primary pipework sizing

[leonslater77]

Hello has anybody got any ideas on primary pipework sizing. We have two Worcester Bosch 40CDI boilers cascaded so was wondering what size pipework we would need to the low loss header. I have ordered the Domestic Heating Design Guide (last week) and although they've taken my money Im still waiting for the book and the customer wants his quote. If anyways got any experience/suggestions I would be grateful.

 

[ecowarm]

I believe 28mm can take 60Kw so you are looking at 35mm if you need 80Kw but you may not need the full output of the boilers

 

[ecowarm]

Welcome to the forum Leon

 

[leonslater77]

Thanks for that. I thought that it would either be 35mm or 42mm but just needed someone with experience on "larger systems" to give me an idea. Once again thanks for your reply. Hopefully my book will be here soon

 

[Nostrum]

In the DHDG it says (20oC D.T) 62kw for 35mm 100kw for 42mm