Relative humidity conundrum
I have an Aprilaire automatic humidifier installed in the return air duct of my HVAC.
The Aprilaire displays RH% and is presently set at maximum (5,000 s.f. home) because we have had a problem with our wood floors drying out too much during the winter. The conundrum is that, for example, when the Aprilaire displays 45% RH, my hand-held RH meter may display only 30% RH. The obvious check of using the same meter in the return duct air stream confirms that the Aprilkaire reading is correct. So how can the 2 readings be so different when the Aprilaire is reading the returning air stream?
Chris — Baffled!!