SUMMARY This article describes the necessity of automatic air vents in a closed loop chiller system. Without automatic air vents, you run the risk of pump damage, bio growth, and water hammer damage.
SYMPTOMS A closed loop chiller system has many operational advantages over an open loop (open vented) system. Engineers and installers must consider automatic air removal when designing and installing closed loop applications. Failure to remove all air can result in: Pump damage, bio growth that will cause loop fluid to turn green and water hammer damage to system components.
RESOLUTION To prevent such problems, Legacy recommends installation of Hoffman Model # 79 automatic air vents on the supply and return headers. Air vents must be installed at the highpoints in the system. Always follow the parts installation instructions provided by Hoffman. Submittal data on the Hoffman #79 has been attached to this article.