Some color temp measurements on my house in sun

strider3700 · 08-13-11, 01:00 PM

I'm in the middle of painting my house and since it's another sunny day I figured I'd do a quick set of readings using the IR temp sensor to see how the different materials and colors affect there temperatures in direct sun. These are all from the front of my house which faces directly south. The sun has been on these areas for just over 2.5 hours at this point.

front yard Air temp 20 C

Raw concrete steps 31 C
freshly painted off white stucco 32 C
just sanded bare wood, 35 C
old color Brown wood, 42 C
fresh painted Charcoal gray wood 47 C

This may make things a little worse cooling wise during late summer but the vast majority of my energy use comes in winter for heating so hopefully the dark gray will assist in heating the house a little bit more then the brown did.

I wasn't expecting the difference between the white and the gray to be so dramatic.

Xringer · 08-13-11, 11:23 PM

I was amazed at how hot the cedar planks on my deck get when under direct sunlight.
Seeing 50C cedar was one of the reasons that I installed those Solar Screens on the west facing windows of my den.

The heat reduction in the den is amazing. I have to made sure I take those off,
the minute it starts getting cold around here!

I have a few layers of extra insulation on my south facing walls, and I'm pretty sure that the outside
color/reflectivity would not make a very big difference in heat loss during the winter.

I think a wise investment would be to reduce your window losses at night,
and try to increase your solar gain during the day.

I wish my south facing windows were bigger!

08-13-11, 01:00 PM	#1
strider3700 Master EcoRenovator Join Date: Dec 2008 Location: Vancouver Island BC Posts: 745 Thanks: 23 Thanked 37 Times in 30 Posts	Some color temp measurements on my house in sun I'm in the middle of painting my house and since it's another sunny day I figured I'd do a quick set of readings using the IR temp sensor to see how the different materials and colors affect there temperatures in direct sun. These are all from the front of my house which faces directly south. The sun has been on these areas for just over 2.5 hours at this point. front yard Air temp 20 C Raw concrete steps 31 C freshly painted off white stucco 32 C just sanded bare wood, 35 C old color Brown wood, 42 C fresh painted Charcoal gray wood 47 C This may make things a little worse cooling wise during late summer but the vast majority of my energy use comes in winter for heating so hopefully the dark gray will assist in heating the house a little bit more then the brown did. I wasn't expecting the difference between the white and the gray to be so dramatic.

08-13-11, 11:23 PM	#2
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	I was amazed at how hot the cedar planks on my deck get when under direct sunlight. Seeing 50C cedar was one of the reasons that I installed those Solar Screens on the west facing windows of my den. The heat reduction in the den is amazing. I have to made sure I take those off, the minute it starts getting cold around here! I have a few layers of extra insulation on my south facing walls, and I'm pretty sure that the outside color/reflectivity would not make a very big difference in heat loss during the winter. I think a wise investment would be to reduce your window losses at night, and try to increase your solar gain during the day. I wish my south facing windows were bigger!