Stay on top of trends and technology. Be aware of
new technologies that could one day benefit your data
center. Huang mentions investigating the economy of
colocation facilities (“data center hotels”) and using Cloud
computing to offload IT services. Indirect evaporative
cooling should also be on your radar. “We’ve used some
new indirect evaporative cooling units, and they use 50%
less energy without adding any moisture to the airstream.
They’re almost as efficient as a free air cooling,” says Vacarro. He adds that fuel cells and rear-door heat exchangers are promising solutions. Chilled beams, immersion,
and liquid cooling are also becoming more popular in data
1. Virtualize your servers. Avoid a one-workload, one-box approach
by consolidating multiple workload types on one host server.
2. Decommission your comatose servers. Some 15% to 30% of the
equipment running in data centers consumes electricity without
doing any computing. Remove obsolete servers.
3. Consolidate your lightly used servers. A typical server’s utiliza-
tion is about 5% to 15% yet it draws full power.
4. Organize and improve your stored data. Storage utilization av-
erages only around 30%. It is common for organizations to have
20 or more copies of the same data, wasting storage space.
5. Invest in technologies that use energy more efficiently. An
ENERGY STAR-qualified server uses 30% less energy than a
6. Take advantage of the hot aisle/cold aisle layout. Try arranging
servers so the fronts of server racks face each other and, there-
fore, the backs of the server racks face each other. This arrange-
ment reduces mixing of hot and cold air to improve efficiency.
7. Contain or enclose your server racks to further reduce mixing
cold supply with hot exhaust air. Use flexible strip curtains or
8. Review general airflow improvement tips. Install blanking
panels to decrease server inlet air temperatures and increase
the temperature of air returning to the CRAC, both of which
improve operational efficiency. Use structured cabling to avoid
restricting air flow to your servers. Install grommets to seal
areas where cables enter and exit plenums (such as a raised
floor). Less leakage helps direct more cold air to the equipment
that needs cooling. A professional airflow assessment can help
to improve cooling efficiency.
9. Adjust the temperature and humidity in your data center. In
2008, ASHRAE revised recommended temperature and humidity ranges at the inlet of the server. However, many data centers
keep very tight controls on humididity and set their temperatures as low as 55°F when the recommended range is 65°F to
80°F. Data centers can save 4% to 5% in energy costs for every
1°F increase in server inlet temperature.
10. Retrofit your air conditioning with variable speed fan drives
that adjust fan speed to accommodate changing cooling loads
in your data center. Retrofit kits for CRACs have a two-year
11. Install an air-side economizer that brings outside cooling air
into a building. Because data centers must be cooled 24/7/365,
air-side economizers may even make sense in hot climates
where they can take advantage of cooler evenings and winter
air temperatures to save 60% on cooling.
12. Install a water-side economizer. Use the evaporative cooling
capacity of a cooling tower to produce chilled water during the
winter months. During water-side economizer operation, costs
of a chilled water plant are reduced by up to 70%.
For more information, visit
centers. A recent study by the Lawrence Berkeley National
Laboratory found that one data center saved an estimated
$200,000 per year in operating costs with a water cooling
Because smart energy management in data centers is a
matter of cooperation among departments, don’t hesitate
to reach out to your peers and others. “There are so many
resources out there,” says Seger. “Don’t be afraid to ask
for help.” B
Jenna M. Aker is a contributing editor.
TOP 12 WAYS TO DECREASE THE ENERGY CONSUMPTION OF YOUR DATA CENTER
Use these ENERGY STAR tips for a smarter, more efficient data center.
Check out this Intel white paper on best practices for data
centers retrofitted for efficiency: www.intel.com/content/