As close to the middle of the space to be conditioned and inside the thermal envelope.

Shorter duct runs generally result in better performance, and being in conditioned space helps with efficiency.

Thank you Brickeyee, that's exactly what I was wanting to know.

if you are in the design stage
then consiter locating the ducts within the
conditioned space along with the equipment.
fur downs work well if plans allow.
what type system?

best of luck.

Yes, I'm in the design stage. Please take a look at my plan from the link below. I will put the return air vent on the dining area wall. But now I'm wondering if my water heater is too far away from everything. Does the water heater have to be in the same closet as the air handler? I don't know what type of system yet? Any suggestions? I'm in central Texas. The water heater and air handler will be on the north side of the house.

Here is a link that might be useful: Floorplan to show air handler and water heater placement.

The water heater is not too far from everything. They don't need to be together. Do you have NG? Are you on a slab? Where are the ducts going to run? (slab/attic/ceiling system/crawl space)

David_Cary,

Yes, it will be on a slab. Normally, the ducts are in the attic in the houses I've seen lately that are in-progress in this area. It will be all electric. No natural gas.

Another question,...just to verify that I can do it this way,...if I put the air handler in the back entry way hall, and have the door to the closet in the same hall(so I can change the filter and service men can access it if necessary), will I be able to put the return air vent in the dining area on the opposite side of the wall that the handler closet is in? I don't want the return vent right by the back door, correct? It will constantly be drawing in hot air every time the back door opens. Correct?

Thanks again,
Carol

- Water Heater. They can fail and flood your home.

- How many a/c returns are you installing?

- Going with dual flush toilets? What brand? I got burned with our toilets when they used "builder model".

- What brand of Windows you going with? I put in new impact windows on one of our homes and it made a difference in the a/c bill. Plus added security/Hurricane protection.

- You going to put in any ceiling fans or just pre-wire in case you want to add later?

I don't see a problem with installing ahu where you have it spec'd.
however I'd make a return from the bedroom side
and add a jump duct for return from master bedroom suite.
undercut of door returns 1 supply mbs would have one or two
returns in bedroom, one in bath and one in master closet.
too much air to return under door.adding a jump duct will allow the air supplied by these supplies to return to
central r/a

best of luck

or electric strip?
there are some nice 15 to 16 SEER
variable speed units that will handle
humidity loads much better than single
speed.

heat pump is a good investment,
electric strip is the most expenisve
way to heat.