Environmental Control Best Practices
The following section details general practices should be considered relating to environmental control in particular.
As a minimum arrange cabinets in rows to establish Hot and Cold Aisles. Cabinets should be aligned front-to-front along cold aisles, and back-to-back along hot aisles.
Within each row, cabinets should be connected side to side with no gaps. This is the most basic first step to achieving cooling efficiency and for this strategy to work, cold air must be delivered to cold aisles and hot air extracted from hot aisles.
Hot exhaust air and cold supply air should not be allowed to mix as this causes short cycling of the cooling system. Use empty cabinets or partitioning to fill gaps between cabinets to reinforce hot aisle / cold aisle layout or containment if installed.
Build rigid enclosures / containment to fully separate the heat rejected from the rear of IT equipment from the cool air intakes on the front. Hot aisle containment is the most effective for a variety of reasons. Alternatively use flexible strip curtains in legacy sites to improve the separation by blocking any open spaces above the cabinets.
Standardise on cabinets designed for High-Density Environments. Standardising on an appropriate cabinet design makes it much easier to establish and enforce effective power and thermal policies. Avoid shallow cabinets to make sure in-cabinet cabling does not obstruct airflow. Select equipment cabinets that do not have an internal configuration that would obstruct smooth cooling airflow through the installed IT equipment.
Overhead return plenums need to be sized to allow for the large quantities of air flow that is required. Common obstructions such as piping, cabling trays, or electrical conduits need to be accounted for when calculating the plenum space required. Blockages can cause high pressure drops and uneven flow.
In non-contained aisles there should be at least 1 metre clearance between the top of the equipment cabinets and the ceiling. Insufficient ceiling height will obstruct the delivery of efficient air cooling technologies such as raised floor, suspended ceiling or ducts within the data centre.