Precision air conditioning

Airflow from the technical floor is the most common method of supplying cooling air – both in the open cold corridor system where the server rack cabinet with IT equipment heat output reaches around 2.5 – 5 kW/cabinet. However, when the power starts to increase, specific air circulation is required with clear indication of the heat collection point from the zone, e.g., suspended ceiling or hot corridor.

Hence, an increasingly common method that is deployed is closing a cold corridor and creating a buffer of the accumulated cold in the given area. This is, of course, a functionality that is required for high density IT cabinets but closing of the cold zone alone is used with lower density cabinets.

This is mainly down to certain air circulation guidelines and the heat load of IT cabinets. This requires alternative airflow management solutions, raised floor system or U (unit) filler panels to seal the rack cabinet. This does not change the fact that room-based air-conditioning is realistically capable of supplying around 5-6 kW for cooling (if no additional ventilator is used) per 600 x 600 mm ventilation grille piece.

We are increasingly installing in-row air-conditioning systems based on air-conditioners fitted directly in line with the IT cabinets and closing cold corridors to create a large buffer of cold air available for the IT equipment.  Such systems are usually very compact (only 30 cm) and are capable of supplying up to 30 kW of cooling from one air-conditioning cabinet. The initial power starts from under 5 kW from the in-row air-conditioner. An advantage of such a system is an increasingly lower price in relation to cabinets with air ducted under the technical floor and in this case a technical floor is not even required (the piping can run from the top of the air-conditioner).