The restaurant exhaust fan and the restaurant hood are both integral parts of any restaurant exhaust system.A restaurant ventilation system is comprised of three main parts that have different vital functions – the exhaust fan, the exhaust hood, and the duct.
The restaurant exhaust fan uses an up blast of air motion to suck the smoke, steam, heat, grease and other food related vapors into the system. The food vapors enter the restaurant hood and channel through a duct to exit the kitchen.
A restaurant kitchen exhaust system can be a single hood and exhaust fan, or can include an entire network of hoods and fans connected through a system of multiple ducts.A correct exhaust fan is sized accordingly to the usage of each individual restaurant. A correct sizing of an exhaust fan will determine the performance of the exhaust system.There are at least 3 commonly used exhaust fans in the F&B Industry. The selection of the fan specifications and model depends on the entire kitchen exhaust system built up and design.Below are the different exhaust fans.
It is a backward curve centrifugal fan which gives optimum performance and higher efficiency yet low operation noise. It is developed & tested with German technology with non-overloading characteristics. This set of ventilation fans is widely used in the market not only for the performance but also simple & easy installation due to its design.
- 20mm/40mm double skinned panel available in mineral wool steel or PU panel for ultra-acoustic insulation.
- Panel of all side can be easily disassembled for inspection or maintenance.
- Air flow can be configured for straight throw or 90 ° direction.
- Best used for kitchen exhaust system. Box fan can replace the traditional bifurcated fan. It generates higher static pressure and motor can be located out of the air stream.
Bifurcated are inline axial flow fans where the motor has been taken out of the airstream which allows the fan to operate at higher temperatures. They are suitable for medium to high volume applications with low pressure development.
Properties of a Bifurcated Fan:
- Designed with a split airway and the motor is protected from the handled air by having its own compartment
- Motor is isolated from the main air stream by a tunnel which extends to the side of the main fan casing.
- Suitable for some mild chemicals that will not corrode the galvanized casing or the seal of the motor shaft through the case.
- When fitted with an anti-spark track can also be used to handle hazardous gases.
Axial fans with adjustable blades cover a wide capacity range due to their large variation possibilities with hub relation, number of blades and blade angle. The allowed temperatures of the conveyed mediums are from -200 C up to +800 C as a standard, following description of motor manufacturer. The standard air flow direction is pressured over the motor. To reverse airflow direction, blade position must be rotated 180° and the direction of motor rotation must be changed.
The fans are suitable for vertical and horizontal installation. The fans are designed for installation in a ventilation system and therefore supplied without protection guard as a standard.
The casings are manufactured from mild steel with hot dipped galvanized finishing after manufactured as an anticorrosive measure and for longer life as a standard. Every casing comes with defined flange master gauge for holes to ensure an easy connection to the duct system. The centrally mounted motor is wired via a flexible weatherproof cable to an external located IP55 protected terminal box on the fan casing.
Axial Fans are installed with cylindrical silencers to reduce the sound to an acceptable level. Cylindrical silencers are commonly used as it can be connected directly to the round inlet or discharge side of a fan.
Silencer casings are of rolled, pre-galvanized steel sheet 1.2mm thick with end flange ring incorporated with self-insert nuts for easy installation. The absorbent material is an acoustic grade noncombustible mineral wool encased by a galvanized perforated steel sheet. When a pod is fitted, it is of perforated metal, retaining an infill of acoustic grade mineral wool. For critically clean and wet conditions, e.g. hospitals and kitchen exhaust or moisture resistance area, Melinex lining of the acoustic infill can be provided to prevent the ingress of moisture or grease. A small reduction of attenuation in the higher frequencies due to this lining are expected.