replacment boiler sizing

greg_30

in sizing a residential hot water boiler where there have been extensive insulation and weatherization upgrades. do you size the boiler to the ammount of connected fintube? do you do a heat loss calc and size the boiler to the heat loss calc results? if your size to the heat loss calc is it necessary to reduce the amount of fin tube?

Ron Schroeder

Hi Greg,

Size the boiler to the heat load and use an outdoor reset control to take advantage of the oversized baseboards.

Ron

Gene_3

check both

for comparison, you need to have a heat loss calc done however with the current window door insulation done. Removing existing baseboard is not rec's unless it is way off. Many contractors do size to current baseboard etc figuring it is fast and you can't do wrong iffffffff it was done right in the first place

remember it is called heat load CALCULATION
NOT HEAT LOAD PRECICELY

greg_30

how does that work?

Big Ed

size

With a hydronic system you size it to your largest load.This may be the potable hot water if boiler is used for suppling. A heat loss calulation will tell you the heat load. If the heat load is largest ,size it using that number. If there is excess radiation in the home ,a lower running system temperature can be used.Which is a good thing....

Ron Schroeder

Having extra baseboard allows the boiler to operate at a lower water temperature and still get enough radiation from the baseboards to heat the house. The lower (but not too low) boiler temperature will allow the boiler to be more efficient.

Ron