Too much humidity?

Brad White_9

I agree with your list of things to check, but are you REALLY going to ask them to reduce heavy breathing?? Cruel. How cruel....

:)

But you are right. Respiration is a major contributor, even in houses without humidification...

Matt_21

humidity

i just installed a nortec resdelux steam humidifier in my first floor air handler. i noticed my second floor storm windows have condensation on them in the mornings but the first floor windows do not. the humidistat is controlled by an outdoor air sensor which regulates the humidity based on outdoor air temp. does is sound like the second floor is getting too much humidity or would the condensation be caused by something else?

Brad White_9

Controlling indoor humidity using OA temperature

is kind of like using a thermometer for a calendar.

You should have two principal controls: The primary low-limit control ("I need humidity") would be ideally a return air humidistat. It would be located at or near the return from the space, (away from any bypass air from the furnace, if any). This way it senses the most homogenous mixture, best sampling of the house average RH.

The second control you need is a high limit in the supply duct downstream of the humidifier injection point usually before the first take-off or in a good sample branch. This is to keep your ductwork dry. This high limit locks out the humidifier above a certain duct RH.

Setting this last one up can be tricky because the air being warmer can appear to be "dry" (low RH) and this rapidly humidifies the space when it cools (doing it's heating work in the space). With me on this?

What I describe are simple wired logic controls. You may have something more electronic and exotic but the location principles are the same.

Using OA temperature is something I cannot comprehend but am open to learn...

Brad

Brent_2

oa

What do you mean when you say "the humidistat is controlled by an outdoor air sensor which regulates the humidity based on outdoor air temp"?
I hope you don't mean you installed the humidistat outside. I know some models have an input for an outside air sensor that lowers the humidity setpoint when the oa temp drops. This prevents condensation in very cold weather. I did not know that you can do this with a resdelux. Humidity is usually pretty consistent through a house. I would doubt the humidity would be higher on the second floor. Do you use your air handlers for heat?

Brent

CHARLES_4

Things to check

Three things which could be affecting the 2nd fl humidity:
*Temp differential from 1st fl to 2nd fl--2nd fl cooler?
*Window treatments @ 2nd fl--closed at night? Lower temp between window and curtains.
*Condition of primary windows @ 2nd floor. If moisture condenses on storm window, inside window is leaking.
*Bonus point: 2nd fl bedrooms? Door open or closed? Too much heavy breathing?

CHARLES_4

Didn't say he/they had to reduce the heavy breathing. Just take it into consideration.

Brad White_9

JOKE

R. Kalia_8

R. Kalia_8

Controlling humidity based on outdoor temperature is nothing new. The idea is that you can't have 60% humidity indoors when the outdoor temperature is -10F; there will be water all over the windows and insides of outer walls and it will do damage to the house. So the humidity setpoint is adjusted based on the outdoor temperature.