It may be due to rccent downszing of power consumption
According to http://www.thehostingnews.com/news-dedicated-server-firm-the-planet-data-center-manager-garners-award-4306.html it claims "Mr. Lowenberg conducted a six-month trial to reduce power consumption and increase data center operating efficiency. Initial results demonstrate that while critical server loads increased by 5 percent, power used for cooling decreased by 31 percent. Overall, the company experienced power reductions of up to 13.5 percent through a broad range of improvements. The new green initiatives were conducted across its six world-class data centers." and also The Planet operates more than 150 30-ton computer room air conditioning (CRAC) units across its six data centers. In one data center alone, the company was able to turn off four of the units. The cooling requirement on two of the units was reduced to 50 percent of capacity, while another nine now operate at 25 percent of capacity. The company also extended the return air plenums on all of its down-flow CRAC units to optimize efficiency. "