Indoor Air Quality (IAQ)

Detailed Overview:  DataPipe’s indoor air quality (IAQ) module may be used standalone or in conjunction with modules for IH sampling or general environmental testing for chemical and physical measures of the environment. If you would like additional information about this module, please contact Knorr Associates directly. An online demonstration can be set up so that you can see this module live on the screen while we discuss how you can utilize it within your organization.

Indoor Air Quality (IAQ), also referred to as Indoor Environmental Quality (IEQ), is an extremely broad topic that has application in many spaces or environments.  Clearly the workspace – a manufacturing site or its associated offices are obvious places where one might think about IAQ.  But other areas include hospitals, office-only buildings, schools, commercial aircraft and private residences.  "Sick Building Syndrome" is a term many people use to convey a wide range of symptoms they believe can be attributed to the building itself. 

For example, the American National Standards Institute has Standard 62.2, “Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings.”  From the Spring/Summer 2004 issue of the ANSI Reporter: 

Are concerns about indoor air quality making it difficult for you to breathe easy in your own home? Guidance to make the air in homes healthier and safer without adding significant costs is provided in a recently published ASHRAE standard. ANSI/ASHRAE Standard 62.2, Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings, is the only nationally recognized indoor air quality standard developed solely for residences. It is intended for use in building codes.

Residential ventilation traditionally was not a major concern because it was felt people were getting enough outdoor air by opening their windows and by air leaking through the building’s walls.

As homes and duct systems are built tighter to save energy, trapping contaminants indoors, concern has risen about indoor air quality, especially now that people spend almost 90 percent of their day indoors — 65 percent of that in their homes. Also, residents are less likely to open windows because of energy costs, security issues, drafts, noise, and dirty air from outside.

Studies from the Environmental Protection Agency on human exposure to air pollutants show that indoor levels of pollutants may be two to five times, sometimes more than 100 times, higher than outdoor levels. People in buildings frequently report discomfort and building-related health symptoms, and sometimes develop building-related illnesses.

Some requirements in the standard that represent significant changes from standard practice include use of sound rated fans (because disruptively noisy fans are now commonly used) as well as use of mechanical, whole-house ventilation, which only a small fraction of houses currently use.

The purpose of the standard is to provide the necessary building service of providing minimum acceptable indoor air quality, according to Sherman. A standard such as 62.2 benefits HVAC&R professionals and allied industries because it defines a demonstrable set of criteria for acceptability, which can be used to provide known value to the owner.

ASHRAE also is continuing its efforts to improve ventilation in commercial and institutional buildings. The society expects to publish Standard 62-2004, Ventilation for Acceptable Indoor Air Quality as well. The standard, which sets minimum ventilation rates and other requirements for commercial and institutional buildings, will contain several new addenda.

In the area of aircraft cabin air quality, ASHRAE continues work on its proposed standard, 161P, Air Quality Within Commercial Aircraft. Standards are needed to ensure that cabin air is safe for crewmembers and passengers, minimizes the potential for adverse health effects and is comfortable to occupants. ASHRAE hopes to approve a first public review draft later this year.

Instrumentation for monitoring IAQ depends, of course, on what one is sampling for.  Dedicated IAQ monitors exist for sampling several common components over long times.  Individual monitoring devices familiar to Industrial Hygienists can be used for more specific contaminants.  Gasses (O2, CO2, etc.), dust, molds, moisture content (humidity) and other components of our breathing environment are candidates.

An ASTM paper, “Overview of Indoor Air Quality Sampling and Analysis” by H. Levin (STP957-EB) is summarized this way: 

During recent years, sampling and analysis of atmospheres for indoor air quality in non-industrial environments have increased substantially. Enhanced understanding of indoor air pollution has resulted. Increased recognition of the complexity of indoor environments has led to even more sampling and analysis. Many methods used for indoor air are similar to those employed in workplace and ambient air. However, sampling conditions are often difficult; a very large number of pollutants are usually present, although at low concentrations; some pollutants of concern are at extremely low concentrations; and complex mixtures can create interferences.

Instrumentation requirements differ from those of ambient or industrial applications. Passive monitors and other unobtrusive monitoring equipment have received much attention. Sampling and analysis for biological aerosols will probably increase during the next few years. Other environmental factors are often critical and must also be characterized or measured. Social science and health investigatory methods are often employed in conjunction with air monitoring. Further research and development are needed for standardization in several areas including the sampling and analysis of organic compounds at very low concentrations, the general acceptance of standardized monitoring protocols, and guidelines for the consistent reporting and interpretation of data.

NIOSH and OSHA investigate IAQ issues.  Regarding the incidence of cases, OSHA has found:

1. The range of investigations of indoor air quality problems encompasses complaints from one or two employees to episodes where entire facilities are shut down and evacuated until the events are investigated and problems corrected. (OSHA)

2. Complaints are often of a subjective, nonspecific nature and are associated with periods of occupancy. These symptoms often disappear when the employee leaves the workplace. They include headache, dizziness, nausea, tiredness, lack of concentration, and eye, nose, and throat irritation. (OSHA)

3. In approximately 500 indoor air quality investigations in the last decade, the National Institute for Occupational Safety and Health (NIOSH) found that the primary sources of indoor air quality problems are: