Getting a new system right the first time
A new heating and cooling system is a large purchase that will run for many years. The equipment brand matters less than the quality of the design and installation: the right size, ductwork that can carry the airflow, a correct refrigerant charge and controls set up for your house.
Start with a load calculation
A proper installation begins with a room-by-room load calculation (commonly called a Manual J) that accounts for your insulation, windows, orientation, air leakage and local climate. Replacing a system with the same size as the old one is a common shortcut, and it repeats any mistake made the first time. Oversized equipment short-cycles, controls humidity poorly and wears out sooner; undersized equipment runs constantly and can't keep up on the hottest or coldest days.
Choosing the type of system
- Gas furnace with central air conditioner. Still common, especially where natural gas is available and winters are cold.
- Air-source heat pump. Heats and cools with one outdoor unit. Modern cold-climate models work well in places with real winters, and some utilities offer incentives for switching from gas.
- Dual-fuel system. A heat pump paired with a gas furnace that takes over in the coldest weather.
- Ductless mini-split. Useful for additions, converted garages and homes without ducts, or for zoning problem rooms.
Ask the contractor to explain why they recommend one type over another for your house, and what the running cost would look like in your area.
Ductwork and airflow
The best equipment performs poorly on undersized, leaky or crushed ducts. A complete quote should say whether the existing ducts will be reused, tested or modified. If the return air path is too small, a new system can be noisy and inefficient no matter how good it is.
Efficiency ratings and standards
Air conditioners and heat pumps are rated in SEER2 and EER2; heat pumps also carry an HSPF2 heating rating. Federal minimums depend on your region: California and Nevada are in the Department of Energy's Southwest region, and Idaho and Washington are in the North region. Your city page lists the current minimums with a link to the source. Higher-rated equipment costs more up front and saves more on bills in climates with long cooling or heating seasons.
Permits and inspection
Replacing a furnace, air conditioner or heat pump usually requires a permit from your city or county, followed by an inspection. Ask who pulls the permit and whether the price includes it. A permitted installation protects you when you sell the house and helps make sure safety items such as venting, gas connections and electrical disconnects are done correctly.
What a complete installation includes
1. A written load calculation and equipment recommendation. 2. Removal and disposal of the old equipment, including proper refrigerant recovery. 3. New equipment set level on a proper pad or platform, with correct clearances. 4. Line sets, drains, venting, gas and electrical connections done to code. 5. Refrigerant charge set and checked by measurement, not guesswork. 6. Thermostat installed and configured, and the system started and tested in both heating and cooling. 7. Registration of the manufacturer warranty and a walk-through of filter changes and basic care.
Questions to ask before you sign
- What size system do you recommend, and can I see the load calculation?
- What happens to my existing ducts, and have they been tested?
- What warranty covers parts and labor, and who honors the labor warranty?
- Does the price include the permit, inspection, disposal and thermostat?
- Which rebates or incentives might apply, and who handles the paperwork?
Get competing quotes in writing and compare what each one actually includes, not just the bottom line.