Most homeowners only buy one or two HVAC systems in a lifetime. By the time you're shopping, the vocabulary feels foreign: SEER2, ton, AFUE, lineset, condenser, air handler. The goal here is enough fluency to read an estimate and notice when something doesn't add up.
Central air conditioning
The system most SoCal homes built 1970–2010 use: an outdoor condenser, an indoor coil on top of a furnace, and ducts. Cooling only; the furnace handles heat. Half the performance comes from install quality.
Heat pumps
Mechanically close to an AC, but reverses to move heat into the home in winter. In SoCal's mild winters, many homeowners replacing both AC and furnace now choose a heat pump.
Gas furnaces
Still dominate older SoCal homes. Rated by AFUE. Like-for-like replacement is straightforward; the bigger question is whether to keep gas at all.
Ductless mini-splits
Skip ductwork entirely. One outdoor unit feeds 1–8 indoor heads. Excellent for additions, ADUs, older Spanish-style homes, and rooms the central system never reaches.
What fits a SoCal home
Coastal homes deal with salt-air corrosion and rarely need real heat. Inland homes face brutal cooling loads. Older homes with leaky ducts often gain more from a duct upgrade than new equipment.
In this pillar
AC vs. Heat Pump in Southern California
Why the heat pump conversation has changed in SoCal — and where a straight AC still wins.
What Is SEER2 and Why Does It Matter?
The new efficiency standard quietly changed which equipment is worth buying.
Next step
Ready to compare contractors?
Once you understand the equipment, the next decision is who installs it.