While some will try their green thumb around the house with hopes of converting indoor dirty air to clean air, researchers have some bad news. Opening a window or a door is far more effective at introducing clean air indoors than a houseplant is.

Drexel University researchers, who just published a study in the Journal of Exposure Science and Environmental Epidemiology, examined over 30 years of previous findings, only to find little evidence that plants do anything to filter contaminants from indoor air.




A 1989 NASA experiment showed  that plants could remove certain compounds from the air, fueling the interest on Earth with growing as many houseplants indoors to freshen up the air. However, as was the case with other studies like it, the experiment took place in a sealed environment that doesn’t necessarily equate to real-life conditions here on Earth.

Decorating your home like a forest could be beneficial though. Study scientists say that to purify your air with houseplants, you’d need anywhere from 10 to 100 plants per square meter –basically an impossible volume to have in a typical residential dwelling. And even at 10-100 plants per square meter, it still would only be as effective as leaving a window open to bring in a fresh breeze.