earlier kitchens present day kitchen common misconceptions of kitchen ventilation. in a commercial...

EARLIER KITCHENS

PRESENT DAY KITCHEN

A ventilation system is usually at the bottom of priorities as it consumes revenue and does not provide direct earning. Kitchen ventilation is perceived as a “necessary evil” and is provided with the cheapest form to satisfy the plan or statutory requirements.

Common misconceptions Common misconceptions of kitchen ventilation.of kitchen ventilation.

WHY DO WE NEED A VENTILATION SYSTEM IN COMMERCIAL KITCHENS ?

1. Remove excess heat immediately

2. Remove particulates of grease , odour, Toxic gases ...

3. Remove moisture

4. Renew the air that is being exhausted while maintaining Indoor air quality in the working space.

WHERE DOES THE HEAT GENERATED IN KITCHEN COME FROM ?

MAINLY FROM

‘COOKING PROCESS’

and

COOKING EQUIPMENT.

Convective heat canbe captured by a hood.

Radiated heat cannot be captured by any hood.

1. Convective Heat

2. Radiated Heat

What happens when we don’t exhaust effectively ?

EFFULENT AND EFFULENT AND HEAT SPILLSHEAT SPILLS

9

Heat Gain ModelCapturing

Radiation

Radiation

Radiation

Convection

Radiation

Spilling

Radiation

Radiation

Captured by Schlieren Thermal Imaging

= Heat + Humidity + Toxic Gases

SPILLING ADDS

SPILLING ADDS HEATMOISTUREEFFLUENTS SUCH AS

Carbon dioxide, Carbon Carbon dioxide, Carbon monoxide, Sulphurdioxide, monoxide, Sulphurdioxide, Nitrous oxide, oil fumes.Nitrous oxide, oil fumes.

EFFECTS OF SPILLING

ProductivityHealthHealthThere are several studies dealing There are several studies dealing

with cooking and health issues. It with cooking and health issues. It is confirmed that cooking fumes is confirmed that cooking fumes contain hazardous components contain hazardous components in both Western and Asian types in both Western and Asian types of Kitchen.of Kitchen.

Kitchen workers may be exposed Kitchen workers may be exposed to a relatively high concentration of to a relatively high concentration of airborne impurities and that they airborne impurities and that they

are potentially exposed to relatively are potentially exposed to relatively high levels of high levels of

mutagens and carcinogens.mutagens and carcinogens.

EFFECTIVE REMOVAL

Advantages of GoodAdvantages of GoodKitchen Ventilation SystemKitchen Ventilation System

Avoids Health & Hygiene RisksAvoids Health & Hygiene RisksKeep kitchen staff comfortableKeep kitchen staff comfortablePrevents Fire Accidents in KitchenPrevents Fire Accidents in Kitchen Improves the Life of Kitchen EquipmentImproves the Life of Kitchen EquipmentPrevents food contaminationPrevents food contamination

Kitchen Ventilation System consists ofKitchen Ventilation System consists of

Kitchen HoodKitchen Hood

KitchenKitchen Ventilation System consists ofVentilation System consists of

Centrifugal BlowerCentrifugal Blower

Kitchen Ventilation System consists Kitchen Ventilation System consists ofof

Exhaust DuctingExhaust DuctingExhaust

Duct

Kitchen Ventilation System consists Kitchen Ventilation System consists ofof

Make Up Air UnitMake Up Air Unit

Kitchen Ventilation System consists ofKitchen Ventilation System consists of

Fresh Air DuctingFresh Air Ducting

Supply air grill

Energy ConsumedEnergy Consumed

Kitchen Ventilation consumes 30% of Kitchen Ventilation consumes 30% of Energy in a Restaurant.Energy in a Restaurant.

1 HP of Current consumed in a 1 HP of Current consumed in a Commercial Kitchen costs Rs. 25,000 Commercial Kitchen costs Rs. 25,000 per annum.per annum.

An average Restaurant Ventilation An average Restaurant Ventilation consumes 20 Hp.consumes 20 Hp.

How do we save energy in How do we save energy in Commercial Kitchen VentilationCommercial Kitchen Ventilation

How do we save energy in How do we save energy in Commercial Kitchen VentilationCommercial Kitchen Ventilation

Selection of Right Kitchen HoodSelection of Right Kitchen Hood

Selection of Right BlowerSelection of Right Blower

Right Duct DesigningRight Duct Designing

Selection of Right Fresh SystemSelection of Right Fresh System

Demand VentilationDemand Ventilation

Selection of Right Kitchen HoodSelection of Right Kitchen Hood

Selection of Right Kitchen HoodSelection of Right Kitchen Hood

Maximum HangoverMaximum Hangover

Selection of Right Kitchen HoodSelection of Right Kitchen Hood

Maximum Capture AreaMaximum Capture Area

Selection of Right Kitchen HoodSelection of Right Kitchen Hood

Minimum Mounting HeightMinimum Mounting Height

Selection of Right Kitchen HoodSelection of Right Kitchen Hood

Side PanelsSide Panels

Side (or end) panels or skirts permit a Side (or end) panels or skirts permit a reduced exhaust rate in most cases, as reduced exhaust rate in most cases, as more of the replacement air is drawn more of the replacement air is drawn across the front of the equipment, across the front of the equipment, improving capture of the effluent plume improving capture of the effluent plume generated by the hot equipment. generated by the hot equipment. Another benefit of end panels is to Another benefit of end panels is to mitigate the negative effect that cross mitigate the negative effect that cross drafts can have on hood performance. drafts can have on hood performance.

Selection of Right Kitchen HoodSelection of Right Kitchen Hood

Minimum Filter Pressure DropMinimum Filter Pressure Drop

Selection of Right Kitchen HoodSelection of Right Kitchen Hood

Avoid DampersAvoid Dampers

Selection of Right Kitchen HoodSelection of Right Kitchen Hood

Insulation of Fresh Air PlenumInsulation of Fresh Air Plenum

Selection of Right Kitchen HoodSelection of Right Kitchen Hood

Right collar sizing.Right collar sizing.

Selection of Right Kitchen HoodSelection of Right Kitchen Hood

Coanda EffectCoanda Effect

Selection of Right Kitchen HoodSelection of Right Kitchen Hood

Capture Jet ConceptCapture Jet Concept

Selection of Right Kitchen HoodSelection of Right Kitchen Hood

Deflection Lip ConceptDeflection Lip Concept

Selection of Right Kitchen HoodSelection of Right Kitchen Hood

Ultra Violet Filter Bank in HoodUltra Violet Filter Bank in Hood

Selection of Right Kitchen HoodSelection of Right Kitchen Hood

Spray mist conceptSpray mist concept

Selection of Right BlowerSelection of Right Blower

Backward Inclined BladesBackward Inclined Blades

Selection of Right BlowerSelection of Right Blower

Direct DriveDirect Drive

Selection of Right BlowerSelection of Right Blower

Low RPM of MotorLow RPM of Motor

Selection of Right BlowerSelection of Right Blower

Performance Curve EfficiencyPerformance Curve Efficiency

Selection of Right BlowerSelection of Right Blower

Discharge Orientation of BlowerDischarge Orientation of Blower

Right Duct DesignRight Duct Design

Minimizing BendsMinimizing Bends

Right Duct DesignRight Duct Design

Large Radius for BendsLarge Radius for Bends

Changes of direction should be by Changes of direction should be by easy bends and well-rounded easy bends and well-rounded corners, not by sharp elbows, corners, not by sharp elbows, unless fitted with guide vanes. unless fitted with guide vanes.

Right Duct DesignRight Duct Design

Maintaining Right aspect RatioMaintaining Right aspect Ratio

Right Duct DesignRight Duct Design

Proper Joints to avoid duct leakageProper Joints to avoid duct leakage

Right Duct DesignRight Duct Design

Suggest Angle Frames for Large DuctsSuggest Angle Frames for Large Ducts

Right Duct DesignRight Duct Design

Proper sizing of Duct for Blower inlet Proper sizing of Duct for Blower inlet connectionconnection

Right Duct DesignRight Duct Design

Proper sizing of Duct for Blower Outlet Proper sizing of Duct for Blower Outlet ConnectionConnection

Right Duct DesignRight Duct Design

Proper insulation of Fresh Air DuctsProper insulation of Fresh Air Ducts

Right Duct DesignRight Duct Design

Auxiliary items, such as grilles, louvers, Auxiliary items, such as grilles, louvers, filters. These items should be large filters. These items should be large enough to keep air velocities through enough to keep air velocities through them down to a reasonable level, them down to a reasonable level, consistent with the velocity in the main consistent with the velocity in the main duct. duct.

Selection of Right Fresh Air UnitSelection of Right Fresh Air Unit

Low Static Pressure Units as Kitchen is Low Static Pressure Units as Kitchen is in Negative pressurein Negative pressure

Selection of Right Fresh Air UnitSelection of Right Fresh Air Unit

20 Microns Filtration more than 20 Microns Filtration more than sufficientsufficient

Selection of Right Fresh Air UnitSelection of Right Fresh Air Unit

Placement of Unit as near to the Kitchen Placement of Unit as near to the Kitchen as possibleas possible

Selection of Right Fresh Air UnitSelection of Right Fresh Air Unit

Consider evaporative air cooling option Consider evaporative air cooling option to Air conditioning in dry Areasto Air conditioning in dry Areas

Demand Ventilation SystemDemand Ventilation System

Senses Temperature in Hood Senses Temperature in Hood

Gives signal to the blower to increase or Gives signal to the blower to increase or decrease speed decrease speed

Give signal to the Fresh Air Unit to Give signal to the Fresh Air Unit to match exhaust blowermatch exhaust blower

Done through VFD based DriveDone through VFD based Drive

Compensating Wall Mounted

HoodFresh Air

Exhaust Air

Fresh Air

Exhaust Air

Flat Oval Duct

ExhaustExhaust DuctDuctFresh air collar

Island Compensating Hood

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