This guide contains information on the (1) description and capabilities, (2) design, (3) installation, (4) operation, and (5) maintenance of the improved sprayfan auxiliary ventilation system. The improved sprayfan system is a modified water spray system that directs intake air to and across the front of a continuous miner to prevent buildup of methane gas and dust concentrations. Although the improved sprayfan system operates on the same principles as the original sprayfan system, the layout and number of spray nozzles differ, providing additional water for improved dust suppression. Underground tests, independent laboratory tests, tests by the Mine Safety and Health Administration, and independent installations by coal producers have confirmed the performance of the sprayfan system. More than 300 sprayfan systems are currently in operation in underground coal mines.