is my heat pump big enough

[brettnandrea]

my house is 1300sqft i am adding a 2 story addition totaling 800sqft, the house and addition will have r13 walls and r23 ceiling. all windows are anderson low-e new windows. i currantly have a 5 ton heat pump. will this be big enough.

also how many vents are needed for a 20 x 20 room with 3exteior walls.

[Rich]

Off the top of my head I would say the 5ton heat pump would be sufficient.
As far as the number and sizing of the vents go - you would be much better off to contact a mechanical engineer or mechanical contractor to size it. They will take into account the exposure from wind, sun, etc to figure the "load" on the room. I will say this - you can put in all the vents in the world and still not have a functioning system. Most often in residential construction the return air is not sufficient and can cause problems.

[roger g]

Get a professional to look at it. Your original ductwork size might not be big enough. Rich is 100% right.

roger