What is an Evaporator Coil?

The evaporator coil is the component that absorbs heat from the indoor air as part of the cooling process. It’s where refrigerant evaporates—changing from a liquid to a gas—pulling heat out of the air and allowing cool air to be circulated back into the space.

🏠 In a Residential Split System:

• The evaporator coil is typically located inside the home, in a metal case (called a cased coil) mounted on top of the furnace or inside the air handler.

• When warm air from inside the home is pulled through the return ductwork, it passes over the cold evaporator coil.

• The refrigerant inside the coil absorbs the heat from the air.

• The now-cooled air is blown through the supply ducts to cool the home.

🔧 Key Characteristics:

• Works with a central ducted system

• Usually paired with a furnace

• Hidden in basements, closets, or attics

🌬️ In a Mini Split System:

• The evaporator coil is inside each indoor air handler unit (wall-mounted, ceiling cassette, or floor-mounted).

• Just like in the split system, warm air is pulled into the unit, passes over the evaporator coil, and comes out cooled.

• Each indoor head has its own coil, allowing for zoned temperature control.

🔧 Key Characteristics:

• Part of the ductless system

• Each indoor unit is a self-contained coil and blower

• Provides room-by-room comfort

🔄 In Both Systems:

• Refrigerant absorbs heat at the evaporator coil

• The refrigerant then moves to the outdoor unit, where the heat is released via the condenser coil

• This cycle repeats for continuous cooling

📌 Summary Chart: