暖通空调（Heating, Ventilation and Air Conditioning，简称HVAC）是指室内或车内负责暖气、通风及空气调节的系统或相关设备。暖通空调系统的设计应用到热力学、流体力学及流体机械，是机械工程领域中的重要分支学科。其目的是创建有益于人类生存的室内人工环境。

有时也在缩写HVAC中加入R，代表冷冻（Refrigeration），缩写就变成HVAC&R或HVACR，或是缩写中加入R，减去代表通风的V，缩写就变成HACR。

暖通空调系统可以控制空气的温度及湿度，提高室内的舒适度，是中大型工业建筑或办公建筑（如摩天楼）中重要的一环。在制药、电子、关键任务设施以及油气等领域和行业中，暖通空调的作用举足轻重。

HVAC (heating, ventilating, and air conditioning; also heating, ventilation, and air conditioning) is the technology of indoor and vehicular environmental comfort. Its goal is to provide thermal comfort and acceptable indoor air quality. HVAC system design is a subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer. Refrigeration is sometimes added to the field's abbreviation as HVAC&R or HVACR, or ventilating is dropped as in HACR (such as the designation of HACR-rated circuit breakers).