Glazing Surface TemperatureDISCLAIMER: This is for informational purposes only, I only own an IR Camera and I am NOT a certified thermographer. I know enough to be dangerous, and that is about it!
Here is my attempt at figuring out the glazing surface temperature at Rochester Passive House. I did 2 different scenario's.
1) Full Solar Gain - South facing window
2) No Solar Gain - Breezeway (north) door glass
Here were my test parameters:
Full Solar Gain: No Solar Gain:
You can see my reflection in this IR Photo.
To get closer to an actual glass surface temperature I took a scrap piece of paper, and covered half with black electrical tape, and covered the other half with 2 layers of painters tape. I taped this square to near the center of glass and let it sit there for a while. I am going to assume the paper will become the same temperature as the glass.
This is the paper I taped to the glass. I needed to make sure the paper was completely opaque. I used black electric tape for half, and 2 layers of painters tape for the other half. According to FLIR electrical tape has an emissivity of about 0.95. The painters tape is not as shiny (lower emissivity) but I wasn't sure if how the black tape would show a hotter temperature with the solar gain.
Here is the Solar Gain Photo:
You can see, the black tape is hotter than the painters tape. But both of them are in the 103-106F range. The hottest temperature is not centered in on the black tape because of the angle the sun is hitting the exterior glass.
I have 2 images for the shaded glass
This one was taken roughly 1.5 ft away at a slight angle. It is roughly 65F
This one was taken about 6" away, but you can see how varied it is, there is quite a bit of reflection going on - but the average temperature is about 62 F
Because I was going in and out of the breezeway multiple times, the breezeway door and interior walls may be a few degrees cooler than normal. I took an IR photo of the interior wall, next to the breezeway door and it was 65F. I didn't post it because it is just an orange square - nothing really to see.
IN WINTER EXTERIOR CONDITIONS
Glazing Surface Temperature of South Windows in full sun = 100-105F
Glazing Surface Temperature of Windows in full shade = 60-65F - within 7F of indoor air temperature.
Someday I am going to do this with an Energy Star Window and compare.