running cooling mode? noises

[Post and beam]

Has anyone that is running cooling through their UFH  heard any worrying noises from the underfloor slab?   I initiated cooling for the first time a couple of hours ago. I just heard a dramatic sound that appears to have come from our floor. Coincidence perhaps and i have no idea what it is. Sounded like a dull crack. Quite loud to be honest.

[JohnMo]

What is your flow temperature, how are you operating, more info needed

[Post and beam]

Flow is set for a desired 12 degrees. Currently flowing at 11.5 degrees.  Internal house temp has been 27 degrees for days. 30 degrees outside. 

[JohnMo]

First your flow temp is too low, you need to increase a couple of degrees to around 14 +. 12 is below dew point. If house is still at 27 you need to flowing about 16, until house cools. Work out your dew points - plenty of tool online.

 

Cooling via UFH is the same as heating low and slow.

 

Suspect the noise is likely to be the floor complaining about you trying too hard and contracting.

[Post and beam]

Understood

[Post and beam]

Backed it off to 16c for a couple of days.

I can now say that even though it only resulted in a few degrees reduction it is noticeable and welcome.

[JohnMo]

2 hours ago, Post and beam said:

Backed it off to 16c for a couple of days.

I can now say that even though it only resulted in a few degrees reduction it is noticeable and welcome.

What I notice with UFH cooling, it knocks of that uncomfortable couple of degrees at the high end, AND the house actually feels cooler than the gauge would imply. But importantly the recovery time to more normal feeling temperatures is way quicker in the evening.