EEVblog Electronics Community Forum
Products => Thermal Imaging => Topic started by: Sandro_Clegane on January 03, 2020, 03:03:34 am
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Hello everyone, I've been a lurker for some time now, but a question came up so I decided to create an account and see what the gurus have to say.
In any case, I'm thinking of integrating a thermal imaging camera into my regular home inspections, my question is, whether a building made out of concrete/brick would make a difference in the results I can expect.
Most of the tutorials and literature I've seen online deal with wood/plaster houses so it got me curious.
I realize this might be a dumb question, but I appreciate your time all the same!
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This may help but remember a large part of thermography surveys is the correct interpretation of what the thermal imaging system is showing you ! That comes with training, study and experience.
http://www.flirmedia.com/MMC/THG/Brochures/T820325/T820325_EN.pdf (http://www.flirmedia.com/MMC/THG/Brochures/T820325/T820325_EN.pdf)
https://crimsoniv.co.uk/wp-content/uploads/2011/05/T559320_EN-Infrared-Guidebook-for-building-Applications-Crimson-Industrial-Vision.pdf (https://crimsoniv.co.uk/wp-content/uploads/2011/05/T559320_EN-Infrared-Guidebook-for-building-Applications-Crimson-Industrial-Vision.pdf)
https://www.grimas.hu/wp-content/uploads/2014/02/SiteCollectionImages/700_FLIR/Hokamera_Termokamera_Prospektusok/Application%20storybook%20BLD.pdf (https://www.grimas.hu/wp-content/uploads/2014/02/SiteCollectionImages/700_FLIR/Hokamera_Termokamera_Prospektusok/Application%20storybook%20BLD.pdf)
http://www.thermokameras.com/PDF-Dateien/FLIR%20Gesamtkatalog%20Bau%20(engl.).pdf (http://www.thermokameras.com/PDF-Dateien/FLIR%20Gesamtkatalog%20Bau%20(engl.).pdf)
https://www.flir.com/globalassets/discover/instruments/3-costly-mistakes.pdf (https://www.flir.com/globalassets/discover/instruments/3-costly-mistakes.pdf)
https://www.europages.com/filestore/gallery/e9/1a/13065409_21a51a80.pdf (https://www.europages.com/filestore/gallery/e9/1a/13065409_21a51a80.pdf)
And no, I do not work for, or sell, FLIR products ! FLUKE may do similar guides.
FLIR catalogue index....
https://pdf.directindustry.com/pdf/flir-systems/building-catalogue/7945-513751.html (https://pdf.directindustry.com/pdf/flir-systems/building-catalogue/7945-513751.html)
NACHI guide....
https://www.nachi.org/ir-reports.htm (https://www.nachi.org/ir-reports.htm)
Fraser
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I think it is a case that wooden frame buildings can have a lot more wrong that you can see with a camera, ie missing insulation.
Block / brick is much thicker and and a better conductor of heat so will tend to spread out any effects.
You will still see all window related effects.
What kind of defects do you get and hope to see ?
For example I could only just 'see' my old oven from outside the house under ideal conditions (cavity block/brick and a very inefficient oven). That was of course conduction to the outer surface.
regards
Bill
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Yeah I have a brick house with air cavity between the exterior and interior wall space and fiberboard on the outside of the studs. Through a FLIR E40/60 the outside of the house pretty much looks monochrome except at the windows and the doors unless the sun has been selectively hitting it.
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I don't think you'll have any issues by using any given camera. I know nothing about wooden houses (in my country all houses are concrete with bricks and external concrete insulation finish), but usually what you're looking for is around doors and windows, all other external wall areas seem to be cold (due to double brick layer with insulation inbetween, or because of extra internal drywall+insulation construction).
So unless something is really bad with the building (old building, bad construction, humidity problems etc), don't expect to see many things on the walls.
Like in the photo below, found on the web, your interest should focus around the openings.
(http://syrianoglou.gr/files/syrianoglou/thermografikos_elegxos/thermografikos_elegxos009.jpg)
It would make more sense to check from within each house too, as any internal problems will not be reflected to the outside building's shell.
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I'm sorry I took a while to get back to you guys. Your answers have been extremely helpful.
The short-ish version is that I've got the possibility of starting an energy audit business in my area, I intended to check houses for air infiltration, moisture, missing insulation, in essence, anything that could lead to an energy loss. I realize that for this purpose a blower door would be extremely useful, but I'm in college and they are relatively expensive, so I'm researching as much as I can and educating myself (considering getting certified) before pulling the trigger.
I was actually excited to see that you could hack a Flir E4 to an E8 since I could save 2 grand, but after going through that thread it seems it's not viable anymore.
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I realize that for this purpose a blower door would be extremely useful, but I'm in college and they are relatively expensive, so I'm researching as much as I can and educating myself (considering getting certified) before pulling the trigger.
Hint: If the kitchen got a cooker hood (exhaust hood?) that blows the air out (not one with circulation only), you will have the same effect (a vaccum inside the house) as a blower door test. Switch it on (first close all doors and windows of course) and you will quickly find all leaks with your thermal camera (well, as long as the house is sealed at least a bit).
Check some areas first and then switch the hood on and check them again after a few minutes. The difference is huge if there is a leak! See some examples attached (fortunately not my house).
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Ohh wow...Thank you! This is really helpful.
I will get the blower door eventually but I gotta save up a bit for it, its like 4k euro or something.
So, two things, if you don't mind.
- Maybe there's something I'm missing and there are cheaper blower door alternatives out there, do you know of any?
- Also, I know there's a gallery on the forum, but I would not mind seeing some more pictures of things you've found during home inspections using your camera, they are really cool!
Thanks again!
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The blower door is expensive for several reasons. But most important is calibration of the fan so that leakage rates can be measured, not merely detect location of leaks. If you can sell a leak detection service, without quantitative data I am sure you can buy or rig something far less expensive. All the way down to a fan purchased at the local HW store, a sheet of plastic and some duct tape. I don't know what the licensing laws in your area allow.
Detectability of the leaks will depend both on achieved pressure differential and temp difference between indoors and outdoors and time available to wait for the system to stabilize. At this point in your career/business you may value your time relatively low and can get away with a low power (inexpensive) fan.
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Although buildings inspection isn't my game, I thoroughly recommend you book yourself onto a suitable thermal inspection training course. Not only will you get a nice certificate at the end of it but you'll also learn a great deal - including what type of thermal camera capability you'll require. Even a half-day course could well pay for itself immediately.
I work in an environment where people have to be licensed and I often see people rushing out and buying gear before they truly know what they're doing. Those who ignore my advice to keep their money in their pocket frequently regret the 'bargain' they thought they were getting when they discover that although it does precisely what it says on the tin, it's not what they actually wanted or needed.
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I have done the poor man's version of a blower door test at my home.
Just wait for a cold day and turn on everything that vents air to outdoors - bathroom vent fans, kitchen stove vents, even the laundry dryer if it vents outdoors (use an "air dry" cycle, there is no need for heat). Wait a while for the patterns to develop - half an hour, maybe? - and then take a look with your camera.
It is entirely qualitative but you WILL find leaks this way.