Raising the temperature in the datacenter also can result in hot spots in areas where cool air doesn't reach an entire rack, a case for implementing "advanced monitoring of rack temperatures and datacenter airflow before nudging the set point higher," suggests Rich Miller at Data Center Knowledge.
Moreover, increasing the temperature in the datacenter means hotter hot aisles -- up to as high as 130 degrees Fahrenheit if you're hitting ASHRAE's recommended maximum temperature. That could spell uncomfortable working conditions for IT staff working at the back of a rack. SearchDatacenter.com blogger Mark Fontecchio has a suggestion to deal with the intense heat: "Simply to pull up a tile where you're going to work in the hot aisle, and replace it with a perforated tile. That way you can get a nice chilly gust of cold air blasting from your feet to counteract the furnace blowing in your face. Sure, putting perforated tiles in the hot aisle is considered a severe no-no in well-designed hot/cold-aisle datacenter configurations. But if it's temporary, and it can prevent the need to have an IV bag of fluids on site just in case of severe dehydration and overheating of employees, well, then it might be worth it."
The potential consequences of a higher datacenter temperature don't end there. When those server fans kick into high gear in response to a higher temperature, there's another potential consequence: more noise in the datacenter. Michael Patterson, a thermal engineer at Intel, told IT Knowledge Exchange that "[for] servers with (variable frequency drive) fans -- the increase in power comes mostly from the increase in fan power after 25 degrees Celsius [77 F]," he said. "Servers in 27 degrees Celsius [80.6 F] may have higher acoustics due to higher fan speed."
ASHRAE says an increase of 3.6 degrees Fahrenheit can result in a noise increase of between 3 and 5 decibels, enough to warrant scrutiny by datacenter managers to ensure that they're not causing harm to datacenter staff: "With regard to the regulatory workplace noise limits, and concern to protect their employees against potential hearing damage, datacenter managers should check whether potential changes in the noise levels in their environment will cause them to trip various 'action level' thresholds defined in the local, state, or national codes."
The bottom line here is that while ASHRAE has given a stamp of approval to running the datacenter at a higher temperature (though some will argue it's still not high enough), there are caveats. Turning up the heat takes some planning and follow-up to ensure a positive outcome.