Since you don't have a heating device on the cool side you will want to take the air temp of the cool side. You can do this by hanging a thermometer with probe a little off the ground, you can also test the ground temp if you want but air will be good enough since you don't have a heat device. I would leave the thermometer probe in there forever lol or until you get a temp gun. That way your able to see if something goes wrong.

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