I have a
Ranco commercial temp. sensor/relay wired into mine.
The temp. probe is submersed in the dehumidifier res., and the controller is spliced right into the power cord going to the wall.
I have been running it this way for almost a year now, with the water at 16 C., and a 3 C range to combat condensation. (Turns on at 19C) It cycles every 15 minutes roughly, and runs for 30 seconds. This is cooling a 1700+@ 2.2 GHz.
Due to the energy crisis of sorts up here lately, I have been running with my water at 24C. Less cycling- every 20 mins.
Prior to this setup, I did run 24/7 for about 3 months, maintaining -10C. This dehumidifier is well over 10 years old to begin with (R12), so I was pushing my luck abusing it that bad, the compressor was damn hot, with no breaks, and surely would have failed before too long.
As for energy consumption, I'd be afraid to guess what this old thing is using, the lights dim for a second when it kicks on... luckily the power is included in my rent.