Furnace Service in South San Francisco

About Furnaces

Furnaces generate heat through combustion (gas or oil) or electric resistance, distributing warm air through ductwork. Gas furnaces dominate the Bay Area market due to natural gas availability and efficiency. Modern high-efficiency furnaces extract more heat from combustion gases using secondary heat exchangers. Furnaces also house the blower that circulates air for AC when paired with central air conditioning.

How It Works

When the thermostat calls for heat, the furnace ignites its burners (gas) or activates heating elements (electric). Combustion gases pass through the heat exchanger, which transfers heat to circulated air. The blower pushes heated air through ductwork. Combustion exhaust vents outside through the flue. The cycle continues until the setpoint is reached.