Header banner
Revain logoHome Page
Jared Coleman photo
1 Level
1320 Review
57 Karma

Review on 🌑 WH8040 1%~99% RH HM-40 Type Digital Air Humidity Control Controller 110V by Jared Coleman

Revainrating 5 out of 5

I fixed my dehumidifier with this pretty impressive little thing!

I never cease to be amazed at what modern global manufacturing is capable of and this is one example. I made a lot of electronic circuits from schematics as a kid (thanks Forrest Mims III!), and now I find I don't have to because even Revain has ready-made circuits for very little money. . Considering there is probably some sort of microprocessor in this unit, it is well made, has good screw terminals, does its job perfectly and is easily calibrated, I am very impressed with its price. Dehumidifier (regular home, no HVAC installation) at my shop with digital control panel. I'm not sure how old it is, probably at least 8 years old, but the button to decrease the humidity setting stopped working a while ago and I had my doubts as to how accurate the unit had become. I connected this controller to it and now I have an adjustable humidity controller again. like a thermistor in the sense that its resistance decreases as humidity increases. I shorted the connections and the dehumidifier display showed "Hello" which happens when the reading is over 90% so I was right which was handy. I put a dab of solder on the board to connect the sensor pins together. Now I had a dehumidifier that was always on. To set it I ran the wires from the bucket/water level switch to a relay connection on the humidistat. Now when the controller says the humidity is too high, it is essentially telling the dehumidifier (which thinks it needs to run 100% of the time, but not when the bucket isn't there) that the bucket has just been inserted so it can run... To avoid that annoying "no bucket" beeping from the dehumidifier, I just ripped the piezo speaker off the circuit board.

Pros
  • Delivery was very quick
Cons
  • Crumpled