Radiant Floor Heat Question

OldSchoolHVAC

Greetings All!

I have a question that comes up every so often and I have yet to find a reliable answer.
Does anyone have a rock solid, sure fire way to locate radiant tubing in a concrete slab? I have customers that install radiant floor heat in commercial applications on a regular basis. A few years later, someone comes along and wants to drill into the slab to anchor a hoist or a shelving structure and they come to me asking how to accurately locate the radiant tubing in the floor.
In the past I have turned off the heat overnight and started the boiler up the next morning. Sometimes this allows enough Delta T that my IR camera can pick the tubing location. Most often, this is not accurate enough to trust using a hammer drill. Is there a better way?
Thank you for your time!

STEVEusaPA

I use my FLIR. It worked every time for me. I would think it would work even if the tubing is buried deep in a slab.

GroundUp

I've never not been able to get within 1" using a thermal imaging camera like a FLIR. I put a 2 post auto hoist in my own shop and the anchors are 4" apart around the whole base- I never hit a tube thanks to the FLIR

Zman

I do this on a regular basis. As the cold slab comes up to temp you need to mark the tubes before they get blurry. I have found this to be accurate with tubes up to 5" deep.

woobagooba

FLIR works for me.

OldSchoolHVAC

Wow! that is an awesome image. Perhaps I need to upgrade my thermal imager?
A big "Thank You" to everyone for your input. It is greatly appreciated.