All About the Timing: Insulation Inspections and Solar Loading

Matt Schwoegler, Infrared Training Center

The effects of the Sun on the surface of a building can make inspections quite challenging for thermographers looking for missing insulation.  The transient conditions created by solar loading not only mask infrared patterns on the exterior, it also impacts the thermal signature on the interior, perhaps leading one to believe (in the right conditions) that a wall appears to be uninsulated, when in fact it is insulated. 

To capture this, I recently set-up an infrared camera at home to monitor thermal changes on a south facing wall from the interior. The plan was to image the pattern reversal that occurs on an interior surface when the Sun heats the exterior up to a point where the direction of heat flow in the wall reverses, even though the air temperature remains colder outside.

I programmed the camera to record an image every 15 minutes starting at 7:00 a.m. Conditions at the time were ideal to check for insulation problems in a wood-frame building given the interior air temperature of 68˚F (20˚C) and an exterior air temperature of 33˚F (0.5˚C). The first image taken, seen here on the right, shows a wall which appears to be mostly well insulated (warm cavities and cooler framing). As the day progressed, however, the situation changed dramatically.

Infrared Training Center Visits Local Elementary School

by Alex Chrusciel
Infrared Training Center

In the pursuit lifelong learning, Alex and Jason of the Infrared Training Center (ITC) paid a visit to a local elementary school looking to recruit the next generation of thermographers. What originally began as a single class demonstration (roughly 25 kids) blossomed into a gathering of the entire fifth grade class, over 90 children! During a brief hour long presentation, the students were exposed to a crash course on infrared application and technology. The session sought to answer three basic questions: what is infrared, why do we use it, and how does it work? The enthusiasm displayed by the students was both refreshing and uplifting. Not only could we see the energy we could feel it as well! The kids were shown hands on demonstrations which made learning about conduction, convection, and radiation heat transfer both fun and exciting. The radiant culture of infrared (no pun intended) left a lasting impression on the children as well as the faculty. The session concluded with a quick photo opp. and an extended invitation to make an annual presentation for the students. “Tell me and I forget. Teach me and I remember. Involve me and I learn” - Benjamin Franklin

ThermalSpeak – building efficiency and thermal bridging

by Jay Bowen
BPI Energy Analyst
ASNT NDT Level 3 Thermographer

Building conversations in training this week brought up the subject of thermal bridging in the structure. Defined by a material of less insulation or greater conductivity. This material bridges or short circuits the better insulation and reduces its effectiveness. This reduces the overall R value rating of the whole assembly. The following website,  http://web.ornl.gov/sci/roofs+walls/AWT/home.htm , addresses this whole wall rating concept. This isn’t a debate of test methods or approaches. It is enough to say that anything put in the wall that reduces the energy of that wall should be addressed in the construction process.

My input on this subject is finding these, before construction begins and discussion with a builder, methods to reduce or eliminate these bridges. Verification of the design or confirmation as building progresses would be where a thermographer can enter the process and provide proof that the building project has conformed to this concept of design.

The images from a qualified thermographer provide detailed analysis of construction detail typically hidden from the inspectors or builders.

Taking a set of images to compare this approach can clearly see the advantage of reducing the vertical framing typical of stick built construction. Even the wide wall of 2x6 framing to increase the side wall dimensions for increased insulation. This is an increase in the R value but the thermal bypass of the stud is still there.

Using SIP to reduce bridging	Standard stick frame wall

Looking at a SIP wall can visualize the reduction in the bypasses by reducing the vertical framing. The corners and joints are still present but can be reduced by the same methods of stick built using exterior insulated sheathing.

Making the bridge elimination or reduction a conscious thought in the whole building process can have substantial rewards in energy saving in the home.

New Live Webcast Topics Added Through June 2015

The Infrared Training Center (ITC) is pleased to announce that a number of live webcasts have been added to the schedule for the 2^nd quarter of 2015 including some fresh topics in the mix.  For a complete listing of available dates and times, please visit ITC’s webinar page here:

http://www.infraredtraining.com/webinars

ITC’s complimentary educational webinars are designed to provide a valuable overview of thermal imaging and its many applications. Participants learn not only the basics of infrared thermography, but also where IR can reduce costs, save energy and increase safety for professionals across a variety of industries.

Can’t make any of the scheduled broadcast dates? Not to worry, all live sessions are recorded for playback at any time. These on-demand presentations are also listed on the main webinar page and are accessed with a simple (and free) registration.