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What is IAQ?

Indoor air quality (IAQ) refers to the quality of the air inside a building. IAQ has been one of the biggest "buzzwords" in the commercial building industry for the last decade. The general consensus in the industry is that the majority of commercial buildings have poor levels of indoor air quality.

There are several reasons why indoor air quality has become a major issue today. During the 1970s, the OPEC Oil Embargo led us to believe that there would be an energy crisis so extreme, measures would need to be taken to save energy in homes and commercial buildings well into the future. This belief created a major change in viewpoints with respect to energy efficiency techniques and products in the building industry; everything had to be made more efficient. Building envelops for new construction were tightened and energy efficient construction techniques were born. Mechanical ventilation systems that were once designed for higher volumes of outside air (ASHRAE 62-73) were now being reduced by 66% to minimize the energy impact on buildings (ASHRAE 62-81). With a combination of reduced outdoor ventilation, tighter building construction and new building materials that off-gassed many chemicals, the construction habits of the 1980s and early 1990s were not positively contributing to the well-being of the building occupants. Today, ASHRAE Standard 62 is the standard for ventilation which provides ventilation levels equal to those that were once found before the energy crisis.

A 1984 World Health Organization Committee report suggested that up to 30 percent of new and remodeled buildings worldwide may be the subject of excessive complaints related to indoor air quality (IAQ). Often this condition is temporary, but some buildings have long-term problems. The indoor contaminants that can cause these problems are called Volatile Organic Compounds (VOCs).

People have less control over the indoor environment of their office than they do in their own homes. Most of us work in an environment with heating, ventilating and air-conditioning (HVAC) systems. These systems are designed to provide air at a comfortable temperature with controlled humidity levels and to filter out concentrations of air pollutants. The complex process of ventilation is the key to providing proper IAQ.

Other terms that are used along with indoor air quality are: Sick Building Syndrome (SBS), Building Related Illness (BRI) and Indoor Environmental Quality (IEQ).

What is Sick Building Syndrome (SBS)?
The term "Sick Building Syndrome" (SBS) is used to describe situations in which building occupants experience acute health and comfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified. Some of the symptoms of SBS include dry mucous membranes as well as eye, nose and throat irritation. These disorders lead to increased employee sick days and reduced work efficiency. The National Institute for Occupational Safety and Health reports that poor ventilation is an important contributing factor in many sick building cases.
What is Building Related Illness (BRI)?
The term "Building Related Illness" (BRI) is used when symptoms of diagnosable illness are identified and can be attributed directly to airborne building contaminants.
What is Indoor Environmental Quality (IEQ)?
The National Institute for Occupational Safety and Health (NIOSH) prefers to use the term "Indoor Environmental Quality" (IEQ) to describe the problems occurring in office buildings and schools throughout the nation. The Institute, through its Health Hazard Evaluation (HHE) Program, evaluates potential health hazards in workplaces in response to requests from employers, employees, employee representatives, state and local government agencies and Federal agencies. NIOSH investigators have found that concerns about air quality may be caused by a number of factors, encompassing much more than air contamination. Other factors such as comfort, noise, lighting, ergonomic stressors (poorly designed work stations and tasks) and job related psychosocial stressors can individually and in combination contribute to complaints.
Is Indoor Air Quality linked to Asthma?
Over 50 percent of our nation's schools have poor ventilation and significant sources of pollution in buildings where nearly 55 million students, teachers and school staff spend the majority of their time. The time spent in these environments especially effects children with asthma who are particularly susceptible to indoor pollutants. Asthma, a chronic childhood disease, is responsible for 10 million missed school days per year. In the last 15 years, there has been a 160 percent rise in the incidence of asthma among young children. About one in 13 school-age children currently have asthma and the number of affected children is increasing. Asthma is the leading cause of long-term illness in children.
How can indoor air quality be improved?
Increasing ventilation rates and air distribution is the most cost-effective means to reduce indoor pollutant levels. HVAC systems should be designed, at a minimum, to meet ventilation standards in local building codes. HVAC systems must be operated and properly maintained to ensure ventilation performance and system performance. In all commercial buildings, IAQ can be greatly improved by providing the ventilation rates found in Table 2 of ASHRAE Standard 62-99 "Ventilation for Acceptable Air Quality". For more information on this standard, please go to the American Society of Heating, Refrigeration and Air-conditioning Engineers Inc. web site.
What are VOCs?
Adhesives, carpet, manufactured wood products, pesticides, cleaning agents and environmental tobacco smoke are among the group that may emit Volatile Organic Compounds (VOCs). There are currently over 60,000 registered chemicals in the building industry used on a daily basis. The research done on VOCs, some of which are known carcinogens, show that chronic and acute health is affected at high concentrations. Low to moderate amounts of VOCs may also produce acute reactions. Products such as carbon monoxide and nitrogen dioxide can be released from unvented kerosene and gas space heaters, woodstoves, fireplaces and gas stoves. All or any of these items negatively contributes to the quality of indoor air (IAQ).
What is Ventilation?

Ventilation is not just the movement of air or the introduction of outdoor air; it is the process of supplying and removing air from inside a building. It is the portion of supply air that is outdoor air plus any recirculated air that has been treated for the purpose of maintaining acceptable indoor air quality. Usually this process includes bringing in outdoor air, conditioning this air by mixing the outdoor airstream with a portion of the exhausted indoor air, and then distributing this air throughout the building.

The quality of the air that is distributed within the building is compromised when one or more of these processes are inadequate. If insufficient amounts of outdoor air are not brought into the building, an accumulation of carbon dioxide (a gas produced when people breathe) will occur. High carbon dioxide (CO2) levels do not specifically cause indoor air quality problems although there are some studies that state that high CO2 levels may lead to drowsiness or lethargy. Levels of CO2 are an excellent indicator of ventilation levels and therefore a measure of IAQ within the building space. Studies in the past have shown that 80% of unadapted occupants are satisfied with the level of indoor air quality when the CO2 level does not rise above 1,000 parts per million. At this level, ventilation rates are typically 15 cfm (cubic feet per minute) per person. The National Institute for Occupational Safety and Health says that poor ventilation is the contributing factor for poor IAQ. The proper design, operation and maintenance of the ventilation system are essential in providing indoor air that is free of harmful concentrations of pollutants.

Are there Ventilation Standards?

In 1973, the American Society of Heating, Refrigerating and Air-conditioning Engineers (ASHRAE) published "Standard 62-1973: Ventilation for Acceptable Indoor Air Quality". This standard was the first "to specify minimum ventilation rates and indoor air quality that will be acceptable to human occupants and is intended to minimize the potential for adverse health effects". Since then, this standard has gone through many more revisions. The standard applies to all indoor or enclosed spaces that people may occupy, except where other applicable standards and requirements dictate larger amounts of ventilation than this standard.

This standard applies to all types of facilities including: dry cleaners, hotels, garages, retail stores, dormitories, sports arenas, schools, etc. The specified rate at which outdoor air must be supplied within the building ranges from 15 to 60 cfm per person, dependent upon the activities that occur in the room.

Standard 62 is a voluntary standard which means it only becomes enforceable once a state or locality adopts the standard into its building code. Building codes are design codes not operation codes. Recently some localities have been working to apply existing design codes and standards to building operations through pending legislation, labor agreements and regulations reviews.

How can I make ventilation cost-effective?
Through the use of heat recovery or energy recovery technologies, ventilating a building becomes more cost-effective because you are using energy that already exists to warm up or cool down the air that is being brought in from outside.
What are HRVs - Heat Recovery Ventilators?

Heat recovery ventilators are air-to-air heat exchangers that transfer heat energy (and in some cases, moisture) from one airstream to another through a plate heat exchanger or heat pipe heat exchanger that separates the supply and exhaust airstreams. Plate heat exchangers and heat pipe heat exchangers contain no moving parts and can be located in any relatively clean airstream.

Plate Heat Exchangers

Plate heat exchangers constructed of polypropylene or aluminum media will transfer sensible energy (dry bulb temperature) from one airstream to the other. HM (Heat Moisture) plate heat exchangers are constructed of a permeable membrane that is capable of transferring sensible energy and latent energy (dry bulb temperature and moisture transfer) from one airstream to another.

Most plate heat exchangers consist of a stack of ribbed plates; easy-to-clean surfaces. Heated air flows on one side of each plate, while cooler air flows on the other side of the plate. The warmer air heats the plate and transfers heat to the air on the cooler side. Polypropylene plate heat exchangers are commonly used for corrosive environmental applications, aluminum for meeting NFPA90A regulations and the HM core, with its ability to transfer sensible and latent energy, is designed for all climates.

Heat Pipe Heat Exchangers

Heat pipes consist of a number of finned tubes (capped on each end) that contain a refrigerant that transfers energy from one end to the other, based on temperature difference.

What are ERVs - Energy Recovery Ventilators?
ERVs typically incorporate an energy recovery technology known as an enthalpy wheel. Enthalpy wheels are devices that are designed to transfer both sensible and latent energy from the exhaust airstream over to the supply airstream. The transfer of moisture occurs when the desiccant applied to the wheel adsorbs and desorbs the moisture based on the vapor pressure differential that is created from the different temperature conditions (exhaust and supply). The result is a reduction in ventilation, heating and cooling loads and operating costs by up to 80%.
What does it mean to be ARI Certified?
The Air Conditioning and Refrigeration Institute (ARI) launched a certification program January 15th, 2001 for energy recovery components (plate-to-plate heat exchangers, enthalpy wheels and heat pipes) that are used in ventilation systems. This certification program ensures that all manufacturers rate their energy recovery components at common conditions for summer and winter. This certification process enables users to compare each manufacturer based on the same conditions, which was never the case in the past. In addition, ARI tests the manufacturers' components for conformance to published ratings on a yearly basis, ensuring that published numbers are highly accurate. This testing procedure provides the users with accurate results and ultimately a professional design when in comes to building air quality, operational costs and indoor humidity conformance. Specifying ARI certified components is a necessity for the energy recovery industry because it provides everyone with the peace of mind for accurate performance.
Where can I find more information on the topics listed above?
Regarding Indoor Air Quality Issues: Regarding Ventilation Standards: Regarding ARI Certification: