HVAC stands for heating, cooling and ventilation and HVAC system is used within building for maintain the indoor air quality of building’s room s and other enclosed areas. HVAC design services has became an integral part of MEP services. In HVAC design services, CAD design and drawing are created for the entire HVAC system of the building such as HVAC duct, duct pipe, heating, and cooling system, etc. When the design is created, the designers need to be very careful other wise a small mistake can create severe performance issues and huge loss of money.