Testing floor heating for leaks using compressed air.
Hi.
Air will leak more easily than water, making air a good test tool if done right. There are a few problems though. The guidelines below should be used:
Test with 0.5 (7,5 psi?) bar gauge pressure when using air.
Test only for two hours
Minimal pressure drops (+-0.01 bar for a short loop) is completely normal.
Why?
The pex is O2 proof, so it should not leak air, but the actual pex is plastic, and flexible. A high pressure will make it expand, and as a result, it will look like the pressure drops. Any hole that does not cause a significant pressure drop after two hours with 0.5 bar pressure will be too small for water to get trough anyway. Any hole made by a screw, nail or similar will leak quite a lot since the tube normally will collapse slightly around the penetration.
The high pressure will make the pex expand. The O2 tight layer in the pex might take damage from expanding too much (not verified, but from at trusted source).
Best way to find a leak is spraying the connectors at each end with soap water. You will see bubbles forming if there is a leak.
-Ko_deZ-
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