It is available the new SCREWLine⁴-i (WDH-iK4) series, the new water cooled liquid chiller for indoor installation, with R513A refrigerant, and inverter screw compressor.

WDH-iK4 series is available with Excellence (EXC) version and proposes very high seasonal efficiency values, SEER up to 8.60.

Excellence version (EXC):
Range 340 – 830 kW: Unit with 1 refrigeration circuit e 1 inverter compressor
Range 705 – 1520 kW: Unit with 2 refrigeration circuits e 2 inverter compressors

Further strengths

Eco-friendly solution
The use of R513A refrigerant, with a low GWP (Global Warming Potential = 631), guarantees an environmental impact that is more than halved compared to traditional R-134a refrigerant (GWP = 1430).

Advanced technology
The technical solutions adopted place WDH-iK4 on top of its category: 
- the Inverter dual-rotor screw compressors for an improved operational flexibility and very high efficiency in all load conditions;
- the spray shell & tube evaporator which reduces the refrigerant charge by 40% compared to a flooded exchanger, and allows an evaporation temperature very close to the supply water temperature, increasing the overall efficiency of the unit;
- the oil recovery system, which ensures optimum lubrication of the compressor and prevent oil circulation in the refrigeration circuit, optimizing heat exchange.

Operations
The WDH-iK4 series offers 3 operating modes:

• Cooling only operation (OCO): standard
• Heating only operation (OHO)
• Operation with water circuit change-over (OHI)

Low noise operation
The WDH-iK4 series offers 2 acoustic levels:

• Standard acoustic configuration (ST): basic version
• Super-silenced acoustic configuration (EN): -3 dB (A) compared to ST

Maximum adaptability
The capacity load from 100% to 12% and a condenser outlet water temperature up to +55°C, and extended up to +65°C with the high water temperature version (HWT), are able to satisfy the requirement of multiple operating conditions. Many options and accessories are available to suit the needs of each plant.

Compact Size 
The space savings are an increasingly important aspect in the design of the building. 
Thanks to the new layout, the WDH-iK4 units are among the most compact units on the Market.

Already complies with 2021 requirements
The Commission Regulation 2281:2016, also known as Ecodesign LOT 21, set minimum seasonal efficiency levels to place products on the European market. WDH-iK4 is already conforming with the 2021 stricter requirements.

Perfect for LEED                                                                                                                      
Sizes from 120.1 to 320.2 satisfy prerequisites 2 and 3 of Energy and Environment thematic area. Furthermore, they match the parameters of Credit 4 that allows to achieve 2 points (Leed 2009). The correlated data are included in the technical bulletin.