Zoneontluchter

Zoneontluchter is a term used in HVAC engineering to describe a device that vents air from a single zone within a hydronic heating or cooling system. The purpose of a zoneontluchter is to remove entrained air from the circuit of a specific zone, improving circulation, efficiency, and comfort.

A typical zoneontluchter comprises a small vent arrangement connected to the zone’s manifold or piping loop. It often includes an automatic air vent (float-type) and a purge or service valve to facilitate air removal. Some designs incorporate a manual bleed option and a purge connection to drain or redirect air and any condensate during maintenance. In operation, the vent releases trapped air while water remains sealed within the zone; during purging sequences the system can be isolated and flushed to remove accumulated air pockets.

Zoneontluchters are used in various applications, including radiant floor heating, baseboard and radiator systems, and multi-zone distribution networks in both residential and commercial settings. They are particularly beneficial in newly commissioned systems, after repairs, or in installations where air locks or noisy operation are observed in a specific zone.

Installation considerations include placing the device at a high point or near the zone’s highest branch, ensuring proper vent orientation, and providing a clear purge path to a drain. Regular inspection and maintenance of vents and purge valves help prevent leaks and ensure reliable air removal. See also: air vent, automatic air vent, hydraulic purge, zone valve.