Indoor Environmental Quality (IEQ)
Indoor Environmental Quality (IEQ) is most simply described as the conditions inside the building. It includes air quality, but also access to daylight and views, pleasant acoustic conditions, and occupant control over lighting and thermal comfort. It may also include the functional aspects of space such as whether the layout provides easy access to tools and people when needed and whether there is sufficient space for occupants. Building managers and operators can increase the satisfaction of building occupants by considering all of the aspects of IEQ rather than narrowly focusing on temperature or air quality alone. Americans spend the majority of their time indoors; not surprisingly, studies have shown an increase in worker productivity when improvements are made to a space’s IEQ. See the IEQ Whole Building System for guidance to improve IEQ.
A space with good acoustics allows for confidential conversations among collaborating workers without affecting those engaged in individual, focused work. It is not too loud, does not echo too much, and controls excess noise pollution from both indoor and outdoor sources.
Adequate Ventilation and Exhaust
Adequate ventilation and exhaust is important to prevent build-up of odors, carbon dioxide, allergens and toxins in indoor air. Provide separate exhaust for copy, printing, break rooms, and food preparation areas. Flush out occupied spaces prior to occupancy. Use energy efficient or variable drive fans for enhanced air movement. Consider bringing in more fresh air into the building. Ensure the building management staff is conducting preventive maintenance on all building exhaust systems (restrooms, garage exhaust fans, etc). Seal ventilation duct opening during construction or renovations to reduce dust and particle build-up.
Adhesives are substances used to bond one surface to another. They include bonding primers and adhesive primers for plastics. Adhesives often emit high levels of harmful Volatile Organic Compounds (VOCs), so care must be taken to ventilate spaces when using them. Many low or no-VOC adhesive products are also available and should be used where feasible.
Air Delivery Monitoring
It is important to provide adequate ventilation for occupied spaces. However, care should be taken to prevent energy waste by over-ventilating. Monitoring systems can be installed to generate alarms when unhealthy levels of carbon dioxide are detected – a sign that additional fresh, outside air needs to be brought in to restore healthy indoor air quality.
ASHRAE (formerly, the American Society of Heating, Refrigerating, and Air-Conditioning Engineers) is the governing body which creates and releases the standards regarding indoor air quality, thermal comfort, and energy efficiency.
Binders are used to hold together two or more ingredients. They are similar to adhesives and must also be used with care. Binders can have high levels of harmful Volatile Organic Compounds (VOCs), which can be dangerous to human health and the environment. Lower VOC binders are preferable, and all spaces where binders are applied should be well ventilated.
The process that focuses on verifying and documenting that the facility and all of its systems and assemblies are planned, designed, installed, tested, operated, and maintained to meet the Owner's Project Requirements. This means testing all systems (HVAC, lighting controls, domestic hot water systems, etc.) to ensure they function as intended. Proper commissioning saves energy, reduces risk, and creates value for building operators. It also serves as a quality assurance process for enhancing the delivery of the project.
Building cleanliness is both the process of removing dirt and contaminates from the building as well as the process of maintaining this state. Keeping the facility clean decreases the occurrence of “sick building syndrome” and uses less toxic chemicals in the process. Occupants are also more likely to express satisfaction and lose less productivity due to absenteeism in a well-cleaned building.
Combined Sewer Overflow
A combined sewer system conveys both sanitary sewage and stormwater in one piping system. During normal dry weather conditions, sanitary wastewater collected in the combined sewer system is diverted to the wastewater treatment plant before it enters natural waterways. During periods of significant rainfall, the capacity of a combined sewer may be exceeded. When this occurs, excess flow, a mixture of stormwater and sanitary wastewater, is discharged at CSO points, typically to rivers and streams.
Construction Air Quality Management
Construction activities can threaten the indoor air quality of an occupied space. Precautions should be taken to protect the health of construction workers as well as the health of occupants. These precautions include ensuring that airborne particles from construction activities are isolated from the permanently installed HVAC equipment; flushing out toxins before occupancy; ensuring absorptive materials are kept dry and that the facility is kept free from mold; and using construction materials low in harmful VOCs.
Daylighting uses natural daylight as a substitute for electrical lighting. While it will likely be counterproductive to eliminate electrical lighting completely, the best proven strategy is to employ layers of light - using daylight for basic ambient light levels while providing occupants with additional lighting options to meet their needs.
An effective daylighting strategy appropriately illuminates the building space without subjecting occupants to glare or major variations in light levels, which can impact comfort and productivity.
In order to provide equitable access to daylight ensure the space is optimized to disperse daylight well. Locate private offices toward the core of the space and specify low workstation panels. Use glass walls and light-colored surfaces on walls and desks to disperse daylight throughout the space. In all daylighting strategies, it is important to consider glare and to take steps to minimize it. Find more strategies below:
Entryway Systems/Walk-off Mats
Toxins are tracked into a building on occupants’ shoes. Entryway systems, like grates, grills, and walk-off mats can greatly reduce the amount of outside dirt, dust, and particulates brought into the building. This makes for a cleaner environment, and cuts down on the amount of cleaning necessary to maintain a high level of cleanliness in the facility.
Ergonomic workspaces are designed to facilitate work while minimizing stress and strain on the body. They also accommodate user preferences and comfort. They include height-adjustable desks that can be easily moved around on casters, fully adjustable chairs, monitor arms, keyboard trays, footrests and document holders. It is important to train employees on how to adjust their workspaces to maximize comfort and health.
ETS (Environmental Tobacco Smoke) Control
ETS is another term for secondhand smoke. It consists of cancer-causing airborne particles emitted from the burning end of cigarettes, pipes, and cigars, and is exhaled by smokers. Good indoor air quality is assured by not allowing ETS to enter the air breathed by non-smokers. This is often achieved by banning smoking within the facility and within a certain distance from openings in the building envelope (often 20-25 feet). Buildings can also install separate HVAC systems to isolate areas within a facility where smoking is allowed.
A finish is the final covering material in an arrangement of building components. It can refer to the finish on the floor, countertop, wall, or piece of furniture. Similar to adhesives and binders, finishes must also be used with care. They can emit high levels of harmful Volatile Organic Compounds (VOCs), which can be dangerous to human health and the environment. Lower VOC finishes are preferable, and all spaces where finishes are applied should be well ventilated.
The odors and toxins released from recently installed building materials and finishes – such as flooring, paints, caulks and sealants, cabinets and work surfaces made from composite lumber products – reduce indoor air quality. To increase indoor air quality, large amounts of outdoor air can be forced through a recently completed building for a period of 3 to 90 days so that the majority of emissions from the newly installed materials can be removed from the building before occupancy.
Tinted glass and glass with a reflective coating are glazing alternatives that reduce heat gain. One example, low-e glass, has a thin metal coating to allow light to pass through the glass; heat remains on the side where it is originating (it keeps the sun’s heat out of the building and mechanical heating inside the building). Low-e coatings contribute to energy efficient window assemblies.
A good green cleaning program uses processes and products with a low-environmental impact while still being effective at removing dirt and contaminants from the building. In addition, it protects the health of the cleaning staff. Green cleaning encompasses the use of non-toxic, biodegradable chemicals and recycled cleaning products, and uses cleaning equipment that has little to no environmental impact. It may also include daytime cleaning, the training of employees, use of microfiber cleaning cloths, and the use of concentrated cleaning chemicals that require less packaging.
The Guiding Principles for Sustainable Federal Buildings are a set of sustainable principles for integrated design, energy performance, water conservation, indoor environmental quality, materials, and climate change adaptation aimed at helping Federal agencies and organizations:
- Reduce the total ownership cost of facilities
- Improve energy efficiency and water conservation
- Provide safe, healthy, and productive built environments
- Promote sustainable environmental stewardship
Healthy people are free of disease and are otherwise well. Buildings with good indoor environmental quality (IEQ) support the health of occupants via high quality lighting, thermal conditions, air quality, acoustics, ergonomic and functional features.
Indoor Air Quality (IAQ)
Indoor Air Quality (IAQ) refers to the state of the air within a space. A space with good indoor air quality is one that is low in toxins, contaminants and odors. Good air quality possible when spaces are well ventilated (with outside air) and protected from pollutants brought into the space or by pollutants off-gassed within the space. Strategies used to create good IAQ include bringing in 100% outside air, maintaining appropriate exhaust systems, complying with ASHRAE Standard 62.1, utilizing high efficiency MERV filters in the heating ventilation and air conditioning (HVAC) system, installing walk-off mats at entryways, prohibiting smoking with the space and near operable windows and air intakes, providing indoor plants, and using only low-emitting / non-toxic materials and green housekeeping products.
Integrated Pest Management (IPM)
Integrated Pest Management is is a process used to reduce or discourage the growth of pest populations. IPM protects human health and the surrounding environment and improves economic returns by employing the most effective, least-risk management option. It uses non-toxic products such as cleaning and physical barriers to entrance before resorting to chemical means. Pests include plants, fungi, insects, and/or animals.
VOCs (volatile organic compounds) are toxins found within products (paints, adhesives, cleaners, carpets, particle board, etc) and that are released into a space’s indoor air, thus harming its quality. Low VOC products are those that meet or exceed various standards for low-emitting materials. Low-emitting standards include Green Seal, SCAQMD, CRI Green Label Plus, Floor Score, etc.
Whole Building Design Guide | Evaluating and Selecting Green Products
Materials used in buildings often contain compounds that have a negative effect on indoor air quality (IAQ) and the earth’s atmosphere. These compounds can be present in adhesives, sealants, paints, flooring, carpets, composite wood and agrifiber products, furnishings, and in ceiling and wall systems. Low-emitting materials release only small amounts of these compounds into the surrounding air over time. Strategies for selecting low-emitting options include ensuring material compliance with the ANSI/BIFMA X7.1-2007 standard for furniture emissions. Non-profit certification programs that verify conformance with the standard including but not limited to SCS Indoor Advantage, Certified Green, Greenguard, and any other program that uses the open ANSI standard.
Minimum Efficiency Reporting Value (MERV) is a rating from 1 to 16 that indicates the effectiveness of air filters. The higher the MERV rating, the denser the filter and the more efficient it is at removing small particles in the air. However, a higher MERV rating creates more resistance to airflow, thus requiring additional energy to push air through the filter. For the cleanest air, a user should select the highest MERV filter that their unit is capable of handling based on the limit of the unit’s fan power.
Moisture control is the process of regulating where, when and how much water and water vapor collect in a building. Mold and other air borne contaminates develop when there is too much moisture.
Noise pollution is the presence of unwanted or unpleasant noise. Noise pollution comes from improperly functioning HVAC equipment, street noise, or the conversations of others. Besides the fact that it is obnoxious and distracting, noise pollution can be detrimental to human health. It is therefore important to consider ways to eliminate noise pollution in project planning.
Workspaces should be designed and operated to support the functional and environmental needs of occupants. Design for thermal comfort should be based on ASHRAE Standard 55. Design for air quality should be based on ASHRAE 62. Occupant comfort should be assessed frequently once a building is occupied, using ASHRAE’s Performance Measurement Protocols for Commercial Buildings.
Workspaces should be designed to allow for occupant control over lighting (light switches, occupant or daylight sensors with override capability, etc) and thermal comfort (operable windows, individual thermostats, and underfloor air diffusers). Building operators should provide information about control use to occupants.
Many office buildings are being overcooled, particularly during the summer. Overcooling has both negative energy and occupant comfort consequences.
Overheating refers to the accumulation of warmth in a building to the extent where it causes occupant discomfort. It can also affect worker productivity and health. Overheating can occur during winter months, as well as in summer months.
Plants not only contribute to the appearance of the office and provide aesthetic value but they can help reduce air pollutants and introduce more oxygen to increase air quality.
Air that is removed from a space by mechanical means and reused again as supply air. Using a mix of recirculated air and fresh air is efficient because it maintains healthy levels of oxygen at healthy levels but doesn’t require excessive amounts of conditioning (heating or cooling).
Sick Building Syndrome (SBS)
When occupants feel sick at work, but not elsewhere, they likely have SBS. SBS often manifests as cold or flu-like symptoms after breathing stale or contaminated air. It harms worker productivity and morale. It may also increase absenteeism and worker turnover. See: http://www.epa.gov/iaq/pdfs/sick_building_factsheet.pdf
Speech privacy is the inability to overhear other people’s conversations and the ability to have a conversation without others overhearing. Poor speech privacy is the most widespread problem in commercial buildings.
Supply air is air delivered to a space by mechanical ventilation. It can be 100% outside air, or it can be a combination of outdoor air, recirculated air and / or transfer air. Although it may seem like a good idea to use 100% outside air, the air needs to be conditioned (heated or cooled) before it can be circulated, so it makes sense to use only as much as is necessary to keep the circulating air fresh and the energy use down.
Workspaces should be designed to provide the optimum level of thermal comfort for the occupants. Occupant comfort should be based on ASHRAE Standard 55.
Thermal Comfort Criteria
Comfort criteria are the specific original design conditions that at a minimum include temperature, humidity, and air speed as well as outdoor temperature design conditions, outdoor humidity design conditions, clothing, and expected activity. Comfort criteria should be based on ASHRAE Standard 55.
Ventilation is the process of "changing" or replacing air in any space to control temperature; remove moisture, odors, smoke, heat, dust, airborne bacteria, and carbon dioxide; and to replenish oxygen. Ventilation includes both the exchange of air to the outside as well as circulation of air within the building. It is one of the most important factors for maintaining acceptable indoor air quality in buildings.
Views (to the Outside)
Building occupants with access to outside views have an increased sense of well-being. Keeping employees happy and healthy is good for business, as happy employees show higher productivity and increased job satisfaction, resulting in less employee turnover. In order to provide equitable access to views, it is recommended that private offices are located toward the core of the space and that low workstation panels are installed to allow for maximum daylight penetration. Use glass walls and partitions to enable views out from interior spaces.
Productivity is the quality and/or quantity of goods or services produced by a worker. Good indoor environmental quality – access to views, comfortable temperatures, comfortable lighting, good acoustics, and ergonomic design, etc. – supports employees’ ability to do a good job. On the other hand, compromised IEQ hinders their ability to work. It makes good business sense, then, to keep employees happy, healthy, and productive. This, in turn, creates more and higher quality output for organizations.
Did You Know?
EPA studies indicate indoor levels of pollutants may be up to ten times higher than outdoor levels.
Source: Environmental Protection Agency (2008). An Introduction to Indoor Air Quality.
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