During an infrared inspection of a large residential facility, Jim and his team encountered a strange phenomenon: the upper portion of the wall (made of vinyl siding) appeared to be cooler than the lower portion of the wall.
So, what's wrong with this picture? Hint: Analyze the terrain in the image on the left.
I would guess there is no wall insulation on the upper portion of the wall and they have air conditioning units operating, or the heat being dischrged from the condensing units is warming up the wall on the lower level.
South facing roof, looks like around noon.
1. Two possible AC units? One heating, one cooling? Little insulation in walls.... nice 16" framing
2. Nice sunny summer day, clothes line empty - the dryer is being used in the house? On a nice summer day !!
Pretty hot spot in the upper corner by chimney race. That could be artifact or reflection of sun... leaky vaulted ceiling in upper floor?
I think due to the angle of the camera, the upper half of the building is reflecting the sky (which is cold).
The demarcation between the thermal hot and cold, appears to correspond with floor plate. If you look carefully you can see the framing members in the picture... three levels. The underside of the roof is very hot, it was in the shade all day. Since this house is south facing... and the shadows by the AC units appear to be underneath them, it implies that this wall hadn't yet been hit with afternoon or evening sun.
Depending on direction the wall is facing, maybe the radiant heat coming off the concrete is just enough to warm the lower portion of the wall it's reflecting on to.
Thank you to everyone who took a stab at last month's Stump the Chump! Congratulations go out to Christopher Robinson (on this comment string) for being the first to correctly guess what is wrong with the picture: "I think due to the angle of the camera, the upper half of the building is reflecting the sky (which is cold)." Check out the full answer and next month's StC question in the recently released September edition of Performance Matters: http://bit.ly/BPISeptemberNewsletter.