Datacenter Airflow Management Part II: Maximizing Return Air Temperature
In part I, we talked about factors that influence efficiency and effectiveness when it comes to data center airflow.
Today, we’re going to dig into another data center objective:
Maximizing return air temperatures by supplying conditioned air directly to equipment air-intake locations.
Conditioned air in data centers should be delivered directly to IT equipment in a way that avoids mixing with equipment exhaust air. Unlike office environments where conditioned air mixes with exhaust air constantly to avoid drafts, data center environments require air to be guided directly to equipment.
Diffuser position is critical
Depending on your data center configuration, you may have limitations when it comes to diffuser placement. Your air diffusers should be placed in a way that delivers air directly to IT equipment. However, at the very least, your diffusers should not be directed at equipment and rack exhausts, and instead they should be directed toward equipment intakes.
Optimize the location of air conditioners
While it may not be practical to perform a fluid dynamics model, there are simple steps you can take to reduce the chances of leakage from supply plenums and ducting. The easiest step is to reduce the amount of space between A/C units that the largest equipment loads in the room.
Ensure adequate supply and return plenum size
Once you’ve identified the correct size for a given room, you should also ensure that any blockages from cabling trays, conduits and pipes are taken into account. Blockages lead to pressure drops and uneven airflow, which is related to the next point.
Use an appropriate pressure in airflow systems
When pressure in an airflow system is too high, the result is typically high fan costs, greater air leakage and short-circuiting of the cooling air. Alternatively, low-pressure situations can result in ‘hot spots’ in areas most distant from the cooling air. Often, the latter is addressed by simply lowering the cooling temperature. However, this fix can result in over-cooling the entire space to address a temperature problem that is really an airflow problem.
Unless you are accurately monitoring these efforts in your data center, they are simply suggestions that may, or my not, work in your situation. Accurate monitoring is the most effective way to determine if your efforts are paying off.