Cold Aisle Containment Systems (CAC)
Cold aisle containment (CAC) isolates the cooled supply air from the CRAC units within direct proximity of the air intake of critical equipment
Sealing the cold aisle prevents hot server exhaust air from coming in contact with the server intake. This allows for optimal operation of critical equipment in a highly controllable and consistent air temperature environment.
CAC Systems: How They Work
This increased control allows the data center manager to accurately choose the temperature supplied to the servers.
ASHRAE 9.9 recommends a maximum supply air temperature of 80.6 F for mission critical applications. Most CRAC units are set to deliver 55 degree air. By the time this air reaches the cold aisle, the temperature will still only be around 60 degrees. This over-cooling is necessary to help mitigate the effect of the hot exhaust air spilling into the cold air’s aisle. By implementing a containment solution, either hot or cold aisle, it is possible to adjust the CRAC set points much higher. A rule of thumb is that for every 1 degree increase in set point there will be a 3-4% decrease in cooling costs. Based on that, here is an example of cost savings based on conservative results.
Annual Cooling Costs: $350,000
10 Degree Increase In Set Point = 30% Savings
Annual Savings = $105,000
With huge savings like this, it is easy to see why cold aisle containment has become a best practice in data centers. To maximize results it is important to also seal in and under the server cabinets to prevent exhaust air from getting to the server intake. Low cost items such as blanking panels and under-cabinet panels are essential accessories to ensure your containment yields the results you expect