Ask them for a price on Goodman instead of Trane. It's the same guts as Trane, without the expensive advertising that goes along with the brand. I have 3 Goodman heat pumps on two different properties that I've been very happy with.

I would not want Goodman especially for a coastal environment like the Holy City.

Sizing for HPs is important for good dehumidification. Keep in mind AC more important than heating.

If heat pump, you want var speed air handler. Either of systems below would be fine.

4656619 Active Systems TRANE XR15 WEATHERTRON TRANE 4TWR5036G1 *AM7A0B30H21 1165 36800 12.50 15.00 35200 9.00 21800 1 HRCU-A-CB 304 772 Yes

4655311 Active Systems TRANE XR15 WEATHERTRON TRANE 4TWR5036G1 *AM7A0C36H31 1225 36000 12.50 15.00 34600 9.25 21800 1 HRCU-A-CB Yes 298 751 Yes

Same systems also available through Am Standard dealer, sister company to Trane.

If nat gas is available to your home, I would prefer a var speed furnace, probably 80% eff with straight AC, over heat pump.

IMO

A load calculation will be performed this afternoon once I can send drawings out.

I've seen corrosion do some crazy things to the old HVAC system at a rental we own across the river from where we live. It ate the thing up to the point that the fins were falling off!

Natural gas is available and actually runs to that air handler location but I'm not sure if the lines are big enough. Current gas appliances are a cooktop and 50 gallon water heater. I'll have to call and ask the guy that ran the short line to the cooktop a few months ago.

I miss the gas furnaces we had at our old house. They seemed much simpler and longer-lasting, and it probably puts less wear and tear on an expensive A/C unit.

While waiting for people to get back with me I ran a load calculation at loadcalc.net. The numbers were...

System #1 - 27,000 BTU cooling, 25,xxx heating (this is the one I have problems with)
System #2 - 25,000 BTU cooling, 23,750 heating

Right now the house has two 3-ton systems and I've hated them since the day we moved in. They never ran very long and humidity was usually between 60-70% before I installed a whole house dehumidifier.

In the email with the drawings of the house I also mentioned that I'm interested in dual fuel since the gas line in the attic runs exactly where it needs to go. Any idea about what cost savings there might be for going with a smaller system?

Your load calcs seem reasonable - 6 tons seems a bit much for your house. Smaller units will run more and dehumidify better. There's nothing wrong with heat pumps - the old dogma that they blow cold air is long since past. Given the high CFMs of high efficiency gas furnaces today, comfort should be comparable between the two. Fuel cost (electric vs gas) will determine the better solution. Dual fuel systems are usually too expensive to justify their cost (in payback terms).

If nat gas is available, I would install Trane XV80 60 K 2 stage furnace and a 2 1/2 ton XR16 AC condenser. Plus best application Trane evap coil. Furnace will require true 2 stage thermostat. Low stage about 31 KBTU which will operate most of the time except for rare cold snaps in Holy City that can and do occur occasionally. This same system also available from Trane sister company, American Standard. Box filter media cabinet as well.

IMO