Cooling
Informations
Hot / cold aisle
Arranging cabinets into hot / cold aisles is a standard solution for data centers. Cabinets are oriented face to face, while cold air is supplied through perforated tiles in a raised double floor. Standard ANSI/TIA/EIA-942-A recommends a cold aisle width of 1.2 metres. This is generally the size of two double floor tiles. Cold air is supplied via perforated tiles at the front of the cabinets which is delivered to each of them by fans. Cold air is supplied to active elements through doors with 80 % perforation. In this case, the double floor is used to deliver cold air and it is necessary that all other openings in the floor, such as the cable entries are covered. The reason is to maintain static air pressure in the double floor and to minimise cold air loss.
Contained cold aisle
The solution of open hot / cold aisles presents possible shortages in the recirculation of heated air and therefore the risk of creating so called hot-spots – locally overheated areas. The solution is a contained cold aisle. This is a closed modular expandable system which physically separates the cold air from the exhalation of hot air. Actually, it creates a separate area for hot and cold air and prevents them from mixing. Cool air is fed into the closed aisle through perforated tiles of the raised floors or locally using the side cooling units, which are mounted directly in line between the cabinet. Standard width of the contained cold aisle is 1.2 metres (two floor tiles) or 1.8 m (three floor tiles). At the ends, the aisle also has a glass sliding door. The use of this solution is becoming standardised and is especially recommended for its cooling capacity and efficiency in achieving the lowest energy consumption of the data center.
Closed modular solution
A closed modular solution enables maximum energy efficiency and scalability of focus for long-term development of a data center. This solution can be designed and manufactured tailored to customer needs. In one room there can be zones not only with different operating temperatures, but also with different density of the thermal load. The solution is characterised by a high-IP cabinet. This also protects the installed components from dust and moisture. Side cooling units are attached directly with the racks to make a closed module with an internal cold zone at the front part of the cabinet and hot zone at the rear of the cabinet. This solution allows you to combine any number of racks and cooling units in the module. Our specialists will prepare a proposal for the project to ensure the space capacity required for installation of the equipment and the corresponding power conditioning, including any needed redundancy.
Floor feed
This method increases the efficiency of the cold air through the delivery from double floor to the installed equipment. The cabinet is installed on the opening in the double floor. A deflector, located at the bottom of the cabinet, directs cool air to its front section. Cold air in this case is further directed in the front section of the cabinet by the door without perforations, these may be of glass or metal. The hot air is extracted from the rack either by doors with 80 % perforation or the cabinet ceiling. By installing a cool air supply regulator to the bottom of the cabinet the amount of air may be adjusted, or delivery can be completely discontinued when the cabinet is not in use. The advantage of this cooling method is great flexibility in planning of the room usage. Cabinets installed in hot and cold aisle is not required if the hot and cold air is separated inside the cabinet. To achieve this it is necessary to install a separating frame inside the cabinets for a strict separation of cold and hot air.
Floor feed with plenum return
A possible disadvantage of cold aisle and cooling supply from the floor and return to the room is that the hot air is brought into the surroundings of the installed equipment. This does not cause a complication when it is already considered in the data center design stage. In certain cases a possible solution is to completely separate the warm air in areas with high thermal loads due to the concentration of the installed equipment. The solution is to supply cooling air from the room or raised floors and return it to the ceiling. This is the solution when the hot air does not return into the hall, but is fed to the ceiling or double ceiling. A rear deflector located in the upper part of the cabinet helps to optimise the flow of hot air into the outlet extension. A large adapter allows the passage of large quantities of air at a relatively low speed. A cold air intake is on the front door of the cabinet, and hot air is discharged through the outlet extensions to the ceiling / double ceiling above the devices. Air conditioning units take the hot air from the ceiling, cool it and deliver it back under the raised floor. The air cooling circuit is closed. This solution provides high efficiency cooling for very large volumes of hot air. Research indicates that this solution can be used to cool up to 30 kW per cabinet.
Our specialists will be glad to help you to choose the optimum solution for your needs.
Selecting the right type of cabinet and accessories, you can save significant money spent on the operation of your equipment.