System types
Right-sizing matters — oversized equipment cycles inefficiently.
- Furnace + AC split: $5,000–$12,000
- Heat pump: $8,000–$15,000
- Ductless mini-split zones: $3,000–$5,000 each
Sizing and efficiency
Manual J load calculation prevents oversizing. Higher SEER/AFUE costs more upfront but lowers bills in hot or cold climates.
- SEER2 ratings on new AC equipment
- Heat pumps for mild climates
- Furnace AFUE in northern states
Ductwork surprises
Leaky or undersized ducts reduce comfort even with new equipment.
- Duct sealing and insulation in attics
- Full replacement in unconditioned spaces
- Return air upgrades in older homes
Size the house, not the old cabinet
Replacing a 4-ton unit with another 4-ton because “that is what was there” is how you get short cycles and humidity. A Manual J that uses your insulation and window reality is the hiring filter. SEER on the box does not fix leaky ducts in the attic.
- Ask to see the load calc, not a rule-of-thumb from square footage
- Duct leakage and insulation are often the better spend than a higher SEER sticker
- Heat pumps in cold climates need a backup or a cold-climate model — say which
What is in an installed price besides the outdoor unit
Line-set, pad, electrical disconnect, thermostat, permit, recovery of old refrigerant, and haul-away are easy to omit in a Craigslist number. A coil that does not match the furnace is a warranty problem. Get the AHRI match in the proposal.
- New thermostat wiring is not always “the old four wires are fine”
- Attic coils can need a secondary drain pan and float switch
- Rebates often require specific model numbers and a licensed installer affidavit