I've heard a lot of great things about this forum, and would appreciate some advice.
I have a 2 story house (1900 sq ft) with a 95% finished basement (1000 sq ft) that does not have ductwork and vents for AC / Heat. I have an 18 year old HVAC unit in the basement that I've been told I should replace because it is so old. I've also been told by neighbors that these original units are not powerful enough for the size of the houses.
The unit does a decent job heating and cooling the main floor, but a horrible job on the 2nd floor; usually a 10-15 degree difference, even with all the main floor vents shut. This means in my GA summers, it will be 75 downstairs and 85-90 upstairs, even with all the 1st floor doors vented.
I'd like to budget for a replacement (I plan to be in the house at least 5 more years), but I don't know if I should:
1) Replace the basement unit with a larger unit.
2) Add an additional unit in the attic for the 2nd floor.
3) Look into a zoning system.
4) Any other ideas?
I hope to have a few HVAC companies give me estimates, but I want to have a better idea of what are the questions to ask, and what I should look for.
Here are the details I could make out of my current system:
1) Outside heat pump: GSH130361AD
2) Furnace: Carrier 58PAV090-14
Thanks for any advice you can provide!