I am in Zone 2 relatively close to the ocean so humidity is fairly high in summer. I have the thermostat at 78" when at work with a humidity set point at 50% both of which were satisfied (temp =78, humidity = 42%) however the AC continue to run at low speed. Changing the humidity set point did not seem to have any affect on compressor as it kept running in low (according to the thermostat log). Inifinty 60K furance with 2 stage 2 ton AC
More info; I have a bypass humidifier for winter use, and the set point of 42% was never satisfied. The lowest I could reach was 52% so the water solenoid was never reached.
I read that the program over rode the thumbswitches so I started looking at the program.
A couple of things I did change recently was that I set up program to bypass mode and since the duct work was sweating profusely (at the phelegm) I allowed a higher low fan speed.
My house is only 1200 sq ft and previously (last winter) I achieved the 40 % setpoint humidity range using the same bypass humidifier and a Shaw thermostat with humidity control built in. I also had no trouble reaching the summer humidity (no control, just a reading) of 40%. The prvious system was also a Carrier pair that provide service for 15 years.
I also purchased a Extech DH305 humidity kit (with humidity cal chambers) which I am using to compare along with a Davis weather station which I also own.
One other question; seems that the humidty set points are not settable were I would say at a comfortable range ~40%. It seems that the limit is 50 %. I also move the thermistor from the AC housing to the North side of my house and according to what I see it is within 1" accuracy.
Sorry for all the long winded statements and appreciate any help you can give.
- posted 8 years ago