Most of the dehumidification is done by the peltier of the cooler. The dehumidifier acts mostly as a heater, allowing the cooler to work more and remove more water. If you put the contraption in a cool place the dehumidifier heats more because less heat is coming from the outside.
The Klarstein cooler has a defrosting cycle where it reverses the polarity of the peltier. Heating the cold side and removing the ice.
If the dehumidifier freezes it does not matter. It still generates heat. And keeps the cycle going.
I’m not sure I agree 100% with this statement, I’ve heard the theory in this thread before and couldn’t prove one way or another, but I think now I can and here’s why. First if you watch the Inkbird graph you can see the system cycling when working. Once the dehumidifier fins freeze and ice forms that cycling stops and rh is shown as a flat line. Also during that time much less water is caught in the drip tray, which tells me less water is being pulled out of the unit. 1/4 cup of water can accumulate on the fins, which of course makes it out once thawed and into the drip tray, but a lot of the dehumidification is done by the dehumidifier, not just heat generation. Here’s what the Inkbird tells me when frozen
And running properly
I have also noted that if left frozen for a long period more ice slowly accumulates but only to a point, but no extra water is in the drip tray, meaning the cooler itself is pulling very little humidity out. In fact the biggest flaw with the cooler design is probably the size of the drip tray as
@gooshpoo pointed out earlier, if the cooler is packed the tray will overflow if not manually emptied, which is just like most home dehumidifiers. I agree the cooler itself helps remove some moisture, but otherwise just a heater would suffice, and it doesn’t. This week I loaded both of mine up packed with fairly large colas, all fans removed but still some large stems in the bigger buds as shown here.
This is the most fresh just harvested bud I have put in at once. I intentionally set one cooler up with a target rh of 65%, and one at 72%. The one at 65% froze up within the first two hours, the other one never froze. I let the one ride overnight frozen to verify what would happen. The rh stayed about constant, the fins stayed frozen, no water at all in the drip tray, the first graph above show this test. The other unit set at 72% had over 1/2 cup water in the drip tray, so the dehumidifier is doing a lot of the water removal in my opinion. I thawed the fins on the one by unplugging it from the Inkbird for 10 minutes, it had about 1/4 cup on the fins. I raised the target rh to 72% and it’s running like a champ pulling way more water out. So, I believe the dehumidifier does the majority of water removal, not the cooler.