Potential customer question.

I received a call today and was asked this question. As I am new to this industry I really am not sure how to answer this so I am posting it here to get feedback from those with much more experience. Thanks in advance for any help.

Can Thermal imaging detect cold spot in pipes?
For example, can it help to trouble shoot where pipes are freezing in the winter, or might freeze?

If a pipe has some areas that are colder than other areas and those temperatures show up on the surface of the pipe an IR camera can show the temperature differences.

For instance, I was able to read a difference in temp of a copper pipe that ran past an open crawlspace vent in a crawlspace to show the client how the pipes can freeze from the cold coming in the vent.

Thanks Larry that helps out. ANyone else have any ideas or thoughts on this subject?

Another one of those questions with a really solid answer…MAYBE… if the exterior conditions are just right or you recreate the exterior wind conditions using a blower day on a cold day in conjunction with IR.

A majority of freezing pipes result from cold air infiltration where pipes are hidden from view. You need the wind to be blowing onto these walls to generate the needed temperature differentials.

You can easily see the affects of cold air on high-emissivity surfaces and then measure the impact to see how close to freezing you might be. Tough to predict but if interior surfaces are approaching the outdoor air temperature, freezing is a good bet during very cold weather!

One proviso, regardless of the type of IR imager you have, you can NOT accurately and repeatably measure the temperature of the copper pipe (unless it is green or black) as it has an emissivity that is too low. If you need to make a spot measurement, put a piece of tape on it and take the reading at that point.

Of the major issues related to cold air infiltration (energy, comfort, condensation and “hard water”), this is usually the most costly.

Thermally yours,

John Snell
ASNT NDT Thermal/Infrared Level III #48166
Snell Infrared
800-636-9820
802-229-9820


http://www.IRTalk.com

Being in Texas this is not a problem I run across.

I would think you could find cold spots - if they are cold at the time of the scan. I think you would have trouble “predicting” potential freezing points. If they were insulated you may be able to find uninsulated points easier with the IR.

So I would agree with the “Maybe.” It would require some practice to figure things out. I do occassionally get asked things from customers concerning IR that I do not have a firm answer for. In some cases I offer to come look out of curiousity and for my own experience, in others I decline because I don’t think it would work the way they want.

What???

I’ve been in Texas only two days in my life…early January, 1974 on way to Mexico/Central America…and there were mud puddles with ice on them in Dallas!!! Was this a rare anomaly I was seeing?

Now I must reminisce…6 month bus trip to Mexico and points south—Myself and three friends bought a 1/2 size, 32 seat school bus the year before, stripped it, built in moveable seats/table that turned into beds, rewired the 1959 Ford 500 engine, etc, installed propane fridge, stove top burners, and of course…an 8 track tape deck!!

Was it painted purple and how many hits of acid did you guys have?:mrgreen:

All great answers. Thanks so much. I was leaning toward a maybe answer myself. I just don’t see how I can re-create winter conditions. I may go out and see what I can do as a learning experience. If I find anything I will be sure to take pictures and post here of course.

Very rare. Yes we get the random freeze or ice storm. I can remember a snowy Thanksgiving in the 90’s - the one where the Cowboy’s scored on themselves. In the 80’s there was a two week stretch below freezing…broken pipes were a big problem then. Most years we are good for a coupe ice storms - they close schools on the threat of such and half the time they don’t develop. Then a couple days later it will be 50 or 60 and sunny and all the overpasses are full of sand.

Jeez, Jerry!! Were you there, too??

You must have heard this by now: “If you remember the 60’s, you weren’t really there!!”

No, we kept the bus conservatively dressed in the beige paint it came to us in; didn’t want to attract attention. But when we met a Mexican “triple A” Houston Astro baseball prospect in Naranjos, he took us to his family’s cantina, fed us, got us drunk and then the next morning after a late night party, he named the bus “Poco Loco” (loosely: “little crazy”) and painted it neatly on the large steel front bumper. Must have been things we did during the very drunk party!! But it was quite an introduction for us when we entered any smaller villages/towns…kids came out to meet us and yell the name!!

What’s all this cold stuff you guys are talking about? And white stuff on the ground? Whatever. 90 degrees today, haha

Anything above 75…too hot for me!

I did an IR inspection last year where the client hired me to find out why her supply pipes were freezing from inside a wall cavity. I showed up and my IR camera immediately detected cold air entering the wall cavity from outside.

Here’s the wall cavity in question…
IMG_2094.JPG

Note the cold air entering this wall cavity (These cabinet doors were left open hours prior to the inspection)…
IR_0256.jpgIR_0255.jpg

I went to the bathroom (above this kitchen)…
IMG_2097.JPG

And my IR camera detected excessive cold air in the same wall cavity from below…
IR_0259.jpg

So it was obvious that this wall needed an insulation upgrade.

Insulation may be a partial solution but unless acompanied by airsealing, it may be only a partial fix. Fiberglass batts do not stop air leakage!! I have seen situations where very cold air coming through fiberglass batts in the rim joist space froze pipes.

Here’s a video from what was the old small gov. energy group I worked for on airl eakage through batts in a flat attic ceiling. This air leakage is more from weak warm air rising from bouyancy. (A little side note: in a 1000 sq ft bungalow on a still 0 deg F night, the total pressure on the ceiling is about 600 lbs!! Or not that much as psi- 0.0042 psi) When the air leakage is wind driven as on sidewalls, much stronger forces are at play and will drive the cold air through the cracks/small holes and through thinner batt insulation while it is still cold. It may be slowed down enough through thicker insulation that its temperature has risen above freezing before it hits pipes.

OOPS!!! forgot this: http://www.conservens.ca/how-to/finding-attic-air-leaks.asp

Yes, improper air sealing could be a factor also, but my recommendation of insulation did correct the icing problem she was having.