In order for water to be used as a refrigerant, it must be transformed into steam. STAC's state-of-the-art turbocompressors enable this process in a circuit where hot water is converted into steam and on to cool air, cooling, ice slurry or heat - depending on the application.
The fact that water as an industrial refrigerant has taken more than 40 years of development work is due to the fact that in vapour form it takes up to a factor of 100 times as much space as traditional refrigerants.
Even some of the world's leading companies have not succeeded in developing this technology. This places high and strict demands on various components that have to handle large amounts of steam. The compressor is the most critical component, as it must both directly suck and compress superheated steam so that cavitation cannot occur as a result of water droplets in the steam.
The use of STAC's complex radial and axial compressors is a prerequisite for STAC's commercial refrigeration solutions based on water as a refrigerant.
The benefit of using water as a refrigerant is increasingly recognized as the most sustainable. As the use of chemical-based refrigerants is already being phased out officially by 2023. More than 200 countries confirms the uniqueness of the use of water as the ultimate refrigerant.
It looks relatively simple, but the prerequisite for the current stage has required a course of development of more than 40 years, which tells a story of efforts far beyond the ordinary.
The EU has put the supply of cooling and heating to European Union citizens on equal footing with effect from October, 2018.
Previously, it only applied to the supply of heat, but increasing global warming means that the supply of cooling is given the same priority.
The new EU legal requirement coincides with the fact that the need for safe, efficient and energy-neutral cooling has never been greater. The global phase-out of chemical refrigerants means that water as a refrigerant has become an area predicted with great growth potential.
STAC Technology has patented various processes where water is used as both propellant and refrigerant. STAC is focused on a commercial product during 2024 in collaboration with international partners who are world leaders in mechanical design of various components for our process plants.
The thermodynamic processes on which STAC's technology is based have been tested, among others at LEGO, which for several decades used a 2 MW system for cooling based on Gunnar Mind's design, which was awarded the European Commission's Environment Award in 1996
STAC's turbo-compressors and electric driven compressors use water as the refrigerant causing zero emission.
Our range of own developed compressors have currently a range from 250 kW - 2 MW and can be used for process cooling (and heating) applications. Solar thermal, excess heat, district heating etc are natural drivers
Ice slurry is a versatile cooling medium and ice storage system. The biggest advantage of the ice slurry is that it is pumpable. In addition to the cooling capacity of the ice slurry, the transport properties (pumpable) can be adjusted. Ice slurry flows like traditional chilled water but boosts the cooling capacity of chilled water 5-6 times.
STAC Technology designs, develop and manufacture new sustainable chiller and ice slurry plants that use water as the refrigerant. It is our dedicated mission to help make smarter environmental friendly cooling solutions replacing outdated non-feasible and dangerous chillers made in the last millenium
The EU, USA and more than 200 other countries have banned or are in the process of phasing-out synthetic refrigerants. This development fits with STACs new sustainable chiller program using water refrigerants
Water, or R718 as it is called in the refrigeration and cooling industry, is the optimal refrigerant for a wide range of applications. At refrigeration temperatures of 0° Celsius or above water is the only environmentally friendly refrigerant neither being toxic nor flammable.
Considerable energy savings are gained as well as higher refrigeration COP values compared to any other process.
In comparison with other natural refrigerant such as ammonia, CO2 and more water is not poisonous nor flammable and doesn't cause health hazard risks locally.
Also water driven chillers requires no special permissions to use and the annual maintenance costs are the lowest