This is a first post for me, so excuse my ignorance.
I have a 3800 sq. ft home in Houston, TX. The home is 2 stories both with equal square footage (1400 sq. Ft / floor) and a very open concept. There is a lot of glass on the west facing side of the home. The house is 16 yrs old with existing Lennox 12 SEER equipment.
Existing equipment functions, but runs non-stop. I've tracked my electicity usage over the last three years and this year sets a new bar.
I've had multiple contractors price out equipment. Weighing both price and quality, I am most comfortable with Lennox equipment.
The contractor that I have chosen recommends the following equipment with plan to utilize a 2 stage system down stairs and a single stage system up. Most of the living is on the down stairs. Currently, the 2nd floor is unoccupied.
Lennox 16SEER 4Ton 1-stage
Slab Coil: CH23-51
Lennox 16SEER 4Ton 2-stage
Slab Coil: CH23-65
Lennox iComfort Thermostats
After repeated requests from multiple contractors, I can't find one to run a Manual J calculation to properly size the system. The size proposed is comparable to what is currently installed. All installers are aligned on the tonnage.
A few questions to the group:
1) Are these systems properly matched?
2) Is it common to utilize a 2-stage system (for comfort) in the main living areas and a single stage system in the remainder of the home?
3) I have some concern that the proposed HVAC system is going to be more efficient than my home - is there a drawback besides the front end cost?