From Google: During the purge process of desiccant dryers, the initial depressurization step leads to a rapid release of compressed air into the ambient environment. While this step is brief, it often results in significant noise levels that can disturb individuals in the vicinity . CAN CONFIRM - even if you're expecting it, it makes you jump . . Like and follow @hvacjess . . . . . . . . . . #desiccant #airdryer #airdrier #hvaclife #hvac #industrialhvac #industrialhvacr #hvacr #hvacrlife #hvacrt