Repourpsing a Propane Boiler

[Junkman]

I am closing down my business since our lease it up, and there is a propane boiler that provided heat to the 4200 square foot store through 3 air handlers. The landlord is putting all new heating units in, and has told me it is OK to take the boiler when we leave. Their plumbers are going to remove it. It is a high efficiency direct vent boiler, but I don't have the brand name with me. I would like to repurpose the boiler to a 4, 5, or 6 zone baseboard radiator system to heat a small cottage (1250 square feet) that I will be rehabbing. I am wondering if I can use PEX tubing to connect the baseboard radiators to the manifold that the boiler will supply the hot water to. The PEX should be a lot less expensive than the copper.

 

[Firebrick43]

WIrsbo and Viega have a 200 degree temp rating, so yes, base board heat is usable with pex. High efficiency boilers are usually condensing to get that efficiency so you wont want to run them over 130 return temps.

So the base board emitters will need to be larger to have the same BTU output at a lower temp.

 

[PoorUB]

Sure, you can use PEX, but the question I have is how many BTU is the boiler? A boiler that heated 4,200 sq/ft seems a bit large to heat 1250 sq/ft.

 

[Firebrick43]

Sure, you can use PEX, but the question I have is how many BTU is the boiler? A boiler that heated 4,200 sq/ft seems a bit large to heat 1250 sq/ft.

Plenty of overhead for driveway snowmelt !

But yea, even if it is modulating and has a 10:1 turndown ratio it could be oversized in the shoulder season and short cycle.

 

[fitter30]

Brand and model # and btu input?
Btu rating could be 3-4 times what you would need and if its not a least two stage it would be way oversize.
Have to use oxygen barrier pex tubing in heating applications.