I have a question concerning my addition I am having built and I am
getting different responses from every HVAC person I talk to. We are doing an addition to our Family room and Kitchen. They will
be both opened up so the new rooms are not enclosed from the original rooms.
The new space is approx 400 sq ft. My current vents from my HVAC unit are
in the floor and one is in the kit and two in the fam room. One of my HVAC
contractors I talked to said I could just extend those three into the new
addition and my unit could handle the extra space since the rooms are
opened up the air will flow between them. My builder says I need to put in a
separate unit that is a GE Vertical Zoneline 17000 btu unit that fits in a 2x2
closet because extending the current vents won't be sufficient. The cost is
about the same to either extend or the GE unit, I would prefer not to use up the
space if we don't have to. My current unit is a YORK Diamond 80 gas fired upflow unit. My house is approx 2900 sq ft with additon making it approx 3300 sq ft.

HVAC unit