Air separators eliminate entrained air efficiently and quickly from the piping system in closed-loop heating and cooling applications. Air separators are multi-pass devices and, over time, will “scrub out” air and bring the dissolved air content down to less than 0.5% of system volume. Removing air reduces corrosion, which destroys moving parts such as valve packings and pump seals. Eliminating air from the system will also reduce noise and improve heat transfer. Using an air separator will help maintain optimum system performance.
Where Should an Air Separator Be Located?
Air separators in a hydronic system should be located where the water temperature is high, and the pressure is low. The solubility of the dissolved gases in the water is lowest at these conditions. The ideal location in a heating system for an air separator is at the outlet of the heat source. For chilled water systems, place the separator in the return to the chiller. In wall-hung boiler installations, mount the air separator in the vertical hot water supply pipe.
Types of Air Separators
Tangential/Centrifugal Air Separators
Tangential or centrifugal air separators create a low-velocity vortex in the center of the tank where entrained air can come out of solution and float to the top of the tank, where it can easily be removed via an air vent or connection to an expansion tank.
In-line Air Separators
In-line air separators feature an internal baffle design and work well in constant and variable flow systems. As fluid enters the air separator, the velocity is decreased, creating a low-pressure area. As a result, the tiny bubbles are released from the fluid and then collected in the coalescing medium. As the bubbles coalesce, they rise to the top of the air separator, where they are released into the atmosphere through an air vent.
Air Purgers/Scoops
Air purgers (or scoops) slow water velocity to separate the air from the solution with an internal baffle. As air and water enter the air scoop, their velocity decreases, permitting the air bubbles to be scooped up by the baffle and directed to the chamber’s top. The air that reaches the top of the air scoop is either immediately vented through a vent or moves into a conventional plain steel expansion tank.
Air Separators by Manufacturer
Bell & Gossett
Bell & Gossett’s line of air separators is designed to make your system more energy-efficient, trouble-free, and long-lasting.
Rolairtrol Air Separator
The Rolairtrol is a centrifugal-style air separator for use in any HVAC system. Its 3-to-1 body diameter to nozzle diameter ratio slows the fluid velocity to help entrained air come out of solution. Its tangential inlet and outlet nozzles induce centrifugal fluid flow, creating a low-pressure vortex and eliminating air through an air vent or expansion tank. Rolairtrol Air Separators are available in sizes ranging from 2" to 36".
Inline Air Separator (IAS)
Inline Air Separators are designed to efficiently separate air from circulating water in hydronic heating and cooling systems and assure quiet operation. Available in 1-3" sizes.
Enhanced Air Separator (EAS)
In Enhanced Air Separators, as system fluid enters through the inlet (either straight or angle), the diffuser distributes flow evenly across the stainless steel, wire brush-like medium. Air bubbles, even micro air bubbles, stick to the brush filaments. Trapped air rises above the diffuser through a baffle where the air is then released through an opening at the top. Treated water then goes back into the system.
Air Separator (EASB-JR)
EASB-JR Air Separators are micro-bubble air separators that make residential and commercial hydronic heating systems more efficient, operate quieter, and last longer.
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Taco
4900 Series Bronze Air Separators
Taco 4900 Series Bronze Air Separators are designed to eliminate air from closed-loop heating and cooling systems up to a maximum temperature of 240°F and a maximum pressure of 150 psi.
4900 Series Commercial Air Separators
Taco 4900 Series Commercial Air Separators remove air and dirt from the system to prevent problems such as reduced heat transfer, loss of efficiency, pipe corrosion, pump damage, noise, and the waste and cost of increased energy consumption.
AC/ACF Series In-Line Air Separator
The AC/ACF Series In-Line Air Separator works great in constant and variable flow systems using its internal baffle design.
Air Scoops
The unique design and internal baffles of Taco Air Scoops slow water velocity to separate the air from solution. Thanks to this design, Taco Air Scoops efficiently remove air to provide noiseless, air-free hydronic heating, cooling, or combination systems. They also offer an economical way to integrate air elimination by connecting either a plain steel or diaphragm expansion tank.
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Webstone
Webstone Air Separators feature a unique stainless steel coalescing medium that removes microbubbles and stagnant air from a hydronic system, thereby eliminating noisy pipes that are a nuisance to building inhabitants. It also improves system efficiency, prevents poorly controlled room temperature, and eliminates excessive wear on system components.
