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

Cottey College - Nevada, MO
From the President's house to the power plant, to almost all buildings on campus, Spirovents have contributed to efficient system performance across the campus.
International ALERT Academy, Big Sandy, TX

“I have not had to vent a coil in the three months since

Unocal - Pacific Northwest, US
4" Spirovent® air eliminator being used to control foam in a bottling operation for transmission fluid and motor oil.
Mercy Medical Center - Des Moines, IA
High velocity 18" combination air eliminator and dirt separator.