Thermal environment of outdoor units of vrv system in highrise building

Variable Refrigerant Volume(VRV) air-conditioning system is more liable to meet thermal environment problem than other systems such as split-type air-or window-type air-conditioner because its capacity of outdoor unit is much higher. When used in high-rise building, hot air dissipated by the outdoor units will induce buoyant airflow and increase the working temperature of units at high floor when these heat can not be dispersed in time. High working temperature could not only degrade the total efficiency, but also cause stoppage of the system. To investigate the influencing factors of outdoor units of VRV system, Computational Fluid Dynamics (CFD) simulation and field test were carried out. Factors such as units combiniation and capacity, building height, set method, structure of the building and special places et al. were discussed. Suggestions for design and installation were given.