I have a converted upright freezer that I use to feed and shelter the local herd of feral cats. It only takes a 40 watt light bulb to keep the Cathouse at 20 F with an outside temp of -23 F but above 0 F and above, the inside temperature soars into the 70-80s.
I want to use a 40 watt ceramic heating element controlled by a Honeywell thermostat wired through a 120 vac to 24 vac transformer using a relay to turn on and off the ceramic heater. Is it really just that simple? Any suggestions?
I might also use a 60 watt ceramic heater and cycle it more often.
Thanks.
imgon
HalfDork
9/16/24 8:06 p.m.
It really is that simple, just make sure the relay can handle the load. The example you gave looks like it is good for 12 amps at 120 v, the light bulb or ceramic heater are less than that. You may find it takes a little experimenting with what to set the thermostat at. I imagine it will heat up fairly quickly being a small area, that may cause short cycling. try and keep the tstat and heat source as far from each other as possible. Go for it.
In reply to imgon :
Thanks. I'd hate to burn my house down. 
I was planning on setting it at 42 F, as low as it goes.
Could you use a thermostat for electric baseboard heat? You wouldn't have to mess with relays and transformers. They are set up for 240 volts, but you could just use one set of terminals for 120 volts.
In reply to rustyvw :
Thanks for the suggestion rustyvw, I got the Cathouse heater finished. Electric power cord wired to the light switch wired to a Honeywell 120 V AC thermostat wired back to the electrical outlet and eventually to the 50 watt heating element. I tested with a night light and inside our house at around 70 deg, it turns on at 70 deg F and turns off at 60 deg F when I turn the knob. I also tested it with my new volt meter for continuity at the plug and all was well. It unfortunately has super short probes so I couldn't test the voltage for any shorts. Anyway, I didn't get zapped while holding it and never saw any smoke. Tomorrow I will install it into the freezer and plug in the 50 volt heating element and test against the thermometer.
And finished. Now to build a stand to get it up off of the ground and wait for the cold weather. Plus replace the plastic near the door with a piece of painted wood to hold the straw in. I also think that I will replace the heat lamp fixture with a smaller one since the heat element is only 50 watts and I want to use the lamp with a 150 watt heat bulb (that I already mistakenly bought) to defrost my snow blower of ice after each use with a tarp draped over the snow blower,
In reply to VolvoHeretic :
About your short test leads on your meter. Last week I discovered that my leads, that look similar to yours, have a removable plastic cap. I've had the meter for a year before I realized.
In reply to Stampie :
lol, so right your are. I never would have figured that out (because I never read directions). Thanks
