<P> Heating , ventilation , and air conditioning ( HVAC ) 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 ( as in the designation of HACR - rated circuit breakers ) . </P>
<P> Heating , ventilation , and air conditioning ( HVAC ) 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 ( as in the designation of HACR - rated circuit breakers ) . </P>
what does the r in hvacr systems refer to
what does the r in hvacr systems refer to
Refrigeration
Refrigeration