# Sweating glass on windows/doors



## kudzuvine (Aug 11, 2011)

Moved into another house. Conventional slab, using natural gas wall heat/gas logs. Haven't used central elec heat and my windows and glass on security doors have so much moisture on them. Humidity in house is showing 80. Going to try a dehumidifier - what's up with this.Janet Oh yeah, house is partial brick and then aluminum siding other half. I believe the house is pretty air tight.


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## TnAndy (Sep 15, 2005)

Aluminum frame windows ?? ( I assume the security/storm door is ).

If so, that is a large part of the problem. 

When the temps dip outside, older aluminum frame windows had no "thermal break" (layer of plastic separating the inside and outside part of the frames/sashes ).....so if it's 25 outside, the INSIDE of the frame is dang near 25 also, aluminum being a good conductor of heat/cold.....and if your house humidity is anything above 30-40%, that moist air hits a cold surface and condenses ( the "iced tea glass" effect ), and either frosts or runs down the frame inside.

Seen many inside window frames/casings rotted or molded up due to this. Aluminum frame windows don't belong north of Dade County, Florida (Miami) in my opinion.

Two solutions: reduce your indoor humidity, or replace the windows with wood framed,or vinyl type windows....both of which are far better insulators.

If you don't have aluminum framed windows, the same theory applies. You have warm, moist air hitting a cold surface.....you need to tighten up the windows ( caulk, weather stripping ), and maybe still consider upgrading to a double pane if single pane....don't spend any money on storm windows, IMHO....vinyl replacements are SO much better choice (installed correctly) over storm windows.

And as for the house being pretty "air tight".....that may actually contribute to the problem.....the moist air inside has no way to escape. Normally, humidity in the winter won't run 80%....it drops along with the outside humidity....cold air holds less moisture than warm air.


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## wy_white_wolf (Oct 14, 2004)

check the chimney to make sure the heater/gas logs are vented outside. 

WWW


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## kudzuvine (Aug 11, 2011)

vinyl windows. Iron or steel security doors. I'll check the vent for fireplace. thanks so much for your reply


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## kudzuvine (Aug 11, 2011)

I also keep temp inside around 65. the house was built in mid 60's, but was gutted and everything replaced (due to fire) a few years ago. caulking is good. I will try my mom's dehumidifier the next couple of nights and see what happens. Then my question is where is the moisture coming from to elevate humidity


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## Harry Chickpea (Dec 19, 2008)

Sometimes it just takes a week or two for a home to dry out in winter, so don't be in too much of a rush.

Moisture sources more or less in order:
Unvented heaters create water vapor and carbon dioxide.
Showers and towels
Unvented laundry
Cooking
Dishwasher
Moisture migration from crawl space
Human occupancy
small leaks
Goldfish spit


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## kudzuvine (Aug 11, 2011)

Goldfish spit...why didn't I think of that! Harry, thanks for your list


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## Harry Chickpea (Dec 19, 2008)

Everyone forgets the goldfish spit.


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## Drewberry (Nov 19, 2013)

Wow, Thanks for all this great info. I don't always have this happen but it has happened a few times. Now, I know what to look for. 

Drew

PS I do have aluminum windows but they are newer ones, double paned..


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## kudzuvine (Aug 11, 2011)

I just put a dehumidifier in and in 20 minutes it's drawing out water. However, humidity is still 80. So I'll report back later


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## kudzuvine (Aug 11, 2011)

OK...it has been running for 12 hrs. 1/2 gal of water and dropped to 75. So, it is slowly removing moisture. Getting our first real cold snap, 22 outside with wind chill in single digits.


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## kudzuvine (Aug 11, 2011)

update - 2 gals water in dehumidifier and humidity dropped once and back up to around 80. So, there is apparently a lot of moisture in the house and either my gauge is not working or there is so much moisture it's going to take several days to get the humidity down. I have noticed not as much moisture on windows and doors.


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## Harry Chickpea (Dec 19, 2008)

I would suspect the gauge at this point. There is a huge amount of drying going on from the colder temps and heating of dry air.


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## kudzuvine (Aug 11, 2011)

Agree. moved to back of house (2br, bath and laundry) and got another gallon in 6 hrs. Happy Thanksgiving Harry.....Janet


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## jwal10 (Jun 5, 2010)

Are the wall heater(s) vented, they produce a lot of moisture. The colder it gets the more they run the more moisture you have....James


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## kudzuvine (Aug 11, 2011)

I have one three burner natural gas wall heater - doesn't require vent and hardly use it, just long enough to knock chill. I think all is ok now using the dehumidifier, but to me, that's like putting a band aid on it, still need to find the source.


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## ralph perrello (Mar 8, 2013)

Do you have single pane windows?
Do you have storm windows?
If you have single pane windows with no storms or poor storms then the glass is cold and causing condensation. Repair the windows or lower the humidity.


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## kudzuvine (Aug 11, 2011)

Ralph..have double pane vinyl storm windows that are 4 yrs. old.


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## homstdr74 (Jul 4, 2011)

In my opinion, your problem is the gas heat. We had that same problem before we finally installed our wood-burning heaters which solved the problem entirely.


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