I vote for number two. The cooling coils take the moisture out of the air. In my curing chamber the humidity always drops when the fridge kicks in and it does not always recover, especially when it runs often. That's when the humidifier does it's job. Another possible reason is that when the fridge is running there is also a fan that kicks in and it will cause the air to become mixed and, more or less equalize the RH in the chamber. When it is not running, the humid air will rise and if your sensor is on the top, it will reflect that.el Ducko wrote:Creepy. Maybe it's a Halloween problem. (Addams Family theme plays in background.)
...couple of wild guesses:
(1) Is there an air leak or air flow?
(2) There is a possibility that, when the refrigerator is running, moisture condenses out on the coils or freezes. Then, when it shuts, the moisture evaporates. It wouldn't take much to make a noticeable swing.
(3) "It's on account a yo' boogaloo situation." (Wolfman Jack, late '50's.)
I'll go for either #2 or #3.
Ross...? ...got some more insight?
Once you get product into your curing chamber, humidity will be even more difficult to control. Swings of several degrees will occur regularly.