Wednesday, February 27, 2013

Minimizing Condensation on Residential Windows in Minnesota


   All double pane windows that have an aluminum or stainless steel spacer between the panes of glass tend to have a condensation problem in the winter.  Moisture in the air will condense on a cold surface like a window.  The metallic spacer around the perimeter of the glass conducts heat to the outside.  This causes the inside pane of glass to get cold enough to condense moisture from the air.
   If  the windows are old and need replacing, you could get windows that have nonmetallic spacers.  If not, there are things you can do to minimize the condensation problem.  Remove the screens in the winter.  That will allow air movement against the window which will help evaporate the condensation as it forms.  Keep curtains open and if necessary direct a small fan at the window or install a ceiling fan in the room.  Any air movement will help minimize condensation.  Finally, if all else fails, you might have to lower the humidity in the house.  See my blog on controlling humidity inside the house.

Monday, February 18, 2013

Composite Windows vs Real Wood Windows in Minnesota

  One alternative to the solid wood window is a window made of a composite of sawdust, small chips of wood scraps and glue or resin to bind it together.  A large window manufacturer in Minnesota makes such a window.
I think it’s a great idea to utilize what would otherwise be a waste product.  The composite frame is covered on the inside with a real wood veneer that is stainable.   It looks like real wood except for the shape of the corners, which are curved in a way that solid wood seldom, if ever, is.  The outside is covered with a thin skin of fiberglass-like material.
It seems to me that the downside of a window like this is twofold.  One potential problem is that the veneer on the inside could peel, especially if it gets wet repeatedly from moisture condensing on the glass and dripping in cold weather.
The other potential problem is on the outside.  There are seams in the protective skin at the corners.  Caulking seals the seams.  If the caulking fails even slightly, water can get in and be absorbed by the composite.  Then it will swell, making the leak worse.  Eventually the window is ruined.
If I had windows like this, I would check the integrity of the caulking every year.  Also, I would make sure no moisture condensed on the windows in the winter.
Solid wood windows are susceptible to condensation dripping in the winter too.  If the finish is ruined they can be sanded down and refinished with no danger of veneer coming loose.  Wood windows are available with an extruded aluminum exterior, which prevents water from ever reaching the wood frame.