Eleven tips for datacenter efficiency

Power consumption at datacenters is once again in the spotlight, after analyst house Gartner came up with a list of best practices in the datacenter, designed to save electricity and improve cooling.

Gartner modestly claims that if companies follow all of its best practices, it could typically expect to save 1 million kilowatt hours. It says that in a conventional datacenter, between 35 and 50 percent of the electricity consumed is for cooling compared to only 15 percent in best-practice, or "green," datacenters.

[ Also check out "Four ways to cut datacenter costs," and for other ways to trim expenses, take a look at Tom Sullivan's "Five outside-the-box ways to cut IT costs." And keep up on green IT trends with InfoWorld's Sustainable IT blog and Green Tech newsletter. ]

"Virtually all datacenters waste enormous amounts of electricity using inefficient cooling designs and systems," said Paul McGuckin, research vice president at Gartner in a statement. "Even in a small datacenter, this wasted electricity amounts to more than 1 million kilowatt hours annually that could be saved with the implementation of some best practices."

The main reason for the waste in conventional datacenter cooling is the "unconstrained mixing of cold supply air with hot exhaust air."

"This mixing increases the load on the cooling system and energy used to provide that cooling, and reduces the efficiency of the cooling system by reducing the delta-T (the difference between the hot return temperatures and the cold supply temperature). A high delta-T is a principle in cooling," McGuckin said.

Gartner's 11 top tips for reducing power consumption are:

1. Plug holes in raised floor.

This point was also raised by SunGard Availability Services last month, as apparently holes in the floor allows cold air to escape and mix with hot air. This single low-tech retrofit can save as much as 10 percent of energy used for datacenter cooling, says Gartner.

2. Installing blanking panels.

Datacenters are full of racks, and unused rack space needs to be covered with a blanking panel so that airflow can be properly managed, for example by preventing hot air leaving equipment in one section of the rack and then entering the cold air intake for other equipment elsewhere in the rack. Gartner says when these panels are used effectively; supply air temperatures can be lowered by as much as 22 degrees Fahrenheit (or minus 5 degrees Celsius).

3. Coordinate CRAC units.
A CRAC unit (according to Gartner) is an older Computer Room Air-conditioning Unit. Apparently these units operate independently of each other when cooling and dehumidifying the air. Gartner suggests that if these units could be tied together with newer technologies, and their efforts coordinated, then the results would be a much more efficient cooling system.