Kitchen Ventilation & Kitchen Exhaust Calculate

KITCHEN VENTILATION 

Ventilation is required in both the kitchen and the adjoining areas because: 

• Considerable convective and radiant heat is given off by the cooking equipment 
• Air becomes laden with odours, grease, fumes and products of Combustion
• During meal preparation and washing up, humidity is increased over a wide area
•  Air replacement and consistency of temperature are required in Adjoining areas 
• Air is required to dilute and replace products of combustion from gas Fired appliances 
• Supply air is required to ensure complete combustion of the fuel 

Kitchens will have good indoor climate and comfortable working temperature with the following factors taken into account:

• Impurities and heat are immediately removed with efficient exhaust hoods. 
• Fresh air is brought in to the working place in such a way that it first refreshes staff and then replaces convection flows. 
• In cases where workers are subjected to large heat radiation (stoves, broiling units. grills etc.) supply air is brought directly to the working place (local cooling).

Design Criteria 

When designing a kitchen hood the following steps are to be followed

• Kitchen hood size. 
• Exhaust air flow rate. 
• Exhaust air fan capacity. 
• Exhaust air duct size. 
• Fresh air flow rate. 
• Fresh air fan capacity. 
• Fresh air duct size.

Effluent Generation in kitchens 

• Heat is a primary ingredients of kitchen effluents.
•  50% to 90% of the appliance energy input is released in the form of a rising thermal plume (Convective). 
• Balance is released into surroundings space through radiation. 
• This plume also contain most at of the good and fuel generation effluents. Primary objective of kitchen ventilation is to capture and remove the air and effluents that constitute the plume through an effective exhaust system. 
• Heat radiated into space from the appliance must be addressed by the space air conditioning system.

Exhaust Hoods 

Type I for removing grease & smoke: used for cooking appliances. Type II for steam, Vapour, heat & odor when grease is not present: used for dishwashers, steam tables, etc. 

Basic Styles of Type I Hoods 

• Wall Mounted Canopy 
• Single island 
• Double island 
• Back shelf or proximity 
• Pass Over 
• Eyebrow

Wall Canopy Hood 

• Cooking appliance placed against a wall. 
• Minimum air flow requirement. 
• 3" built in gap between hood & wall. 
• Three finished sides. 
• Less susceptible to cross drafts. 
• front for full capture. 
• Minimum Overhang requirement: 6" on sides and 6"-12" in front for full capture.

Single Island Hood 

• Cooking appliance/s (row) placed in the middle (not against a wall).
• Four finished sides.
• More susceptible to cross drafts. 
• Recommended overhang: 6-12" on all 4 sides. 
• Baffle filters in "v configuration.

Double island Hood 

• Double row of appliances placed back to back. 
• Two wall canopy hoods placed back to back. 
• Recommended overhang: 6" 12" on all 4 sides.

 Basic Styles of Type II Hoods 

• Oven Hoods 
• Condensate Hoods 

Type II Hood OVEN Hoods 

• Removal of heat & Odor.
• Canopy hood with no filters. 
• Hood size determined with oven door open.

Type II Hood-Condensate Hood 

• Removal of heat & Odor & moisture. 
• Condensate baffle and gutter to condense moist air & drain the water. 
• Used over dishwashers.

HOOD OVERHANG

Minimum Exhaust Flow Rates By Equipment's Category CFM Per Linear Meter Of Hood.

For video tutorial