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Dehumidification, HVAC?

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  • Dehumidification, HVAC?

    OK, I've read lots of threads about humidity sensors (iButtons, DalSemi chips, Honeywell chips, Motorola chips, etc.). How are these sensors actually any use in an HVAC system? Unfortunately these seem relatively hard to find, but I found one at"]][/URL][/url]

    For instance, I have one HAI RC-100 and I'm going to add another for the upstairs. I've got a RUUD heat pump system with a variable speed blower and a humidity cycle. My question is how do you make HS part of the logic to call for heat/cool? I mean, the tstats are connected *directly* to the HVAC as well as the PC, but the PC doesn't get any say in whether the HVAC should turn on, even though it has more information (i.e. humidity info) and brains than the tstat!

    Ideally I'd like to make HS an integral part of the decision to call for heat/cool. For instance, if I set the tstat to 70 and the relative humidity is 20% it may "feel like" (i.e. heat index) 68. If the indoor temp goes to 72, it may "feel like" 70 in the house and therefore the HVAC should not turn on, thus saving energy.

    Is it possible to get an iButton switch that you can set from HS and somehow wire it inline in the HVAC wiring so that the switch has to be closed for the system to operate?

    Someone has to have tried this... Basically I want the benefits of a Climatouch tstat without spending another $400! Yeah, they're about $200 each, but I need/want 2. Besides, they don't communicate.

    Any ideas?



  • #2
    Have you considered measuring the humidity using a Pic? PIC Temp/Humidity Sensor



    • #3
      The way most people would do what you want is to have HS adjust the setpoint of the thermostat based on the humidity calculation.

      Probably some tweaking might be needed to integrate the signal so it's not always trying to control the temp/humidity too rigidly. Luckily the HAI therms have a cycle time control so it wont go on/off too rapidly.