Even though you may work hard to keep your home clean and fresh, your indoor air is almost guaranteed to be more polluted than the air outside. That's because even those products that we consider clean and safe can contain volatile organic compounds, and the enclosed spaces in which we live trap those compounds in the air we breathe.

This is never a greater concern than during the winter when people spend more time indoors than during any other time of the year. HVAC professionals stay busy throughout the season installing indoor air quality products like electrostatic filters and ultraviolet air purifiers, but there's also a low-tech solution you can start using right away: houseplants.

Invisible Threat

In 1989, NASA completed a study to determine which houseplants were most effective at cleansing volatile organic compounds from the air, with hopes that the answers would provide a simple, natural way to keep the air clean in space stations.

The study focused on some of the most common compounds that cause health risks:

  • Benzene, commonly found in detergent, paint, and plastics, which can cause eye irritation, dizziness and headaches
  • Formaldehyde, commonly found in furniture and paper products, which can cause nose, mouth and throat irritation
  • Trichloroethylene, commonly found in varnishes and adhesives, which can cause headaches, nausea, and vomiting
  • Xylene, commonly found in rubber and leather products, which can cause mouth and throat irritation, headaches and problems with the heart, kidney, and liver
  • Ammonia, commonly found in cleaners and fertilizers, which can cause eye irritation, cough, and sore throat

The Winners

Two common houseplants were determined to be effective at filtering all five compounds: the Peace Lily and the Florist's Chrysanthemum. The chrysanthemum has the added benefit of bright, attractive blooms, but it needs a sunny spot and tends not to rebloom, so it will need to be replaced annually. The Peace Lily, on the other hand, is a hardy plant that loves shady spots and is easy to care for.

Other good choices include the Red-Edged Dracaena, the Variegated Snake Plant, and English Ivy, all of which filter benzene, formaldehyde, trichloroethylene and xylene. Use caution if you choose the snake plant for your home, though -- it's toxic to pets.

If you're concerned about purifying ammonia, consider the Flamingo Lily or Broadleaf Lady Palm, which also filter formaldehyde and xylene. Lilyturf is another option, effective against ammonia, xylene, and trichloroethylene.

Rounding out the finalists that effectively filter at least three volatile compounds are Cornstalk Dracaena, Barberton Daisies and Devil's Ivy.

If you want to go beyond the power of houseplants and boost the air purifying properties of your HVAC system, reach out to your local home comfort experts to learn about the latest high-tech solutions.