A healthy indoor environment is critical. These ventilation strategies can improve comfort and save money.

Indoor Air Pollution is Nothing to Sneeze At


Business woman sneezing

Have you ever heard somebody say they're going to get some air? In fact, most people get plenty. On average, people ingest 30 pounds of air a day, compared to four pounds of food and two pounds of water.

People do most of their breathing indoors, and that's what makes good indoor air quality so important. Health issues resulting from indoor air pollution cost billions of dollars each year and reduce productivity.

Make a fresh start by focusing on ventilation system maintenance and design. You'll improve the health and comfort of your facility and help increase your bottom line.

Indoor air quality, health and productivity

Indoor air pollution is caused by the build-up of contaminants coming primarily from inside the building. Common sources of indoor air pollution include biological organisms, building materials and furnishings, cleaning agents, copy machines and pesticides.

These pollutants can contribute to building-related illnesses that have clearly identifiable causes, such as Legionnaire's disease. Poorly maintained ventilation systems can contribute to Sick Building Syndrome, which produces physical symptoms without clearly identifiable causes. Common symptoms include 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 identifies poor ventilation as an important contributing factor in many sick building cases.

Ventilation system problems and solutions

When the ventilation system isn't working correctly, indoor air quality can deteriorate. Increasing the amount of outdoor air is the most commonly used fix, but a number of system design and operational issues can affect your indoor environment.

  • Variable airflow. Designs specifying HVAC system operation at reduced or interrupted flow in response to space conditioning needs may impair contaminant removal. Define minimum ventilation rates by air cleanliness and distribution, as well as temperature and humidity.
  • Vent placement. Air supply vents located near sources of pollution — such as exhaust vents, heavy traffic areas and trash dumpsters — provide a pathway for contaminants. Carefully evaluate the location of all air supply vents.
  • Air distribution. Ensure registers aren't blocked by furniture or equipment and that partitions or other barriers are positioned so they don't restrict airflow. Locate air supply and return air vents at a reasonable distance to ensure balanced air distribution.
  • Scheduling. Ventilation system scheduling is critical to maintaining good indoor air quality and should be based on occupancy levels or operating hours. Demand-controlled ventilation using carbon dioxide or volatile organic compound sensors can optimize indoor air quality and save energy. Consider monitoring outdoor air quality as required by green building codes.

Pay close attention to these issues. It will help you quickly spot potential sources of indoor air pollution and take steps to eliminate them.

Keep it fresh

Optimizing indoor air quality requires ongoing monitoring and a commitment to continuous improvement. Record keeping is also important. Document inspection and maintenance activities, as well as any indoor air quality problems and measures taken to solve them. Stay up-to-date on code changes or revisions to ventilation standards, such as ASHRAE Standard 62.1, Ventilation for Acceptable Indoor Air Quality. Also, follow the recommendations in ASHRAE's Indoor Air Quality Guide - Best Practices for Design, Construction, and Commissioning.

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