Dual Fuel Sizing Help Needed

[locusthill]

I live in the Greensboro, NC area and I am planning to replace my 20 year old Amana furnace (94.3% eff, propane fired) and Amana 2.5 ton AC (high SEER, can't read info plate) with a dual fuel system (gas furnace plus heat pump). I could use some advice to help with proper sizing and features of the heat pump.

My home is single story rancher with 1,300 sq ft upstairs and 600 sq ft of finished basement; the remaining basement is garage space. The attic has 14 inches of blown insulation (R38) and the walls have 6 inch studs with R19 insulation. The doors are metal with foam core and the windows are low E double pane, plus storm windows. In a typical year, I use 430 gallons of propane for home and hot water heating. Electricity is about 9.3 cents/KW and propane is about $2.10/gal.

The main systems being quoted to me include: Amana, Carrier, & Lennox. Most combinations include 2.5 ton 14 SEER heat pumps; although one person quoted a 2.0 ton heat pump. [Note: I did one of those on-line sizing calculations and came up with 1.96 tons.] The two stage heat pumps only come in full tone increments. Thus if I wanted a two stage compressor I would have to either put in a 3.0 ton or a 2.0 ton one. Some of the contractor comments include: "You will not have enough heating with a 2.0 ton heat pump". "The two stage 3.0 ton HP is over kill." "The two-stage 3.0 ton heat pump will give better humidity control as it will run on the smaller stage 65% of the time. "Your cooling load is 21,000 BTU and heating load is 29,000 BTU (figured on 19 degree outside---of course I would switch over to gas at 35 degees or higher). If I could use an even ton unit (Amana) then I could get a dual speed compressor and a higher SEER heat pump (16 vs 14)

The heat pump would be used in conjunction with a high efficiency gas furnace.

Any comments would be appreciated concerning sizing or the value of a two-stage heat pump (Copeland compressor).

Thanks, locusthill

[dandyme]

Some of the contractor comments include: "You will not have enough heating with a 2.0 ton heat pump".

isn't that the point with dual fuel