ABSTRACT
This chapter provides a thermally comfortable temperature, humidity, air cleanliness and freshness for the users of the building or it satisfy operational conditions for machinery or processes. Air conditioning describes an air cooling system that reduces excessive temperatures but does not guarantee precise conditions, to minimise capital and operational costs. The chapter explains the working principles, applications and limitations of 16 categories of air conditioning system; also describes why a particular system is being proposed for an application by means of description and sketches. Mechanical ventilation includes the moving of air by means of fans, air filtration, heating, humidification, heat reclaim for economy of operation and free cooling that can be obtained from the external atmosphere. Low cost air conditioning only cool inside the building by a specific number of degrees Celsius below the outside air temperature or limit the internal percentage saturation to 70". This is the upper limit for comfort and for the risk of microbiological growth.
