ASHRAE Research Project 1480 Report - Food Service Technology ...

Tailored exhaust bias for double island hoods may improve hood performance. With more
exhaust volume focused over the more challenging appliances, the exhaust rate can be reduced
for a given configuration. However, application of a specific bias for other applications or hood
dimensions may yield different performance results and should be verified.
Specification of enhanced hood edge geometry should be considered by manufacturers and endusers.
While each design would need to be properly evaluated for the impact on hood
performance, the design tested in this project was effective and was typical of edge design
currently found in the industry.
Verification of performance in the field should be performed to ensure proper hood capture and
containment operation. As was shown during this project, many factors interact in the kitchen
and affect hood performance. These interactions cannot be perfectly predicted for each
installation. Therefore, a field test would be best to verify proper kitchen ventilation and hood
performance.
The recommendations for future research focus on ideas to augment the data found in RP-1480,
which will further support direct comparisons in the ASHRAE Handbook and provide
information needed to develop design guides. With this project being the first to examine the
performance of island canopy hoods in detail, many questions were answered while other
questions were discovered.
The recommendations include: 1) Investigate the performance of single island canopy hoods in
more detail, with a focus on the v-bank design. This study could quantify hood performance for
the v-bank island with a smaller 4-foot depth. 2) Study the impact of the filter bank design on
capture and containment performance. This project could evaluate the height relative to the
distance between the bottom of the filter bank and the lower edge of the hood, as well as filter
size and filter bank geometry. While this study would focus on the island hood configuration, the
discoveries from the project could be applied to wall-mount and proximity hoods as well. 3)
Study the displacement ventilation layout and hood capture and containment performance in
greater detail. This project could address questions that arose during ASHRAE RP-1480
regarding the performance of side panels and potential issues with supply air distribution
locations and currents.
Two additional studies could take place, one of which was shown during this project as critical to
kitchen hood performance. These are: 1) Investigate the performance of single hood and multihood
ventilation systems. Since ASHRAE RP-1480 has shown the profound performance impact
of positive/negative pressure areas within a commercial kitchen, this proposed study may
provide a foundation to improve the energy and environmental profile of complex commercial
kitchens, while taking into account the needs of the kitchen ventilation system to provide
optimized performance for each hood. 2) Study the whole-building approach to supply and
makeup air impact on indoor air quality in commercial kitchens. This project could look at the
effects of supply air distribution and makeup air introduction on capture and containment
performance at different outside air conditions (e.g., extreme or design days), with a focus on
how air movement, heat and humidity affect the thermal comfort in the kitchen.
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