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Bigdog8
05-29-2009, 08:11 PM
Building a new house and my HVAC contractor has done a Manual J 8th edition calculation., not sure what the numbers mean but he said I could go with a 3 or 3 1/2 ton split system. The numbers below are for the first floor only, 2nd floor has a bedroom, bath and bonus room total 861 sq ft which will be getting a 1 1/2 ton heat pump. Your thouights on the numbers?

Sq Ft 2161 Sen Gain 35,186 Lat gain 4317 Net Gain 39557

SEN Loss 92875 SYS HTG CFM 1161 SYS CLG CFM 1549

Thanks

HVAC/Stud
05-29-2009, 08:27 PM
Have him explain the numbers.
I'd go with 3.5 ton.

Don't let him stop at Manual J. Make sure he does a room by room load cal.

Then do a Manual S, this will ensure the unit will remove the latent load.

Next is the Manual D, this is for the duct work.

Make sure he installs dampers and balance each room CFM to match the sensible BTU's

Remember you are paying for a quality install, make sure you get it.

Vist the ACCA web site for info.

Good luck,
STUD

beenthere
05-29-2009, 08:33 PM
Big house for that amount of heat loss on a new house.

Edwin73
05-29-2009, 10:22 PM
Building a new house and my HVAC contractor has done a Manual J 8th edition calculation., not sure what the numbers mean but he said I could go with a 3 or 3 1/2 ton split system. The numbers below are for the first floor only, 2nd floor has a bedroom, bath and bonus room total 861 sq ft which will be getting a 1 1/2 ton heat pump. Your thouights on the numbers?

Sq Ft 2161 Sen Gain 35,186 Lat gain 4317 Net Gain 39557

SEN Loss 92875 SYS HTG CFM 1161 SYS CLG CFM 1549

Thanks

Where is the location of the new house?