There are several options for air conditioning of commercial spaces—ducted PAC, rooftops, heat pump chillers and VRF—and the system performance/reliability is heavily dependent on the compressor characteristics. The current heat pump technology limits the usage of these systems to ambient up to -5°C. Copeland Scroll™ compressors for commercial applications
(both standard and digital scroll) are available with vapor injection technology, which allows for better efficiency during cooling, heating capacity at low ambient and allows the system to operate down to -20°C.
The concept of vapor injection can be explained using the compression theory, which states that inlet volume and outlet volume are directly related to each other. This means that the compressor capacity can be raised by increasing the volume of inlet refrigerant. In application, the vapor injection line is added inside a Copeland Scroll compressor
to directly inject vapor refrigerant into the scroll unit, making it work like a two stage compression. Higher mass flow and sub-cooling in the system leads to capacity gain and better efficiency.