Air Separator eliminates air from water within the Hydronic System. Because piping noise can be caused by air, the Hydronic System must be equipped with air separation devices to minimize the amount of entertained air in the piping circuit. Air should be vented highest point of the system. In-line air separator reduces the water velocity to 1.5 to 2 fps to allow air to separate from water. The location of the in-line air separator should be on the supply pipe between the boiler and pump. In the Chilled Water system the location of the air separator should be on return pipe between the chiller and pump, because air separates are more efficient in higher water temperatures.
The Air Separator should be installed at the point of lowest solubility in the system, that being where the temperature is the highest (after boiler and/or heat exchanger for hot water or before the chiller and/or heat exchanger for chilled water) and the pressure is the lowest (before pump suction). As with all Hydronic system piping it is recommended to house the Expansion tank connection to the system on the suction side of the pump.
Air Separator must be mounted in a straight run of horizontal piping in a perfectly upright position to allow the vent to operate freely.