Why it works

How air conditioning works

Short answer

Air conditioning uses a refrigeration cycle to collect heat indoors and release it outdoors, while usually removing moisture.

The simple explanation

  • The evaporator absorbs indoor heat.
  • The compressor and refrigerant carry that heat.
  • The outdoor condenser releases it outside.
  • Closed windows help prevent cooled air escaping.

Why it works

This advice follows US Department of Energy guidance and the underlying principles of refrigeration and dehumidification.

Important exceptions

Safety, health, weather and the design of your home can change what is appropriate. Stop if an action makes conditions worse.

Related guides

Sources & evidence

Reviewed 2026-08-21

  1. US Department of Energy: Home cooling

    Supports: Fans, ventilation, evaporative cooling, air conditioning, shading and energy use.

    official guidance · Accessed 2026-08-21