Comfort Line - Questions and Answers
Indoor Air Quality by Charles J. Brand This quarter our questions and answers segment discusses indoor air quality.Why indoor air quality?
According to the U.S. Environmental Protection Agency, there is a growing body of scientific evidence indicating that air within homes and other buildings can be more seriously polluted than outdoor air. This is true even in industrialized areas. Since we spend approximately 90% of our time indoors, health risks due to exposure to indoor air pollution are often greater than outdoor air pollution.
What causes indoor air problems?
A major cause of indoor air quality problems is pollution from sources in the home that release particles or gases into the air. An example might be fibers from a carpet. Often there is insufficient ventilation to add fresh air and expel stale air out of the home. In addition, high humidity levels can increase the concentration of pollutants by creating an environment where mold and mildew can flourish.
What are the most effective ways to improve indoor air quality?
There are three primary methods to improve indoor air quality. The first is to eliminate pollutants from the home. The second is through the use of air cleaners, which can be effective at removing particles from the air. However, air cleaners are generally not designed to remove gaseous pollutants. The third method, which is often the easiest to implement, is by improving ventilation. Ventilation adds fresh air to the home and expels stale, musty air.
How does outdoor air enter a home?
Outdoor air enters and leaves a home by infiltration, natural ventilation and mechanical ventilation. The rate at which outdoor air replaces indoor air in a home is described as the air exchange rate.
How can I improve the air exchange rate in my home?
The simplest way would be to open a window on each side of the home. The disadvantage of this approach is that it will increase your heating and cooling costs. A more practical way of increasing ventilation is through the installation of a mechanical ventilation device. Two effective mechanical ventilating devices are Humidex and an air-to-air heat exchanger.
How do Humidex and an air-to-air heat exchanger differ?
Humidex is a relatively simple device that was developed in Canada but is rapidly gaining acceptance in the U.S. market. Humidex is installed in the basement or lowest level of a home. It expels the polluted air from the basement and replaces it with fresh air from the upper levels of the home. An air-to-air heat exchanger is a sophisticated device that directly exchanges outdoor air with air in the home. It is designed to extract heat from the indoor air before it’s expelled outside of the home and is used primarily in commercial buildings.
