table that might be usefull

[stevetheplumber]

thought this might be of some use

installations have a volume less than 0.035 m

3
:

25 m of 35 mm copper pipework (assuming U6 fitted)

10 m of 35 mm copper pipework (assuming U16 fitted)

20 m of 32 mm
corrugated stainless steel tube (C
SST) pipework (assuming U6 fitted)

8 m of 32 mm CSST pipework (assuming U16 fitted).

 

[AWheating]

thanks for posting this steve.