Humidifiers and Dehumidifiers - Humidity and Condensation

Hi all.
First, this is a great site and this forum has been extremely helpful. Following the tips and advice to others from the mods, I was able to install an HE 220A bypass humidifier without any problems two weeks ago. I have the humidifier and humidistat on the return duct, water supply from the hot water piping, and wired to the HUM on my furnace board, with a transformer. Aside from the installation taking me 6 hrs, it worked the first time the furnace was switched back on. :)

The humidifier was needed because I had the main floor redone with hardwood this year and it gets extremely dry where I am in the winter months. Also gets very cold!

The humidifier has been working fine. I’m running the furnace with a programmable thermostat and have it scheduled to go down several degrees at night, heat up first thing in the morning, drop during the day when we are away at work, heat back up in the evenings. I had set the humidistat to 50% and the house (1200 sqft) humidity varies between 35 and 45%, as measured by the thermostat and a standalone humidifier (that is now no longer in use).

Now I have noticed that all of my windows (upstairs and main floor) have condensation showing up along the bottom of the glass on the inside, about 1-1.5 inches high. My question would be, is this normal? or should I be doing something about it, to reduce/eliminate it?

I did have all of the windows and doors replaced last year to energy efficient. As well for the exterior of the house a 1 inch Styrofoam insulation layer was added between the outer walls and new vinyl siding. In other words, the house is probably pretty tight now. As I said above, the winters are cold where I am (northern Alberta), this week the average high will be -12C (10F) and the nighttime lows will be -20 to -25C (-4 to -13F), well below freezing!

I think I will try adjusting the humidistat, but I do want to keep the average humidity at 40% as that is typically recommended for the hardwood. Is there anything else? The table on the humidistat suggests a setting of 20-30% for the outdoor temps above, but I need it higher for the hardwood!

Thanks for your thoughts.

Glad to hear that we have been a great help for you hooking up your humidifier.

On the wet windows upstairs, do those windows have blinds or shade on them? If so, they kinda help "trap" the humidity in the cooler area between the windows and blind, and it is normal.

I have hardwood floors, and I am in Minnesota, and have cold winter nights. (tonight -2˚f), and my t-stat lowers the humidity down as it gets colder out... It's about 33% now.

I have no issues with my hardwood floors in the past 4 winters we've been here in our home.

Turn it down a little, when it gets cold snap, and bring it back up when it's warmer (That's why I have an outdoor sensor on my system, I don't ahve to change it by hand)

Hi Jay, thanks for your comments ... interesting as yes, I do have blinds on all of the windows. Quality wood blinds, thought the humidifier would help them out as well! I never thought they could trap mositure but it makes sense. I have raised them up some and turned the slats all the way over from normal such that the angle when opened a bit is facing up, not down. The rising warmer air should flow better and get trapped less this way. Interesting enough, a vent is below each upstairs window as well, so I guess I shouldn't be surprised to see some condensation. Also turned the humidistat down and with the blinds adjusted, there appears to be some improvement. I'll keep monitoring it but won't worry about it.

A note on the hardwood, the flooring co. wouldn't warranty the work against shrinkage, etc. if a humidifier wasn't installed. I had a handful of extra planks stacked loose in the basement and have already noticed that some of them have warped a bit.