DISPLACEMENT VENTILATION—THE MORE EFFICIENT WAY TO COOL A KITCHEN:
Most conventional kitchens use mixing ventilation to cool the space: the cool conditioned air is typically supplied through ceiling diffusersat a high discharge velocity. This high velocity is required to create a high momentum air jet for efficient mixing of supplyair with room air.
This air distribution system may not neces-sarily be the best fit for a commercial kitchen for two reasons:
1. High discharge velocity from mixing diffusers createsunwanted air movement and cross-drafts in the kitchen thatmake it difficult to capture and contain the plume fromcooking appliances with the hoods.
2. All the heat rising from multiple heat sources in the kitchenis mixed within the space.
An alternative air distribution system—thermal displace-ment ventilation- is a better fit for the kitchen envi-ronment. In TDV systems cool air is supplied at low velocity directly into the occupied zone.
Rather than mix the heat and contaminants in the space, as the mixing system does,TDV stratifies and displaces them out of the occupied zoneinto the upper part of the space. As a result the air velocity inthe space is low, with no undesired cross-drafts, which makes it easier for the hoods to capture and contain plumes.
Most conventional kitchens use mixing ventilation to cool the space: the cool conditioned air is typically supplied through ceiling diffusersat a high discharge velocity. This high velocity is required to create a high momentum air jet for efficient mixing of supplyair with room air.
This air distribution system may not neces-sarily be the best fit for a commercial kitchen for two reasons:
1. High discharge velocity from mixing diffusers createsunwanted air movement and cross-drafts in the kitchen thatmake it difficult to capture and contain the plume fromcooking appliances with the hoods.
2. All the heat rising from multiple heat sources in the kitchenis mixed within the space.
An alternative air distribution system—thermal displace-ment ventilation- is a better fit for the kitchen envi-ronment. In TDV systems cool air is supplied at low velocity directly into the occupied zone.
Rather than mix the heat and contaminants in the space, as the mixing system does,TDV stratifies and displaces them out of the occupied zoneinto the upper part of the space. As a result the air velocity inthe space is low, with no undesired cross-drafts, which makes it easier for the hoods to capture and contain plumes.
