There’s something about house plants that makes a place homier. Bringing green into your home feels comforting, especially in winter months when the plants outside are often dormant, bare or brown. Plus, we know that plants breathe in carbon dioxide and breathe out oxygen. This is at the core of the symbiotic relationship between animals and plants. But even good indoor plants do even more than we realize.
In addition to providing air for us to breathe, indoor plants clean the air as they do so. We may not think about it but indoor air pollution is a real thing.
Airborne particles can contain harmful chemicals from cooking, cleaning, environmental heating and cooling, mold and pollen, tobacco smoke, building materials (e.g., asbestos), paints and solvents, machinery, radon, office products (think printer toner and whiteboard markers), and many other potential sources. In fact, indoor air can be up to five times more polluted than outdoor air. (1)
As plants breathe, they filter the air (biofiltration). This is good news for animals (humans included), as many of the pollutants found indoors are cleansed by houseplants. (2)
Watch this short video that shows how it’s done:
If that’s not enough, plants also help cool your home.
That’s right: plants draw moisture from the soil in which they’re planted through the roots. In a process called transpiration, moisture is drawn up into the stems and leaves. Like human perspiration, some of this moisture is released to the underside of the leaves and evaporates into the air. You may not see the water as you would your sweat after a workout but to give you a sense of scale: a large oak tree can transpire 40,000 gallons of water a year! (3) Like human perspiration, the evaporation process cools the leaves and surrounding air. Water from moist soil also evaporates into the surrounding air, multiplying this effect.
It’s been generally found that good indoor plants with high transpiration rates are also the best air cleaners, as air is pulled down into the plant to the roots as the water evaporates. (4) As summer approaches in the Northern Hemisphere, we start to think of long warm days—sometimes too warm for comfort. A total win-win way of naturally cooling (and purifying) your home’s air is by adding some key houseplants whose transpiration rates will help to keep you cool as well.
6 Good Indoor Plants to Naturally Cool Your Home
If you don’t have these yet, you should!
1. Aloe Vera
This succulent is hardy and remarkably useful. Always great to have on hand for burns and rashes or as a moisturizer, aloe is highly medicinal for a variety of ills. When it comes to cleaning the air, aloe is among the most efficient houseplants for removing formaldehyde, long-term exposure to which can cause skin conditions, respiratory illness, and cancer. (5, 6) Because the aloe leaves retain a high water content, its temperature remains low. (7) Find suggestions for growing aloe at home here.
2. Areca Palm Tree
The areca palm is a popular houseplant because it is so pretty. It has large leaves and is an exceptional air purifier. What’s more, the areca palm has been dubbed “the most efficient air humidifier”. With the transpiration rate of a quart a day for a healthy 5-foot tree, that’s a lot of cooling going on. (8)
This type of plant likes it shady and moist because it grows from a spore rather than a seed. There are around 9000 types of ferns, though the Boston fern is specifically known for its ability to clean the surrounding air of volatile organic compounds (VOC), including formaldehyde and benzene. Keeping soil and fronds moist will maintain a healthy fern, in turn keeping the air clean and cool. (9, 10) Place ferns on tall furniture or in hanging baskets for optimal growth.
4. Ficus Tree
Also known as a “weeping fig”, the ficus is a highly decorative plant. Its ability to decontaminate the surrounding air is nothing short of amazing. One study found ficus leaves to absorb heavy metal particles like a sponge does water. (11) Another found ficus to be at the top of the list for removing benzene. (12) Transpiration is higher during the day than at night, meaning this plant will keep you cool when you need it most. (13)
A ficus will grow well under fluorescent lights and is adept at absorbing sound, making it a good option for an office environment. (14, 15) To really spoil your plant, keep it in a bright room near a window and watch its leaves multiply before your eyes!
5. Golden Pothos
This is an easy-to-grow plant with large deep green leaves that grow on a vine. Golden pothos is highly effective at removing indoor pollutants benzene, formaldehyde, trichloroethylene, and ozone. (16) Pothos grow well in soil and in water-filled vases, but they should be kept away from household pets since the plant is highly toxic.
6. Snake Plant
Some may know this as “mother-in-law’s tongue”. This plant (along with golden pothos and spider plant) was tested for effectiveness in reducing indoor ozone, a common pollutant and oxidant. All three were effective in steadily reducing ozone levels. (17)
The snake plant is supremely easy to grow, requires little attention, and will get quite large if it’s not over-watered.
Making use of plant transpiration for indoor comfort is an easy alternative to air conditioning. Plus, they improve the larger issues of global warming and air toxicity indoors and out. Increased levels of atmospheric carbon dioxide reduce transpiration of land plants, so the more plants you keep, the better they will be at cooling your home. (18)
Most of all, fostering the growth of good indoor plants is beneficial for your home and crucial for the planet, so plant away!