# Help! Sick of Window Condensation!



## Turquesa (May 30, 2007)

Every fall and winter, as the temperatures drop, we get condensation on the inside of every window of our house. The condensation leads to mold, which then leads to endless hours of scrubbing it out.









Could somebody PLEASE give me an idea as to what is going on and how I can correct the problem. It is driving me CRAZY! :headbang

Here is what I know is NOT the problem:

1.*Leak in the window seal.* These are double-pane vinyl windows. The condensation is only on the inside of the window, right along the edges. A leak would show either on the outside or between the panes.
2.*Needing new windows.* I actually looked into window replacement a couple of years ago. I got three bids. Two guys just tried to sell me windows, of course. The third told me that condensation was NOT an indicator of needing new windows, and he even gave me a brochure about it. He told me that if anything, it meant that the windows were doing their job and not leaking.
3.*House is "too tightly sealed."* No other house in my subdivision has this problem, nor do any of the tightly sealed Energy Star houses of my friends and family.
4.*Excessive humidity.* This MAY be a problem only because I can't tell if our humidistat is working. But we live in a dry, deserty area. We run the exhaust fan during and after showers. We cook with the fan on and everything vents to the outside (including our dryer). Our crawlspace is completely dry and covered with vapor barrier, and there are no leaks or standing water. Also, the problem is most prominent when we wake up in the morning-before we shower or run any appliances.

I know that the warm air from our house is meeting the cold air on the windows, creating an effect like the condensation on the outside of a glass of iced water. So why are our windows getting so cold? Don't everybody's?

Please! I'm getting so, so sick of this issue! I'd love to hear some feedback, especially if you or your DP know a thing or two about construction or home mechanics&#8230;or if you've experienced this yourself and solved the issue. Any ideas?? TIA!


----------



## Ola_ (Sep 5, 2008)

I'm thinking the excessive humidity. We have a humidifier attached to our furnace and use it during the winter because having the heat on makes the house dry. However we've had to fiddle with the settings because we get humidity on our windows also (on the inside, and we saw it in the morning as well). If it was between the panes I would think it would be the seal (we have a couple of old windows with that problem) but since it's on the inside I don't think it is.


----------



## ChristyMarie (May 31, 2006)

I'm also thinking excessive humidity.

Do you have window coverings? I find that the combination of a humidifier and keeping curtains closed will lead to condensation. Open your curtains/blinds/whatever each morning. And when I moved my couch too close to the window it didn't get enough air circulation and I had condensation. Moved it out a couple of inches and now it is fine.


----------



## nd_deadhead (Sep 22, 2005)

We have the same problem, but we KNOW it's excess humidity. Our house has windows in both bathrooms, so no bathroom fans were installed. I did put an exhaust fan in the upstairs bathroom a few months ago. I put it on a time, so it can run for an hour after a shower.

The other problem for us is that we have 2 large fish tanks - one in our bedroom and one in DS's room. We love that we don't get bloody noses in the winter due to dry air, but the window condensation thing is a drag.

The other change I made recently was to buy a big dehumidifier, which I have near the downstairs bathroom (the one without a fan). Even with the air conditioning running this summer, which should pull out a lot of moisture, we were dumping close to 2 gallons a day from the dehumidifier! One is not supposed to run a dehumidifier in the winter, but we'll run it as long as we can this fall.

Temperature is the other issue. I live in North Dakota, where it gets really cold in the winter. I've had a 2-inch-thick layer of ice on the bottom of some windows!

What we do in the winter is put 3M plastic on all the windows in the late fall. That provides an extra air layer between the window and the inside. I still get condensation on the plastic if it's really cold out, but it doesn't freeze, so I can wipe it off with a towel.

You might check to make sure your dryer vent is clear - you may be venting dryer exhaust into the house without realizing it.


----------



## Turquesa (May 30, 2007)

Thanks for all of the advice.

ND Deadhead, is it pretty dry where you live, or does it get humid? It's really dry here, so a humid house just doesn't seem right.

The condensation occurs overnight, but the days are still warm. This means that I'm still hanging clothes on the line and not using the dryer, so I don't think the dryer vent is an issue.

We don't own a humidifier, and our couches are arranged in a conversation pit away from the windows.

One builder I talked to on the phone tried to convince me that our windows weren't properly sealed when they were installed, and that all houses built around the time mine was are that way. Well, I've learned from talking to my neighbors that they don't have this problem. And a lot of them had the same builder.









It is so dry here that nobody bothers selling dehumidifiers locally. I have to go online and order one. Since the problem is apparently a rarity here, I'm wondering if a dehumidifier would just be an unnecessary bandaid.









Again, thanks for the suggestions. I hope I solve this mystery soon.


----------



## SleeplessMommy (Jul 16, 2005)

Quote:


Originally Posted by *Turquesa* 
One builder I talked to on the phone tried to convince me that our windows *weren't properly sealed when they were installed*, and that all houses built around the time mine was are that way. Well, I've learned from talking to my neighbors that they don't have this problem. And a lot of them had the same builder.









Your dual pane windows are supposed to be vacuum sealed or argon filled. Lets say they were vacuum sealed windows originally (lower cost than AR) and the seals on these windows failed (letting air in). Now, they will no longer insulate to the degree they once did, resulting in condensation ont he inside at night. Just like a Thermos bottle will no longer keep coffee hot if you drill a small hole through the outside layer.

Your windows MIGHT have some internal fogging like this: http://kandkwindowservice.com/wp-con..._failure_2.jpg

Or they might just look like normal windows. The hole to let air in would be very very tiny.

Another option is the builder got a delivery of the wrong windows (just air not AR or vacuum sealed) and they ended up on your house. Could happen.

What is the humidity like inside your home? Do you have a humidity monitor?

If you call in a home inspector, you can get an unbiased answer. Alternately, if the manufacturer is listed on the windows you could try taking with them.


----------



## Turquesa (May 30, 2007)

Quote:


Originally Posted by *SleeplessMommy* 
Your dual pane windows are supposed to be vacuum sealed or argon filled. Lets say they were vacuum sealed windows originally (lower cost than AR) and the seals on these windows failed (letting air in). Now, they will no longer insulate to the degree they once did, resulting in condensation ont he inside at night. Just like a Thermos bottle will no longer keep coffee hot if you drill a small hole through the outside layer.

Your windows MIGHT have some internal fogging like this: http://kandkwindowservice.com/wp-con..._failure_2.jpg

Or they might just look like normal windows. The hole to let air in would be very very tiny.

Another option is the builder got a delivery of the wrong windows (just air not AR or vacuum sealed) and they ended up on your house. Could happen.

What is the humidity like inside your home? Do you have a humidity monitor?

If you call in a home inspector, you can get an unbiased answer. Alternately, if the manufacturer is listed on the windows you could try taking with them.

Very helpful. Thanks. The humidity this morning was 51%. That is high for where I live. I'm wondering if it's a circulation problem, although none of the HVAC commission salesmen/"service" men that I talked to had any answers.

Yes, the condensation is only on the inside, like the pictures you showed me. A number of window companies are claiming that it's just well-sealed houses and appliances running. But....we don't run any appliances overnight, and the condensation is there BEFORE we shower and run exhaust fans.


----------



## SleeplessMommy (Jul 16, 2005)

How old is your house? How old are the windows?

What temperature is it outside at night when you get condensation?

You have forced air heating, right? Natural gas, propane or oil? It has been serviced professionally in the past year, right?

Humidistat = humidifier on the furnace. Is THAT set at 51% or do you have a separate humidity meter in the home? Does your furnace have a "lever" for duct bypass (labeled winter/summer) The picture on the left shows the bypass duct, but not the lever to change from summer to winter.
http://electronicaircleaners.com/ima...ower_r3_c2.gif

Does your home have heat recovery ventilation/energy recovery ventilation (found in newer homes) or neither?

When you run the kitchen vent fan, have you verified that is vents outside, like it is supposed to? (many houses have a recirculating vent fan on the microwave, which is a really really bad idea with and gas cooking)

Have you inspected the entire length of the dryer duct to make sure that it vents outside? (rather than disconnected at back of dryer.)
......
There are 2 different window condensation situations - it sounds like you have "a" not "b"... but it is important to confirm this.

a) condensation on the "room" side of the window unit. In this picture it is ICE!
http://37c.org/lhom/img/InsideIce.jpg
-or-
http://gallery.hd.org/_exhibits/buil...unit-2-DHD.jpg

b) condensation between the panes. It might be there all the time. This is caused by a failed window seal.

http://69.94.107.132/springshomes.co.../image8925.jpg

What state or region are you in?

...
And a test to try, assuming the windows have option "a" above:

If you are setting the humidistat at 51%, you might have an actual humidity of 60% or more ... assuming there is some error in the control of that unit.
I suggest turning the humidifier OFF all the way, setting the bypass to "summer" if you have one, and mounting a humidity meter (from Walmart) in a central hallway. Keep the humidifer off until humidity inside drops to 30%.

If you still have condensation at 30% RH, then you most likely have a window problem - the wrong windows for your climate.

If you don't, then you just have the humidifier turned up *way* too high. You need to find a happy medium between comfort and condensation/mold.

If the humidity does not ever drop to 30%, you have another problem, possibly serious (for example faux stucco siding or a hidden pinhole plumbing leak or HVAC problem) I would call in a home inspector in this case, ASAP.

let me know!


----------



## nd_deadhead (Sep 22, 2005)

51% is pretty high. Am I correct in assuming you're getting condensation on all the windows? We get condensation on the downstairs bathroom window when someone showers, because there isn't an exhaust fan in that bathroom. Keeping the bathroom door open helps dissipate that moisture to the rest of the house.

That much humidity isn't just a problem for your windows (and an annoyance), but a serious problem for the woodwork, sheetrock, and other parts of the house.

The moisture is obviously coming from somewhere. I still think the dryer vent is the most likely culprit, though I would definitely get your furnace inspected. One of the products of combustion of heating gas or oil is water, and if you are getting flue gas leaking into your house, that's a pretty dangerous situation!

Good luck figuring it out.


----------



## Turquesa (May 30, 2007)

Sorry I'm late getting back to you. I'm not good at juggling all of the threads that I participate in.









Quote:


Originally Posted by *nd_deadhead* 
51% is pretty high. Am I correct in assuming you're getting condensation on all the windows?

Yes, although some worse than others. We've made a couple of changes, and since then, the problem hasn't been as bad. First, I applied exterior caulk between all of the window frames and the siding. This was a recommendation from a home energy auditor.

Second, I've started keeping some of the shades half open at night so that air can circulate. I may regret this second measure...we'll see when the heating bill comes!

There is still a TRACE amount of condensation along the very sides of the windows, right next to the frame where it's (ideally) sealed.

Quote:


Originally Posted by *nd_deadhead* 
The moisture is obviously coming from somewhere. I still think the dryer vent is the most likely culprit, though I would definitely get your furnace inspected. One of the products of combustion of heating gas or oil is water, and if you are getting flue gas leaking into your house, that's a pretty dangerous situation!

This was a good suggestion. Thanks. I called our go-to HVAC guy and fortunately he doesn't think this is the problem. He said that we would definitely smell something, or our CO detector would have picked it up by now.


----------



## Ygle (Mar 2, 2007)

I don't know if this applies in your situation but what we discovered is that we had really bad condensation on the windows where we put the shades right up to the window... we have cellular shades and they fit perfectly and I thought it would be more insulating to have them inset as far as possible right up to the glass almost. Once we realized this was a problem and moved the blinds out with a big gap between the windows and blinds we noticed much less condensation.


----------



## Norabella (Mar 14, 2008)

Do you have lots of house plants and/or do you do a lot of cooking involving boiling water (pasta, beans, grains)? Both of those things can be a significant source of indoor moisture, and just because morning is when you see the condensation on the windows, doesn't mean that overnight/early monring is when the moisture is introduced to the air, it just means that is when the variables of inside warmth/outside cold and less air circulation all line up.


----------



## Edwig68 (Dec 3, 2010)

I have double glazed windows in my flat and i have to say i have no problem with the comdensation anymore.... Sometimes with extrem cold weather (-20 °), some condensation appear, but it's not so awful than before.


----------



## BetsyS (Nov 8, 2004)

This is a very helpful thread. We're in a new (to us) house this winter, and we have horrid condensation. In our case, our house was built in 1957, with the original windows. They are drafty and COLD. And, it's not even all that cold here (we've only had a couple of nights when it dipped below freezing) yet. The mold is gross and a pain in the rear to clean.

I'm in the process of putting up window quilts to insulate, plus I'm thinking of getting a dehumidifier.


----------

