Variable Refrigerant
Flow (VRF) Air Conditioning. In this
system up to eight indoor units can be operated from a single outdoor unit. The
main advantage of this system over multi splits is that each indoor unit can operate
either in cooling or heating mode independently of the other units. This is achieved
by having collection vessels for both vapour and liquid refrigerant (below figure).
A sophisticated control system redirects these two refrigerant phases to the
indoor units as required. As a consequence VRF air conditioning systems
incorporate heat recovery in their mode of operation. Waste heat say from rooms
on the south side of the building can be re distributed by the refrigerant to
indoor units on the north side of the building. The distance between indoor and
outdoor units can be up to 100m including a vertical rise of 50m.
Filtered and
tempered air can be supplied to each unit from a centralized air handling unit
to provide ventilation as well as heating/cooling.
