sizing a steam boiler - misc. loads and how to calculate

bikerboy

I spent a lot of time chasing down radiator EDR's from a dozen apartments on a one pipe steam system. To size a boiler, I am aware that there are issues regarding setting a pickup factor. How are the following addressed:



Pipe loss - the cellar supply and condensate return are all insulated with 1" insulation but the risers are not uniformly insulated esp. as they are  often the  heating for bathrooms and kitchens



Domestic Hot water coil - As this runs concurrent with the heating system, I have to assume that this is added to the load.



There  is also a hot water zone for some selected cellar areas that uses boiler water at the moment but really ought to come off of its own coil as it has it's own controls. I'm assuming that I would use the pickup factor for a hot water system for this zone.

Al Letellier_21

sizing boiler

Add all the connected loads in the system together and size the boiler to that. All manufacturers these days allow for pickup loads in their sizing charts. Don't worry about adding for the tankless. Never have in a steam boiler and never any complaints.....that is unless you have an unusually high hot water demand.

IF the connect steam EDR and the hot water loop added up match up with a boiler size you will be OK