Which describes the hot aisle/cold aisle concept used in arranging server racks in a data center?

Answer: C. Arranging racks so that intake sides face each other and exhaust sides face each other, separating the cold-air aisles from the warm-exhaust aisles so that the air does not mix

Servers generally take in cool air at the front and exhaust warm air at the back. Sending cool air into the aisles where rack intake sides face each other (cold aisles) and returning warm air to the air conditioners from the aisles where exhaust sides face each other (hot aisles) keeps the two from mixing and raises cooling efficiency. Enclosing the aisles with walls or doors (aisle containment) increases the effect further and also helps improve the PUE.

• A. Each rack takes in the warm exhaust of the rack in front of it, which lowers cooling efficiency.
• B. Mixing cool air with warm exhaust lowers cooling efficiency.
• C. Correct. The intake and exhaust aisles are separated so that the air does not mix.