UFH - Free Design Software ?

[bwel]

I have an existing 20+ year old UFH install but don’t have the original designs or design Flow Rates per circuit.
I have measured up the rooms and using thermal camera can see the circuit spacing is approx 150mm in Spiral layout.

I’ve flushed all the loops and cleaned all the flow meters, but now need to set each circuit for correct Flow Rates for the circuit lengths and room heat loss.

It was working previously but not so well balanced even heat and a few flow meters were previously stuck. I’m not sure if flows have been fiddled with but I guess they would have been in the last 20 years.

Are there any suggestions of free online design apps for UFH systems design / documentation ? My objective is to get it drawn up and calculate lengths and flows for each of the 12 circuits.

Many thanks,

 

[SpecialK]

Any markings on the pipes as they come in to the manifold? Some pipes have measurements on them...

 

[bwel]

Yes, the PEX is marked but no lengths written on them. If I can redraw the layout of the spiral pattern within a room dimension, I can calculate the flow length Plus the run out distance.

 

[DetlefSchmitz]

I did something related recently and just used squared paper and called each square 150mm. Also a pencil and rubber. Didn't take too long.