2.6 Window Systems and Curtain Walling

The thermal damper is one of the main factors affecting the cost and depth of the NAT Vent Box. Replacing the damper with an openable or motorised vent/window, eliminates both the thermal damper and weather louvre from the box make up. This typically reduces costs by ≈50% and can reduce its depth by ≈225mm.
Facade and window manufacturers can easily accommodate openable vents in curtain walling or window frames. Placing the NAT Vent Attenuator directly behind an open vent, provides a simple, cost effective design solution for preventing noise break-in.

High level air inlet
In the case where noise levels are exceptionally high, for example due to motorway noise, flight paths or inner city noise, the depth of the attenuator is required to be increased. The additional depth of the NAT Vent Box can be accommodated by using a high level bulkhead 11.