If you have a furnace and ducts, most of a central air system is already there. The furnace blower moves the air and the ducts carry it to every room. Adding AC means adding an indoor coil, an outdoor unit and the lines between them.
What goes in
- An indoor coil on top of the furnace. On an upflow furnace in a basement, it sits right above the furnace in the airflow.
- A line set of two copper lines from the coil to the outdoor unit. The larger one is insulated. In a basement they usually leave through the rim joist.
- A 240-volt circuit from the panel to a shutoff beside the outdoor unit.
- A condensate drain from the coil to a floor drain or a small pump.
- The outdoor unit on a level pad, with room around it for air and service.
What we check first
Cooling needs more airflow than heating. We look up the furnace model, check what the blower can move, and size the system to your house with a load calculation.
We also look at your electrical panel. If it has no room for a new breaker, a panel upgrade costs extra. A photo of the open panel tells us right away.
When to replace the furnace too
If your furnace is 20 years old or more, a new coil on it may need redoing when the furnace fails. Replacing both in one visit saves that second coil job. The price explorer shows both prices.
Get your price
Send four photos: the furnace, its label, the open electrical panel and the spot outside where the unit could go. Send photos or schedule an in-home estimate. For brands and how install day goes, see what an AC install includes.
Common questions
Can my furnace handle central air?
Most can. Cooling needs more airflow than heating, so we check the furnace model and blower before sizing the coil. A weak or very old blower is the usual reason to replace the furnace along with the AC.
How long does the install take?
One to two days. A first install takes longer than a replacement because of the new circuit and line set.
Should I get a heat pump instead?
It goes in the same way and cools the same way. It also heats your house through most of the winter. It costs more up front and qualifies for heat pump rebates.