How Many Plants does it take to clean the air?

This is the big question and one that is difficult to calculate because there are so many variables including:

•    Size of the room
•    Number of windows and doors open or open from time to time
•    Number of people occupying the room
•    Number and size of plants
•    Humidity levels
•    Whether or not ventilation is natural or by air conditioning

Andrew Smith from John Moore’s University in Liverpool’s research in Scotland in an open plan office found that 1 plant per 3 people worked.

At this level the plants made air significantly cleaner including removing carbon dioxide (by approximately 50%) and carbon monoxide.

Dr Ronald Wood, working out of the University of Technology in Sydney, did some research to attempt to calculate a guideline using 34 real offices around the city and suburbs of Sydney.  The guidelines for how many plants needed to clean the air are:

•    In a 10 - 12²m room with a height of 3 – 4m
•    Occupied by one person
•    3 floor standing or specimen plants
•    Or 6 table top plants
•    Will reduce VOCs in the air consistently by 50 – 70%

In research in Norwegian schools VOCs were reduced by 35% in planted classrooms.

Sources:
www.plantsforpeople.org
www.plantscleanair.com