Upflow system platform

[larrytbm]

Our home was totally destroyed by fire in Sept. and I am building a new house using lots of volunteer help. The slab and exterior shell are already complete. This week interior framing begins. Anyway, my question is what is the typical height of the platform for an up flow heat pump split system? I'm guessing maybe 24 inches, that should handle an 18" or 20" high filter. Any input appreciated.

House is 1300 sf, concrete slab, steel building. Walls will be 10 inches thick, 6 inch purlin plus 2x4 stud wall with a total of R30 insulation. Wall common with garage will be 2x6 stud wall with R19 insulation.

Thanks in advance,
Larry

[catmanacman]

for a heat pump air handler 24 inch platform would be fine . I would sheet rock the closet below the platform with green sheetrock and make sure the underneath is sealed as you do not want to draw hot air down the stud cavities .although it is not code in most places but make sure the contractor installs the largest overflow pan with a float switch that will fit ,it can just sit on the floor.i have seen plenty of carpet and wood floors ruined from backed up condensate drains

[precision hvac]

Depending on your area- you may have to duct that return in either sheetmetal or flex to have it 100% sealed. Some areas don't allow for framed chases used for RA, even if drywalled. Check with the installing contractor or inspector.

[ACFIXR]

Where will the platform be? In the garage or in the living space?
Now is the time to bring in an HVAC contractor so he can save you from making some framing decisions that could possibly cost you plenty down the road when you are trying to finish up. I start doing my walk throughs with my builders at this stage looking for framing that is going to have to be re-done because it is in the way.
#1. In the wall range duct
#2. Supply duct sizes and chases.
#3. Return duct and chases.
At 1300 sq ft you wont have a lot of duct to deal with but now is the time to get it done right and not "hack" it in later.

Raised platforms can be any size you want depending on whats on them.You definently want to line it with metal,seal and insulate it.

Here is a typical track home style;

http://i1201.photobucket.com/albums/bb359/Chuck_Phelan/HVAC/Customs/Track_Style.jpg

Here is a custom home style;

http://i1201.photobucket.com/albums/bb359/Chuck_Phelan/HVAC/Customs/MetalBox_Framed.jpg

Here is what the custom platform looks like before we line it with sheetmetal;

http://i1201.photobucket.com/albums/bb359/Chuck_Phelan/HVAC/Customs/Framed_Platform.jpg

Good luck.

[genduct]

not just insulate, but acousticly line the return to reduce insertion noise. Hopefully the filter and the little liner will be enough.
if you think not then you may need to run vertical to a high return grill so you can reduce noise potential