OK, so I found a Broan mechanical humidistat (de-humidistat, actually) that I connected to the fan. But the point where it clicks on and off does not agree with the electronic temp/humidity meter I have (old radio shack item). The humidistat clicks on at what is marked as 45% on its scale when the electronic meter is reading 25%. If I set it to the desired 25% on the humidistat, the fan runs forever and the electronic meter eventually goes down to 20% and then eventually reads "L%" which I assume means too low for it to measure. Which one is likely more accurate?
Are the simple mechanical humidistats calibrated only for room temp? The thermostat and electronic meter both agree that its 53 degrees in the garage.
Based on the condensation and ice on the windows, I tend to believe the electronic meter, but I want to use the humidistat to control the fan. Is this typical and just take that into account when setting the knob, or should I look for a more accurate humidistat?