1yr Old House Window Condensation

[jblnut]

When it gets below 20F our windows condense to the point of water gathering on the bottoms. We wipe it up morning and evening but it's getting old. House is set to 71F all the time. Humidity has been below 40% downstairs for as long as it's been cool out. Seems to happen on all the windows, upstairs and on the main level. No basement. Windows are double hung vinyl Thermotech.

EDIT details added - two story slab on grade. No basement or crawl spaces. Moved in Dec 21'. House is built with an ICF foundation, SIP walls, blown in attic, radiant on main floor and forced air upstairs. An outdoor wood boiler supplies the heat so the way it's all setup now I can't leave the furnace fan on or it'll cook us out of the house. That didn't click right away and I turned it to on and left for a few hours. It went from 70 to 85 in the house lol. Oops.

This was a few days ago when it was 10F outside. Today it's -15F and the water is frozen on the inside. I think the damn windows may be junk


Screenshot from my TempStick. Currently upstairs it's in the coldest room in the house. Prior to that it was downstairs on the main level sitting on there thermostat.


Any ideas ?? We do not have an air exchanger as everyone I talked to said hold off and do a ducted dehumidifier if needed. I like fresh air so once in a while I'll open the front door and a window upstairs if things get stale. That's maybe once a week in the winter. In the summer the AC ran and did it's thing with no air quality issues.

 

[nh_yota]

I'd say your windows are ****. Mine are too because they're 100+ years old, but my parents have a mixture of Andersen and Marvin windows in their house and they never show any condensation even when it's below zero.

 

[dogdog]

There might be a leak in the windows, or you did not completely close the windows properly

 

[jblnut]

I'd say your windows are ****. Mine are too because they're 100+ years old, but my parents have a mixture of Andersen and Marvin windows in their house and they never show any condensation even when it's below zero.

I'd sort of agree. My parents have the same windows in their new house and they're also wet like this. I understand a little condensation but to be running into a large puddle like this is dumb. I called the lumberyard where we've been doing business forever and they said it's mostly a new house thing and it takes a year or two for all the moisture to come out (which I don't really believe) and it'll get better. He also said they should not be running like they are so

There might be a leak in the windows, or you did not completely close the windows properly

I was crazy **** about how they got installed and followed the guys around with a case of that expandy foam in a can squirting it into every nook and cranny. The house is a SIP home so it's fairly well insulated already.

The windows don't latch properly if they're not closed properly so I think they're all actually closed. The picture is from a window that doesn't open so

Thank you !!

 

[nh_yota]

I know newer houses tend to have moisture issues because they're sealed up much better now than they used to be, but that condensation seems excessive.

 

[mike93lx]

It's your windows. I had crappy windows in my last house and encountered the same problem. Other than dehunidifying or replacing them, I think you are stuck. Your humidity levels are not excessive at all, so I wouldn't dehumidify.

 

[Denwood]

It’s a combination of double glaze and zero insulation in the vinyl frame when the temps drop. I’ve taken FLIR of mine and confirmed this. Other than using triple glaze in renovations, I found a solution that works with the -35 C temps we get. I installed inner magnetic acrylic windows on all the double hung sliders, and fixed windows. This raises temps at the inside about 10C…a lot. The acrylics do need to be installed properly so that warm moist air cannot leak past them.

Triple glaze has a higher R value, but the frames typically are wider too, allowing 2-3 air chambers in the frame which help with cold weather.

Having taken FLiR images of newer triple glaze low E units more or less beside the acrylic treated “inner storm” window openings, they perform about the same. The inner acrylic panels also drop noise transmission by about half…again similar to a quality triple pane. That extra air gap makes a big difference.

Also, at -15 F you want your interior RH closer to 35 %. An HRV would address this.

FLIR images of sealed double glaze at extreme temps:

Woody's Works Garage

1/2, GFCI and RCD look to be very similar, although the spec here for current leakage is

www.garagejournal.com

 

[NS68RT]

You windows might be junk? I don't know from here, but you probably need some ventilation. 40% at -15 is kind of high. Does your house have a fresh air intake? Also, use exhaust fans when showering and cooking.

 

[BillK]

71 degrees and 40% and I would have a Tee shirt on Right now our house is at 67 and 35% and I feel perfectly comfortable with jeans and a sweat shirt. Our house is 44 years old and has single pane windows with add on storm windows and we only get a little condensation when its around 20 out.

 

[loganb]

Your humidity in the house is too high, it's as simple(and as complicated) as that

Ignore all the rest of the elements, and focus on the elements in play and what we can easily control/manage. Condensation is a function of humidity and surface temp at the core...yes airflow can play into it but at the simplest form it's temp vs humidity and at the surface of the glass where the condensation is forming. To reduce the condensation you can do 2 things(again simplifying):

• Decrease moisture level
• Increase the temp of the surface that condensation is occurring on

Of those....reducing humidity in the house is far simpler. Yes there are ways to increase the surface temp of the glass, but they're expensive like bumping up the temp of the whole house, replacing the windows in the new house, picking up the entire operation and moving to a warmer climate(lol)....

This is part of the joys of a new to you(and in this case new) house of learning it's quirks and habits. The humidity level that worked at the old house may not work at this one due to air flow patterns, temp gradients across the wall, the curtains/drapes over windows(heavy drapes make condensation worse not better), the glazing package used on the glass etc. Coupled with the nasty cold front that @Denwood and friend kicked south out of Canada, there will be a lot of condensation on windows across the upper midwest this week. The old house was far "leakier" than what you've got now so the humidity created inside the house is going to stick around far longer than before. Cooking, long hot showers or similar activities that put additional moisture into the air will all probably have a bigger impact than before

My advice...get the RH below 30% and see what it does and completely toss out the perspective of "my humidity is too low or too high because it's X%"...if it's condensing on the windows and bothering you, it's too high regardless of what number it's showing. As the temp's swing, the 30% RH that worked last week may now be too high...again it's relative...use the house as your indicator of "too high" and the number as a reference of how much it's moved

 

[wrenchguy]

Above and I had the same problems 36 years ago with premium windows. Its a new house thing in northern climates. It gets better over the years.

 

[loganb]

Had to go back and reread, mis-read the part about negative temps. 40% humidity is roughly 2x as high as most recommendations call for at that outdoor temp. Again these are rules of thumb and don't account for all the variables like airflow and double vs triple pane windows, "tightness" of the house etc but assuming you've got a humidifier on that furnace, I'd cut the humidity level shown on the dial by at least 50% and then let it set for a week and see how things acclimate.

For a bit more information see link below, the same temp/humidity chart is referenced by a bunch of other sites/manufacturers. The manufacturer of the windows likely has their own condensation booklet/brochure to aid customers on their Support Page, but it's going to say the same thing

Wintertime indoor humidity levels

Indoor humidity levels are important. In this blog entry we discuss wintertime indoor humidity levels and humidifier settings. Too little humidity is not good. Too much is not good either. Too much humidity in the home can cause mold, and other undesirable health effects. Too little can leave...

www.buildingsciencesllc.com

 

[fitter30]

Frames cold or glass? How the window sill? What's the space between the glass? RH flows from hi to low. Run the exhaust fan when taking a shower or cooking. Look at page 2

https://www.google.com/url?q=https://www.aprilaire.com/docs/default-source/default-document-library/relative-humidity-defined.pdf%3Fsfvrsn%3D2&sa=U&ved=2ahUKEwjp-Z65kIz8AhX1MDQIHYnoDwIQFnoECAUQAg&usg=AOvVaw2uQlcPAqBAzHvv68yUyD9T

 

[mogandave]

Unless I'm missing something, if it's 20F, the humidity has to be coming from inside the house as there would be relatively (pun intended) no humidity outside, yes?

Aside from people breathing and bathing and whatnot, the house drying out makes sense to me.

I only ever have condensate on the outside of my windows...

 

[larry4406]

On our new houses, we tell customers it takes a full season of heating and a full season of air conditioning for the house moisture content to equalize. Some components give it off while others absorb it but ultimately house comes into equilibrium.

For my area (northern VA and MD), this process sometimes results in condensation on the windows, but usually it’s just nail pops, corner beads separation, and caulk separation.

 

[billconner]

Just on sources of moisture indoors, crawl spaces, basements, and firewood rank among the largest.

https://www.labenvironex.com/en/environment/bacteria-and-mould-analyses/moisture-sources-in-houses/

 

[glueistheansW3r]

Above and I had the same problems 36 years ago with premium windows. Its a new house thing in northern climates. It gets better over the years.

hey, im very sorry if i am bothering you, because now i have this problem, nearly the same as OP has, i dont wanna make a new thread, but if you won't answer i will.My premium windows are 5 years old already. I am worried because i wasted too much money on architectural glazing company services. Again, dont wanna bother you wrech, if u think this information is not enough i will simply make new thread

 

[dcg9381]

Are your temps way cold?
Modern homes that I've worked on up north have humidity controls. As @mike93lx said you either have to control the humidity or you'll need a higher performance window.

Even the best windows are inferior to an insulated wall.

 

[pcmeiners]

I called the lumberyard where we've been doing business forever and they said it's mostly a new house thing and it takes a year or two for all the moisture to come out (which I don't really believe) and it'll get better

Funny, did this guy take a class called "How to dazzle them with ******** 101" . Have 40 year old Anderson windows, at -7° F last year not one window had condensation.

 

[4x4Pete]

Get your humidity to 30% or less when it's below freezing outside. See what happens. Run a dehumidifier, run exhaust fans, whatever it takes. It's not the windows.

 

[walrus]

new construction, wood, concrete still drying ?