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: 475

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

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

tedkidd commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"Yep, this thread has some good discussion. Back to dehumidification.  This may be…"
1 hour ago
Jim Gunshinan commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"Thanks for the clarification Nate. If I had the ability to precisely measure what $50 of health…"
2 hours ago
Nate Adams commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"Jim, Just a clarification, it's not DEhumidification I'm worried about in your climate,…"
2 hours ago
Chris McTaggart posted events
2 hours ago
Jim Gunshinan commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"Hi Nate, I'm glad this post has generated so much good discussion, since that is its main…"
3 hours ago
Diane Chojnowski's group was featured
Thumbnail

Facebook Pages

Does your company or organization have a Facebook Page?This group is for pros who have facebook…See More
3 hours ago
Tom White joined Diane Chojnowski's group
Thumbnail

Facebook Pages

Does your company or organization have a Facebook Page?This group is for pros who have facebook…See More
3 hours ago
David Valley's photo was featured

ceiling_infrared

Cold air infiltrating the lower right portion of this wall and ceiling.
3 hours ago
Christopher Morin's 2 blog posts were featured
3 hours ago
Kurt Shafer's blog post was featured

What is your opinion about members promoting products here?

Hello,I am a whole house fan and attic ventilation expert in Temecula CA. I started studying whole…See More
3 hours ago
Scott Mellberg's blog post was featured

Lessons from Energy Efficiency Advisors: Getting Homeowners Onboard with Home Performance

Homeowners are often aware of the different problems they experience in their homes: uncomfortable…See More
3 hours ago
Trip's discussion was featured

Starting a Home Weatherization Business. Considering it...

I am considering starting a home weatherization business. (I live in Southeast Alabama)  Currently…See More
3 hours ago

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service