XTW – water condensed chillers with oil-free compressors - no oil in the refrigerating circuit means a very high efficiency in the heat exchange: XTW by HiRef combines different brand new technologies to provide the highest COP, especially at partial loads. Refrigerant R1234ze, oil-free centrifugal compressor, compact flooded evaporator, special layout designed for low noise emissions, regenerating internal heat exchange, small footprint.