I just received a used Maytag dehumidifier (Model # M3DH30B2A) without a manual. It has a knob labeled “Humidistat” with settings ranging from 1 through 8, plus “Continuous Run”, and “Off”. But relative humidity is expressed as a percentage. Does anyone know (or know how I would figure out) what the mapping is between Maytag’s scale of 1-8 and the standard way of measuring humidity? With this cryptic scale I have no idea how to ensure that I keep my home at the recommended humidity level.
there may have been some correspondence given though maybe not. it would be very crude and may change over the years anyway. get a hygrometer (humidity meter), you can find these paired with thermometers and barometers, plentiful used at thrift stores and rummage sales.
If you want a good, accurate hygrometer, ask a friend who works in (a company that runs) a testing lab. Some companies don’t think it’s worth the cost to recalibrate them every year.
I think 1-8 are just its power settings, like a heater with no thermostat. So it runs at a fixed rate and your RH will depend on the weather.
From the manual : - “Automatic Humidity Control
The humidistat control automatically turns your dehumidifier on or
off to maintain the humidity level you select. Allow dehumidifier
to reach room temperature, then turn control knob to number 5
(normal average setting). The fan and compressor will run together,
dehumidifying the room. If unit does not turn on at this setting, this
generally means that the relative humidity is already low and
dehumidification may not be needed at this time.
After operating several days at this setting with doors and windows
closed, you may readjust this control to a slightly higher number
for lower humidity (drier air) or to a slightly lower number for
higher humidity (moist air).
If knob is turned to “Continuous Run” then the compressor will run
regardless of actual room humidity. If not properly monitored, this
setting could cause excess energy usage.”
You can download the manual here : click
Thanks everyone for your suggestions, and thanks to am77494 in particular for finding the manual. That’s great!