Message Board Thread - "Window & Door Seal Question"

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Window & Door Seal Question msm 1/27/2010
I'm new to infrared thermography and have done a half a dozen inspections. I'm seeing a pattern that each of my inspections show that the windows and doors are leaking air -- especially in the corners. All the houses I've scanned are less than 10 years old and the Windows are high quality Andersen windows. Please look at this image and let me know how you would diagnose ... I'm starting to think that I'm missing something here and all these windows/doors can't be leaking??
Re:Window & Door Seal Question Raphael ITC Eurasia 1/27/2010
Most of the time, the problem does not come from the manufactured product, but from how it is installed!
Air leaks are better visualized with a blower door, a system that pressurizes / depressurizes the building.
Re:Window & Door Seal Question Brad Carr 1/27/2010
This is what air infiltration looks like using a blower door. Are you trying to check for air infiltration? It shouldn't be too hard to find a used blower door to place the home under negative pressure. You could try turning on the bathroom fans, rangehood and dryer to depressurize the home.The results won't be as good . I would suggest a IR building sciences course. Scott Woods is a great ITC instructor . Not sure if He's still teaching.
Re:Window & Door Seal Question mobilenuke 1/27/2010
Keep in mind that thresholds are usually metal
and can have a "cooler" look if the outside temp is lower than inside. Same goes for window frames (even vinyl).
Don't confuse heat transference with air infiltration.
Re:Window & Door Seal Question GRG Ottawa 2/9/2010
Windows are rated for resistance to air leakage. Resistance, not absolute barrier (although, generally, there should be no air flow through fixed glazed windows). Therefore, some air leakage through perimeter seals of operable windows and doors can be expected. Depending on wind pressure, stack effect and mechanical system operation, air may be flowing into or out of a bulding through the perimeter seals. In your case, it would appear than inward air leakage during cold weather is occurring.

Air leakage tends to be more intense at corners because there are usually joints of one type or the other there; window and door manufacturers may apply additional weatherstrip to bridge the joints ('dust plugs' or similar). Air leakage through window sash / frame joints between corners should be less.

To determine if air leakage is problematic, a proper field evaluation is required. Blower door depressurization is not good enough; a test chamber should be constructed across the room-side surface and the chamber exhausted to a chamber / exterior pressure difference of 75 Pa, the rate of exhaust monitored at a steady-state condition, then some simple math to determine the air leakage rate, either by crack length (Canada) or area (US). Infra-red scan cannot be used to quantify air leakage rate in windows.
Re:Window & Door Seal Question Rookie 2/9/2010
Could this just be a difference in emisivity or a black hole?
Re:Window & Door Seal Question glassman 2/9/2010
Hi Guys, firstly, you need to know what type of frame and or door you are dealing with. A common fault is where the sealing gasket has either shrunk due to cold or has not been fitted correctly. If the cold ingress flair is on the leading edge then either the frame has twisted or the door had developed a twist. Most common in humid climates and especially with hard wood doors.
You say they are anderson manufacture, although I live in England we recognis ethe quality of manufacture. Unfortinatlly this does not mean they have been well fitted and that is the issue in nine cases out of ten. Another consideration is useage. If the door is subjetc to heavy domestic traffic then there will be an impact.
There are many influences that can give you this problem and all I can say is that the door or window is not either sealing correctly when closed or has not been sealed corretcly in the case of a fxed light when built.

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