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My wife and I recently built a home on the coast of Maine and cant seem to keep the windows from sweating (on the interior glass) now that the colder weather is here. The windows are double insulated, argon gas charged, wood interior with applied mulions, aluminum exterior windows from NORCO. We have tried turning up the heat as well as closing doors, but the windows still seem to sweat. Any suggestions?
Jason- Edgecomb, Maine
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Replies
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There are a multitude of things that could be causing this. First is a defective window, allowing the inner pane to get cold enough to induce condensation. High humidity levels in the house is another cause. Just a couple high humidity culprits are improperly vented kitchen and baths, improper vapor barrier in the basement or crawl space. Furnaces and hot water heaters using natural or propane gas not vented correctly. That list goes on and on.
Now that I've been through all that you could just have a house that is too tight. Older houses, like mine, breathe through natural voids and cracks so moisture does not build up. You may want to discuss with a HVAC contractor about putting in an air exchange unit.
Scott R.
*I use a lot of Norcos on the Maine coast too.I would bet that your problem lies in the fact that this is a recently complewted home. It is tight enough to not breathe like an old one and your materials (concrete, studs, drywall, paint, etc) have not dryed out yet. A stud at 19% is still wet. It can take a year or so in this climate for equilibrium to set in. Another possibility is that ytou have no vapor stop at ground level. What sort of foundation do you have and how is it segregated from the living area where you are experiencing trouble with the windows?'Course it's always possible you've got a baad batch of lites, too.
*Do you have a lot of plants that transpire? Do you turn on the fan (or open the window a crack) when you shower? Overhead fan when cooking??
*Gee, you guys. How 'bout the obvious? Could be an otherwise good window leaking at the casing. Or, incorrect or no insulation in the walls.
*Jasondo you have one of those ventless fireplaces/heaters?Iron Helix
*Thanks for the input- good to hear from a local contractor. We have a poured concrete foundation, the only segregation from the living space is the floor joists and floor, there is no insulation in those joists. The basement is insulated on the outside of the concrete with R-7 foam board from the footing to the sill.
*So, is there an actual basement with a poured concrete floor, sealed and with a vapor bar under it, or a crawlspace with exposed dirt? Our clay soils are famous for holding moisture, which can then be ascending through the house and condensing on cold spots.
*JasonCondensation on your windows obeys some rules of physic/chemistry that relate to the amount of moisture in the air in your house and the temperature of the cool surface of the glass and is known as the dew point. The term is commonly used in weather forcasts to indicate at what point it will rain when to weather fronts meet.The same thing happens in your house. Go to the local hardware store and buy a humistat so you can know the amount of moisture in your house's interior. If the humistat registers more than 20% with your heating system on and the outside temp at freezing then your windows will condense moisture from the air in your house. Much in the same way a cold glass of ice water "sweats" in the summertime.If the humistat reads high and your windows are sweating then the job is find the source of the water vapor withn your house. Souces may be: clothes dryer vented improperly, heating system humidfier malfunction, bathroom vents not working, house plants in abundance, open containers of water as in spas, swimming pools, water fountains, unvented gas fireplaces, moisture migration through structure.Find the source, lower the house humistat below 20%, and the windows will cease to sweat.Let's play detective...................Iron Helix
*Thank you for the info
*The basement is poured concrete, 8" walls and a 4" floor. Under the floor is approx 8-10" of stone with a layer of poly sheeting on that. Our soils are all glacial marine clays however.
*Just a note to add to all the responses- What temperature do you all recommend keeping the heat at? We prefer to keep the house pretty cool. 60 degrees upstairs and mid 60's on the first floor.
*Anything above freezing. :)
*The point of having a house is to keep you comfortable - not the other way around. Set the thermostat accordingly. Warmer air will hold more moisture though. One problem building scientists have is that a wood house is happiest at about 16 -18% humidity while humans are happy and healthy closer to 40%Mr Iron Helix condensed the whole thing well - no pun intended.
*We tell the owners of the new houses we build that they can expect some moisture on the windows during the first winter after construction. There is a lot of water in the materials and it takes time for everything to dry out. If there is a problem after that, the house is too tight and we need to install more ventilation. We usually recommend heat recovery ventilation in our houses but this is also usually cut from the budget in the early stages. Opening some of your windows just a crack will also help your problem. Good luck
*I posted a very similar question here when we finished a 1000 sq foot addition in 1998. These folks told me it was probably due to everything - paint, wall mud, concrete, lumber - drying out at the same time. I used fans and opened windows when possible that winter. The next winter we had no condensation. Hey - these guys were right! I hope time takes care of your problem as well, and that you enjoy your new house.
*As Schelling and Lisa have pointed out, houses have a lot of moisture their first year. Think of all the weight of the paint, floor finishes, and drywall mud and texture. Much of that is water. Plus all that non-kiln-dried lumber. It was only an issue in my house for 2 or 3 days after painting, but I have a heat recovery ventilator that runs off a humidistat - high humidity causes it to exchange more air. -David
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My wife and I recently built a home on the coast of Maine and cant seem to keep the windows from sweating (on the interior glass) now that the colder weather is here. The windows are double insulated, argon gas charged, wood interior with applied mulions, aluminum exterior windows from NORCO. We have tried turning up the heat as well as closing doors, but the windows still seem to sweat. Any suggestions?
Jason- Edgecomb, Maine