I have had One moisture IR job and two full house inspections today and my mind is in over load and my A** is dragging. lets make this simple for all the non IR guys Bob if one has the same temp on the exterior of the home as the interior one should just leave the IR camera in its case because you will see nothing even if moisture is present. We try to create a Delta T by using the A/C unit or the furnace depending on the season on the images above it was early morning 8:30 am did not have time for any exterior wall warming by the sun and the A/C was operating inside very close to the same temp as on the exterior I just happen to catch a good image in a known water area this was my second trip to the home I already knew where the moisture was I was just re-checking after another rain as no repairs had been made at this point in time we are just documenting for the lawyers. Dry set stone in use and bad window flashing I have 5 of these this year.
The camera’s thermal sensitivity should be mentioned also. A $2000 “instant thermographer” thermal imager will not detect this without manipulating the existing conditions.
A camera with 0.1°C or less at 20°C is acceptable
For what application?
envelope
OK.
The point I was trying to make is that Charley, with his camera’s ***< 0.05°C @ +30°C ***NETD can detect this moisture without manipulating the surroundings. Good luck doing that with a camera with 0.1°C or less at 20°C ***without manipulating the scene. ***
RESNET requires a minimum resolution of 0.10°C at 30°C for energy audits.
For the sake of argument Bob, we can assume that with this scenario, moisture can never reach equilibrium with the indoor air.
In laboratory conditions we can create this environment but it never exists in the real world. Even when we do basement concrete block scans that are below grade and everything is the same temperature, there is vapor pressure differences affecting conditions and if the air was actually 100% saturated then we wouldn’t be bringing our $25,000 cameras into that environment anyway!
As soon as you walk into a room with your thermal camera you disrupt the equilibrium of the room!
The situation we are discussing is one of the main reasons why you must have a camera better than is recommended by the cheap camera salesman!
The understanding of psychometrics, thermodynamics and thermography is also necessary beyond the rainbow infrared training.
On a side note, Charley mentioned that we manipulate the environment when doing thermal scans by turning on the heat or air conditioner. Would anyone like to take a stab at what happens to a wet anomaly when heat is added to the room? And why?
Level II thermographers, please but your tongue for a little while.
Level III thermographers need not respond. You’re not qualified to do home inspection thermography anymore anyway! 
I’m sure the “certified infrared thermographer’s” here will have no problem with this as it pertains to building thermography 100% and was fully explained in your course.
I think I answered this one once David when you posed a similar question elsewhere. If so I will sit this one out. I love these thread topics, I’m saving up for my Level I courses.
Thanks Cameron!
I’m still waiting for the “main man” to take a whack at this one, but that’s unlikely to ever happen!
Don’t wait too long to get started!
These things take time to become profitable and level one is just kindergarten in the scheme of things.
I think you’ll do quite well. You appear to have a very analytical way of thinking through the abstract and I think this ancillary service will do you well.
Yes, with a better camera, its easier to detect moisture, without manipulation.
Been there, done that. (FLIR BCAM vs. FLIR T400)
But, the standard I was referring to was from Infraspection.
Notwithstanding, I did not see that a reference to Delta T 10C (18F) for moisture detection in the standards for infrared inspections of building envelopes, only for energy.
Does anyone know one?
So there is more to the price than a prettier picture through better resolution eh. OK
Just bought a divining rod and a dog who is water sensitive.Will let you know how it works out.
Been seeing so much split block lately it is getting hard to not be tempted to purchase soon though $2,000 cost sure would have made life easier.
Thanks Charlie.
Took IR courses through Will but it has been a while.
Peter,
You did not miss anything and your comment is correct. My post was in response to Bob’s comment:
I was attempting to clarify for him that the 10 degree Delta T that Charley was referring to is from infrared inspection standards and refers to the difference in temperature between the exterior and interior (not the difference in temperatures shown on the scale in each image that Charley posted).
I apologize if I caused any confusion with my comment.
No problem.
Charley had great find, but in the standards for building envelope surveys, I can not find any standard for delta t requirement for surveying of moisture. According to Tyler the “standards for infrared inspections of building envelopes, the minimum Delta T should be 10C (18F).”
Anyone find it?
Peter,
Please see my post above yours. I stated that your comment was correct. The minimum Delta T of 10C (18F) refers to infrared inspections for energy loss.