Which makes most sense?
1850 sq ft lower floor with a 350 sq ft bonus room over garage
1) 3.0 ton downstairs and 1.5 ton to bonus room upstairs
2) 2.5 ton on one end of house (kitchen, great room with 12 ft ceiling, dining, kids bedrooms)
and 2.0 ton on the other end (master bedroom/bath, utility room, and bonus room)
Much of the time the bonus room will not be being used. My master bedroom also faces south.
Why not size unit for the whole house and then zone it?
The money you spend on two systems could buy one top of the line high effiency system and save you lots of dough on your energy bills.
A load calculation, Manual D,Manual S by a PRO is the most sense to me. Otherwise, WAG, and at 1.5 tons for 350 sq ft I'd venture to say it would be a tad bit oversized.
If everything was always done "by the book"....the book would never change.
4 ton 2 stage with 4 or more zones
What's my post count now?
UA Local 636
What does the Manual J say? New contruction? Well built? Then both seem big, especially the 1.5 ton for only 350 sq ft. Friend of mine lives in a space around that size about daughter's garage. Got a 1 ton 5kw unit in the kneewall. Keeps the place ice cold in the summer and toasty in the winter. In fact during our bitter spell, the kids gathered up there with her because the hideously under ducted main unit wouldn't stay off limit enough to heat the house
I thnk you would be better off zoning, instead of spending money for a unit for a 350 sq ft room that won't be used all the time.
can't see your house from here, but with the limited use of the room, if a through-the-wall heat pump such as a "zone line" is not applicable, then as previously discussed zoning is yhe way to go and you more than likely can do it without capacity increase- load calc as must though.
remember, with electronics; when its brown,its cooking and when its black, its done!!!
Zone. kids bedroom =1
master = 1
rest main floor =1
either an alternate unit of another zone for the bonus room, BUT get LOTS of airflow to bonus room and use nothing less then cellulose for walls and ceiling.
the zones will allow you to heat where people are and aren't as well as account for different thermal loads.
trust me on this last. Bonus rooms are a bastard to heat/cool. I may yet re-do mine...
A system zoned makes not a system efficient!
With 350sq. ft., though, I still wouldn't put it on its own system.
Originally Posted by Special Ed
I'm about to decide just to put in a single stage 4 ton and forget about it. I just really don't see using the bonus room enough to justify a seperate system either. Especially when my kids will be gone in a few years. I'll probably use it for storage then or if I'm lucky rent it out to a hot, college coed. If she gets too hot she can always come downstairs to cool off...lol
Did u insulate the floor of your bonus room?
Originally Posted by danf58