What type of ducts are designed to remove air under positive pressure?

The choice of ducts designed to remove air under positive pressure is associated with supply air ducts. Supply air ducts are responsible for delivering conditioned air into a space, providing a positive pressure that ensures an even distribution of air throughout the area. This positive pressure is crucial in maintaining comfort levels and enhancing indoor air quality.

In the context of duct systems, exhaust ducts primarily serve to expel air, which may be stale or contaminated, from a building to the outdoors. Fresh air ducts facilitate the introduction of outdoor air into the building but do not operate under the principle of removing air under positive pressure. Return air ducts are tasked with collecting air from the occupied space to send it back to the heating or cooling system, but they manage air flow under varying pressures, primarily balancing the air volume in a system rather than operating strictly under positive pressure.

Understanding these functions helps clarify why supply air ducts are the correct choice, as they are specifically designed to work under conditions of positive pressure to effectively push air into the living or working spaces.