Tips for Improving Indoor Air Quality

What causes air problems?

Indoor air quality is compromised when inadequate ventilation prevents outdoor air from diluting emissions from indoor sources. Indoor contaminants can come from sources such as print toner, cleaners, smoking and debris in crawl spaces.

Outdoor contaminants such as industrial pollutants and fungal spores; nearby emissions (dumpsters, traffic exhaust); and soil gas (pesticides, landfill contaminants) can all seep indoors, which takes a toll on the building’s air quality as well.

Common contaminants include:

Radon: According to the former U.S. Surgeon General, more than 20,000 Americans die of radon-related lung cancer every year. “It is one of the most important air pollution problems indoors and outdoors we face,” says National Association of Clean Air Agencies (NACAA) executive director Bill Becker, who recommends radon testing in residences.

CO2: The 2009 LEED EB report recommends a CO2 sensor or sampling location for each densely occupied space and comparing it with outdoor CO2 concentrations. (Sampling location must be between three and six feet above the floor.)

Sick Building Syndrome (SBS): A health condition that leads to headaches, nausea or lingering infections, SBS is caused by exposure to contaminants as a result of poor ventilation.

Becker says that close to 40,000 people in this country die prematurely each year from exposure to air pollution from particulate matter, generated by sources such as coal fire power plants and wood stoves.

While this is a serious problem, many indoor air issues can be resolved simply by running a test, upgrading filters or opening a window, and many problems can be prevented with proper maintenance.

Revisit your preventative maintenance routine

“The first thing you should do is have a maintenance scheduling program to address the maintenance intervals of your units,” says Brian Pine, director of operations and maintenance at State University of New York at New Paltz, who has worked as a facilities manager in hospital, jail, and university settings, Thorough documentation will not only resolve future problems, but it can deflect unrelated complaints.

Efficiency-improving methods

1. UV light: The latest edition of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) handbook includes a chapter on ultraviolet lamps and their use in purifying ducted air.

Ultraviolet light can be installed in the air unit to kill microbial particles. Systems based on UV have been designed to target problematic contaminants while leaving harmless dust particles. Plus, energy savings range from 15 percent to 33 percent of the energy cost of an equivalent filter system. 

2. Heat Wheels: Heat or enthalpy wheels are rotary air-to-air heat exchangers that recover the energy expended in air conditioning. They can reduce the ventilation air-conditioning load by absorbing and transferring vapor from one air stream to the other. Heat wheels are compact and highly effective in transferring heat, and they have a relatively low air pressure drop, so freeze protection is not an issue. However, disadvantages include installation costs, possible cross-contamination of air streams and an increase in service needs in cold climates.

3. Filters and purifiers: Filters can be integrated into some existing HVAC systems with a bypass configuration, where a portion of the airflow is segregated and passed through a separate filter. A bypass duct removes air from the regular airflow and cleans it through the filter, before returning the cleansed air to the regular circuit.

As an alternative, place a portable air purifier separate from the main system in the affected room or area.

4. Air monitoring instruments: Equipment such as air pumps, particle counters, aerosol monitors and fit testers can be used to measure particulates, microbial contaminants, and chemicals that affect the environment in buildings. In addition, night ventilation pre-cooling cleanses the air at night by circulating outdoor air into the space during cooler hours.