Additional Heating Capacity: In the heating mode, it provides the additional capacity needed to maintain comfort condition in the room, particularly at higher ambient temperatures. This is achieved with an improvement of COP.

Improvement in Cooling COP: In order to get the benefits of vapor injection on the COP of the system, the compressor has to be sized smaller.  The reason is that activating the vapor injection in effect increases the size of the base compressor.  Since the heat exchangers are sized for the cooling capacity, a smaller compressor has to be used that delivers a larger capacity (with vapor injection turned ON) and provides the COP benefits.  In the cooling mode, vapour injection enables us to achieve higher COP with a smaller size compressor.

Other benefits:

1. It offers a means to modulate compressor capacity with varying load requirements.
2. Liquid lines and thus refrigerant charge can be used thanks to reduced mass flow rate with higher enthalpy across evaporator coil.
3. Suction line pressure drop is reduced compared to conventional cycle delivering the same capacity.
4. Less excess cooling capacity during winter operation translating into less modulation of the compressors with the associated benefits in terms of ease of control, reliability and energy consumption.

Vapor Injection technology is a powerful tool to improve the capacity and COP in a system.  It can be used to improve the cooling COP – by using a smaller compressor in the system and get the same cooling capacity and better cooling COP with vapor injection turned ON.  It can also be used in heating – get 20-30% more heating capacity at low ambient operation.  The reliability of this technology builds on the base Digital Scroll compressor that has a 99.996% field performance spread over 9 years.  The applied cost of vapor injection technology is minimal – it needs a set of solenoid valves, flash tank/heat exchanger and an expansion device.  This technology addresses the 2 needs of the HVAC industry – better cooling COP and increased heating capacity/COP at low ambient operation.