FINAL 2013 ASHRAE DENVER KT - Rocky Mountain ASHRAE...duct design 6. Demand control ventilation...
Transcript of FINAL 2013 ASHRAE DENVER KT - Rocky Mountain ASHRAE...duct design 6. Demand control ventilation...
Design of Kitchen Ventilation
Systems
T H A N K YO U F O R AT T E N D I N G
2013New Ideas & Technologies
Design Considerations• Performance • Heat • Humidity• Comfort• Energy• Cost• Fire safety and prevention
Too often, the Kitchen is...
As suggested by John A. Clark, P.E., Minneapolis
•Too Hot•Too Noisy•Too Smelly•Too Greasy•Too Slippery•Too Expensive•Too Energy Consuming
Commercial Building Energy Consumption
Food Service
Food Sales
Health Care
Other
Lodging
Office
Education
0 50 100 150 200 250 300
Thousand BTUs
SustainableFoodservice.com
Energy Use in Restaurants
16.4%
15.7%
24.4%
6.8%
16.6%
5.6%
4.7%
9.8%
RefrigerationSanitationFood PrepCoolingHeatingVentilationOthersLighting
Refrigeration
15.7%Sanitation
24.4%Food Prep
16.6%Heating
6.8%Cooling
999999999 8%%%%%%Lighting
5.6%Ventilation
44444 777777%%%%%Other
SustainableFoodservice.com
HVAC 29%
Integrated Design Approach & Future
INTEGRATED DESIGN
1. Designed as systems instead of pieces and parts, from hood to fan
2. Understanding type, load and volume of cooking
3. Robust performance at lowest exhaust (CFM)
4. Improved kitchen/ building comfort and IAQ
5. Fire prevention and safety including grease duct design
6. Demand control ventilation becoming standard for many applications
IMC• Section 507 - Commercial Kitchen Hoods
• 507.2.1 Type I Hoods: Type I hoods shall be installed where cooking appliances produce grease or smoke, such as occurs with griddles, fryers, broilers, ovens ranges and wok ranges.
• Require fire suppression, listed filters and grease duct.
• 507.2.2 Type II Hoods: Type II hoods shall be installed where cooking or dishwashing appliances produce heat, steam, or products of combustion and do not produce smoke, such as dishwashing machines.
Schlieren Technology
What the Eye Sees
Courtesy of FSTC CKV Lab
Effluent Drawn from the Hood by Exhaust Fan
How Hoods Work
Effluent Circulation
Courtesy FSTC
End Panel Performance
Courtesy FSTC
End Panel Design Options
Minimum 6” Overhang
Courtesy FSTC
18” Front Overhang
Courtesy FSTC
Recommended Overhang
OVERHHANGEQUIPMENT FRONT SIDECharbroiler 18” - 24” 12”
Fryer or Griddle 12” 6” - 12”Conveyor Oven 12” 12” past conveyor
Convection Oven* 24” 6”Upright Broilers 18” - 24” 12”
Solid Fuel 24” 24”Woks 24” 24”
Dishwasher 12” 24” inlet & discharge
** General overhang recommendations for wall canopy hoods for improved capture and containment performance **
Size of Hood Reservoir•Hood should contain surges of effluent:
- Door Openings- Lid Openings
- Turning Food- Lowering Baskets
of Food Hood should be
Centered over Applianceand Larger
Hoods• Appliance Positioning
- Heavy Duty Appliances in the middle of the line (charbroiler)
- Light Duty Appliances on the end of the line (ovens)
- Push Back Appliances
- Group Like Duty Appliances together
SUSTAINABILITY
Equipment Classification
Light Duty Equipment
(400-450° F)
Medium Duty Equipment
(400-450° F)
Heavy Duty Equipment
(600° F)
Extra-Heavy Duty
Equipment (700° F)
Ovens
Cheesemelters
Rethermalizers
Steam-Jacketed Kettles
Compartment Steamers
GriddlesFryers
Pasta CookersTilting SkilletsBraising PansRotisseries
Conveyor (Pizza) Ovens
Open-Burner Ranges
Electric/Gas Underfired
Broilers
Salamander (Upright) Broilers
Chain Broilers
Wok Ranges
Appliances using Solid Fuel
(Wood, Charcoal, Briquettes and Mesquite) to provide all or
part of the heat source
*Equipment Classifications from IMC
IMC• Section 507.1 General:
Commercial kitchen exhaust...• Exceptions:
Factor-built commercial exhaust hoods which are tested in accordance with UL710, Listed, Labeled, and installed in accordance shall not be required to comply with sections:
• 507.4 Type I Materials• 507.7 Hood joints, seams, penetrations• 507.11 Grease filters• 507.12 Size and location• 507.13 Capacity (Exhaust Air Rate Calculations)• 507.14 Non-canopy size and location• 507.15 Exhaust outlets
Exhaust Rates (Listed vs. IMC)Type of Hood
UNLISTEDIMC MINIMUM REQUIRED CCFM per Linear FFoot of Hood
UNLISTED Light Duty Equip Medium Duty Equip Heavy Duty Equip Extra-Heavy Duty Equip
Unlisted Wall-Mounted Canopy
200 300 400 550
Unlisted Backshelf 250 300 400 Not allowed
Type of HoodLISTED
TYPICALL LISTED CFM pper Linear Foot of HoodLISTED
ETL / UL 710Light Duty Equip Medium Duty Equip Heavy Duty Equip Extra-Heavy Duty
Equip
ListedWall-Mounted Canopy
150-200 200-300 200-400 350+
ListedBackshelf 100-200 200-300 300-400 Not
recommended
Effluent• Includes gaseous, liquid and solid contaminants
• Products of combustion - Carbon Monoxide, Carbon Dioxide and Nitrogen Oxide
• Grease Characteristics:- Both Vapor, Small and Large
Particles
- Grease Vapor is ~ 30-90%
- Hotter Cooking Process = more grease vapor
Grease Emissions
Grease Emissions
Grease Problems•Greasy Exhaust Fans
• Environmental Impact
•Rooftop Damage
•Grease Accumulation behind the filters
• Significant Buildup on Fusible Links
• Fire Hazard with Grease Accumulation in the duct and plenum
INTEGRATED DESIGN
Filter Efficiency TestASTM F2519: “Grease Particle Capture Efficiency of Commercial Kitchen Filters and Extractors”
- Pressure Drop as a function of airflow through the filter
- Particulate Capture Efficiency by particle size
Incorporation of filter selection and affect on design of entire system, including IAQ.
INTEGRATED DESIGN
Visual Performance Test
System design incorporates make-upair tempering and delivery strategy
Makeup Air Problem?
INTEGRATED DESIGN
IMC• Commercial Kitchen Makeup Air
• 508.1 Makeup Air. Makeup air shall be supplied during the operation of commercial kitchen exhaust systems that are provided for commercial cooking appliances. The amount of makeup air supplied shall be approximately equal to the amount of exhaust air. The makeup air shall not reduce the effectiveness of the exhaust system. Makeup air shall be provided by gravity or mechanical means, or both. For mechanical makeup air systems, the exhaust and makeup air systems shall be electrically interlocked to insure that makeup air is provided when the exhaust system is in operation.
IMC• Commercial Kitchen Makeup Air
• 508.1.1 Makeup Air temperature. The temperature differential between makeup air and the air in the conditioned space shall not exceed 10°F.
• Exceptions:1. Makeup air that is part of the air-conditioning
system2. Makeup air that does not decrease the comfort
conditions of the occupied space
Makeup Air: How & Why
• Air removed from the kitchen through the hood must be replaced.This can be achieved by the following pathways:
• Transfer Air• Displacement Diffusers, floor or wall mounted• Ceiling Diffusers (4-way, slot diffusers)• Perforated Ceiling Diffusers• Exhaust Hood with Integrated Makeup Air
What’s wrong with this picture?
4-Way Diffuser - Causing Spillage
Courtesy FSTC
Engineered Makeup System?
Dedicated MUA
http://www.energy.ca.gov/reports/2003-04-10_500-03-007F.PDF
Designing for Dedicated MUA
Dedicated ‘Local’ Makeup Air:
• Typical 70-80% of exhaust
• Proper air velocity is critical
• Correct design, placement
• Enhanced performance
• Minimal diffusion
• Less heating and cooling
• Temperature 55° to 85°F
• Improved comfort
Temperature is important!
• Hood performance• Comfort conditions• HVAC heating / cooling
performance + comfort + efficiency
INTEGRATED DESIGN
Poor capture performance in field
Robust capture performance in field
ELECTRICAL controls
Electrical Codes• Light control• Fire system integration• On/Off control or demand ventilation• Interlock of exhaust fan and make-up air unit• Auto-on integration
IMC 2006, Section 507.2.1.1Type I hood systems shall be ... installed to automatically activate the exhaust fan whenever cooking operations shall occur through an interlock with the cooking appliances, by means of heat sensors or ... other approved methods.
INTEGRATED DESIGN
Variable Speed Exhaust?
Fan Energy - Savings & Penalties
Cooking Exhaust Temperature
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100.389
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77.593
129.09
77.307
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Tem
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Time
Grillhouse Pagoda
Pizza Hacienda
Large Buffet Chain RestaurantRaleigh, NC
Demand Ventilation Systems
• Automatically adjusts exhaust and makeup air fans
• Temperature sensor and variable frequency drives modulate fans speed
• Satisfies IMC 507.2.1.1, automatic activation requirement
• Rebates and incentives from many utility companies
Grease Duct Issues• Size and velocity• Static pressure drop• Integrity of the welds and joints• Number of tees and elbows• Radius not mitered elbows• Access for cleaning• Clearance requirements
Leaking Grease Duct
Duct ConstructionIMC 2009, 506.3.2Joints, seams and penetrations: continuous liquid-tight weld or braze made on external surface
- Exceptions:1. Penetrations shall not be required... where sealed by devices listed for
application2. Internal welding shall not be prohibited provided that the joint is formed
or ground smooth and provided with ready access3. Factory-built commercial kitchen grease ducts listed and labeled
Clearance to Combustibles
NFPA 96-2008 Appendix
Hinged upblast exhaust fan
Roof
Ceiling
Exhaust Hood
10 ft
40inches
18 inches
Grease DuctText
IMC 2009506.3.6 Grease duct... serving a Type I hood shall have a clearance to combustible construction of not less than 18 inches (457 mm), and shall have a clearance to noncombustible construction and gypsum wallboard attached to noncombustible structures of not less than 3 inches (76 mm).
Factory Built Grease Duct• Listed to UL 1978 (Single)• Listed to UL 2221 (Double)• Exceptions:
- Grease duct materials
- Joints, seams and penetrations
- Duct-to-Hood joints
• Improved fire safety• Requires no welding• Zero clearance to combustible
INTEGRATED DESIGN
Ductwork Design• Correct size and velocity• Static pressure drop estimated accurately• Minimize number of tees and elbows• Radius not mitered elbows• Access for cleaning• Use of listed ductwork - integrity of welds
verified with dye testing• Double Wall ductwork where applicable
UL1978 Testing
Temp & Abnormal Temp Test
Access Door Test
UL2221 Testing
External Engulfment Test
UL2221 Testing
Internal Fire Test
Recent Fire
UL300 Testing for Hood Fire Suppression System
Factory Built Grease Duct
Summary• System design for kitchen ventilation
systems- critical• Equipment under hood is #1 thing to
understand• Make-up air strategy • Controls- how will system work with
building• Ductwork for fire safety and decreased
energy
INTEGRATED DESIGN
Questions?
INTEGRATED DESIGN