Question: What’s the best way to clear the air: filters, cleaners or just open the windows and let outdoor air in?
National Center for Energy Management and Building Technologies says all three
options work, but using air filters is more energy efficient than opening a
Researchers said that when associated energy
costs were considered, studies found that that use of air cleaners could result
in energy savings when compared to the dilution effects of opening
The center also found that various off-the-shelf
induct air filters, ultraviolet and portable air cleaners are generally
effective in removing volatile organic compounds.
to the report, “sorption” technology- as used in typical air filters - “is an
effective strategy for indoor air quality control” in a residential setting.
using activated carbon attached to a pleated filter removed between 70 to 85
percent of six out of eight tested VOCs in the laboratory test. A second
product, a combination of activated carbon and impregnated with alumina,
removed 50 to 60 percent.
Although the tests found that
heavier, denser filters were effective in removing heavier low-volatility
compounds, the denser filters also tend to cause a drop in the air pressure moving
through the filter.
According to officials with the center,
the trade-off of higher filtering capability isn’t worth the loss in air
pressure. On the other hand, activated carbon did not perform well for removing
formaldehyde, and none of the filters were effective for removing
Air cleaners effective, energy efficient, says study
September 1, 2009