The Benefits of Air Quality Sensors in Building Management - Eric Germain

Could air contaminants affect our health?

Good air quality in buildings is vital for people who spend much of the day indoors. We spend an average of 90 % of our time indoors, more than 20 hours in enclosed spaces. We breathe in almost 400 million litres of air in a lifetime to provide sufficient oxygen to stay alive. Indoor air quality does affect our health and therefore, badly managed air quality can have economic and legal implications.

• Pollutants can cause or contribute to short and long-term health problems, including asthma, respiratory tract infections and allergic reactions etc.

• Indoor air pollutants can cause discomfort, increase absenteeism and reduce productivity.

• Poor indoor air quality strains relationships among employees, family members, teachers and students.

• Indoor air quality problems can result in litigation.

What can contaminate the air we breathe?

There are many sources of indoor air pollution in buildings. Occupants of a building are the main source of carbon dioxide and volatile organic compounds (VOCs) are emitted as gases from certain solids or liquids. Carbon dioxide is exhaled as a byproduct of living processes. People in the office environment exhale carbon dioxide at a rate of about 0.3 l/min when performing light office duties. VOCs include a variety of chemicals (for example formaldehyde), some of which may have short and long-term adverse health effects. Concentrations of many VOCs are consistently higher indoors (up to ten times higher) than outdoors. VOCs are emitted by a wide array of products numbering in the thousands. Examples include paints and lacquers, paint strippers, cleaning supplies, pesticides, building materials and furnishings, office equipment such as copiers and printers, adhesives and marker pens.

Carbon dioxide is not generally found at hazardous levels in an indoor environment. It is, however, often measured when trying to determine the indoor air quality of a building. It is a good surrogate measure of how well the ventilation system is working in relation to the number of occupants. If the levels of carbon dioxide are high, it is assumed that there may not be adequate ventilation into the area and this in turn may allow for the build-up of other indoor pollutants. Inadequate ventilation can definitely increase indoor pollutant levels by not bringing in enough outdoor air to dilute emissions from indoor sources and by not transferring indoor air pollutants out of the building.