Home Forums Hunting & Shooting Hunter's Campfire Advice on electrical/thermostat issue

I built an insulated trailer a couple years ago to use as a portable meat locker, and am finally getting it up and running. Its 6x8 with an 11000btu a/c unit cooling it, and by moving the sensor out of the trailer I can take it down to near freezing. All I need now is a way to cycle the compressor to maintain the proper temps and not freeze up. A Coolbot won't work with the unit I have,and it also quite pricey. I'm thinking of using a small bulb attached near the sensor that will be cycled on/off using either a timer or a thermostat. The timer I have been unable to find, although if I could it would probably be the simplest method. Thermostats that operate in the proper range are available, quite cheap on amazon although the chinese instructions are indecipherable by me. Apparently they do work though, if a guy can figure out the programming. Do you think this idea will work sufficiently, or do you have a better one? If anyone knows where to get a suitable timer that would let my cycle on/ off times at say 6 minutes/1 minute, or a suitable thermostat, that would be great too.

Surely we have AC guys on here.

Can't you find a 10 year old to program a thermostat for you?

I've never done this so I might be in error on some of it but it might get you thinking in the right direction. Hopefully an a/c guy will chime in.
I wouldn't go with a timer. You don't have any control over the temp with that. It could work if the outside temps and sunshine were the same every day and night but that's too variable. You'd end up having to mess with the timing constantly when you should be out hunting. It will also shut off the fan and you don't want that.

This can be important: Some window a/c's are set up so that if the power goes off, it won't come back on automatically when the power's restored. You have to manually turn it on. That will preclude the use of a line stat. I have a window a/c like that. It has a reset button in the end of the power cord. I don't know if replacing that with a regular plug would make it come back on or not.

If you haven't done it, you need to remove the existing stat from the a/c. If you can find a stat to wire in in place of the original stat, you've got it solved. A line stat, that's one that plugs into an outlet and the a/c plugs into it, would work but it has some problems. It would shut off the a/c if the existing stat is outside the trailer as you say but when it shuts off, it shuts off completely. You need to keep the fan running all the time to prevent freeze ups. That's where the Coolbot comes in because it will both override the a/c stat and prevent freeze ups. Many a/c's have an option to keep the fan running full time or to shut it off between cooling cycles to save power. A stat replacing the original stat would make use of that option and keep the fan running.
One way to use a line stat is to jury rig the a/c so the fan goes around the line stat. You'd need to cut the wires to the fan motor and attach them to an extension cord that will plug into an outlet separate from the stat. I don't know if that's possible on your a/c. You'd need to double check every time you used it to be sure the fan is running or you'd REALLY freeze things up.


Go to Coolbot's site and read all of their stuff on building a cooler. They give a lot of hints that you might find useful in your case. They sort of tell you all the stuff you need to do if you don't use a Coolbot and that's what you need to read. I have a home cooler on the drawing board that I hope to start building shortly. I read through all of their stuff and got lots of good info. I'll be needing to buy a new a/c and I'll use the Coolbot even though it's expensive.

A/c units are not designed to be used for refrigeration.
You want to make a cooler, use a refrigeration system

The chinese timers work.

It does take some thought while reading the instructions.

You are right they are cheap,so when you buy get 2 or more just in case.

While not designed for it, they actually work quite well if you get around the controls. For a home cooler, they keep the cost to a reasonable level. A 6x8 cooler using a regular refrig system puts it well out of the price range for what it's to be used for. There are many 1000's of them in use out there now and they do a very good job.

A poor man's heat pump w/o sophisticated defrost controls.

We have about a dozen fruit trees. I'm planning a cooler because the fruit normally gets ripe during the hottest part of the summer. I'm tired of losing apples because I can't keep them cool. Then my wife has a new project going. She's planting huge numbers of flowers with the intent of cornering the local farmers market cut flower market. She'll be needing the cooler for storing flowers as she cuts them. Meat storage will be important but almost a sideline. Because of the flowers, I need to get this thing under construction pretty quick to have it operational when she needs it.

Just a thought... Most of the timers, I am familiar with, will have about 6-8 on/off cycles per 24 hrs. This might be enough and it might not, depending on the weather. I'm pretty sure they make timers with more on/off cycles per 24 hrs, but good timers can get pricey.