« The Real Deal On Portable Air Conditioners | Home | Options For Air Conditioners »
Adding a Thermostat to an Air Conditioner
By admin | February 19, 2010
I finally decided to add a thermostat to the repaired air conditioner. Here’s a look at how I did it.
Duration : 0:5:22
Topics: Air Conditioning Units | 25 Comments »
March 1st, 2010 at 7:06 am
Maybe, instead of a …
Maybe, instead of a fancy wiring do da, you could have a reptile heating thermostat that controls cooling, you plug if into the wall, place the probe somewhere then plug the a/c into the thermostats plug, set the temp. and viola!! cooling, however, the only way to turn it off would be to pull the plug or to set the temperature really really high.
March 1st, 2010 at 7:06 am
maybe some cleaner …
maybe some cleaner will do wunders…. (see your door and knob)…..
March 1st, 2010 at 7:06 am
I think window a/ …
I think window a/c’s are wonderful!
March 1st, 2010 at 7:06 am
Your quite welcome …
Your quite welcome
Trust me I would NEVER be able to figure that out lol
March 1st, 2010 at 7:06 am
have youre ac …
have youre ac friend come over and look at it and barter some more:)
March 1st, 2010 at 7:06 am
Thanks!
Thanks!
March 1st, 2010 at 7:06 am
Thanks!
Thanks!
March 1st, 2010 at 7:06 am
Also found a …
Also found a 10,000BTU A/C thrown out with an electronic circuit board thermostat that was no good, jammed a wall wart and relay (standard automotive style) in there and threw that to a yo-yo as well. That unit is still in operation–gave it to a friend; I have central air now. The coil of the relay can use plus or minus a few volts as long as the coil engages securely. So a 9V wall wart *may* engage a 12V coil relay. Use old junk you have already, take a relay from one of those cars!
March 1st, 2010 at 7:06 am
I did something …
I did something like that a long time ago, using a heavy-duty extension cord, an old 12-volt wall wart transformer, a heavy duty switch, a project box from RadioShack, and an old yo-yo thermostat I had around. The heavy duty switch could be selected for heating or air conditioning, so that the thermostat would either “turn on” or “turn off” the appliance plugged into it. Worked great, but have no real need for it anymore.
March 1st, 2010 at 7:06 am
Yeah, I had heard …
Yeah, I had heard that before too. I think it had something to do with preserving the leather. It took them years to go crazy though. Hell, glow in the dark watches were made with radium back in the day, and watchmakers died from radiation poisoning because they licked the bristles of the paintbrushes to smooth them out. Bristles that had radium on them. But anyway, I digress lol!
March 1st, 2010 at 7:06 am
The whole idea has …
The whole idea has been to do this on the cheap. However, safety was carefully considered. No point in being cheap if it’s dangerous.
All the wiring is heavy enough to stand the load, it will be put into a proper metal electrical box, and the transformer is going to get an inline fuse.
The light switch (which is a “master kill switch” that cuts power going to the transformer to ensure the system will stay off) and outlet will be put outside the box and probably mounted to the wall.
March 1st, 2010 at 7:06 am
I’ve heard of …
I’ve heard of people playing with mercury like that before. I can’t say as I think it’s a good idea. Hat makers used to use mercury for something (don’t know what), and that’s where the phrase “mad as a hatter” comes from. (Provided, of course, that the source I heard that from many years ago was correct.)
March 1st, 2010 at 7:06 am
Yep, that’s exactly …
Yep, that’s exactly what happens. And in the best case, they just don’t work well. In the worst case, stress eventually gets them.
March 1st, 2010 at 7:06 am
Myself I would get …
Myself I would get the model number and look up the replacement thermostat from places like RepairClinic or other appliance parts sources – I personally hate electrical fires so no rigging for me.
March 1st, 2010 at 7:06 am
Well, that’s one …
Well, that’s one way to make it work, I’ve been told you can also get thermostats that are designed to hook straight to line voltage. I’m working on a little project at work that may need a line voltage thermostat.
March 1st, 2010 at 7:06 am
Ingenuity working …
Ingenuity working through you again
Now you even have a digital display so you know exactly what the temperature is.
March 1st, 2010 at 7:06 am
Like, the …
Like, the compressors and such aren’t getting enough voltage to run effectively?
March 1st, 2010 at 7:06 am
Yeah, the longer …
Yeah, the longer the run, the higher the resistance gets. In that case, heat build up shouldn’t be a problem but sagging voltage will. Sagging voltage is hard on compressors and stuff.
March 1st, 2010 at 7:06 am
You need a resistor.
You need a resistor.
March 1st, 2010 at 7:06 am
I learned the bit …
I learned the bit about the wiring being too small from the Mythbusters Christmas Lights, lol! But the danger of having a wire being too long is due to the resustance of the copper, right?
March 1st, 2010 at 7:06 am
Yeah, I have a …
Yeah, I have a mercury switch thermostat in my apartment. Just the other day here in Ohio, some Eagle Scouts doing an Eagle Project near a reservoir were digging up an old pumping station and found pools of Mercury. It’s some nasty stuff. Funny thing is, I have spoke to older people who said when they were in school, they poured mercury into their hands and played with it. While I confess that does sound fun, it strikes me as very stupid. Of course, they didn’t know any better back then.
March 1st, 2010 at 7:06 am
When the thermostat …
When the thermostat says “it’s time to turn on”, the 24 volts goes through the thermostat and to the heavy relay you saw near all that wiring. The relay is close to the furnace or A/C, so its heavy wiring and contacts are not a problem…they are kept short (to avoid heating and voltage drop caused by wiring that is too small or run too far) and close to the equipment being controlled.
This also drastically improves safety, by not running high voltage/high current all over the place.
March 1st, 2010 at 7:06 am
The wiring going to …
The wiring going to such a thermostat would also have to be huge, so it wouldn’t get hot and let the voltage sag. This would all be extremely impractical.
So a small transformer sends 24 volts to the thermostat, something that even a tiny switch can handle. This used to be a mercury switch that would be tilted by a temperature sensitive metal strip, but mercury is hazardous (it gets into the water table when thrown into landfills) so now it’s a small relay in the thermostat.
March 1st, 2010 at 7:06 am
And a little …
And a little explanation of what’s going on here…basically, air conditioners and furnaces are high voltage, high current devices. You could always hook a switch up and turn them on and off directly if you wanted to do nothing but mind the furnace or A/C all day.
A thermostat takes care of this, but because high voltage and high current demands that you have large contacts, and wiring heavy enough to support the load, a thermostat that switched the furnace directly would be HUGE!
March 1st, 2010 at 7:06 am
Enough electricity …
I don’t touch anything above 240 volts AC. Nor do I like things like huge or ultra-fast running fans–I’ll confess the racket that they make scares me.
Enough electricity makes me nervous too.
Incidentally, this was the first run of this thing after I put it together.