Multiple choice Which of the following gases is present in an air conditioner? Neon Freon Methane Helium Reveal answer Fill a bubble to check yourself B Correct answer Explanation Freon is a chlorofluorocarbon (CFC-113). In addition to being used in air conditioning systems, it is also used as refrigerant in refrigerators and freezers and also in firefighting systems, and as an aerosol propellant.