Start with conditions, not a product
Duct leakage, thin attic insulation, and undersized returns show up as cold rooms just as often as a failing furnace does — worth ruling out before replacing equipment.
Build a complete scope
- A load calculation for this house, not a swap of the existing tonnage
- Duct condition and leakage in unconditioned attic space
- How upper and lower floors are zoned, which drives most comfort complaints
- Humidity control, since oversizing satisfies temperature and not moisture
- Electrical work, permits, commissioning readings, and warranty registration
Cary context
Cary's winters are mild most years, but cold-air damming off the Appalachians brings occasional ice storms that catch underpowered heating systems off guard.