In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
Heat Load assessment different from quuted Boiler Size
I made heat-load calculations (see attached excel) for the large 3-storey home pictured in the attached photo. We're planning on using the existing hot-water radiators and installing a new mod/con gas boiler.
One quote for the job suggested we get the NTI TFT 155, which has a heating capacity of 144 MBH.
There seems to be a huge difference between my calculation of heatloss (~62,000 BTU/ hr) and what he thought would be an appropriately sized boiler (144,000 bth/hr). Which one of us is off?
What makes me suspect that I might be closer than the contractor was, is the fact that the existing radiators tend to match (roughly) the heatloss calculations on a room by room basis.