I purchased a 2 story fixer-upper. I had the old coal-oil furnace removed for an electric heater and heat pump. This was connected to the existing ductwork. The duct work for the upstairs went through the wall in to the attic and branched off into four 6" ducts to the different rooms. The stairway apparenty was used for the return.

I wasn't a big fan of running the duct in the attic, which would lose heat and cold. I since have worked on remodeling the house and eliminated the duct running to the attic. I was planning to run new duct work for the upstairs in individual ducts through the wall cavities.

Is this the best way to heat and cool the 2nd level? The air handler is supposed to be large enough to push the air upstairs, but after reading about some problems with similar situations, should I do something else with the upstairs? Is the split level a/c the answer with 700 sq. ft. between 5 rooms upstairs?

I eventually will remodel the upstairs and insulate it well, but I want to know if I should run the ductwork to floor diffusers upstairs and use the stairway for a return, or plan for an different system alltogather.

Thanks,
Ryan