Discussion

Can anyone provide a reference or guidance material for sizing expansion vessels for unvented HWS? We have two large Hamworthy Direct Gas Fired Calorifiers and need to convert them from open vented with F&E tank to unvented mains fed.

All of the vessel manufacturer calculation methods I have found assume the total system volume is known.

The syetm is part of a 9 storey building which has been modified over the years and I have no usable as fitted info.

Is there an approved method of estimating system volume, similar to that used for sealed heating systems???

Any guidance greatly appreciaited.

Mike