Anybody come up with good solutions for tying in humidistats for override control on bath exhaust fans? Here in California it is code now that fans be run via humidity sensor that turns them on when moisture is too high. Panasonic makes one with it built in, but the problem with that is you can't then elect to turn in on to exhaust odors. I have one of these on order to experiment with integration via CC to back of adjacent keypad (with fan load run back to RPM), to see if I can get best of both worlds:
I'm just curious if anyone has a better idea. The problem with the above is that it requires an outdoor sensor wired to it (to check relative humidity) and requires 24 vAC to power it so no hopping a ride on the keypad power.... Would certainly vote for some kind of humidistat as an offering from Lutron. Could be other great uses like HVAC control for wine storage. :)
Did you try the Honeywell sensor? Did it work? Have you found anything better?
Originally Posted by whdigital
Humidistat or Dehumidistat Options for HomeWorks or RadioRa2
Originally Posted by whdigital
I've just been tasked with this issue as well and have come up with the following:
Depending on the manufacturer, most in-ceiling exhaust fans have an option for humidity sensing and can be turned on/overridden manually with a switch or a control system.
- Panasonic has the WhisperGreen Select series with plug-in modules and a 2-wire contact to turn on the fan manually, this is a contact only and no voltage should be applied; there must be constant power connected to the fan for the sensors to function. The model I was given was FV-05-11VK1, utilizing the FV-CSVK1 condensation sensor. Wiring diagrams can be found on the support page. This is essentially a 4-wire setup; 2 for power, 2 for the override closure
- Broan has an in-ceiling fan with sensing abilities, model QTXE110S or similar, can utilize a 3-wire option where you have hot/neutral/switched wiring to the fan; this may need to be verified by Broan that it can be wired with a constant hot.
For inline fans it gets a bit more complicated as I haven't found a single manufacturer, so far, that has an inline fan with remote humidistat sensing options like the in-ceiling fans.
- At this point your best bet is to utilize a Honeywell Tstat with a remote humidistat sensor that can output a contact or 24 output that either closes a relay or/then connects to an input on the HomeWorks/RadioRa2 system. Through programming you would specify from keypads and the input from the Honeywell how the fan will behave.
- I spoke with Honeywell and at this point the only viable option is the TH8321R1001 Tstat utilizing either the wired humidity sensor C7189U1005 or the wireless sensor C7189R1004, which I would place in the vent duct as close to the vent grill in the bathroom as possible. Our clients want to control the world, but not see the parts to do it.
- Using this Tstat you would only be utilizing the humidity sensor, so you'd want to make sure you disabled any temperature control or any other settings.
- You could in theory use the output of the tstat to close a relay that would provide power directly to the exhaust fan in parallel with a power output from an RPM module or switch, or some variation of relays; eliminating the need for programming an input.
I hope this helps anyone with this issue in the future, but always research your options before telling a client it can be done.