Filtering indoor air with plants?

Question

I have a daughter that has bad allergies. To help keep her allergies in check I use an electrical air purifier to keep the air in my house clean and filtered. I heard that houseplants could in effect do the same thing.

If that is true are certain plants better for cleaning the air than others? Also, are there any guidelines for how many plants would be needed for a certain square footage?

Answer 1

There was a NASA study that indicates that house plants can indeed help clean indoor air.

More recently there was a TED talk where the speaker indicated that just three types of plants are needed:

1. Areca Palm (Chrysalidocarpus lutescens)
   • Works well in the day time
   • Great for living areas
   • One needs about 4 shoulder high plants/person
   • Needs to be put outdoors once every 3-4 months
   • The leaves of the plant need to be wiped everyday in Delhi and perhaps once a month in a cleaner city
   • The soil used should be of vermi manure or use hydroponics
2. Mother-in-law’s Tongue (Sansevieria trifasciata)
   • Converts CO2 into O2 at night
   • One requires about 6-8 such waist high plants per person in the bedroom
   • Leaves need to be wiped in the same way as the Areca Palm
   • The soil used should be of vermi manure or use hydroponics
3. Money Plant (Epipremnum aureum)
   • Excellent for removing Formaldehyde and other VOC’s
   • Best grown using hydroponics

Answer 2

Almost any plant will pick up particulates on its leaves (as permaculturists will tell you this is actually one of the functions of a leaf) so some things to think about would be:

Can you spray the plant down periodically? Most of the time, leaves function in part to trap particulates that can then be channeled down to be food for the plant (this comes up with regard to hedge rows and manure control from time to time). Being able to spray down a plant in simulated rainfall is likely to be helpful for a plant to maintain this role. so if you can water it in a way in which the leaves get washed that would be ideal.

This answer is tailored on the assumption that you are looking specifically at pulling particulate allergens from the air. Other areas may prove different.

Answer 3

As a side note to the accepted answer (I don't have enough reputation to comment), most, if not all, of the plants on the NASA list are poisonous to cats and dogs. So if you have animals to worry about as well, choose wisely. Aside from that it is a great list.

Edit: I have found a page saying that a spider plant is good for cleaning the air and is non-toxic to cats.