Indoor Environment Quality

Indoor environmental quality is an important aspect to the tenants wellbeing and productivity. When considering the indoor environmental quality the following should be considered:

• Ventilation Effectiveness
• Low Emitting Materials
• Controllability of Systems
• Thermal Comfort
• Daylight & Views
• Visual Comfort
• Noise
• Airborne Pollution Mitigation

Ventilation Effectiveness

Ensure that provision has been made for the effective delivery and mixing of fresh air to support the health, safety, and comfort of building occupants.

Install high efficiency filtration system consisting of 2 filters the second of which should be 85% efficient or a High Efficiency Particle Arrestor (HEPA ) filter.

HVAC systems to be easily accessible and easy to clean.

Give priority to an economiser cycle.

Ensure operations manual reflects importance of maintaining indoor air quality. As a minimum it should include:

• Regular maintenance of major HVAC components and ensure filters are replaced regularly.
• Ensure outdoor air dampeners are operating effectively and providing maximum amounts of fresh air.
• Clean outdoor air intakes, louvers and screens on a regular basis.
• Regularly check air diffusers and returns to ensure proper air distribution. Test, adjust and balance air to reflect impact of space changes.
• Check supply ducts for leaks and water damage. Ensure no mould growth in areas where moisture accumulates. Clean areas susceptible to dust build up.
• Flush building prior to hand over of fitout and replace return side air filters.

Low Emitting Materials

Encourage the reduction of the quantity of indoor air contaminants that are odorous or potentially irritating to provide installer and occupant health and comfort.

Request Material Safety Data Sheets (MSDSs) from manufacturers. These sheets should identify information on chemical identification, hazardous ingredients, chemical characteristics and fire hazard data. This information may be requested as part of the material data sheets used for life cycle assessment.

Consider materials and products in terms of their contribution to volitile Organic compounds in indoor air.

As a minimum consider the implication of the following materials and specify maximum of gassing potential values in a cost effective manner for:

• Floor finishes
• Paints
• Ceilings
• Furniture
• Partitions

Control possibility of microbial compounds:

• Specify material resistant to microbial growth
• Encapsulate materials such as insulation which might support microbe growth
• Materials susceptible microbial growth due to wetting during construction should be removed
• Carefully design external façade and install appropriate moisture barriers and retarders

The detailing of the building envelope prevents moisture accumulation problems (micro-organisms) from exterior wall penetration. Explicit directions provided to ensure that in-situ materials involving wet construction would be adequately dried before applying finishes.

Inspect and test ducts for microbial contaminates. Clean drain pans etc. to avoid mould growth.

Controllability of HVAC/Lighting System

Ensure that provision of a high level of individual occupant control of thermal, ventilation, and lighting systems to support optimum health, productivity, and comfort conditions.

Use building control systems to monitor and maintain indoor thermal comfort conditions to ASHRAE (American Society for Heating Refrigeration & Airconditioning
Engineers) 55. 2001

Workplaces which provide a stable environment for health, comfort and safety, and which have all of the following characteristics in place, are more likely to have happier and productive staff. Differences of 20% in perceived staff productivity between buildings have been recorded (Source: Building Use Studies plc: UK).

Perceived control is highest when:

• occupants are able to fine-tune the environment around them, especially to adjust the conditions to avoid discomfort;
• the heating, cooling, lighting, ventilation, noise and privacy arrangements normally work in unison rather than conflicting with each other;
• where conflicts occur, they are management, and staff can choose the trade-off of one against the other (e.g. choice between noise and heat);
• the controls provided are easy to use, give a clear indication that they are operating, and immediately feed back to the user whether or not their operation is having the desired effect; and
• the building’s facility management system supplements good basic conditions, and responds rapidly to complaints and requests for changes or improvements.

Thermal Comfort

Thermal comfort can be described as the sense of feeling too hot or cold, draught or stuffy. There are six factors that affect a persons thermal comfort, these include:

• Metabolic Rate
• Clothing Insulation
• Air Temperature
• Radiant Temperature
• Air Speed
• Humidity

National Capital Exhibition Halls, Canberra, Australia (2000)

In Canberra, Australia, Arup have designed a building with a temperature range from 19C in winter up to 26C in summer with no control of humidity. This naturally ventilated building has been well received by the occupants, who have expressed feeling healthier due to the improved indoor air quality.

The ASHRAE Standard 55 recommends that an office plate should achieve a perdicted percentage diatisfied(PPD) of 10% or less; this is equivalent to ±0.5 PMV. For perimeter zones a presicted percentage dissatisfied of <15% is recommended.

Ensure operations manual reflects importance of maintaining thermal comfort. As a minimum it should include:

• Regular monitoring of occupant complaints.
• Blinds to reduce solar loads, consider installing super insulating blinds on problem orientations.

Daylight & Views

Studies substantiate that daylighting creates healthier and more stimulating work environments than artificial lighting systems and can increase productivity. Daylighting provides changes in light intensity, colour and views that support worker productivity.

Surveys have shown that most employees prefer to work in spaces with windows and a view of the outside.

• Ensure that daylighting features are in place and maintained for optimum performance.
• Verify with building owner that a glass cleaning and systems maintenance schedule is in place.

ARUP Campus, UK. Daylight maximised

Visual Comfort

Aroura Place, Sydney. Glare Study

Visual discomfort is generally experienced in the form of glare. It is highly subjective and related to a variety of physiological and psychological factors, which include issues of age, illness and view. An individual may experience glare from either excessive illumination or from excessive contrast of illumination. Glare is generally defined in two ways:

• Disability Glare - causing the occupant to be unable to perform a task such as reading or writing.
• More subjectively, Discomfort Glare - causing discomfort or irritation.

Disability Glare is encountered in situations of reduced contrast between the object and its immediate background. For example a white rabbit may appear invisible against fresh snow.

Discomfort glare is a sensation causing annoyance or pain caused by extreme brightness or non-uniform distribution of brightness. Discomfort glare plays a very important role in designing natural lighting as special illumination ratios vary considerably with location, daylight penetration and window size.

Issues that should be considered when reviewing glare should be as follows:

• Blinds, semi transparent blinds may not cut out glare entirely.
• Orientation of computer screens to glazing, computer screens should ideally allow for occupant to orientate them perpendicular to the façade.
• Glare free lighting system.

Noise

Ambient noise can disturb other sites reducing indoor environment quality. Ensure that adequate precautions have been introduced to prevent it.

The major areas that should be considered when reviewing acoustic criteria are as follows:

• Façade sound insulation - ensure appropriate wall and slab constructions that meet the criteria set at design are specified. The constructions specified will need to be tested on site after construction to ensure transmission loss criteria are met.
• Internal noise levels including partition/wall constructions and speech privacy - the internal finishes should be developed to meet reverberation time criteria for the various spaces.
• The design of the HVAC systems will need to include appropriate noise control to meet the internal noise levels specified at scheme design stage.
• In open office areas where speech privacy may be an issue the specification of a noise masking system may be required.
• Control noise based on internal fitout design. Consider using white noise to aid privacy in open offices.

Powergen Headquarters, Phase 1, UK
Sound absorption panels integrated into light fittings

Airborne Pollution Migration

Minimise the migration of airborne pollutants from printing/photocopiers. Isolate activities such as photocopying and kitchen use and ventilate separately. Ensure no smoking in building.

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