Selection of a pump for a hot water loop off steam boiler

Abracadabra

I've been requested to install a hot water loop off a steam boiler. Loop will be about 325-350' of 3/4 copper including the approx. 50' of slant/fin baseboard. What pump am I using here? I'll be pumping boiler condensate instead of going thru a heat exchanger, so I'll need a brass pump. What does everyone use? Standard B&G 100AB? Anything more efficient?

Charlie from wmass

Stainless steel is a better price since brass now needs to be lead free. I have had good luck wit Taco 100 pumps in Stainless steel.

Abracadabra

Thanks @Charlie from wmass

You think a 110-24S would be sufficient for this application? hot water heat design is not my forte..

My concern is that this pump is rated for 33gpm @ 7ft head. I only need about 3gpm. How do I dial it down since pump is not variable speed

Charlie from wmass

You don't dial it anywhere. You could use a heat exchanger to make it a closed system for the loop. Then you can use variable speed on the hot water side and the taco on the condensate side.

Charlie from wmass

Will the boiler accept a tankless coil? Then you do not need a three piece circulator.

Abracadabra

Charlie from wmass said:

Will the boiler accept a tankless coil? Then you do not need a three piece circulator.

Nope.. no coil available.. that would have been optimal. So when you are pumping condensate directly thru the loop, we're pushing ~30gpm? Doesn't that affect the BTU output of the fintube? I was thinking of using a couple of strategically placed globe valves to slow down the flow..

Charlie from wmass

I think.the pipe holds it back to around 12 gpm. It will be fine.