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Hi Ryan,

Controller arrived on Friday and was installed on Saturday. Works great. I actually have used it operating in a differential  pressure mode with a flow probe prior to the filter on the return and a flow probe about 2/3 of the way down the main duct (as I was taught for VAV systems).

I’m very pleased with how this works and it has solved the control problem I was dealing with. The Bosch airhandler in the installation is capable of two speeds, but of course the ECM 4Z doesn’t care about those. One possible improvement for your controller is to allow for a different HI set point for Stage 1 and Stage 2 call. Stage 2 could be at a higher TESP, which would be a bit noisier, but generally wouldn’t be used. As is stands the ramping up of the fan is gentle and not very noticeable unless you listen for it. Much better than before.




The unit I installed the FAC-120 on is working great, it has gotten the temps closer to each other and has brought the humidity down to 52-57% before I was lucky to see 59%, so far I’m very impressed with this product


Leander, TX


I am thrilled over the first installation of your Fanhandler and look forward to installing MANY more. I did one on a gas fired hot air furnace and next I'm installing it on a heat pump wihich should work even bettrer. You have a great product.

Don Berg


I'm a homeowner that installed one of your units on a HVAC unit with heating and cooling, it must be about 7 years ago...or whenever it was that oil was about 60-80 cents a gallon. I've never had a problem with your Fan Handler (other than sorting out the original wiring details and finding a good place to mount it), and I rave about it every year, in amazement about how comfortable our home is...and why it is! A quality thermostat (in my case, a Honeywell electronic with fuzzy logic) teamed up with your fan controller is a great combo. I really appreciate the quiet ramp-up and ramp-down of the fan speeds in accordance with plenum temps. As a building official in CT, years ago I saw a lot of low-end single speed (and possibly oversized) mobile home hot air furnaces installed in closets adjacent to living areas... with cheap thermostats, resulting in temp overshoots and a lot of fan noise, and felt sorry for the occupants. Sorry that they didn't have your system installed.

Thanks for all the comfort I've enjoyed... all these years!

Don Berg

Willington CT.

John Brittain

I have been using fanhandler in my home for over 5 years and had no problems with the GE motors in Ruud equipment.