Whole House Humidifer - Any concerns with air leaks

[stee6043]

Due to an extended basement remodel project I'm sadly going to be heating primarily with natural gas this year and not wood. As such, I decided it's time to invest in a whole house humidifier to help keep things comfortable.

As I prepare to cut a rather large hole in my return plenum I started wondering if this hole creates any problems for the system if the humidifier isn't running? Say in the summer when the AC is on will the furnace draw significant amounts of return air from the humidifier opening and perhaps impact the rest of the house somehow?

I'm assuming this is not the case since these systems are quite popular. But it still peaked my interest

 

[Retired Guy]

Ours has a damper on the duct from the hot air plenum to the unit that we close after the heating season. Just restarted ours a couple weeks ago.

 

[stee6043]

Mine has a fan rather than a damper or bypass. I'm just curious if the fan runs anytime the furnace blower is on? I guess I just need to install it and see.

 

[DickRussell]

Why would the switch from wood heat to natural gas make you think about adding humidity to the house? Before you think about installing a humidifier, read this:
http://www.greenbuildingadvisor.com/blogs/dept/qa-spotlight/why-sheathing-moldy

Other threads on hearth.com have talked about excessive humidity.

 

[stee6043]

Why would the switch from wood heat to natural gas make you think about adding humidity to the house? Before you think about installing a humidifier, read this:
http://www.greenbuildingadvisor.com/blogs/dept/qa-spotlight/why-sheathing-moldy

Other threads on hearth.com have talked about excessive humidity.

You can find equally as many posts/links to stories regarding the damaging effects of low humidity. I think the link above has a lot more to do with quality of construction than it does the dangers of excessive RH.

I can't tell you why but it surely does seem (perceived or otherwise) that my humidity is considerably lower when heating with my nat gas furnace vs my wood boiler and hot water coil. This year is the first year I've actually measured it, however. We haven't come close to peak heating season yet and my home is already in the mid-upper 20% range of RH most days. We were mid 30% yesterday as I was installing my humidifier thanks to some sun and decent temps outside.

For what it's worth I installed an Aprilaire that adjusts RH automatically for outside air temp. So far, it's pretty slick. It's getting a lot of run time so far as it tries to get up to 40% (45% is max). I have a lot of wood floors that need to soak some water back up...