Any comments on these configurations? The house is 8 years old and in Northern VA. There are two systems, this is for the main floor one. A second system is in the attic. In the winter peak heating bills can run up to $450 to $500 a month for one or two months. Summer AC bills run $200 to $300 for hot months.
I have added weatherstripping to all windows, spray foamed around the frames of a couple of the worst, and added extra insulation in floor joists at foundation.
Honeywell 2 stage thermostat
Coil: Matching, not specified
Comfort Sense 7000
None of the contractor did a Manual J calculation when I asked how they size the units. One said that the Manual J is filed with the county when the design of the house is built and it should be good.
Other comments were that my original system is mismatched with the furnace being too small for a 4 ton AC unit. They also change out the refrigerant lines and said that R410A is not compatible with R22 and if not flushed out properly it would cause problems.
One contractor told me to close off the outside air intake in the winter to save money. The house leaks provide enough air exchange. (The windows are drafty. The builder would not let me upgrade and with about 30 windows it would be small fortune with a long payback to replace them)
Only one contractor quoted a cold air return in the basement. There is not one now.
I think I need to call a couple more contractors. Many of these companies only have receptionists that answer phones and can’t talk about load calcs and leaves it to the sales rep.