The Rittal SK 3301800 is a roof-mounted cooling unit for cooling IT equipment in individual enclosures located in secondary rooms. The unit is mounted on the roof of the IT enclosure and cools the air volume inside the enclosure, supporting the typical front-to-back airflow of IT technology. Warm exhaust air from the servers is drawn in from the rear area of the enclosure, cooled within the unit, and then blown back as cool supply air in front of the 48,3 cm ( 19 inch )-rack. Temperature control is based on the setpoint of the server supply air temperature, ensuring constant and even air distribution.

Applications
This cooling unit is specifically designed for cooling IT systems in individual enclosures that are not located in a central data center but in separate, secondary rooms. It is suitable for applications requiring individual climate control per enclosure to maintain the operating temperature of IT systems within the specified range. The cooling capacity is sufficient for heat loads up to 3 kW, which is adequate for many standard IT loads.

Functions and Features in Detail
The unit features a condenser with hydrophobic RiNano coating, which reduces condensation formation and simplifies maintenance. The integrated electrical condensate evaporation ensures that the generated condensate evaporates directly within the unit, eliminating the need for an external drain. Temperature control is managed via a Comfortcontroller, which sets the supply air temperature setpoint between 20 °C and 25 °C. Additionally, supply air temperature monitoring is provided to enable early detection of deviations. The unit is pre-wired and connected to the power supply via a pluggable terminal block.

Technology Explained Simply
The cooling capacity, according to DIN EN 14511, is 3,200 W at an outdoor air temperature of 35 °C and an indoor air temperature of 45 °C. The airflow in the outdoor circuit is 2,000 m³/h, and in the indoor circuit 1,450 m³/h. The energy efficiency (EER) is 1.6, meaning the unit produces 1.6 kW of cooling per kWh of electrical energy consumed. The rated operating voltage is 230 V, 1~, 50 Hz, with a maximum rated current of 10.4 A. The inrush current can temporarily reach up to 36 A. The duty cycle is 100 %, meaning the unit can operate continuously.

Compatibility and Accessories
The unit includes a air guide plate in the delivery scope, which supports airflow in front of the 48,3 cm ( 19 inch )-rack. Additionally, a drilling template and mounting hardware are included to facilitate installation. Suitable accessories include a door position switch, a filter mat for models SK 3382.../SK3383.../SK 3384/SK 3385, an air guide plate DK 5501805 (W/H 600x2000, RAL9005), and a condensate hose 12 x 2 mm, length 10 m. These components can be used to extend functionality or adapt to specific requirements.

Installation and Mounting
Mounting is performed on the roof of the IT enclosure. A roof sheet with a corresponding cutout for the enclosure dimensions is required to securely fasten the unit. Installation is simplified by factory wiring and the included drilling template. The protection rating is IP 20 for both the outdoor and indoor circuits, providing protection against finger contact and solid foreign objects, but not against water or dust. The unit is made of sheet steel and painted in RAL 7035.

Operational Advantages
Thanks to the setpoint-dependent control of server supply air temperature, consistent cooling performance is ensured regardless of ambient temperature fluctuations. The integrated condensate evaporation reduces maintenance effort, as no external drain is required. The even air distribution in front of the 48,3 cm ( 19 inch )-rack ensures optimal cooling of all devices in the enclosure. The unit is designed for continuous operation (duty cycle 100 %) and is therefore suitable for 24/7 operation in IT environments. The refrigerant R134a is used in a quantity of 1.2 kg, with a Global Warming Potential (GWP) of 1,430.

Key Technical Features

• Cooling capacity: 3,200 W (L35 L45 according to DIN EN 14511)
• Airflow: Outdoor circuit 2,000 m³/h, indoor circuit 1,450 m³/h
• Energy efficiency (EER): 1.6
• Rated voltage: 230 V, 1~, 50 Hz
• Rated current: 10.4 A (50 Hz)
• Inrush current: 36 A (50 Hz)
• Protection rating: IP 20 (outdoor and indoor circuits)
• Refrigerant: R134a, quantity 1.2 kg
• Adjustable range: 20 °C to 25 °C
• Dimensions: W 597 mm, H 417 mm, D 895 mm
• Material: Sheet steel, color RAL 7035
• Delivery scope: Condenser with RiNano coating, integrated electrical condensate evaporation, connected cables, drilling template, air guide plate, mounting hardware

The unit is designed for use in IT enclosures located in secondary rooms and provides reliable, individual climate control for IT systems with a maximum heat load of 3 kW.