Here are a few images I took while conducting a Home Energy Performance Survey yesterday. They were taken while the house was depressurized to CFM50. They were taken at the ceiling/wall intersections in the front bedrooms (2nd floor). The wall area is underneath soffit vents and there were no insulation baffles in the attic. In addition, the top plates were not sealed.
There thermal patterns seem to indicate that it’s wind washing from the lack of air sealing and baffles, but they also appear to have patterns associated with moisture. I measured the wall with both a surface and pin type moisture meter - no detectable readings.
My first inclination is to say wind washing as there was an enormous amount of air movement through the attic and conditioned space. But, the patterns have me second guessing myself. Another scenario would be residual moisture stains from ice daming or condensation. It’s probably both! The Delta-T was extremely low (4 Deg F).
Anyways, thought I would post them here and get any feedback.
Kevin What kind of insulation is in the walls? It looks like a blow on or foam wall insulation. The center pattern may be due to one of these types of insulation with some settling. This would give you this kind on image.
I would check on the type on insulation used in the walls.
One way or the other please post this information on the board. This is an odd IR Image.
Both of the images were taken on exterior walls (front of home). The insulation in the walls was confirmed to be Fiberglass Batt (R-11). This an end unit Town Home with brick veneer cladding (built 1976).
You have lot’s more experience than I, but my guess is a convection current. I’m thinking the insulation near the top of the wall has settled or squashed down. Take a look at the top sill plate from the attic. I’m sure it’s not sealed. The gap is allowing a convection current within the walls.
However, the warmest part of the first thermogram is the window; so you actually have less than 3.8 deg delta T. Far from ideal.
Hey, Kevin nice pictures. A little off topic but if I may ask how are receiving most of your energy survey business? Are you marketing direct to public, newspaper, word of mouth, radio etc? Im completing my infraspection training and about to take the plunge this winter, any suggestions would be appreciated. Feel free to PM me if you prefer. Thanks in advance Kevin!
Right now I’m just relying on leads from my website, which has done pretty well since it’s launch last month. I also market to current clients at each inspection. Next month, I plan to market to all of my past clients and Realtor base.
Or you can seal off that room by closing other doors to create more pressure, turn on kitchen/bath fans ETC. Due to such a low delta t it’s a tough one.
Introducing heat would of help too as would a bore score and a small hole in the wall to check the cavity.
I do a scan of the interior of the property before conducting the blower door. I’ve found it better that way, because I can get a baseline of what the property looks like before depressurization. Once I turn on the fan and get it stabilized to CFM50, I go out and find air leaks and do zone oriented pressure testing. I like to keeping the fan running until I finish with all of my tests.
The walls did show a faint thermal anomaly, but was much worse once the blower door was running. What I should have done is capture the images before the blower door and then compare the two.
The house was already depressurized to CFM50, so turning on the fans would not make a difference. Although, heating the room would of helped.
I’ve been thinking of getting one of those wall scopes, but not sure how in depth I want to go it. I have said here many times that I’ve conducted 100’s of energy audits, but I’m just touching the surface with respect to conducting them to BPI Standards - specifically with the Blower Door.
I’m definitely getting some unique and interesting images! I don’t care what Level you are, Building Thermography is challenging.
I’m not sure about those scopes either. I wonder if you make a small hole in the wall will you actually be able to see what’s in there, or not and how well will the image be, then you have a small hole to fix.