IR Scan for radiant floor

I’m doing a home inspection and IR scan on a house next week with emphasis on zone checking the radiant floors and moisture intrusion in the exterior walls. The house is empty so I’m sure the heat is off.

Question: For scanning the walls obviously I’d like to create a delta T by having the house warmed up before I get there. If the radiant floors are warmed up will I still be able to get a good image with the camera give there will be less delta T between the floor covering the radiant system and the heat pipes in the floor?

I’m thinking not, but figured I’d get some opinions form some of you NACHI IR experts.

Any advice or tips are welcome.


What camera are you using?

What kind of camera are you using, Radiant heat in the floor will shine like a Diamond in a goats Butt as for moisture in a wall depends on numerous factors is the moisture from the interior or the exterior how long since the last rain and the list goes on and on.

I have a challenge next week I will be looking for a 12 year old leak on a 40 foot indoor water fountain no one has been able to locate the location beneath the floor???

Frank, Charlie,

Thanks for the replies.

Camera: FLIR E40 with 45 degree lens.

So when should I have them turn on the floor heat before the inspection (is so how long in advance) or will I get a heat signature if I turn it on when I get there? It’s a 3 story house and my understanding is that it’s tube over floor set in thin-set concrete with slate on top.

Concern of client is not so much a leak in the system, rather are the all the zones working.


Have them turn it on at least one hour prior to your arrival and turn it up to where it does not cycle off

Radiant floor heat is tricky , be careful of what you tell your clients. IR is great for leaks and pointing out areas of the floor where they didnt run any pipes BUT there is the Human factor. What I mean is that your client may not have ever lived in a radiant heat house before and may have different expectations of the heat it provides. I had a client that i showed that there were no leaks etc but a month after living in the house they didnt like how slow the heat ‘came on’ in the morning. They were so used to forced air. They disconnected the radiant and added baseboard. They hinted that I should have done a heat efficiency test or something and that the pipes may have been buried too deep in the slab to provide proper heat. Yeah right ! Maybe the pipes were buried too deep, maybe they just didnt like radiant heat. Bottom line - thermostat produced heat. Thats all we are to check , so be careful of what you say in report and educate them on how radiant heat works.

You need to do the radiant heat before it is turned on to heat up the house for the wall test…

Leaving the heat on will wash out the floor scan.

Yes it will but observing the supply and return headers will tell you if the loops are functioning and unheated portions of the floor will be clear.

And if there is a leak, you won’t see it if it was left on for hours…

True it is. :slight_smile: