Computer rooms can often account for over 20% of a companies electricity requirements. In the case of one client the total computer room fan power and cooling system electrical load cost approximately £800,000 per annum.

The majority of these computer rooms are legacy systems with the air conditioning systems being grossly oversized for the current requirements. These systems were typically chilled water or DX based cooling systems with “in-room” close control air handling units (CCUs). These rooms because of their critical nature, also have built in running redundancy.

We recommended that a trial was undertaken in
one of the computer rooms. This involved installing
EC fans to replace the belt driven units, reconfigured
the CCU controls (to our bespoke control philosophy) and rebalance the air distribution within the rooms. The result was an 80% reduction in fan power and a corresponding reduction in cooling load. The saving from the trial was in excess of £25,000 per annum.

Following the success of the trial, a project to upgrade 30 computer rooms containing 80 CCUs was undertaken. This project included the following:

•  Replacing all belt driven fans with EC fans.

• Upgrading controls and programmes to the new standard.

• Optimising operation of CCU to minimise energy consumption whilst maintaining room temperature and humidity condition.

• Reconfiguring floor grills and removing unwanted ones to improve air distribution.

• Connection of each CCU to the site BMS system and collection of key CCU performance data. (to ensure continued efficient operation).

The project was conducted over a period of 12 months and cost £500,000. The saving achieved was in excess of £350,000 per annum give a project payback in under 18 months.

Joule Consultants managed the whole process and undertook the CCU control configuration and the final commissioning. Approximately 50% of the saving was as a result of the new equipment and the bespoke control strategy, the other 50% saving was as a result of the rebalancing works and our understanding of how to maximise savings through the different
control options available which can be unique to each computer room.