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Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

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Presentation on theme: "Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011."— Presentation transcript:

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2 Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011

3 Essentials of a healthy workplace Indoor Environmental Quality Presentation Overview Copyright © 2011 Business Environment Council

4 On average, adults spend more than 90% of time indoors. Better IEQ protect our health, contribute to our comfort, improve productivity, increase profitability and value of the property, and attract and retain more tenants. Poor IEQ may lead to discomfort and illness, more sick leave and higher absenteeism, weaken our competitiveness. Essentials of a Healthy Workplace Copyright © 2011 Business Environment Council

5 Acute health and comfort effects that appear to be linked to time spent in a building; No specific illness or cause can be identified. In a particular room or zone, or may be widespread throughout the building. What is Sick Building Syndrome (SBS)? Copyright © 2011 Business Environment Council

6 Headache; dry / itchy skin; cough; dizziness and nausea; fatigue. No clinically defined disease or specific chemical or biological contaminant Relief soon after leaving the building. SBS Indicators: Sick Buildings Copyright © 2011 Business Environment Council

7 Contributing Factors of SBS: Chemical contaminants from outdoor sources: Vehicle exhausts, building exhausts, etc. Chemical contaminants from indoor sources: Adhesives, upholstery, carpeting, copy machines, manufactured wood products, cleaning agents, pesticides, VOCs, tobacco smoke and combustion products,etc. Biological contaminants: Pollen, bacteria, viruses and molds, etc. Inadequate ventilation: Inadequate in design stage, shut down of ventilation facilities etc. Sick Buildings Copyright © 2011 Business Environment Council

8 What is BRI? Symptoms of diagnosable illness are identified and can be attributed directly to airborne building contaminants such as : Legionnaire Disease, and Humidifier Fever, etc. Building Related Illness (BRI) Copyright © 2011 Business Environment Council

9 Legionnaire Disease: The first known outbreak was in Philadelphia of USA in A total of 221 people contacted the disease and 34 died (15.4%). Building Related Illness (BRI) Copyright © 2011 Business Environment Council

10 The bacteria reproduce to high numbers in warm, stagnant water (32 °C – 40.5 °C): Plumbing systems; Water tanks; Cooling towers; Evaporative condensers; and Whirlpool spas. Sources of aerosols with Legionella bacteria: Building Related Illness (BRI) Copyright © 2011 Business Environment Council

11 Humidifier Fever: Uncertain etiology. Exposure to amoebae, bacteria, and fungi found in humidifier reserviors, air conditioners, and aquaria. Symptoms: Flu-like illness with symptoms: Hypersensitivity pneumonitis and marked fever, headache, chills, myalgia, and malaise but without prominent pulmonary symptoms. Subsides within 24 hours without residual effects. Building Related Illness (BRI) Copyright © 2011 Business Environment Council

12 Indoor Air Quality Thermal Comfort & Ventilation Lighting Noise & Acoustics Indoor Environmental Quality Copyright © 2011 Business Environment Council

13 Distinguish between discomfort vs health hazard Discomfort (examples)Health Hazard ThermalWarm / cool sensationHeat stress, Cold stress IAQOdourInhalation of toxic gases VisualGlare, Eye strainsRetina damages due to blue- light hazard: Excessive illumination with blue light or UV radiation AuralNoise annoyanceHearing damages Normally, IEQ problem in built environment would not lead to hazardous level, although sick symptoms may be reported. Discomfort Vs Health Hazard Copyright © 2011 Business Environment Council

14 Carbon Monoxide (CO) Oxides of Nitrogen (NO X ) Respirable Suspended Particulate (RSP) Volatile organic compounds (VOCs) Carbon dioxide (CO 2 ) Biological contaminants Radon (Rn) Formaldehyde (HCHO) Ozone (O 3 ) Environmental tobacco smoke Indoor Air Quality Copyright © 2011 Business Environment Council

15 Carbon Monoxide (CO) from vehicle exhaust at road surface & car parks Oxides of Nitrogen (NO X ) from vehicle exhaustions & incomplete combustion in industry Respirable Suspended Particulate (RSP) from vehicular exhaust, construction activities, power plants etc. Outdoor Sources for Indoor Air Pollutants Copyright © 2011 Business Environment Council

16 Carbon dioxide (CO 2 ) and biological contaminants from people, pets & plants Radon (Rn) from building materials Volatile organic compounds (VOCs) from consumer products such as cosmetics, pesticide, cleaning agent, etc. Formaldehyde (HCHO) from pressed wood products such as MDF furnitures Ozone (O 3 ) from printing machines Environmental tobacco smoke from smoking Indoor Sources for Indoor Air Pollutants Copyright © 2011 Business Environment Council

17 Effective filtration systems Avoidance of short circuiting Accessible HVAC ducts Control air pollutant generation at source eg. water based paints for VOCs & materials finishes for Radon Fresh air to dilute pollutants as last resort (energy inefficient) & could be linked to air pollutant sensors Regular monitoring IAQ Management Copyright © 2011 Business Environment Council

18 1997 – consultancy study to characterize & quantify IAQ in offices (40) and public places (33) in Hong Kong 70s – study to prevent occupational diseases at workplace for persons with long exposure. Aug 2003 – IAQ Management Programme for Offices & Public Places with 2 level objectives (IAQ-O) : –(Excellent class) : standard for high-class and comfortable buildings –(Good class): provide protection for all population IAQ Development Copyright © 2011 Business Environment Council

19 IAQ Certification Scheme Source: Source: Copyright © 2011 Business Environment Council

20 Indoor Air PollutantsUnitExcellentGood CO 2 ppm<800<1000 COµg/m 3 <2000<10000 RSPµg/m 3 <20<180 NO 2 µg/m 3 <40<150 O3O3 µg/m 3 <50<120 Formaldehydeµg/m 3 <30<100 TVOCµg/m 3 <200<600 RadonBq/m 3 <150<200 Air-borne Bacteriacfu/m 3 <500<1000 Room TemperatureºCºC20 – 25.5<25.5 Humidity%40 – 70<70 Air Movementm/s<0.2<0.3 IAQ Objectives Copyright © 2011 Business Environment Council

21 IAQ Certificate Issuing Body Copyright © 2011 Business Environment Council

22 Thermal comfort depends on Physical & (personal) factors : Air temperature Summer : 23 °C and 26 °C Winter : 20 °C to 24 °C Relative humidity (RH) Indoor RH between 40% to 70% High RH prevents growth of micro- organisms Air Speed and Distribution Air speed between 0.1 to 0.25 m/s. Dir distribution depends on design – allocation of diffuser location & type of diffusers. Thermal Comfort Copyright © 2011 Business Environment Council

23 Efficient ventilation & proper maintenance of ventilation systems : provide a comfortable environment avoid various invisible health hazards in buildings. Functions of ventilation : Supply fresh air Remove airborne contaminants Maintain temperature and humidity Ventilation Copyright © 2011 Business Environment Council

24 Natural and mechanical ventilations Different building types adopt different ventilation rate and air change Provision of adequate fresh air to meet stipulated requirement Fresh air intake locations away from exhaust & pollutant points Exhaust points at high level and not directed to neighbouring buildings. Independent exhaust for pollutant generating areas Ventilation Considerations Copyright © 2011 Business Environment Council

25 Visibility Security Social & Communication Individual Well-being Mood & Comfort Health & Safety Aesthetic judgment. Architecture Forms Composition Style Codes & Standards Economics Installations Maintenance Operation Energy Interior Lighting Copyright © 2011 Business Environment Council

26 Light Output Levels (Lux level) e.g. 500 lux for Office Light Output Quality Colour Rendering Index (Ra > 80) Glare Index (GI < 19) Lighting Performance Copyright © 2011 Business Environment Council

27 Eyestrain eye irritation blurred vision dry burning eye headaches Adverse Effects of Poor Lighting Copyright © 2011 Business Environment Council

28 Utilize Natural Daylight Combine natural and artificial lighting with photo-sensor and dimmer to improve lighting at workplace; Optimum and Energy Efficient Keep optimum illuminance, e.g. 200 lux for general offices and 300 to 500 lux for normal desktop; and Use of T5 fluorescent or LED tubes Management of Lighting at Work Copyright © 2011 Business Environment Council

29 Avoid Poor Contrast Reposition, avoiding use of polished surfaces and reducing the contrast between work station and surrounding Avoid Shadow Effect Change light sources direction to avoid shadowing effect Tackle Poor Lighting Arrangement Relocation of light sources to provide comfortable and uniform illumination and suits actual office layout Management of Lighting at Work Copyright © 2011 Business Environment Council

30 Control Light flicker Set up lamp replacement schedule and remove cause of flicker; Adoption of high frequency electronic ballast to reduce flickering; and Avoid Discomfort Glare Reposition of workstation to prevent too bright light sources. Management of Lighting at Work Copyright © 2011 Business Environment Council

31 Healthy light Renewable energy source Reduces air pollution - use less fossil fuels Fixed electricity cost at daytime Less maintenance and chemical waste disposal Increases comfort – less eyestrain and glare Improves visual acuity Reduces lighting heat gain Benefits of Natural Day Lighting Copyright © 2011 Business Environment Council

32 Unwanted/Annoying Sound Annoyance depends on loudness, quality of sound & personal attitudes More annoying at night - sleep interference Measured in dB / dB(A) Sound pressures vary from 20µPa (threshold of hearing) to 100 Pa (threshold of pain) What is Noise? Copyright © 2011 Business Environment Council

33 Physiological Effects Short Term - muscular response, etc. Long Term - heart attack. Hearing Impairment (Nerve cell damage) Temporary threshold shift Permanent threshold shift Noise – Effects on Humans Copyright © 2011 Business Environment Council

34 Threshold of hearing at 0 dB SPL of domestic environments below 60 dB Construction equipment eg. pneumatic chippers can generate 100 dB Jet Engine at 25 m emits 140 dB, threshold of pain Typical SPLs in the Audible Range Copyright © 2011 Business Environment Council

35 Building Services Systems : Chillers Extraction Fans Air Handling Units Fan Coil Units (FCU) / Variable Air Volume Units (VAV) Vertical Transportation systems (lift motors, etc) Indoor Noise Pollution Sources – Commercial Building Copyright © 2011 Business Environment Council

36 Could be based on maximum intrusive level for building design – British Standard : Below 45 Leq, dB(A) for privates offices and conference rooms Below 50 Leq, dB(A) for open plan offices Acceptable Indoor Noise Levels for Office Copyright © 2011 Business Environment Council

37 Time for the sound to decay 60 dB below its original level. RT in a room determined from surface area & absorption coefficient of materials RT for office = 0.6s or below RT shorter for lecture room & longer for theater Reverberation Time (RT) Copyright © 2011 Business Environment Council

38 Noise Mitigation Measures – Sitting of Noisy Equipment Copyright © 2011 Business Environment Council

39 Spring isolator (vibration) Flexible connector (vibration) Silencer (~20 dB) (sound absorption) Acoustic Enclosure (~ 20 dB) Noise Mitigation Measures for Noisy Equipment Copyright © 2011 Business Environment Council

40 Acoustic wall panel (~ 20 dB) Floating floor (~ 30 dB) Isolation ceiling (~ 20 dB) Noise Mitigation Measures Copyright © 2011 Business Environment Council

41 Seal up any gaps around doors, window and partition walls An office environment (Cross talk noise) Noise Mitigation Measures for Office Copyright © 2011 Business Environment Council

42 Porous Finishing Material on Wall or Ceiling Acoustic Door Cross Talk Silencer Furniture, Carpet Noise Mitigation Measures for Office (RT) Copyright © 2011 Business Environment Council


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