After weeks of educating myself with much help from this forum, I have narrowed my search to 2 dual fuel heat pump/natural gas furnace proposals. Several were just way out there. I had my local electric co-op independently check the house and it is very efficient and they provided me with cooling and heating sizes. Several of the proposers also ran a Manual J calculation that approximated the co-op calculation.
The house, built in 1994 in extreme Northwest Arkansas, is about 3700 sq ft with a walk out on the lower level, extreme southerly exposure with lots of windows. The existing 80% gas furnace is an 88,000 Btu's and the split (10 SEER?) AC is a builder's model 4-ton. Both seem adequate as the house is tight, insulated, good vinyl windows, additional 6 inches of cellulose in attic on top of probably original 10 inches fiber glass.
York Affinity YZH04811 4-ton, 18 SEER, 2 stage heat pump, 410A
York Affinity YP8C100C20MP11 100,000 Btu, modulating, VS 80% furnace
ASPEN 5 ton coil (AHRI 3227959)
York Thermostat SI-THERM22P7Y 2H/2C 7-day programmable (?)
2 Tube ultraviolet light (needed for rebate)
Merv 11 Air Cleaner (needed for rebate)
10 year parts, lifetime compressor, 1 year labor with reasonable 10 year labor option
Flush and reuse line set in garage floor
New pad if needed
Contractor worked very closely with district sales manager and the unit was made to qualify for the $1,500 tax credit (AHRI 3227959) and York $1,700 Enhanced Premium System Rebate
Can't figure out which thermostat that is but has to be "matching" thermostat for the credit. Can I control humidity with it?
Lennox 19 SEER, Dual Fuel, 2 stage, 4-ton heat pump
Lennox G60UHV60C90 2-stage VS 80% furnace
Condenser (?) XP19-048
ASPEN 60D44 coil
Thermostat YO349 (Honeywell ComfortSense 7000?)
10 year parts, 20 year heat exchanger, 1 year labor with reasonable 10 year labor option
Install new line set
New reinforced pad
Qualifies for the $1,500 tax credit (AHRI # not provided yet) and Lennox $850 rebate
I finally asked that neither propose more than 80% furnace although they had to be VS and modulating if possible. Winters here are only 1-2 months and not very serious like the Upper Mid-West gets. Both will seal the return air plenum that concentrates an upper and lower floor return in a plywood plenum exposed to fiber glass insulation before going into updraft furnace.
Really appreciate your input. They look good? Any holes you would fill?