Message Board Thread - "Residential Ceiling"

Back to Threads | Back to Forums

TitleByPosted On
Residential Ceiling JP277 3/3/2010
This image was taken on a ceiling of a home, checking for insulation. The complaint was that the room was too cool in the winter and too warm in the summer. This image shows warmer ceiling joists than the other side of the house. The sun had set about an hour before and I thought that it would have been warmer on the other side of the home where the sun had setthan this side. If you could guide me in the right direction I would greatly appreciate it. Thanks.
 
Re:Residential Ceiling IRJay 3/4/2010
I believe you are seeing the stored heat in the joists. This is why the ASTM C1060 states specific times and other factors to consider when inspecting a dwelling. Solar loading can reverse the heat transfer on a structure and confuse the expectations. We offer an energy audit class to address the understanding of the heat tranfer and standards.
 
Re:Residential Ceiling JP277 3/4/2010
IRJay wrote:
ve you are seeing the stored heat in the joists. This is why the ASTM C1060 states specific times and other factors to consider when inspecting a dwelling. Solar loading can reverse the heat transfer on a structure and confuse the expectations. We offer an energy audit class to address the understanding of the heat tranfer and standards.
Thanks for the reply. I orginally wanted to do the IR scans at 6am, but these folks are not morning people. I had thought that the heat from the sun might be a problem on the ceiling, but I did not know to what extent. If I do another scan at say 9 or 10 pm with the sun out that day would I still receive the same results? I also could wait for a cloudy or rainy day to do the scan. This image is from the front of the house the sun hits in the morning.
 
Re:Residential Ceiling qhinspect 3/4/2010
JP277,

I copied your image and did some manipulation
and some spot temps. There is only a 1.4F degree difference between the joists to the left and the ones that are across the ceiling.
I would bet that the joists of the flat section have more insulation above them. It appears that this is Gambrel style roof with the ceiling flat in the interior. If that is the case then there is more room for insulation.
 
Re:Residential Ceiling JP277 3/5/2010
Thanks for the reply. I am not sure if he wants to put more insulation in, since he had this ceiling put in about 5 years ago. I am going to mention it to him.
Thanks for the help. Have a blessed day.
 
Re:Residential Ceiling Ea1Services 3/11/2010
IRJay wrote:
ve you are seeing the stored heat in the joists. This is why the ASTM C1060 states specific times and other factors to consider when inspecting a dwelling. Solar loading can reverse the heat transfer on a structure and confuse the expectations. We offer an energy audit class to address the understanding of the heat tranfer and standards.
Could you send me a link to your offer of classes

Jfrishof@yahoo.com
 
Re:Residential Ceiling Gary Orlove 3/30/2010
Link to the Energy Audit Class

http://www.infraredtraining.com/courses/weatherization_certification.asp

Gary Orlove
Infrared Training Center
 
Re:Residential Ceiling dandersen 4/2/2010
This is what you are looking for.

Actually this is not that big of a deal relative to the comfort in this room.

Is this a "bonus room" (room over a garage etc.)?

HVAC system design is generally the main problem in the "comfort conditions in rooms like this.

All walls, ceiling and floors are against unconditioned spaces and the subsequent heating/cooling loads or considerable and not properly figured into the HVAC system design (usually found to be worse than the rest of the house). There is little or no attic space above the ceiling and knee wall storage areas ventilate poorly due to low vertical rise and restricted air baffles above the insulation.

Heat transfer is more likely radiant, and there is no space for added insulation without further restricting ventilation which will cause even higher conduction.
 
Re:Residential Ceiling happlin 4/2/2010
Keep in mind that wood has an R value of around 1.4 per inch, if these stud/rafters are 2x6 than you can estimate that the R value of the studs to be R6-7 so the insulation between them is in that vicinity. I would suggest that you look at ventilation problems in the roof and maybe consider a spray-in foam if ventilation is okay.
 
Re:Residential Ceiling Scott Wood Associates 4/2/2010
JP277’s original thermogram showing “warm” studs is due to thermal capacity of the wood as Jay described in his response. The second image shows both cooler and warmer studs and excellent example. Since moisture has such a high thermal capacitance, its presence in the wood causes the wood to heat slower as well as cool slower than the stud bays. Danersen’s image shows patterning is pretty typical of a non-uniform insulation pattern expected in most home insulation installations. This image shows poor applications of insulation as well as possible air infiltration.
Happlin’s suggestion of spray foam insulation is a very good one, since it usually provides a more uniform insulation, more insulation (higher R-value or lower conductance) as well as performing very well as an air barrier (convection).
For more information on applying thermography to building applications including weatherization I strongly recommend the building science thermography course ITC provides. In it we describe the applications of thermography in buildings (Heat, Air, Moisture) as well as the building science, exploring IR as an excellent tool for observation.
Scott@buildingsciencethermography.com
 


  • Back to Threads
  • Back to Forums

     

  •   Copyright © FLIR Systems, Inc 2012