... with windows with a better R-value than walls ?

http://www.good.is/post/thermogram-shows-the-extreme-efficiency-of-...

--- i'm skeptical...

 

 

Views: 186

Replies to This Discussion

You should be skeptical, Davide!! Something is clearly not right. Windows are about 20% reflective but all of them at that angle could be reflecting the same cold sky.

 

I think the interior temperatures of the buildings were different. I have R=10 windows and even they are warmer than my R=45 walls!


As the image below shows, we can make windows appear pretty much an...
 Interior temps in this image were all the same; the difference is what is being reflected, cold sky (top), warm surroundings (bottom) or a mixed background (middle).

Here is another image showing R=10 windows (Serious brand) on the right and conventional double-glazed, nitrogen-filled windows on the left (there is a screen on the right window of these). Interior temperatures are identical in both rooms.

John

Is the emissivity difference between the glass and the wall making a difference too?

Ed Minch

It is certainly possible as I no longer have the exact specs for the older windows. My belief, however, is that exterior surfaces of both old and new glazings are uncoated so what we are seeing is related only to the difference in actual heat transfer.

For the other image (3 windows stacked), all three windows are identical. The difference in "apparent temperature" is entirely due to differences in the reflected background temperatures.

RSS

Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy,) and brought to you in partnership with Home Energy magazine.

Latest Activity

Craig Foley replied to George Kopf's discussion Real Estate Professionals need our support - but how?
"Thanks Jan, your insight, as always, is invaluable. Your suggestions regarding a top down approach…"
9 minutes ago
Hal Skinner replied to Hal Skinner's discussion An example of what an RCC can do with no R- insulation in the walls.
"Brett, you just asked the million dollar question when it comes to OUR coating. Now I will let the…"
21 minutes ago
Melissa Ulbricht commented on Melissa Ulbricht's blog post When windows aren't the culprit of a leaky building, solve the mystery with an energy audit.
"Well said, Don! Now is the time to invest in energy efficiency to help keep homes and buildings…"
58 minutes ago
Bret Curry replied to Hal Skinner's discussion An example of what an RCC can do with no R- insulation in the walls.
"Thanks for the prompt reply Hal. Do you have any third party infrared white papers (including…"
1 hour ago
Don Fitchett commented on Melissa Ulbricht's blog post When windows aren't the culprit of a leaky building, solve the mystery with an energy audit.
"Yep, winter is coming and there are not many out there trained to do IR Infrared Thermography…"
2 hours ago
William B. Ramsey commented on Chris Laumer-Giddens's blog post Mini-Split Heat Pumps are Quirky, Especially their Capacity
"Excellent post, thank you!I live in a humid climate and the mini-split heat pump I have will not…"
2 hours ago
Hal Skinner replied to Hal Skinner's discussion An example of what an RCC can do with no R- insulation in the walls.
"Good morning Bret. Solar Reflectivity -    0.83 Thermal…"
2 hours ago
Jan Green replied to George Kopf's discussion Real Estate Professionals need our support - but how?
"I agree Craig, on all points.  I do think that a top down approach would be more effective.…"
2 hours ago

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service