New Tech Note: Top Ten Myths About Thermal Imaging Cameras

We have just published a new tech note: “Top Ten Myths About Infrared Thermal Imaging Cameras”. This 10 page presentation should be of great use to people buying their first TI camera.

http://www.pembrokeinstruments.com/_download_pdf_897/_Pembroke-PDF-Downloads/Top-Ten-Myths-IR-Thermal-Cameras-Pembroke.pdf

Les

http://pembrokeinstruments.com

You know what is weird is that FLIR produces a 12 things to look for in an infrared camera, and yours and theirs are not the same. Weird how two different sources come up with 22 combined different things.

JJ

Any reason you did not put the Fluke Ti32 (same price as the TiR32) in your brochure? lol.

Also fix your temperature range on the TiR32. I find it better to make sure my stats are correct before I publish stuff like this.

JJ

Misc quotes from the PDF:

“The greater the thermal sensitivity a camera has, the better it will work for my thermal applications. FALSE”

Really? You might want to be more exact on what applications you are referring to. If you get a call from someone wanting to watch the thermal patterns of a bunch of soy bean plants to see which is engineered better, you are telling me the thermal sensitivity doesn’t matter?

Thermal imaging cameras should never be used in the daylight. FALSE

Weird because I am almost sure that if you are doing a flat roof inspection with shadows on the roof, it is going to be basically impossible to do a scan properly.

JJ

**THREE: The color of the target will impact thermal measurements. FALSE
**
Dark colors can be warmer in sunlight than lighter colors.
Light colors can be cooler in sunlight and some are more reflective.

**FOUR: Thermal imaging cameras should never be used in the daylight. FALSE
**
Sunlight (UV radiation) can influence the surface materials being scanned, and
make it more difficult to see things that could have been seen before the UV rays
heated those materials.

The bottom line is this:

A thermal image of a ceiling, by itself, is as good at informing you about the effectiveness of the attic insulation as shining a flashlight on an air return vent will tell you about the effectiveness of the heat pump.

I don’t think so…

http://acsillc.com/blog1/wp-content/uploads/2010/02/Insulation.jpeg

Meaningless.

Many guys point their cameras looking for missing insulation and think that they have saved the consumer money when they spot things like you just did. Big deal.

Second to fenestration, the biggest losses of energy occur from air leaks through the ceiling…and to an air leak, insulation is nothing but an “air filter” for the air as it leaves the building.

Then, while your camera shows areas that are presumably insulated…it fails to note the fact that the insulation has been smashed into place or otherwise flattened, or fails to be flush with every edge, or is bent to make it fit…which can reduce its R-value by up to 50%. None of that shows up in your picture which makes your picture, at best, misleading.

Just weeks ago you were a critic of IR technology, now after the purchase of an IR camera, a blower door and a certification course you’re a pro…un f u c k i n g believable!!!

Incorrect.

1- Insulation deficiencies in the ceiling are a significant issue. (try
reporting that you did not inspect the ceiling insulation because it
is meaningless… LOL).

2- Air leaks are bad, but even without air leaks, the insulation
deficiency is still a real issue (btw… thermal imaging can reveal air
leaks as well - to the trained thermographer).

3- Thermal imaging can easily reveal insulation deficiencies, even
after a RESNET and BPI inspector passed the house (the naked eye
cannot see the things IR reveals). These issues can be caused by
the insulation being smashed into place or otherwise flattened, or
fails to be flush with every edge, or is bent, or even more reasons.

Smashed insulation has one signature. Air gaps around the edges
of insulation has another signature. The IR camera can many times
see these distinctions. A visual inspection will miss these issues
many times, but IR can see it very easily. An energy auditor
without an IR camera is 50% blind.

Since you have never been trained or used an IR camera, then you
don’t know these things.

You stated one time that unless the interior and exterior temperature
are exactly the same, thermal imaging would not work well. Do
you still proclaim this error? Any trained thermographer will tell you
that this condition is exactly the environment to avoid and is called
by the term “low delta T”.

The above comments are “infrared 101”.

You sell training and cameras and gain, financially, from your unsubstantiated claims.

I am not “incorrect”. You are, and for obvious reasons.

If you do not own and use a blower door, you cannot quantify air leaks…nor are you able to safely recommend mitigation. If you were properly trained, you would know this.

According to a Resnet study, both of those statements are incorrect. The number one cost to consumers when associated with energy (heating/cooling) loss is via the ducts.

If armed with that information you are mostly correct. Using IR for the ducts is mainly pointless due to line of sight and emissivity issues associated with duct work.

In my opinion you are throwing out a couple of considerations to the benefits of IR. In your example you want to crawl up in the attic and do a visual of all the insulation. At the end of the day, you are correct, you will find all the same issues that you did with IR. First, how long will that take you vs IR? Second, is your process non evasive (you will be moving and compacting insulation as you move around)? Where fiberglass exists do you really want to be crawling and breathing that? What about an attic with asbestos, same questions, plus the legality of even messing around up there is a concern. Finally I would invite you to come to AZ and crawl around in attics all day long during the summer doing this while an IR inspector is down in the AC doing the same job. There are a few others like line of sight with your flashlight, tight areas etc.

IR is just a tool, like any tool it has its time and place. You are 100% correct, IMO, that using it solely is not a means to the end. However, when used in conjunction with other tools, experience and in the hands of someone with a background in what they are pointing the camera at, IR can find and isolate issues that would otherwise potentially not be found or properly diagnosed.

Personally, in your example, I use IR, and a blower door, to isolate the issue and then still end up in that hot attic with the flash light and all the aforementioned issues to deal with anyway. The good news is I can limit my time up there and provide the consumer with additional qualitative information (my flash light will not show the 10 degree delta T that John’s camera showed).

JJ

Not!

Well, maybe. What do you mean “by itself”?
Is this a leading statement?

You can’t get the R-Value with just one click of the camera, if that is what you mean.

You **can **determine the R-Value if you also take other measurements for the process.

More “Not”.

If there is any change in density of the insulation, it does in fact show up.
And you can determine the differential of the R-Value with the camera.

Second to fenestration?
Ceiling air leaks are a greater loss in many, if not most energy losses that I find.

#1 HVAC loss (it is always under the high (+/-) pressures during operation).
#2 Upper level air leakage (relative to the pressures of stack effect). Though this is tested a 50 pa, you will never see pressures as close to the HVAC equipment with stack effect.
#3 Lower level leakage (proportuniate with upper air leakages as well as outdoor ambient conditions like wind).
#4 Insulation losses.
#5 Turning up the heat/ac too much.

What an incredibly ignorant and ridiculous statement.

I will grant that air loss is important. I will also grant that a 1 x 1 square of missing insulation in a 20 x 20 room is not overly significant and tell my clients that.

However, I find several houses a month with SIGNIFICANT (more than 50% of a wall of ceiling) missing insulation or even room with none at all. Usually in completely inaccessible attics that would require destructive investigation to inspect. These are hugely significant.

Stupid statements like that just make everyone in our field look dumb. Please refrain unless you have something constructive to add.

Insulation over an air leak is nothing more than an air filter for the outgoing conditioned air.

An energy audit conducted only with a camera does not measure or find the leaking air. Recommendations to tighten a house…without knowing how it will affect the exhaust of the combustion appliances…is not only amateurish and plain stupid…but deadly.

The public needs to know that there is 80% more to a real energy audit than a thermal image. You are not helping.

I am going to have to disagree with you on this one Jason!

The thermal imaging camera can identify and document inadequate performing insulation that is not visible to the naked eye (even if you can manage to get to it in the unconditioned space)!

I find thermal losses all the time where if I can access them are almost invisible through visual inspection. Even a very slight gap or displaced insulation that is not against the sheet rock vapor barrier (which you cannot see) will cause a convective loss that is identifiable with thermal imaging. And this loss is in fact considerable.

So the option of selecting a visual inspection over a thermal inspection is out of the question in my opinion! :slight_smile:

And we all stand here and say the same thing about the blower door!

I am not questioning your perception, rather you are misleading statements.

It is my personal opinion that a true audit should not be performed without both applications.

There is a possibility that you will not see air leakage with a thermal camera due to the direction that the air that is flowing away from the camera. However, a high-end camera will see the effects of air leakage because it changes the temperature of the surrounding building materials as it passes through and it can be easily seen regardless of which direction the air is flowing (thus my ranting opinion that you can’t do building inspections with a piece of crap camera!).

I concur that in many cases an untrained and under equipped thermographer will in fact miss things which are otherwise detectable with the blower door.

On the other hand, even though I can register air leakage with my blower door I cannot definitively identify the location of every air leak.

Just telling someone that they have some amount of air leakage is not fulfilling the complete audit job either.

This discussion is futile!
You can’t do an audit with just a thermal camera or just the blower door without limitation.

Though air leakage is a 200% efficiency loss for every occurrence (air leaking out must be replaced by air leaking back in) and is the most cost-effective approach to improve energy performance, it doesn’t cover the situation 100%.

Using a thermal camera to point out thermal bridging at the eve (the juncture between the interior wall of the ceiling) that exists in every house due to insufficient space for both installation and ventilation to share is also ridiculous. I see this on the Internet all the time! This is where determining the actual R-value with a thermal camera comes into play. A thermal camera can show these efficiency losses as major issues when they actually are not always as they seem.

Are we twisting people’s statements John?

You know that the color of an object of the same emissivity has no effect in the infrared spectrum.

Actually, I see a difference between the different colors in the example!

Anyone care to guess why?
There are two answers to this question.

“Should never” be used in daylight. Daylight is not the same as solar loading.

Different colors respond to UV in different degrees. In these
cases it matters. Simple to understand and no twist needed.

Your posts make good points David. I agree.

I think Bushart would do well to read them.

IR always has more than one consideration when dealing with
certain issues. High end cameras can see air leaks much better
than a low end camera. I agree. If someone is going to try
and do an energy audit with the minimum RESNET requirements
for IR, then they had better make sure they are in a high delta T
environment in order to scan for air leaks (yes, I agree a blower
door helps… but they can also create some side affects that not
everyone feels good about… but that is another discussion).

If someone does an energy audit without an IR camera, they are
50% blind… IMHO. I go behind RESNET and BPI guys all the time
who did not use an IR camera and get them in trouble. My IR
camera finds huge energy defects, even when I am not trying
to do an energy audit…!!! I find them very easily and the energy
auditor ends up trying to explain how I could see these energy
issues, and they could not.

Happens all the time.