Rick Bagwell’s main point was that island style cooking so popular in today’s operations present major challenges for the designer. An island style canopy or hood being used as a focal point in a serving line or over a bank of cooking equipment in an exhibition kitchen are unique. The designer must be aware that this type of hood presents significantly more difficulty with regard to maintaining a proper plume of heated exhaust air into the overhead canopy or hood. UP YOUR STACK™ has recreated his presentation in text form for your convenience.

DESIGN CONSIDERATIONS

• Adjacent hoods can play havoc with island hoods or canopies
• Pass-through openings create drafts and will affect proper plume movement
• 4 way diffusers should never be used near any kitchen exhaust hoods

THINGS TO NOTE

• Plume development for an island canopy or hood is considerably different than a typical wall hood
• Island canopies or hoods require a higher exhaust flow to maintain the exhaust plume
• Larger overhangs are suggested

During Rick’s presentation, he showed slides that clearly identified how the plume development differs from that of a wall style hood. This presentation was the best we have seen that illustrate how the plume develops and can be interrupted by inattention to design features.

The slides demonstrated how the “Coanda Effect” moves the thermal plume against the back wall of the typical wall type hood to garner effective capture. This coanda effect allows for lower exhaust flow rates in a wall mounted hood.

Without the wall and resulting coanda effect in an island application, the plume has the opportunity to expand. When this expansion occurs, the upward velocity of the plume declines making it more susceptible to other room variables such as:

• Cross drafts
• Supply air movement
  • High velocity
  • 4 way diffusers
• People movement
• Doors opening and closing

The intricacies of interaction between various plumes in a cooking line are a challenge as well. These multiple plumes react differently to:

• Adjoining types/pieces of equipment
• Their relationship to one another
• Placement of the equipment within the line

Rick indicated that additional study needs to be conducted that further addresses many questions including:

• How the interaction listed above affect the total plume development.
• How to decrease the impact of the plume spread in island hoods.
• How to negate the room variables with loss of plume velocity to lower C & C rates

He shared with the audience a new innovation for island type hoods and canopies that consisted of an air curtain directed upwards behind and at the level of the cooking equipment.

Please contact Rick at rbagwell@haltoncompany.com for more information regarding his slide presentation or other details you may be interested in learning about.