Heating systems are a mystery to most builders,
even those who talk a good game. When the
moment of truth comes and they're face to face
with an old forced hot air furnace in a dank, dusty
corner of a customer's basement, the best they can
do is find the manufacturer's stamped label and
read the capacity rating. But it takes more than
Btu's to make a forced hot air system work
efficiently, especially when adding on to an
existing system to heat an addition.
One of your responsibilities as G.C. for an addition
or renovation is to figure out if the existing
heating system can handle the extra ductwork.
The more you