Hi everyone,

   I am new at understanding how to read an infrared camera. I want to see what a wall looks like with or without insulation. Here's my question:

Does there need to be a temperture difference from the inside of the house  to the outside to see if there is insulation in the walls?

What should that difference be? ie 15 degrees.

Do you ask the homeowner to turn up the heat in the winter or turn on the A/C in the summer.

How best do I find out if there is insulation in those walls?

Thanks for your comments

Judi Lyall w/ SHE BUILDS GREEN

Views: 1830

Replies to This Discussion

Thanks John, i appreciate you taking the time to answer my quirey. do you know what the indoor ambient temperature was at the time of the photo? thanks again for helping me understand.

Dale,

I looked up the BD test.  At the start of the Blower Door the inside was 70 and the outside was 43.  From what I remember, the outside didn't change much all day.

Judy

An important thing to remember is that the delta T (temperature difference) that's needed refers to "surface" to "surface" differences when investigation insulation issues.  Ambient temperatures can be a little misleading sometimes when we are investigating energy transmission issues.  For example, If the interior has a surface temperature of 70F and the exterior ambient is 30F we would think that the heat would move from inside to outside (2nd law of thermodynamics - hot to cold).  But what if you are looking (from the inside) at a south wall that has been effected by the sun for a few hours?  That wall might be 120F.  Now the heat movement is from outside to inside.  Missing insulation would look warm from the inside.  And if you go over and look at a north wall, which is not effected by the sun, missing insulation would look cool.  So, I always ask myself: What's the direction of the heat movement surface to surface, inside to outside or outside to inside?  And then I identify the color of the path of least resistance.  The framing members should be the path of least resistance in a fully insulated wall.  If insulation is compromised or missing then it will show as the path of least resistance.   That being said, air leaks usually require much less of a temperature differential, maybe only 3 degrees F and that is ambient to ambient, not surface to surface.  The sensitivity of the camera detector system can certainly have a positive or negative effect on the delta T needed in both scenarios.

RSS

Videos

  • Add Videos
  • View All

Twitter

Latest Activity

Rob Madden, Solar Home Broker joined Leslie McDowell, BPI's group
Thumbnail

Building Performance Institute (BPI)

BPI is the nation's premier standards development, quality assurance and credentialing organization…See More
8 hours ago
Rob Madden, Solar Home Broker posted a discussion

Indoor Air Quality Monitors and Meters

I'm considering purchasing the AirAdvice for Homes indoor air quality monitor but it seems to have…See More
9 hours ago
Rob Madden, Solar Home Broker joined Sean Lintow Sr's group
Thumbnail

Best Practices (Residential)

Best Building, Retrofitting, or even Auditing Practices - what are they, what should change, what…See More
9 hours ago
Nate Adams replied to Diane Chojnowski's discussion Poll: How confident do you feel about the future of home performance?
"Matt Golden commented on a parody video "Single Pane" a few months back that the 9 year…"
13 hours ago
tedkidd replied to Diane Chojnowski's discussion Poll: How confident do you feel about the future of home performance?
"Words are jargon until they become common. They become common when they refer to something…"
14 hours ago
Evan Mills replied to Diane Chojnowski's discussion Poll: How confident do you feel about the future of home performance?
"Not too surprising that "home performance" is unfamiliar jargon to the average citizen…"
19 hours ago
Craig McManus added a discussion to the group Job Board
Thursday
Chris Heenan replied to Luis Hernandez's discussion ERV Configuration
"Can you use…"
Thursday

© 2016   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service