Most of us take our heating and cooling systems for granted. We expect them to keep us cool during the summer and warm in winter. But how many of us actually know the simple basics of how they work? If you’re one of the many who don’t know, here are the fundamentals to help you become a more informed consumer.

All cooling and heating systems or units have 3 basic components:

  1. A source of cooled or warmed air.
  2. A means of delivering the cool or warm air to rooms.
  3. A control to regulate the system (thermostat).

Sources of cool air (such as an air conditioner) and warm air (such as a furnace) often use the same control and distribution system. If your home has a central heating and cooling system, warm air probably flows through the same ducts as the cool air, and both are regulated by the same thermostat. When a cooling or heating system malfunctions, the problem could be caused by any of the three basic components.

Both air conditioning and heating work on the same principle – heat moves away from warm objects to cooler ones; the same way that water flows from higher levels to lower levels. Air conditioners remove heat to make rooms cooler, while furnaces put heat into the air to make rooms warmer.

All heating and cooling systems need energy. Most heating systems use fuel oil or gas (sometimes electricity), while air conditioners use electricity. A heat pump (an electrically driven climate control unit) cools and heats air. In winter it pulls in warm air, and in summer it removes warm air.