Install the Spirovent® at the point of lowest solubility, which is the place in the system where the temperature is the highest and pressure the lowest. Note as well to always "pump away" from the expansion tank, never towards it.

Related Work

University of Arkansas Medical Sciences - Little Rock, AR
High velocity 18" air eliminator on the hot water system, and custom high velocity 30" air eliminator on chilled water system.
North Mississippi Medical Center - Tupelo, MS
High velocity 18" combination air eliminator and dirt separator.
Purdue University - West Lafayette, IN
Spirovent exceeds expectations and leads the University to purchase and install (32) additional units at the village.
Kansas State University - Manhattan, KS
Following the installation of numerous smaller units on campus that met all expectations, a separator upgrade was proposed for the central plant.