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

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

--- i'm skeptical...

 

 

Views: 185

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

Christopher Talarico posted a discussion

Heating with Tankless Water Heater & Hydronic Air Handler vs. Gas Furnace

Hi,I've looked around online and haven't found a lot of good information on home heating with…See More
8 hours ago
Profile IconSara Sabol, Christopher Talarico and Aaren Stewart joined Home Energy Pros
10 hours ago
Hal Skinner replied to Andy Gostisha's discussion Disguising Ductless Heat Pump Units
"Hi Andy. The bare metal units on a roof stick out like a sore thumb .  Coating them with our…"
10 hours ago
Paul Morin replied to Stephen Standley's discussion Which reading is more reliable on a Minneapolis Duct Blaster?
"Sorry for chiming in so late.  Sean’s comment early on in the discussion was the closest…"
13 hours ago
jerry gentile posted a status
"hello- anyone challenge the written QCI exam?"
16 hours ago
Kevin Jordan posted photos
21 hours ago
Susan E. Buchan's event was featured

EEBA Excellence in Building Conference at Doubletree Union Station Hotel

September 23, 2014 at 8am to September 25, 2014 at 2pm
yesterday
Susan E. Buchan posted an event

EEBA Excellence in Building Conference at Doubletree Union Station Hotel

September 23, 2014 at 8am to September 25, 2014 at 2pm
yesterday

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service