As the UK and wider Europe push towards net zero, heat pump technology is central to decarbonising heating and cooling. By using electricity—preferably from renewable sources—heat pumps reduce dependency on fossil fuels across residential, commercial and industrial applications. Discover the key benefits of heat pump systems here.
Daikin Applied’s expertise in multi-purpose HVAC solutions stems from decades of innovation and industry knowledge. Our four-pipe systems—also known as polyvalent or multifunctional units—are designed to deliver simultaneous cooling and heating from a single unit, along with domestic hot water. This integrated approach not only offers greater flexibility but also supports energy recovery, helping to reduce running costs.
Four-pipe units such as Daikin’s EWYS-4Z are ideal for installations requiring year-round comfort, from offices and hospitals to mixed-use developments. Unlike conventional systems, they eliminate the need for seasonal changeovers and can significantly enhance system efficiency when correctly specified and applied. However, careful design is crucial—while these units offer clear benefits, incorrect application may lead to suboptimal performance or inflated capital costs.
Discover how the Daikin EWYS-4Z multipurpose unit combines innovation and sustainability. Explore our case study on inverter screw technology in a London commercial building.
The EWYS-4Z offers a capacity range of 400 to 800 kW for both heating and cooling, achieving a Total Energy Efficiency Ratio (TER) of up to 7.89. Its inverter-driven single-screw compressors use Variable Frequency Drive (VFD) and Variable Volume Ratio (VVR) technology to ensure optimum performance in part-load conditions.
Designed for reliability and speed, it reaches comfort set points quickly—even in low water volume systems—and operates efficiently across a wide range of ambient temperatures, from -18°C to +50°C. Chilled water output spans 8°C to +20°C (with glycol), while hot water temperatures range from 30 °C to 60 °C.
Electrical characteristics are also optimised: the unit keeps inrush current below the full load current and maintains a high power factor above 0.95 to minimise losses and avoid penalty charges. Its capability to switch seamlessly between air-to-water and water-to-water operation in under a minute enhances flexibility across a range of applications.
To determine when and where these units are the right fit, please review our guide to multipurpose units or contact us for project-specific advice.
Daikin’s refrigerant-cooled inverter technology ensures reliable performance, regardless of environmental factors such as temperature or air quality. The integrated VVR system within the compressor dynamically adjusts the compression ratio, further enhancing efficiency under variable loads.
You can learn how inverter technology can transform system performance here.
Daikin’s single-screw compressors are engineered to distribute mechanical loads evenly, which prolongs component life and reduces vibration and noise, essential for acoustically sensitive environments. These compressors also maintain high volumetric efficiency at variable speeds, making them ideal for multipurpose units.
Each polyvalent system incorporates two separate water circuits and three key heat exchangers per refrigerant circuit:
When heating and cooling loads coincide, the system maximises energy recovery by bypassing the source exchanger. The independent modulation of refrigerant circuits ensures the system continuously adapts to building demands, without seasonal switchover.
These capabilities make polyvalent systems a strong choice for sites with consistent, simultaneous thermal demands, like hotels, hospitals, and retail centres.