wwarner;991288]Conduct your own experiment Jim and let us know the results.
Keep in mind though (against what many are taught) not all moisture intrusion will appear as a dark/cool thermal exception… and under some (very commonly encountered) conditions will be completely hidden in the infrared spectrum even when it is plainly visible to the naked eye. The latter will likely be encountered more with lower end / “entry” level equipment. I’m seeing this more during cold weather.
Place a drop of tap water on your kitchen counter and see how long it takes to become “thermally invisible” if it does at all. Immediately.
Do the same with a drop of hot water. Immediately.
Perform the same tests in an unconditioned basement on the slab floor. Not available tonight.
Perform the same tests in a heated bathroom with exhaust fan off… then again with it on. Done.
Make sure to capture images at regular intervals for comparison. Done.
Now do all of the above but place the drops on an absorbent material. I used a white dry washcloth, cotton.
It literally is an eye opener in each setting. Experiencing the results first hand is the best way to learn. Sorry but the only eye opening experience was my wife, because apparently I used one of the Good washcloths for my experiments.
I saw the heat differentials and with the absorbent material, it was just spread out further.
Complete understanding and comprehension of thermodynamics and evaporative cooling as it relates to thermal imaging under various real world applications is vitally important for accurate use of infrared technology in a residential application.
This past summer, turn on the ac, scan the house, then verify with my moisture meter, no problems.
Now that winter is here, all kinds of problems. Even though the Delta T is sufficient, I find myself climbing up and down the ladder a lot to verify with my moisture meter, and it turns out to be fine…getting tired of all the extra climbing.
Like you stated “and under some (very commonly encountered) conditions will be completely hidden in the infrared spectrum even when it is plainly visible to the naked eye”. I seen this two days ago on a bathroom floor. I seen it with my eyes, but the ir camera didn’t.
Again my goals will be in baby steps this year, so one class, and maybe an ir camera upgrade around $4000.
I do appreciate the help and advise.