Indoor Air Quality

ArchitectureArchitectureIndoor Environmental Quality

SustainableSustainable

SUSTAINABLESUSTAINABLE

DESIGNDESIGN

1- Sustainable Site Planning

2- Safeguarding Water and Water Efficiency

3- Energy Efficiency and Renewable Energy

4- Conservation of Materials and Resources

5- Indoor Environmental Quality

Innovation and Design Innovation and Design ProcessProcess

5. Indoor Environmental Quality5. Indoor Environmental Quality

Indoor Air Quality Indoor Air Quality (IAQ)(IAQ) Light QualityLight Quality Acoustic QualityAcoustic Quality

Building Materials & Volatile Organic Compounds (VOCs)

Ventilation Effectiveness

Temperature and Relative Humidity

Controllability of Systems - as much control as possible is given to Controllability of Systems - as much control as possible is given to individual users, without compromising the effectiveness and efficient individual users, without compromising the effectiveness and efficient control of the overall systemcontrol of the overall system

Building Services Noise and Vibration

Control

Noise Control at the Source

Sound Isolation and Room Acoustics

A highly efficient light level distribution that improves visual quality while reducing electrical use may be achieved through efficient lighting layout, lamps, and luminaires.

Controllability of Systems

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Controllability of Systems - as much control as possible is Controllability of Systems - as much control as possible is given to individual users, without compromising the given to individual users, without compromising the effectiveness and efficient control of the overall systemeffectiveness and efficient control of the overall system

Low-emitting Materials

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Sources of Offgassing in Building Materials: 1- Paints 2- Ceiling tiles 3- Carpeting 4- VCT floor tiles 5- Manufactured wood products

Environmentally Friendly Architecture Reduces the use of materials that may Environmentally Friendly Architecture Reduces the use of materials that may release indoor air contaminants that are odorous or potentially irritating and release indoor air contaminants that are odorous or potentially irritating and might be harmful to occupant health, comfort and well-being. These materials might be harmful to occupant health, comfort and well-being. These materials must meet or be lower than the permissible VOC content limits (0.5 mg/m3)must meet or be lower than the permissible VOC content limits (0.5 mg/m3)

Ventilation, whether mechanical or natural, Ventilation, whether mechanical or natural, may be used for:may be used for:

Air Quality ControlAir Quality Control

Direct Indoor CoolingDirect Indoor Cooling

Direct Personal CoolingDirect Personal Cooling

Indirect Night CoolingIndirect Night Cooling

to control building air quality, by diluting internally-generated air contaminants with cleaner outdoor air

to directly cool building interiors by replacing or diluting warm indoor air with cooler outdoor air

to directly cool building occupants by directing cool outdoor air over building occupants at sufficient velocity

to indirectly cool building interiors by pre-cooling thermally massive components of the building fabric

Three Fundamental Strategies to Natural Three Fundamental Strategies to Natural VentilationVentilation

Wind-driven cross Wind-driven cross ventilationventilation

Buoyancy-driven Buoyancy-driven stack ventilationstack ventilation

Single-sided Single-sided ventilationventilation

Mixed Natural Ventilation Mixed Natural Ventilation StrategiesStrategies

Stack Ventilation With Sub-Stack Ventilation With Sub-slab Distributionslab Distribution

Elaborations of the Basic StrategiesElaborations of the Basic Strategies

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• 1- Wind-driven cross ventilation occurs via ventilation openings on opposite sides of an enclosed space.

• 2- Buoyancy-Driven Stack Ventilation relies on density differences to draw cool, outdoor air in at low ventilation openings and exhaust warm, indoor air at higher ventilation openings.


• 3- Single-sided ventilation typically serves single rooms and thus provides a local ventilation solution.

• Compared to the other alternatives, single-sided ventilation offers the least attractive natural ventilation solution but, nevertheless, a solution that can serve individual offices.

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• Mixed local/global and stack/wind ventilation strategy.

• Stack ventilation with sub-slab distribution

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Elaborations of the Basic StrategiesElaborations of the Basic Strategies

Mixed Natural Ventilation Strategies

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Zion National Park

Visitor Centre

1. Passive Down-Draft Cooltowers

2. computer-controlled operable windows

3. roof-integrated PV panel

4. radiant floor heating

Passive Down-Draft CooltowersWater sprayed on pads at the top of the towers evaporates, cooling the air. The cool, dense air “falls” through thetower and exits through the large openings at thebottom of the towers.

Natural VentilationThe high clerestory windows help coolthe center by allowing hot air to escape while low windows near thedoors allow cool air in. Computer controlsoperation of the clerestory windows.


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Zion National Park

Visitor Centre


18/04/23 13Zion National Park Visitor Centre

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Zion National Park

Visitor Centre


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Torrent Research Center,

Ahmedabad, India

Stack Ventilation With Sub-slab Distribution

• External walls (shielded from direct sunlight) • Heavy building mass• The enormous thermal mass of the building is used to regulate

the air temperature • Windows are small and do not exceed 25 percent of the

exposed surface area

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Office Block in Office Block in Harare, Zimbabwe Harare, Zimbabwe suitable for hot suitable for hot zones,zones,Architects Pearce Architects Pearce PartnershipPartnership

(Source: Slessor, 1996)(Source: Slessor, 1996)

Major Technical Barriers to Widespread Use of Natural Ventilation

• Air and noise pollution in urban areas and city centres. presently lack proven filtration capabilities

• Controlling ventilation when natural driving forces are small

• Recovering heat from natural ventilation systems (an issue of concern to countries with very cold winters)

• Combating summer overheating• Integrating and maintaining natural ventilation

systems

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Acoustic Quality (Noise Control)

• Controlling noise at the source• Controlling noise along its path

Reflected sound may be reduced by placing sound absorbing materials on surfaces from which sound will be reflected.

• Controlling noise at the receiver Direct ear protection (ear plugs or ear muffs) is often used to protect workers’ hearing when source and path noise control are not practical or possible (Temporary) Enclose the listener in an acoustically effective enclosure or Room (Permanent)

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Attributes of Good Acoustic Quality

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Sound rated partition up to ceiling

Sealed wall penetrations and acoustic baffle duct sections

Sound absorbent dropped ceiling

Sound absorbent insulation

Junctions vibration dampened

Sound rated partitions placed on structural floor

Sound absorbent partitions and furnishings

Floor slab floating on insulation

Sound reflecting transparent partitions to contain noise where feasible

Sound rated glazing

Sound absorbent flooring

“The technology of noise control both inside and outside buildings is well developed today. The problem is that it is too seldom used.” Robert B. Newman, Architect

YORK UNIVERSITY Computer Science Building - Case Study

Sustainable architecture main features• A central atrium to capture heat stratification

opportunities, thermal "chimneys" on the roof and a large component of operable perimeter glazing that maximizes free cooling in spring and fall and night time "flushing" in the summer. The result is stunning - energy consumption is 50% less than comparable buildings.

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• The building features a planted roof, putting green space on the infill site to a "higher" use. The planted roof also acts as a holding tank for stormwater

• HVAC Plant is 50 % of normal size, resulting in significantly less emissions during operation.

• Natural Daylighting - All spaces access natural light either exterior or to interior atriums.

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• Natural Ventilation: 100% Natural Ventilation during swing seasons. Operable window throughout, atrium spaces, thermal "chimneys" on roof; wind sensors control opening and closing of windows in upper atrium spaces.

• The building is acoustically sealed; reducing noise in or out. Extensive acoustic research was developed in concert with natural ventilation strategies. Acoustic lining is utilized to control noise in high air movement areas.

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• Spaces are simple and fully flexible to accommodate changing future technologies. A continuous perimeter raceway allows cabling flexibility.

• Significant undercover bicycle storage ; shower rooms on every floor including disabled use. Building is also readily accessible via public transit.

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• Building Section: diagrams natural daylighting and mechanical systems in winter season.

• Partial Section showing Natural Vent mode during shoulder seasons (Spring/Autumn).

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• The building has the capability of performing as a naturally ventilated "tropical" structure. The hot climate design incorporates a central atrium to capture heat stratification opportunities. Thermal "chimneys" on the roof and a large component of operable perimeter glazing maximize free cooling in spring and fall and night time "flushing" in the summer.

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Indoor Air Quality

Documents

cool outdoor air

warm indoor air

indoor air contaminants

higher ventilation openings

low ventilation openings

local ventilation solution

efficient control

stackwind ventilation