Displacement ventilation, using DR90 diffusers from Price, was the ideal solution to provide improved indoor air quality and comfort in the
cooking and serving areas of both schools.
Displacement ventilation injects low velocity air that is drawn at a low level towards heat sources. Once it reaches the heat source, the
air fresh air rises up due to thermal plumes before being exhausted from a high level return.
Displacement provided the ability to locate the diffusers near the floor, ensuring that clean fresh air would be delivered to staff before
being exhausted through the kitchen fume hoods. This strategy meant that the risks of system “short circuiting” common to mixing systems could be avoided.
The DR90 diffusers were positioned as far from the kitchen hoods as feasible, typically in the corners of the rooms. This helped ensure a superior
airflow pattern as the air would be drawn towards heat sources such as the exhaust hoods.
Another advantage of displacement ventilation in commercial kitchens is that the airflow pattern makes it extremely effective at drawing away
kitchen odors, and contaminants are not recirculated in the space.
Price supplied stainless steel displacement diffusers that would meet regional health regulations, which mandated surfaces in a cooking areas lower than
3’ must be stainless steel. The DR90 floor mounted diffusers used on the project were also slightly raised with a small kick plate to ensure water would
not enter the face of the diffuser during kitchen cleaning and maintenance.
The mechanical engineer worked closely with the kitchen consultants during the design stages, to ensure that appliances were placed in an appropriate
manner that would not inhibit airflow.
Beyond meeting the challenges of providing superior indoor air quality and comfort to kitchen personnel on both projects, displacement ventilation
provided improved energy efficiency relative to an overhead system, reducing total airflow, and allowing both facilities to use 100% outside air on the
project – further improving air quality and occupant comfort.