Hi!
My wife and I built our home several years ago and chose Marvin low-E wood double hung windows. Ever since they were installed the windows have sweat in the winter and fogged up in the heat of the summer. We live outside St. Louis, MO so our winters are not terribly harsh but our summers can be quite humid. We’ve had the house tests 2 times by the Marvin rep for tightness and levels of humidity and have passed both tests with flying colors. The house is 2X6 construction w/ blown in cellulose insulation and house wrap.
Marvin has not come up with any solution or answer for us. Our concern is that the life our windows will be drastically shortened as the windows are already showing signs of wear from the moisture. Should we consider purchasing storm windows? Has anyone else experienced this problem with wood windows, from Marvin or other manufacturers?
Thanks for any input.
Terry57 in Illinois
Replies
What is the humidity level in the house?
What tempature do you keep it at?
What kind of "window treatments" do you have?
Which windows have the problem?
With condensation in both summer and winter it would imply you have a moisture problem in the house. Is your house built on a slab, crawl space or with a full basement? This is the most likely source of too much moisture in a home. Another could be a malfunctioning humidifier if you have one installed on your furnace. Many have a damper that needs to be manipulated to a summer or winter position.
Is your clothes dryer vented to the outside and functioning properly? Do you have a carbon monoxide detector? (everyone should!) Is your furnace and water heater (if gas) vented properly, and the flue not clogged?
What method/s did the Marvin rep. use to test your house? I seriously doubt this is a window problem, but more likely a house problem. You said wood windows, are they wood outside too, or aluminum clad? What kind of siding is on the house?
You could also check and see which surface of the thermal pane has the low-e coating. Hold a match near the windows and look at the reflections. If you look from the proper angle you will see 4 reflections. One for the interior and exterior surfaces of both panes of glass on your thermal panes. The reflection that is a different color fron the other three is the one with the coating. It will be on one of the surfaces inside the sealed portion of the thermal pane. What I don't know is which one it should be on for your area. Probably the inside of the interior pane.
Here's some clarification...
Windows are wood jams/sash and aluminum clad exterior. They are low-E w/ the argon gas between panes. They condensate on inside panes (interior of house) in winter and fog outside panes in summer (exterior). All windows in the house condensate. Marvin tested our humidity levels w/ what they called a wet bulb test. They swung it around and around in all rooms of the house and then measured humidity level with that, plus checked w/ an electronic checker. All readings within 2% of each other in all rooms and all readings were at or below 30%. Testing was done at about 25 deg. outside.
House has a full basement, unfinished, uninsulated. We have no water leaks in basement. We keep our house at 65-68 deg. in the winter and in the summer, 75-78 in summer. House is full brick exterior. We have perforated soffet all around eaves of house and ridge venting at peaks (roof is combination hip and gable) and 2 end gable vents, both facing same direction, one into garage and one into south end of house. We do not have a humidifier on our furnace, which is electric and water is electric as well.
Thanks to all for your suggestions...
Terry57 in Illinois
What was the condensation effect WHILE they were doing these tests?
Does the condensation occur regularly (every day) or just on certain days? The St. Louis area can get brutally humid from time to time.
Do you have (and use) kitchen vents and bath vents?
The condensation in the winter is present each morning ( starts forming in evening after sun goes down) and when temps dip below about 32 deg. In the summer, when the temps are above 92+ & humidity is high, usually around 85-100%.
We have sun shades (cellulose material) but only drop them in the summer to block the sun. We leave windows uncovered during winter.
Marvin rep was here in on winter days when temps were around 25 deg. We left condensation so he could see.
Yes, we have bathroom and kitchen vents and use them regularly. Additionally about 90% of our heat vents are directly below the windows. Don't know if that may have something to do with problem.
thanks again...
Terry57 in Illinois
Check your basement floor for water vapor. Lay a sheet of plastic over an area of floor for a day or two, ( a lawn leaf bag will do) lift the bag up and see if the floor or underside of the plastic show signs of moisture. If they do this is indicative of alot of moisture entering your home through the floor. Probably through the walls too. Water vapor has an associated pressure. It "flows" from higher to lower concentrations and moves independently of any air movement. We often think that moisture is carried along with air and that if we stop the air from moving through our walls we will stop the water vapor also. Not so. Have you checked to see which pane has the low e coating? What is the space between the window panes? As was mentioned earlier, what is happening is that the glass temperatures are reaching the dew point. In the winter the inside surface is getting too cold for the humidity levels in the house, and in summer they are getting too cold for the humidity level outside.
What about the dryer vent?
Do you have a ventless fireplace?
Large amount of indoor houseplants?
Gas cook stove?
Hot tub/Jacuzzi?
Indoor fish pond?
Aquariums?
The 30% number does not seem to fit your situation! Without added water vapor there should be minimal condensation unless the insulated glass is not insulated.
An infrared thermometer should give you instant readings to plug into some dew point tables to see where you really are1
Something is a-miss, can't put my finger on it...keep searching!
.......................Iron Helix
I threw in the towel on this post when the humidity level was reported at or below 30%. I've been in the widow biz a long time and this one either needs building sciences to investigate.... because it goes against every proven fact of humidity and condensation... or they need a paranormal investigator.
This may be because of cardinal glasses collapsed glass issue as stated by a previous poster... but if they came out and checked the windows... or if you just looked at them from the outside the issue would be apparent.
I'm thinking haunted windows.
So,,,,, in the winter there is condensation on the inside if the windows in the house
and in the summer there is condensation in the outside of the windows outdoors.
Is this what you mean?????
H
Terry,
Many moons ago, my mom had the same problem with her 6' tall Marvin casement windows which were in the living room, just off of the kitchen. I always thought that there was too much humidity in the winter when she cooked. She never liked to put the hood exhaust on. However, for some reason the Marvin windows always had more condensation then any other windows in the house, including the kitchen windows. The Marvin windows were also over two floor heat registers. All she did was just try to make it a routine to wipe the condensation. However, three years after installation they finally started to deteriorate as ice crystals started to come out of the sash joints. There were black areas in the sash itself. That I found very hard to accept in believing that could happen.
I contacted Marvin Windows and was told to send photos. I sent photos and a cover letter with my office letterhead. I received in return a standard Marvin package about condensation. What puzzled me more was that there was no cover letter from them and no acknowledgment of seeing and reviewing the photos I sent. It seems you at least got some out there to look at the windows hopefully after the first contact.
What I did next was send a followup letter responsing to what I felt was a response from some kid in their secretarial pool. I thanked them for their "non-professional service" and let them know I would be letting my peers and trades people know of this experience as well as write a few letters to a few trade publications. After that letter, I recieved a telephone call within a week, a scheduled visit from a rep, and replacement sash for one of the worst windows. No charge.
My mom still cooks her soups. but tries to remember to turn on the exhaust fan to get out some of the humidity. It works somewhat as I believe the condensation is not a much as before. I also tried tweeking with her humidifier, but that HVAC system was installed by a low ball contactor while I was out of town one year. That's a different topic all together.
Try to get adjust the humidfier. Less humidity.
Why the condensation forms is not because of the window, but a function of humidity and temperature. Water condensates out of air when it's temperatue is reduces to a level where it can no longer be carried. Think your windows are bad with condensation??? Just imagine what's happening in your walls and attic at the same temp.
Do an experiment... Take a big glass and fill it with as much ice as it will hold. Then top it off with water. Put it on a table near a window. I'd be interested in your observations.
Edited 11/30/2006 9:36 pm ET by sledgehammer
Ever since they were installed the windows have sweat in the winter and fogged up in the heat of the summer.
What do you mean by "fogged up"? Is the fogginess in between the sheets of glass, or is it just surface condensate? If it's between the sheets of glass, it's a separate problem (due to failed seals or inadequate dessicant) and one that Marvin should address.
In my opinion, the surface condensate (as others here have indicated) is probably due to the humidity level within the house. Adding storm sash *might* help; if you can keep the inside surface of the glass warmer, it will help stay clear of hitting the dew point. However, I'd definitely focus on trying to lower the humidity level first.
Edited 12/1/2006 2:35 am ET by Ragnar17
I am also unsure from your description whether you have condensation on the in and out surfaces of the glass units, or if the condensation fogging up is on the surfaces between the two pieces of glass. If the later, there is a problem with the insulating glass that Marvin should correct. if the former, the problem is with your local humidity levels in contrast tothe temp and RH on the opposite side of the units
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