Ventilation System
Air Pollution
Common Problems |
Causes |
Relevant Environmental Control |
Excessive emission of cooking odour & greasy fumes |
Exhaust outlets locating too close to the nearby air sensitive receptors |
Under the Air Pollution Control Ordinance, Cap. 311, all air emissions from a restaurant should not cause air pollution problem, including odour nuisance, and should be free from visible fume. Any person causing air nuisance must adopt air pollution abatement measures. |
Inadequate air pollution control measures |
Practical Solutions
- Avoid locating the exhaust outlets in close proximity to the air sensitive receptors for restaurants and food business
- Locate the exhaust outlets in a good ventilated and dispersive area, e.g. extending kitchen exhausts to rooftop
- Locate and orientate the exhaust away from the nearby air sensitive receptors
- Preference should be given to extend the exhaust to a level of at least 3m above the highest point of the restaurant's own building and any adjacent or attached buildings within a 20m radius
- Seek advice from environmental professionals when locating exhaust outlet
- Install appropriate air pollution control equipment (recent tests indicated that the combined use of electrostatic precipitator and hydrovent can remove up to 94% of oily fumes)
- Install appropriate odour control equipment, such as activated carbon filter, for cooking activities which emit strong odour
- Conduct regular cleaning and maintenance of all air pollution control equipment
- Maintain an easy access for serving and inspecting air pollution control agent
- Monitor the quality of cooking fumes and odour emissions regularly during peak hours
- Install transparent inspection window/panel for the air pollution control equipment
- Adopt automatic switch-on function to synchronize the operation of the cooking device with air pollution control equipment
Indoor Air Pollution
Indoor Air Pollutants |
Typical Sources |
Potential Health Effects |
Carbon dioxide (CO2) |
Smoking, breathing & burning |
Headaches, dizziness & nausea at high concentration |
Carbon monoxide (CO) |
Burning, smoking & engine exhaust |
Headaches, decreased alertness, flu-like symptoms, nausea, fatigue, rapid breathing, chest pain, confusion, impaired judgment & even death at high concentration |
Respirable suspended particulates (RSP) |
Burning, smoking, photocopying & engine exhaust |
Allergic reactions, e.g. dry eyes, nose, throat, skin irritation, coughing, sneezing & respiratory difficulties |
Nitrogen dioxide (NO2) |
Burning, smoking & engine exhaust |
Eyes & throat irritation |
Ozone (O3) |
Photocopying, printing using laser printers & high voltage discharged from air purifiers |
Tingling sensation in the nose, dry & sore throat, tearing, burning, stinging & pain in the eyes |
Volatile organic compounds (VOCs) |
Cleansing agents, disinfectants, paints, solvents, printing inks, furniture, furnishings & smoking |
Some VOCs are carcinogen, e.g. benzene |
Formaldehyde (HCHO) (also a VOC) |
Pressure-wood products, urea-formaldehyde foam insulation, adhesives, paints, furniture & smoking |
Irritation to eyes, respiratory tract & damage to lung tissues at high concentration |
Radon (Rn) |
Granitic products |
Lung cancer |
Microbials (bacteria & fungi) |
Proliferation under humid & suitable conditions |
Flu-like symptoms & fever |
Environmental tobacco smoke (ETS) |
Smoking |
Respiratory irritation, adverse effects on the cardiovascular system & lung cancer |
Practical Solutions
- Appoint an indoor air quality manager to conduct indoor air quality assessment and supervise the management of the indoor air quality programme
- Locate the fresh air intake in well ventilated area and free from obstruction
- Arrange a regular cleaning and maintenance programme for ventilation and air-conditioning systems
- Avoid setting low temperature and adopt humidity control equipment, such as heatpipe, to minimize growth of microorganisms such as molds and fungi
- Conduct pest control practices in non-business hours and adopt non-chemical methods where possible
- Prohibit tobacco smoking or establish smoking area with independent exhaust
- Isolate renovated areas with physical barrier and introduce local exhaust and air pollution control equipment, such as photocatalytic oxidation reactor (PCO Reactor)
- Promote good practices on improving indoor air quality to internal staff, occupiers and tenants:
- Fix all water leakages and water spills promptly to minimize the growth of microorganisms
- Schedule renovation activities in non-business hours
- Use product with no/low volatile organic compound
- Naturally aerate new furniture before use to reduce chemical emissions and odours
- Isolate and provide special ventilation for pollutants-generating office equipment such as copiers, printers and fax machines
- Establish clear procedures for responding to indoor air-related complaints
- Keep a record of reported health complaints to aid in solving indoor air-related problems
Noise & Vibration Pollution
Practical Solutions
- Place noisy equipment inside a plant room with thick walls as far as possible
- Locate the equipment away from the nearby and future NSRs
- Orientate the duct openings/air inlets/air outlets away from NSRs
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Orientate the exhaust outlet away from noise sensitive receivers to minimize air flow noise. |
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- Choose equipment of low noise brands or models
- Make reference to the statutory noise limit and include noise levels specification when ordering new equipment
- Conduct regular maintenance, such as lubricating moving parts, tightening loosen parts (bolts/nuts, driving belts, panels, etc.), replacing worn-out components (bearings) and inspecting equipment alignment
- Implement proper noise control measures:
- Erect noise barrier, partial and completed enclosures to block the noise propagation path to the NSRs
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Use noise barrier to block the noise propagation path to the nearby NSRs. |
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- Install silencers at air inlets and outlets
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Install complete enclosure for noisy machine and silencers for air exhausts. |
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- Install inertia block and vibration isolator to isolate the vibrating machines and to prevent structural vibration transmission
- Apply damping material on the vibrating duct work
- Provide acoustic mat on the water surface of water cooling towers to reduce the water splashing noise
- Adjust the operation mode, such as reducing fan speed and switching off non-essential equipment at night
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