In air conditioning, heating, ventilation, and air conditioning (HVAC) are more commonly used than AC. AC refers to air conditioning alone, whereas HVAC refers to heating, ventilation, and air conditioning. The abbreviation "AC" is frequently used to refer to various residential air conditioning systems. The two most prevalent types of HVAC systems are window air conditioners and central air conditioning. In addition to air conditioning units, heating, ventilation, and air conditioning systems (HVAC) may include heat pumps and gas furnaces. This suggests that HVAC systems handle both heating and cooling. Since many HVAC services in Chandler provide heating and cooling solutions, the terms are frequently used interchangeably. The phrases will be used interchangeably by businesses. In addition, HVAC includes ventilation and ducting.