HVAC is a short form of Heating Ventilation and Air-conditioning System. HVAC design act a major role in Building construction based on the principles of Thermodynamics, Heat transfer and Fluid mechanics. In HVAC design we have to calculate load calculation, ductdesign, ductfabrication, pipesizing, pressure loss calculation, etc. The main aim is to maintain living and working comfort to people and also to maintain proper ventilation too.