Overview Building Features Grade JK-6 Grade 7-12

Displacement Ventilation

Real Time Data
a Return Air Temp °C °C
b Classroom Temp °C °C

Supply Air Temp °C


VAV 1-4 Occupancy Sensor On/Off


VAV 1-4 Window Status On = Open/Off = Closed


VAV 1-4 Velocity Pressure Inches of H20

Displacement ventilation - Mechanical RoomDisplacement ventilation (DV) is a building system air distribution arrangement in which ventilation air is supplied to a space at a low level directly to the occupied zone. The air is conditioned such that it enters the space at near set point temperature to promote a stratification effect within the space; the new fresh air accumulates in the lower level and the contaminated air rises (or is displaced) to the ceiling level before getting exhausted by the air system. Air is supplied at a low velocity to the space (50 feet/minute or less) to prevent mixing with stale room air and to reduce the likelihood of creating uncomfortable drafts for the occupants. Objects within the space such as people and equipment tend to give off heat, and when air is locally warmed, the stale room air rises and is replaced with the slightly cooler new air from below. This air rising effect has been termed as the "thermal plume".

The DV air distribution differs from the more typical mixed ventilation arrangement where ventilation air is supplied from high level with the intent to mix with existing room air and dilute space contaminants rather than exchanging the air entirely. Benefits of DV include increased indoor air quality, lower noise levels, increased comfort and increased energy efficiency.

Download Classroom Ventilation Presentation.

How it is used in the school:

Displacement VentilationA DV air distribution arrangement is used throughout the majority of the building including classrooms, gymnasium and the administration area. The ventilation effectiveness coefficient is a measure of how well ventilation air is delivered to a space. The majority of the DV system at the school has a coefficient of 1.2; more common mixed ventilation systems are less efficient with coefficients in the 1.0- 0.8 range. A typical classroom in the building is arranged such that the ventilation air is supplied by low level perforated air diffusers along the window wall, and a high level exhaust grille along the corridor side wall. An infloor heating and cooling system is used in conjunction with the DV system to achieve a comfortable indoor environment for the teachers and students. 

Greater Essex County District School Board