Bypass humidifiers only for Heat pumps?

Consumer question:

I recently had an HVAC guy come and look at my furnace because it got wet in a flood and he took care of me by drying out everything and luckily everything fired up properly, but he took one look at the Aprilaire 600 humidifier that I installed myself several years ago with the help from people on this forum. He told me that particular bypass model was not intended for my gas furnace and was really only good for heatpumps. He said I would need the kind with the fan built in. I am pretty sure this has been working for all these years but wanted the opinion of the members here. Is the bypass type humidifiers not appropriate for a gas furnace?

Aprilaires’ response:

Thanks for you question. With the exception of the 400, our humidifiers are made to operate with either a gas furnace or a heat pump. Although a heat pump would require hot water for optimal efficiency, a gas furnace can use either hot or cold water because it has a higher plenum temperature. It sounds like your unit is installed on the right system. No need to worry about it!

0 thoughts on “Bypass humidifiers only for Heat pumps?

  1. Mark

    On your bypass humidifiers does a call for humidity only turn on water or is there any air flow control. IOW is plenum air still being feed back to the supply duct even when the humidistat is not calling for humidity,

  2. Bill Williams

    I have the aprilaire 600 installed on Carrier 38YDB (Puron) heat pump. It was connected to the cold water line. Should that be connected to the hot water line for optimal performance?


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