A comparative study of the cooling performance of HVAC systems based on the reversed air cycle

A numerical study on the cooling performance of new air-conditioning systems based on the reversed air cycle is conducted through a specifi cally developed computer code. The main peculiarity of such HVAC systems is the combination of the roles traditionally played separately by the chiller and the air handling unit, as the expanded cool air is directly supplied to the indoor ambient for its environmental control. For any system proposed, simulations have been carried out for a wide variety of psychrometric states of both outdoor air and supply air, and for different effi ciencies of the heat exchangers and the turbomachinery. Among the main results obtained, it is found that for hot and dry climates, as well as for temperate climates, the values of the cooling performance of the most advanced confi gurations are of the same order as those typical for traditional HVAC systems served by vapour-compression refrigerating units.