1. make sure the duct is sealed and wrapped.
2. Depending on how tight your home is, you may need a
make up air kit.
3. If there is room for it in the utility closet, have it installed in there. If you have a counter flow furnace, the furnace will need to sit on top of the coil.
4. Have a hvac company come out for an estimate and request a manual j load calculation. This will tell you the proper size of furnace and a/c.
5. Make sure that you have adequit return air for the system.
6. Check into uv lights for your system. This will help your allergies.