Six years ago, using outdoor air in cold climates for data centers was limited. Data centers have been reluctant to adopt this technology, perhaps because outdoor cold air is naturally dry, and when it picks up heat in data center spaces, its relative humidity drops to levels where humidification is needed to protect the IT equipment from static electricity. This and other problems were addressed efficiently in an innovative system installed in a new state-of-the-art data center in West Jordan, Utah. This article details the free cooling system used in this data center, which has been operating for more than a year.