Air conditioners may soon be a thing of the past, as major companies like Facebook, eBay (NASDAQ: EBAY) and Google (NASDAQ: GOOG) make the switch from mechanical cooling to outside air cooling to regulate the temperature of their IT equipment. EBay is operating its new Phoenix data center with 100 percent free cooling year round, even on 115-degree-Fahrenheit days, while Facebook’s Prineville data center in Washington State was built to use only free cooling.

Now, a new set of maps will help other companies follow suit. At a conference in March, The Green Grid, a nonprofit aimed at improving energy efficiency at data centers, unveiled its updated free cooling maps. The maps, based on guidelines from the American Society of Heating, Refrigeration and Air-conditioning Engineers, show where in the world and for how many hours per year outside air can be used in place of air conditioners and other cooling devices.

Companies in those regions would be wise to consider making the switch. Cooling systems account for a whopping 70 percent of a data center’s total non-IT energy consumption. Eliminating cooling mechanicals, such as computer room air conditioners and chillers, could result in an average of 20 percent in energy and cost savings, according The Green Grid’s survey of data-center operators. But in regions with hot or humid climates, isn’t mechanical air conditioning a necessity to keep IT equipment humming? 

Not so, according to The Green Grid’s report. Free cooling can be used year round in more than 75 percent of North America and more than 97 percent of Europe, even in places with temperatures as high as 113 degrees Fahrenheit. Other countries present more of a challenge, such as Japan’s environment, where some areas can only use outside air 14 percent of the time. The map of North America above, taken from The Green Grid’s report, shows free cooling ranges for more delicate IT equipment, classified as A2 by the American Society of Heating, Refrigeration and Air-conditioning Engineers, with A4 being the most heat and humidity tolerant.

There is a caveat: to achieve 100 percent free cooling in certain locations, operators may occasionally need to function outside the recommended A1 to A4 heat and humidity range. But the potential savings of using outside air often outweighs the risk of a failure of IT equipment. In that case, free cooling may certainly be worth a try.

Big data-center operators aren’t waiting to put theory into practice. Yes, companies like eBay and Facebook do deploy masses of servers on a monthly basis and don’t have voided equipment warranties to worry about. But most technology refreshes happen on a three-year time frame, meaning it's probably not too far off to assess your free cooling options for the next planning cycle.