FLIR Home Energy Audit Tools

What tools do Home Energy Auditors and Home Inspectors use? Shopping for the right Home Energy Auditor or Home Inspector can be a timely process. Beyond their certifications and experience, you should also consider the types of tools they use to perform their tasks.

Here’s a video with Tom O’toole of FLIR Systems and Flemming Lund, a certified Energy Auditor & Home Inspector, talking about the tools used in the various phases involved in a home energy audit.

Building Thermal Envelope Commissioning - Free White Paper

This application paper, written by ITC instructor Bill Schwahn, was originally presented as part of the proceedings at ITC’s 2015 InfraMation Conference. It discusses the process of using thermal imaging to determine the air tightness of a structure so that it meets the requirements of the 2012 International Energy Conservation Code for Commercial and Residential Structures.

Click Here to Download

InfraMation 2016 will be held in Las Vegas, Nevada at the Rio Hotel and Casino on September 27-29, 2016. The event will also include a pre-conference training day on Monday, September 26. Save the date and plan to join hundreds of other thermography professionals where you’ll learn the latest thermal imaging techniques and applications while making valuable connections! If you’re not sure what to expect, here’s just some of the great content and entertainment that attendees experienced at InfraMation 2015 in Nashville.

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.

Warm Feet, Cold Reality

Matt Schwoegler, Infrared Training Center

It can take being uncomfortable for some homeowners to really start thinking about the efficiency of their house. Certainly, the bill from the electric company or that propane truck *once again* backing into the driveway all serve as painful reminders that your home uses (too much) energy. However, when air leakage across the floor leaves you with cold feet, or you find yourself always shivering from a draft on a windy day, it starts to get old...fast. Experiences like this can help motivate one to consider putting energy efficiency improvements on the fast track.

This assumes, of course, that the occupants are *feeling* cold in the first place. How about when it might not be as obvious, such as the case here? Sometimes thermal imaging can help a homeowner understand why what they are experiencing (feeling) is very different from what is actually happening.

These infrared images (above) were taken near the rim joist in the basement of a contemporary-style home built in 1984.  The residence has wood floors, fiberglass insulation and, not surprisingly, a decent amount of air leakage (3550 CFM 50).

As expected, one of the larger areas of air infiltration in the structure is located around the rim joist. What you will notice too is that the home also has a radiant floor heating system (images below):

New Live Webcast Schedule Available

ITC’s successful series of free, live webinars, continues into 2015 with a number of new topics and dates that have been added to the schedule.  We've added steaming video from our production studio for most presentations and have improved the audio quality to deliver a better overall broadcast of the live webinars. On-demand sessions also available:

http://www.infraredtraining.com/webinars

These 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. Attending these sessions also demonstrates why pursuing a professional certification in thermography is a necessary step to becoming a successful thermographer.

If you’re in the electrical, maintenance, or home inspection business, infrared thermography can help you spot a number of issues that your eyes simply can’t see.  Join us for one, or perhaps all, of these webcasts today to learn more!

Registration is now available at www.infraredtraining.com/webinars where you’ll also find a number of on-demand recordings from past live events that can be viewed at any time.

Analyzing Building Images Acquired at Different Times

A camera user writes:

"I find that images taken of the same structure, not much separated in time, sometimes look very different.  This poses a problem for me as I’m trying to compare the heat images of different houses (to detect homes that need weatherization).  Presently I’m not confident that images of two homes reflect actual differences in the structures, or are caused by minor environmental changes or even by artifacts in the photography.  Here is an example.

Attached are two nighttime images of the front of my house, which faces east.  IR0310 was taken at 10:40 PM, IR0408 at 11:11 PM. (The clock on the camera is two hours fast.)  It was a cold night with little temperature change over the half hour between pictures.  The house thermostat was constant. 

I've set the palette and temperature range to give me good differentiation of houses along the street.  I took the first image of my house as I began imaging houses on my street, and I took the second image when I finished the street scan. 

I am surprised, first, that my house looks so different in the two images. And second, that the outside looks warmer in the later image.  If anything, I'd have expected the outside to have cooled.

Glad for any interpretation of this.  Needless to say, with this kind of variation on a single house, it is hard to get good images for comparing houses. "

Vented Soffits or Cover-up?

By Kenneth Brown, MD

A homeowner recently requested our services to help her understand why her attic temperatures could remain so high. For some reason she had placed an electronic thermometer in the attic. In late spring when the outside temperature was pleasant, i.e., in the 70's, in her home in Pennsylvania the attic air temperature, 24” below the ridge vent, were 40-50 degrees warmer.

A new roof with 25 year architectural asphalt shingles, in a moderately dark brown had been applied  within the previous 12 months. At that time a new ridge vent was put in place, and the attic already had 2 gable vents, each approximately 16X24 inches and the pitch of the roof was 8X15.  Finally, there were two 6 inch by 16 inch vents in the horizontal soffits at the front and at the back of the house.

Why was the attic not cooler?

Sometimes the IR data is critical and other times it is merely useful, or on occasion just interesting. In this case it was certainly instructive and required no removal of any materials to get to difficult-to-access construction.

Figure 526 is one of the vents in question. Nothing striking about it at first glance. What’s wrong in this photo?

Fig 526

Figure 523 and 525 are both thermograms of the soffits on the rear of the house taken > 4 hours after the sun has no longer been on them. They are close enough to each other that there is no significant cooling from the breeze, and if so, it would have had equal effects. So, why the temperature difference between the two? Note that Fig. 523 appears to have irregular patterns of cooler temperature areas. On removing the vent from the soffit, we noted that someone had cut a large opening with approximately 30 inches space for air flow in the soffit. Such is not the case for the “vent” in figure 525. Rather  the screen-backed "vent" was put in its place after the builder drilled a few holes.

Fig 523 (good ventilation)                     Fig 525 (poor ventilation)

So we go to Figure 535 to see how effective these so-called soffit vents should have been. Note that the golden dots- holes meant to provide ventilation, in reality only provided us with a little entertainment.

Fig 535 (restricted air flow)

So, what did we learn from this exercise? It reminded us that:
        Even if you use a B300, you still have to think.

To get air flow in a closed or semi-closed space such as an attic, there has to be air intake in order for there to be air exhaust. Seems simple, but there are many sites on the web that do not seem to understand it.

Ideally, the ventilation should be designed to provide cooler incoming air through the soffits. If you have incoming air only from gable vents, then it will be short circuited and not pass along the slope of the attic roof, closest to the shingles heated by the sun.

If there are gable vents AND soffit vents AND ridge vents, it may be appropriate to actually block off the gable vents in order to avoid the short circuit in air flow described above. The calculations by which you determine the needed amount of area for the vents for incoming and exhausting air (in square feet or square inches) are determined by the area of the attic “floor” and the pitch of the roof (http://www.1728.com/gradient.htm).

There is more than a small chance that your roofer (much less your builder) may not calculate it herself/himself - the roofer from whom this customer sought help did not and said “we are not engineers- the manufacturer of the vents tells us how many use.” And the proposal was to put one 3 inch diameter vent between each pairs of rafters, front and back; at 7 square inches apiece, and putting 30 in front and 30 in back, this would have provided 420 square inches, far short of the minimum of 576 square inches needed (30ftX40ft)(144 s.i./s.f)/300. Not to mention how they would detract from the appearance of the soffits.

So, without blushing, ask your supplier of your roofing/ventilation services for the basis of the calculations used on your house. You may add years to the life of your roof.

Just as we are now asked to think and be responsible for our health, we have to do so for the homes we live in. Caveat emptor! Get ventilated, not covered up.

Can I Inspect Stud Walls when the Weather is Warm?

"Am I right in thinking that the weather/ delta T are not in my favor for stud wall analysis during the summer?"
 
 
This is a question many new thermographers have. If you think about the heat transfer, the answer is you should be able to get good images from an external wall providing you have sufficient Delta T.  

Right now it is hot outside.  So, if you are observing the exterior wall of an air conditioned residence, you should have a Delta T of 10°C or 18°F or better, if the interior temperature is about 70°F and the exterior is about 88°F or more.  Remember that the air temperature does not necessarily have to be 88°F, if the sun is heating the wall (and has been for a few hours), that will work too. If the building does not have air conditioning and the windows are all open, this would certainly make things more difficult.

Here is an infrared image of an exterior wall taken during a hot day (taken from the interior of the building). Notice the hot studs (vs. the cold studs you would see during the heating season).

You can learn more about this application in the Building IR Basics course.

FLIR introduces Bluetooth MeterLink Technology

FLIR demo of the new Bluetooth MeterLink technology that feeds live moisture or amperage readings into the infrared camera and attaches it to the infrared image automatically.

ITC introduces Live Instructor Led Webinars

Webinars are live instructor led seminars conducted via the world-wide web. Participants listen and interact to the webinar through their own computer. All that is needed is a telephone and high speed internet connection.

The Infrared Training Center introductory webinars are designed to give students a straight forward explanation of how Infrared technology fits into a specific application or industry. The sessions are hosted live by an Infrared Training Center instructor and webinar director.

There are three to choose from:  

• Introduction to Indoor Electrical Surveys using IR Thermography
  
• Introduction to Outdoor Electrical Surveys using IR Thermography
  
• Introduction to Residential Energy Audits using IR Thermography

  
Infrared Training Center

ITC E-Learning Web Portal

Tips to find moisture in wall cavities and insulation

"I'm looking for moisture in wall cavities and insulation, all in the interior of homes. I can't even see the studs let alone the screws."

To find moisture in building materials, the infrared camera must see a temperature difference on the surface being viewed: no temperature difference, no detection. The question is; under what conditions can a temperature difference due to moisture occur?

The most common scenario for moisture detection involves a temperature difference due to the evaporation of water from a surface. When water evaporates, the surface will become cooler. In order to evaporate well, the air dewpoint temperature should be lower than the air temperature, the lower the better.

If the relative humidity where you are trying to inspect is 90%, you are not going to get much evaporation, hence not much cooling, hence very low temperature differences that might not be spotted with your IR camera. In such a situation, use a dehumidifier in the room to lower the humidity (it also adds heat to the room which raises the temperature and also lowers the humidity as well).

Always confirm your readings with a moisture meter.

Wet insulation has a lower R value, or resistance to heat flow compared to dry insulation. So in situations where you have a temperature difference on either side of a wall, the wet insulation would allow heat to flow more easily, hence a thermal indication on the wall. Again, you need a temperature difference between both wall surfaces that has been there for several hours.

Will the wet areas appear hot or cold? That depends on the temperatures on the wall. For instance in the winter, where the inside is warmer than the exterior, you would expect to see a cool area when viewing from the interior. In the summer where the exterior wall temperature is higher than the interior, you would expect to see a warm area from the inside. Again, always confirm with a moisture meter, because there can be other reasons for hot or cold areas as well (like missing insulation, poorly fitted insulation, air leakage, heating ducts, etc.)