In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
Is 100k BTU the right size of boiler (or HTP heater) for both baseboard heating and indirect DHW
We are thinking to install a new 91% gas boiler and a 45 Gal indirect DHW to replace the old 62kBTU/44kBTU boiler and 50Gal water heater. Two contractors suggest about 100 BTU (input) for the new boiler, does it sound right size to you?
Here are details:
* two zones of hydronic baseboard heating, the total room area is 1300 sq ft (the rest of house is heated with forced air by furnace)
* I did a preliminary heat loss cal, by slant/Fin heat loss calculator, which is about 31,000 BTU for those two zones. We are in Boston area, 70F / 5F was used when calculating heat loss.
* the existing baseboard: 77 ft. The baseboard Fin is about 3 inch by 3 inch
* 45 Gal of Indirect DHW
I hope I can hear your opinion about whether 100K BTU (input) sound right size for new gas boiler with 91% AFUE to provide both baseboard heating and DHW ?
If we use HTP Versa Hydro (or Pioneer) as a combination unit to provide both DHW and 160F water for baseboard heating, instead of a gas boiler plus an Indirect, how much BTU a Versa Hydro needs to have for such a load, giving the fact that Versa Hydro is using lower temperature water (160F install of 180F) to heat the baseboard?
Will 77ft Fin baseboard sufficient long when reducing water temp to 160F?