Carrier develops integrated free cooling for chillers
Free-cooling using a patented system based on the well established thermosyphon principle is now offered with Carrier Aquasnap chillers using R410A.
Carrier now offers an integrated direct-expansion free-cooling system as a factory installed option in its Aquasnap Puron chillers. The system is available on models up to 500 kW of these R410A chillers. The system overcomes many of the disadvantages of using an auxiliary glycol/air heat exchanger on the outside of the refrigerant condenser coil. It uses a patented system based on the well established thermosyphon principle; no glycol is needed, only water. The chiller incorporates a refrigerant pump and uses the natural tendency of a refrigerant to migrate towards an area of low temperature to satisfy some or all of the cooling load at low temperature without operating compressors. Naturally cooled evaporator water is circulated to the building to provide air conditioning. The system can be applied to any building using a chiller and having a high cooling load, even at low ambient temperature. Many well insulated buildings now require a low level of air conditioning all year round, so they can benefit from free cooling. Free cooling cannot be retrofitted, but these chillers lend themselves to refurbishment situations as they have a relatively small footprint and can be integrated readily with existing chilled-water systems.