The Variable Water Volume system, said Petra, offers large savings in energy and initial costs – two deal-clinchers in their own right. The system can be used in multi-storeyed buildings, office complexes, hotels and villas, Petra added.

The system comprises air-cooled water chillers, indoor units with three-way valves, a control package, pumps, expansion tanks, storage tanks, water piping and integrated complete system control, Petra said.

It is regarded as a safe system, Petra said, since it is water that is used inside the building as the cooling media. The refrigerant, Petra added, is only used in the outdoor units, which takes out of the equation the typical concern of refrigerant leak hazards in occupied areas. Compared with refrigerant flow systems, it does not have any restrictions related to distances or elevations, Petra claimed.

Additionally, the system does not encounter problems associated with oil return and is designed to work at even 55 degrees C ambient conditions, according to Petra.

It has a capacity control modulation feature, Petra said, down to one per cent of the load. A central plant, Petra added, allows up to 60% diversity from the indoor connected load.