a. Housekeeping and Laundry

• Use biological pest control or use physical methods e.g. use UV light to attract insects to electrical exterminators and flame guns to control weeds.

• Where application of chemical pesticides and herbicides is unavoidable, select the less harmful chemicals e.g. some insect sprays are based on pyrethrum, a natural insecticide obtained by extraction from chrysanthemum flowers. Details of environmentally friendly use of pesticide and herbicide can be found in Chapter 8.

• Explain to the colleagues concerned the recommended operating procedure of the ozone air purifier from the product instruction sheets.

• Use non-aerosol packaging such as pump dispensers, which are just as effective as aerosols for spray cans containing spot-cleaning liquids, bathroom and other surface cleaners, paints, pest and other plant sprays.

• Convert all refrigerants of the kitchen equipment to CFC-free substances .

• Install efficient greasy fume control equipment to treat kitchen emissions prior to their exhaust e.g. use of electrostatic precipitators (EPs), water spray hoods, air washers, packed scrubbers, etc.

• Use odour and volatile organic compound removing technology such as activated carbon filters.

• Install suitably sized stoves that meet operational requirements. Inappropriate design and layout of cooking devices will not only increase emissions of air pollutants but also waste energy.

• Install separate exhaust systems for handling emissions from those cooking processes that may generate strong odours to prevent over-loading the control equipment.

• Install thermostats in frying equipment to prevent overheating of cooking oil and reduce greasy fume emission.

• Place exhaust outlets in proper locations in order for the emissions to thoroughly disperse into the atmosphere and to avoid nuisance to the neighbourhood.

• Properly operate and maintain the air pollution control devices to ensure that they are functioning normally. Clean the equipment frequently and check the parts on a regular basis.

• In kitchens, air pressures must be slightly negative.

• Avoid all products manufactured with CFCs such as foams, aerosol sprays, fire-extinguishers and solvents. Replace the chemical with an alternative without completely replacing the equipment (See Table 3.2) or purchase new equipment with the use of alternative refrigerants.

• Frequently leak-test refrigerating systems, especially when loss of capacity is obvious, from temperature loss or constant operation of compressor. Perform regular checks with electronic leak detectors or simple soap solution (apply soap water to refrigerant coils and hoses, the bubbles show where there are leaks).

• Reduce energy consumption through better insulation, heat recovery, energy efficient lights, computerised controls, efficient equipment and other modern technology items. Details can be found in Chapter 7.

• Use a freon recovery unit to remove freon from the system, condensing it so that it can be stored for re-use. This process removes virtually all the refrigerants in the refrigerator, reducing CFC emissions, and saves money on the cost of repurchasing refrigerants.

• Improve efficiency of boilers by adjusting air / fuel ratio and regular maintenance.

• Recondition diesel-burning boilers to use clean energy such as natural gas or cleaner fuel oil, for example, with sulphur content, less than 0.5%.

• Investigate the possibility of reducing driving by using public transportation, car pooling, other communication means (phone, fax, telex).

• Plan your journey using the most direct, least congested route.

• Switch off engine while idling to avoid exhaust gas from polluting the environment.

• Do not over rev the engine in low gear. Pulling away too fast will produce more air pollution than gentle acceleration.

• Buy Euro III or above standard for hotel vehicles, which consume less petrol and emit less pollutants, or even vehicles with alternative fuel or power source if possible.

• Clean and replace air filters regularly.

• Check the engine and exhaust system promptly if you notice a change in the way your vehicle, functions, fuel efficiency drops or a warning light goes on.

• Check the fuel injection system according to manufacturer’s recommendation. Fouled fuel injectors reduce fuel efficiency, make the vehicle more difficult to start and drive, and significantly increase pollutant emissions.

• Keep the tyres properly inflated and check the pressure every two weeks. Maintaining the proper pressure saves money, reduces pollution and is safer.

• Check the coolant level weekly by observing the overflow tank. Never remove the radiator cap unless the engine is completely cold.

• Retrofit emission control devices such as particulate traps or catalytic converters to the hotel vehicles (see photo 3.8).

Table 3.1 – Traditional Refrigerants

(Source : A more extensive list is available on the Internet at http://www.unepie.org/ozonaction.html)
* Ozone Depleting Potential (ODP) relative to CFC-11 (OPD=1.0) – the extent to which CFCs destroy the layer of ozone is known as ODP

Table 3.2 – Main Substitutes for Traditional Refrigerants and Other Ozone Depleting Substances

(Source : Internet at http://www.unepie.org/ozonaction.html)
* Ozone Depleting Potential (ODP) relative to CFC-11 (OPD=1.0) – the extent to which CFCs destroy the layer of ozone is known as ODP

(Photo 3.10) The performance of water spray hood and air washer is directly related to the design of the equipment.

Box 3.1 - OVERVIEW OF GREASY FUME CONTROL TECHNOLOGIES

Greasy fumes emitted from hotel kitchens may cause a negative impact on neighbouring residents. Using suitable air pollution control measures can improve the quality of kitchen emissions. The commonly available greasy fume control measures include:

a . Electrostatic Precipitators (EPs)

EPs are the most preferable type of greasy fume control equipment. They effectively collect oil mist and the removal efficiency exceeds 90%. Kitchens that involve frying processes are advised to adopt this equipment for the control of greasy fumes.

EP uses an electrostatic field to remove greasy fumes. Airborne particles or liquids are electrically charged under an intense electric field and then collected by charged collector plates. Since the accumulation of grease on the collector plates reduces the removal efficiency, EPs should be cleaned and serviced regularly.

Hotels should consider choosing the EP models equipped with auto-cleaning systems because these systems can regularly eliminate the grease accumulated on the collection plates. As a result, this type of EP can maintain high removal efficiency without the need for frequent cleaning. EPs can be divided into two categories: duct type and hood type. These two types of EPs have their own advantages and both can achieve high oil mist removal efficiency.

b. Water Spray Hood and Air Washer

Water spray hoods (hydrovents) are used to remove oil particles, smells and fumes generated from cooking. When greasy fumes are passing through the water curtain, the oil particles are removed by the water flow.

Although water spray hoods are commonly used in local kitchens, use of this equipment alone could not reduce greasy fumes to acceptable levels. Some designs combine a water spray hood with an air washer for control of greasy fumes. The performance of water spray hoods and air washers is directly related to the design of the equipment. If they are not properly designed, they will not be able to remove greasy fumes effectively. Therefore, in the design of water spray hoods, it is necessary to ensure that the nozzles used in the hoods are capable of creating fine water mist and will not easily get clogged.

When designing water spray hoods and air washers, the following issues should be considered:
• Avoid leakage of greasy fumes from any gaps.
• Allow sufficient residence time.
• Provide adequate air-to-water-ratio.
• Select appropriate scrubbents.
• Ensure that the equipment is easy to maintain and clean.
To ensure efficient greasy fumes removal, hotels should frequently clean the nozzles and replenish the scrubbents.

(Photo 3.11) Packed scrubber is less efficient and requires more space when compared with electrostatic precipitator.

c. Packed Scrubber

Electrostatic Precipitators with Water Spray Hood

High efficiency in removal of greasy fumes with auto cleaning function

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