How do Low Superheat and Ultra-Low Superheat work?

To maximise energy efficiency, Advansor offers Low Superheat for racks below 100 kW and Ultra-Low Superheat for racks above 100 kW. Both options allow the evaporators to run with a very low superheat setting without the risk of liquid CO₂ returning to the compressors. Typically, the evaporation temperature can be increased by approximately 4–5 Kelvin, delivering energy savings of around 10%.

Ultra-Low Superheat is designed to operate the evaporators at the highest possible evaporation temperature, without running them completely flooded. This option consists of a suction accumulator, an internal heat exchanger and an optional ejector:

• The suction accumulator captures any liquid returning from the evaporators and separates the gas from the liquid.
• The primary function of the internal heat exchanger is to evaporate and superheat the gas and liquid CO₂ coming from the suction accumulator. The secondary function is to subcool the liquid line, reducing mass flow across the entire system and minimising pressure drop.
• The ejector empties liquid from the suction accumulator. If a gas ejector is used, it also moves flash-gas from the MT compressors to the parallel compressors. If an ejector is not included, any remaining liquid is evaporated within the internal heat exchanger.

Low Superheat provides the same efficiency benefits for smaller capacities.

For optimal energy-efficient results with either system, we recommend Advansor commissioning support and training – including pre-commissioning – for the first installation. We also advise having a specialist from the controller manufacturer on site to assist with setting up the system manager and case controllers.