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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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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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Page 1: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

Sustainable Workplace in PracticeC F Leung

Senior Manager

Building & Energy Efficiency and Indoor Air QualityBusiness Environment Council

4 August 2011

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

Essentials of a healthy workplace

Indoor Environmental Quality

Presentation Overview

Copyright © 2011 Business Environment Council

Page 3: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

• 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

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

• 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

Page 5: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

• 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

Page 6: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

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

Page 7: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

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

Page 8: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

Legionnaire Disease:

The first known outbreak was in Philadelphia of USA in 1976. A total of 221 people contacted the disease and 34 died (15.4%).

Building Related Illness (BRI)

Copyright © 2011 Business Environment Council

Page 9: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

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

Page 10: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

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

Page 11: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

Indoor Air Quality

Thermal Comfort & Ventilation

Lighting

Noise & Acoustics

Indoor Environmental Quality

Copyright © 2011 Business Environment Council

Page 12: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

• Distinguish between discomfort vs health hazard

Discomfort (examples) Health Hazard

Thermal Warm / cool sensation Heat stress, Cold stress

IAQ Odour Inhalation of toxic gases

Visual Glare, Eye strains Retina damages due to blue-light hazard: Excessive illumination with blue light or UV radiation

Aural Noise annoyance Hearing 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

Page 13: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

• Carbon Monoxide (CO)• Oxides of Nitrogen (NOX)

• Respirable Suspended Particulate (RSP)

• Volatile organic compounds (VOCs)• Carbon dioxide (CO2)• Biological contaminants• Radon (Rn) • Formaldehyde (HCHO)• Ozone (O3)• Environmental tobacco smoke

Indoor Air Quality

Copyright © 2011 Business Environment Council

Page 14: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

Carbon Monoxide (CO) from vehicle exhaust at road surface & car parks

Oxides of Nitrogen (NOX) 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

Page 15: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

• Carbon dioxide (CO2) 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 (O3) from printing machines

• Environmental tobacco smoke from smoking

Indoor Sources for Indoor Air Pollutants

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Page 16: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

• 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

Page 17: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

1997 – consultancy study to characterize & quantify IAQ in offices (40) and public places (33) in Hong Kong

70’s – 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

Page 18: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

IAQ Certification Scheme

Source: http://www.iaq.gov.hk/images/IAQ_Cert_excellent.jpg Source: http://www.iaq.gov.hk/images/IAQ_Cert_Good.jpg

Copyright © 2011 Business Environment Council

Page 19: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

Indoor Air Pollutants Unit Excellent Good

CO2 ppm <800 <1000

CO µg/m3 <2000 <10000

RSP µg/m3 <20 <180

NO2 µg/m3 <40 <150

O3 µg/m3 <50 <120

Formaldehyde µg/m3 <30 <100

TVOC µg/m3 <200 <600

Radon Bq/m3 <150 <200

Air-borne Bacteria cfu/m3 <500 <1000

Room Temperature ºC 20 – 25.5 <25.5

Humidity % 40 – 70 <70

Air Movement m/s <0.2 <0.3

IAQ Objectives

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Page 20: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

IAQ Certificate Issuing Body

Copyright © 2011 Business Environment Council

Page 21: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

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

Page 22: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

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

Page 23: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

• 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

Page 24: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

• 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

Page 25: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

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

Page 26: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

• Eyestrain

• eye irritation

• blurred vision

• dry burning eye

• headaches

Adverse Effects of Poor Lighting

Copyright © 2011 Business Environment Council

Page 27: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

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

Page 28: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

Avoid Poor Contrast

Reposition, avoiding use of polished surfaces and reducing the contrast between work station and surrounding

Avoid Shadow Effect

Change light source’s 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

Page 29: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

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

Page 30: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

• 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

Page 31: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

• 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

Page 32: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

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

Page 33: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

• 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

Page 34: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

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

Page 35: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

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

Page 36: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

• 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)

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Page 37: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

Noise Mitigation Measures – Sitting of Noisy Equipment

Copyright © 2011 Business Environment Council

Page 38: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

• 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

Page 39: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

• Acoustic wall panel (~ 20 dB)

• Floating floor (~ 30 dB)

• Isolation ceiling (~ 20 dB)

Noise Mitigation Measures

Copyright © 2011 Business Environment Council

Page 40: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

Seal up any gaps around doors, window and partition walls

An office environment (Cross talk noise)

Suspendedceiling

Wall

a good (bad) sound path is present above aperforated false ceiling => reduction ininsulation of the wall of 10 dB or more.

Noise Mitigation Measures for Office

Copyright © 2011 Business Environment Council

Page 41: Sustainable Workplace in Practice C F Leung Senior Manager Building & Energy Efficiency and Indoor Air Quality Business Environment Council 4 August 2011.

• 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