Unit 12 - Air Conditioning & Heat Pumps

Confidence Level

❄️ Evaporator Coil (INDOOR coil):

  • Located inside your home, usually near the furnace or air handler.
  • Job: Absorbs heat from the air in your home.
  • When warm air from your house blows over this coil, the cold refrigerant inside the coil absorbs the heat, making the air cooler.
  • Think of it as a sponge that soaks up heat from your indoor air.

🌬️ Condenser Coil (OUTDOOR coil):

  • Located outside your home, in the unit with the fan.
  • Job: Releases heat into the outside air.
  • The refrigerant, now carrying heat from inside your home, travels outside to the condenser coil. A fan blows outdoor air over the coil to dump the heat into the environment.
  • Think of it as a radiator that gets rid of the heat.

🔄 Heat Exchange:

  • This is the process of moving heat from one place to another.
  • In cooling mode, heat is moved from inside your home to the outside.
  • In heating mode (if it's a heat pump), heat is moved from outside to inside.
  • The system doesn’t create cold or heat—it just transfers it, using refrigerant and coils.

📦 In summary:

  • Evaporator coil = absorbs heat (inside).
  • Condenser coil = releases heat (outside).
  • Heat exchange = the process of transferring heat from one place to another to cool or heat your home.
  • In a heat pump, the coils reverse roles depending on the season:
    • In cooling mode: evaporator coil is indoors.
    • In heating mode: evaporator coil is outdoors (it pulls heat from outside air).

But in AC mode, yes — evaporator coils are always indoors.