged on the string LOTS of times). Are you guys interested? We could pool our accolades. [:D]
