Clever, Stupid, Possible? Wall Thermostat!

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davepeds

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Good afternoon everyone.
I've purchased a cheap chest freezer for serving my beer. I'm also thinking about doing a fermentation chamber, one day.

The power company has a new gig where they come out and install a fancy thermostat for your AC. I already had one that was programmable, and they cut it down and gave it to me. Who thinks that it's possible to rig this Honeywell thermostat up as my temperature controller? If you think so, who wants to tell me how?

DOB

photo-6.jpg
 
That thermostat switches low voltage DC. You'd need a DC power source (cell phone wall wort is a common choice - so $$free), and then connect it (via thermostat wire, $10) to a relay/SSR - $6 to $15, depending). The relay/SSR would switch the AC needed to drive your freezer. You'd have to put that in a project box ($5, depending), with an outlet ($2) and a plug to run to the wall ($5). You might want a fuse or two ($1, plus holder $5).

Back of the envelope cost estimate, excluding the thermostat (and maybe wall wort) you already have, is about $40. Plus the time and effort to figure it out.

You sure you don't want to spend $50 on an analog Johnson controller instead?
 
Look at it this way...you got the answer you wanted to hear. Yes, it can work. However you would need the additional parts listed above. By the time you buy everything needed to make it work, you basically bought a ready to go/out of the box controller where all you need to do is plug the freezer into the controller, plug the controller into the wall, then, set it and forget it.

In short, if you have the itch to tinker, go for it because it is possible. It's also possible to tell time with a sun dial; but you probably rather just look at a clock, right?
 
The only down-side to using a thermostat that I see is most that I've seen are battery powered which means when the batteries die, your thermostat will no longer trigger to cool your fridge.
 
annoyingrob said:
The only down-side to using a thermostat that I see is most that I've seen are battery powered which means when the batteries die, your thermostat will no longer trigger to cool your fridge.

and the sensor is inside the unit!
 
That thermostat switches low voltage DC. You'd need a DC power source (cell phone wall wort is a common choice - so $$free), and then connect it (via thermostat wire, $10) to a relay/SSR - $6 to $15, depending). The relay/SSR would switch the AC needed to drive your freezer. You'd have to put that in a project box ($5, depending), with an outlet ($2) and a plug to run to the wall ($5). You might want a fuse or two ($1, plus holder $5).

Back of the envelope cost estimate, excluding the thermostat (and maybe wall wort) you already have, is about $40. Plus the time and effort to figure it out.

You sure you don't want to spend $50 on an analog Johnson controller instead?

Assuming it is a standard thermostat, it is built for 24v AC, not DC ... but still wont power a freezer by itself.
 
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