Daikin’s multipurpose four-pipe EWYS-4Z employs inverter-driven single-screw compressors and operates with the low global warming potential (GWP) refrigerant R-513A. Its performance is also boosted by highly energy efficient variable frequency drive (VFD) and variable volume ratio (VVR) features.
The polyvalent units deliver capacities from 400 to 800 kW in cooling and heating mode with a total energy efficiency ratio (TER) as high as 8.00. They operate in outdoor temperatures from -18°C to +50°C and provide chilled water in a range between -8°C (with a water/glycol mixture) to +20°C. Heating water temperature is available from +30°C to +60°C.
The Daikin EWYS-4Z units are a versatile way of controlling indoor temperature and are well suited to buildings with variable temperature needs, such as hotels, hospitals, and large offices. They capture heat recovered when producing chilled water, which also makes them a popular addition to the industry’s range of solutions for reducing carbon emissions from buildings.
The range is also available with noise attenuation achieved through lower fan speeds and a specially designed soundproof compressor cabinet. Enhanced insulation on the refrigerant pipes and special compressor connections also significantly reduce vibration.
The EWYS-4Z is equipped with two Shell & Tube heat exchangers on the waterside: one always operates as an evaporator (cold heat exchanger) and the other as a condenser (hot heat exchanger). Copper-aluminium (Cu/Al) fin and tube coils are used to dissipate excess cooling or heating energy. 
These design features allow the Daikin polyvalent units to simultaneously meet cooling and heating requirements by following two setpoints simultaneously all year round, adapting to changing climatic conditions. 
Unlike reversible heat pumps, a multi-purpose unit does not require seasonal changeover and by controlling the two refrigerant circuits independently, it can respond quickly and accurately to a building’s cooling and heating demand patterns.
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