The modern industrial, commercial or office building consists of many sophisticated systems; these systems include foundation and support structures, electrical and lighting and plumbing and fixtures. Another major part of any building that often taken for granted by its inhabitants is the HVAC system. 

A practical consideration for HVAC is air quality, it is an essential to maintain productivity, comfort and health of the occupants and it should not be trivialised. Recirculated conditioned air can carry contaminants which contribute to respiratory illness. Good indoor air quality and temperature are the two fundamental criteria in the design of an HVAC system. It is the HVAC systems job to remove contaminants and dust from the air using filters at various stages. As crucial as this consideration is in an average office or commercial building, this feature is even more critical in facilities that contain clean rooms, medical facilities or hazardous materials.

Our concerns regarding the HVAC system do not end with health; energy-efficient is another essential factor in consideration with the spiralling cost of fuel, HVAC systems must also be efficient and economical. Energy-efficient HVAC systems might incorporate variable air volume designs, use of indirect evaporative cooling and etc. Including components designed for operation at low pressures,  using digital control systems and high efficiency electronically commutated fan. Or implementing mechanisms for reclaiming heating or cooling benefits from exhaust and intake outside air.