Top Ten Flaws of Data Center Air Flow
By: Rob Nash-Boulden, Vice President – EDI, Ltd.
The Data Center Services professionals at EDI, Ltd. have assembled a list of the ten most severe problems with data center airflow:
1. Mixing – When hot air corrupts and warms the cool air supply. Standard condition for most data centers.
2. Recirculation – When warm air escapes its planned return path and re-enters computer equipment, warming it instead of cooling it. Affects top-of-rack and end-of-row servers especially hard.
3. Short Circuiting – When cool air escapes back to the CRAC without doing any cooling work.
4. Leakage – When supply air from beneath the floor air sneaks into the room through cable openings and cutouts.
5. Under-Floor Obstructions – Hidden enemies of proper cool air supply, such as ridges and divides of cables, trays, piping, and structural incursions.
6. Poor Return Path – When the warm air has no clear route to return to the CRAC. Heat build-up provokes operators to try homemade solutions.
7. Dehumidification – Happens when air reaching the CRAC is so humid that the moisture it carries condenses on the CRAC, and then the air has to be re-loaded with moisture. Very expensive problem that is poorly understood by owners.
8. Venturi Reversal – Happens most often in front of the CRACs when the cool air traveling at high velocity pulls air from the room down into its path.
9. Vortex Generation – When misplaced CRACs generate swirls under the floor whose centers have not enough pressure to cool the equipment above them. Seldom diagnosed without simulation.
10. Wrong-Way Racks – When computer racks are installed so that they intake from a hot aisle and vent into a cold aisle. Common in computer rooms that have seen considerable growth over several generations of equipment.