© Future Facilities Ltd. 2007 By Stuart Crump

The Value of Blanking Plates

Server equipment will suck the air supply it requires from wherever it can within a facility whether this is from a floor grille or the hot exhaust of other equipment. This presentation

demonstrates the effectiveness of use of blanking plates to control the provision of a conditioned air supply to the equipment.

© Future Facilities Ltd. 2007

6SigmaRack software is used to predict the inlet temperatures of equipment

with & without blankingIsolated racks have been created with & without blanking plates between their equipment.

Both racks have the same equipment with the same power. Both racks receive the same cooling from the floor grille.

The blanked rack receives lower mean inlet temperatures since all of the supplied air is coming directly from the floor grille. The un-blanked rack obtains a portion of its air supply from the equipment exhausts at the rear and therefore receives a higher mean inlet temperature.

Without Blanking Plates With Blanking Plates

Blanking Plates

© Future Facilities Ltd. 2007

Recirculation effects are worsened when the cabinet is installed in an operating

environment

The following Virtual Facility represents an operational data centre. The net flow through thefloor grilles is displayed.

The amount of cooled air from the ACU’s reaching the equipment through the floor grilles varies significantly throughout the facility.

All cabinets contain exactly the same equipment as in the previous isolated scenario and are all un-blanked.

In some areas there is insufficient air to supply the equipment. Equipment will suck in the nearest air that is available regardless of its temperature.

NET Grille Flow in an Operational Data Centre

A

The ACU is blowing air under these grilles so there is very

limited up-flow to the equipment

© Future Facilities Ltd. 2007

Streamlines allow it be seen from where equipment gets its air supply

The following cabinet (marked ‘A’ in the previous floor plan) is an example of a cabinet from the fully populated Virtual Facility shown previously. It is completely un-blanked.

Some of the exhaust air is re-circulating into the equipment inlets

Un-Blanked Cabinet

There is severe mixing of the hot exhaust air and the cool air front at the equipment inlets

Plane of Temperature through Un-blanked Cabinet

© Future Facilities Ltd. 2007

A temperature plane has been placed directly in line with the inlets of the equipment to show the temperature of the air entering each server.

Equipment close to grilles with low flow rates is more likely to draw air from equipment exhausts.

The plane is coloured red in this area indicating the presence of the hot exhaust air close to the shorter arrows.

6SigmaRoom is used to show the variation of air supply in one row of a facility’s equipment.

Equipment in close proximity to grilles with low flow rates receive

hotter air supply

© Future Facilities Ltd. 2007

Cabinet A is now shown after having been its vacant U-slots completely blanked.

The blanking plates block the path of the hot exhaust air preventing it from being recycled.

The installation of Blanking Plates prevents recirculation

The exhaust air streamlines are blocked

from entering the equipment inlets

Blanked Cabinet

There is no longer any mixing of the cool air and the hot exhaust air as the re-circulation path has been

blocked by the blanking plates.

Plane of Temperature through Blanked Cabinet

© Future Facilities Ltd. 2007

The thermal situation has been significantly improved by the addition of low cost blanking plates particularly in the areas where the grille supply is low.

Thermal improvements can be noted at the intake of every single cabinet which goes to prove that, even with a very good up-flow from the floor void, a small proportion of exhaust air will still be re-circulated if blanking plates are not utilised.

The effect of Installing blanking plates to the vacant U-slots in every cabinet

Un-Blanked Facility Blanked Facility

© Future Facilities Ltd. 2007

Future Facilities Ltd. recommends the use of blanking plates when installing new front ventilated cabinets filled with new front ventilated equipment.

Installing blanking plates in existing cabinets is beneficial in the majority of situations however

Future Facilities recommends the use of 6SigmaRoom & or 6SigmaRack to confirm this

before installation.

Slide 8

© Future Facilities Ltd. 2007

providing design & management software and services for data centre facilities

1 Salamanca Street Albert Embankment

London SE1 7HX

http://www.futurefacilities.com

Tel: +44 (0) 20 7840 9540

Fax: +44 (0) 20 7091 7171