Hussmann has further expanded its refrigeration systems offering with the Protocol CO2. The Protocol CO2 will continue to deliver the same efficiency and energy standards that the Protocol is known for — with the use of a natural refrigerant. The Protocol CO2 integrates a new medium temperature compressor with direct vapor injection and features a variable speed scroll technology for capacity modulation and greater energy efficiency. In addition to the compressor features, the Protocol CO2 will also incorporate an economizer to reduce gas cooler return temperatures to further improve efficiency.