Visiting teams may take batting practice as early as noon, and the roof may be closed to accommodate them. Also, if it is not cool enough to open the roof as the game begins, it may be opened in the fifth or seventh inning, Barrett said. All of the experiments will be closely calibrated to expected temperatures, humidity and wind speed. The wind is likely the key factor, said Kelly Redmond, regional climatologist for the Western Regional Climate Center at the University of Nevada, which keeps weather data for the Western states. On a model evening, the temperature in the lower deck will be 72 degrees, while the average in the upper deck will be 82.
Hot air rises, cold air sinks.
However, if a breeze develops, all the air tends to mix, warming everyone, Redmond said. The park's cooling system includes seven chillers in the basement. Unlike residential air-conditioning systems, which force cold air through vents, chillers pump cold water through pipes. Once the water has been pumped through the stadium, it will go back to the basement. Then it will be pumped under the railroad tracks south of the stadium to a series of four cooling towers, which will cool the water through evaporation.