Future of Air Conditioning Hybrid Technologies
The air conditioning industry is changing In much the same way the automotive industry is adopting new, hybrid technology to power vehicles in the face of changing legislation and rising fuel costs, so too is the HVAC sector beginning to blend innovative and traditional methods in the search for greater energy efficiency and lower long-term operating costs. At the heart of the new system design is a Hybrid Branch Controller (HBC) box, which is connected to the outdoor unit via traditional refrigerant piping. The HBC is the gatekeeper. It allows refrigerant to enter from the outdoor unit; and ensures that only water leaves the HBC to service occupied spaces. The Hybrid Branch Controller is the key part of this system because it also supplies the heat exchange mechanism between refrigerant and water. A HBC box is required to deliver both heating and cooling to the fan coil units it is servicing, the outdoor unit delivers a mixture of liquid and hot gaseous refrigerant to it. This mixture first passes through a plate heat exchanger to heat water by condensing the gaseous refrigerant. Liquid refrigerant then passes to a second plate heat exchanger to provide cooling. The present design of the HBC box, which would typically be installed in a ceiling void, has eight pairs of flow and return connections to fan-coil units. Each circuit can independently deliver heated or chilled water via an arrangement of 3-port valves to connect to one of the plate heat exchangers using a speed-controlled pump in the HBC box. A valve on each circuit controls flow rate. Between the HBC and indoor fan coils, the system uses plastic or copper water piping but still offers high sensible cooling and stable room temperatures for maximum comfort. For organisations looking to reduce energy consumption and also to take a more ‘green’ approach to their property management, H-VRF offers a flexible and reliable option.