Plants improve air quality and cut energy consumption, reports international scientific conference


ISSN: 0263-2772

Article publication date: 1 March 2000




(2000), "Plants improve air quality and cut energy consumption, reports international scientific conference", Facilities, Vol. 18 No. 3/4.



Emerald Group Publishing Limited

Copyright © 2000, MCB UP Limited

Plants improve air quality and cut energy consumption, reports international scientific conference

Plants improve air quality and cut energy consumption, reports international scientific conference

Keywords: Working conditions, Indoor pollution, Sick building syndrome

Earlier this month, over 1,000 scientists and academics gathered in Edinburgh for the 8th International Indoor Air Conference. With escalating concern about the quality of the air that we breathe in the workplace and on-going concern about sick building syndrome, there are more scientific papers strengthening the case for interior landscaping to improve health and comfort in the workplace.

Three key papers addressed using plants to absorb toxins from the air, believed to be contributory causes of sick building syndrome (SBS), reducing the occurrence of minor ailments often linked to SBS and using plants to reduce energy consumption.

New results from down under

Dr Ronald Wood from the University of Technology in Sydney presented findings based on the well established fact that plants absorb toxic compounds from the environment and detoxify them.

Concentrating on three internationally used indoor houseplants, the Kentia palm, Dracaena Janet Craig and the Peace Lily, he showed that they can remove between two and five times the maximum recommended occupational exposure levels of specified VOCs, namely n-hexene and benzene.

A very new factor of Dr Wood's research showed that the plants' capacity to remove these toxins, commonly emitted by cigarette smoke, photocopiers, wall and floor coverings, ceiling tiles and paint, is increased by exposure to the chemicals.

Research was carried out over periods of approximately 30 days and the rates at which the plants continued to remove the toxins from the surrounding air were not affected by lighting conditions or growing medium, i.e. soil or hydroponics.

Plants delivering health improvements

Professor Tore Fjeld from the Agricultural University of Norway presented findings from two research projects looking at the effects of houseplants on minor ailments in the workplace known to be affected by poor air quality.

Her findings produced good results both in an office setting and in the X-ray department of a hospital, where the reduction in overall symptoms such as headaches, coughing and fatigue, was 23 per cent and 25 per cent respectively.

Fjeld found that the reasons for this could be attributed to better air quality, increased humidity levels, a general feeling of well-being, an imitation of the more "natural" surroundings enjoyed by our ancestors, and lower stress levels due to the presence of plants.

"The occupants felt better around plants", commented Fjeld, "but the reason could be attributed to several factors. According to earlier research carried out by Roger Urlich with hospital patients, showing that plants reduce stress levels, these factors are psychological as well as physiological." Fjeld continued, "Like Urlich, Virginia Lohr also found that plants help to reduce stress amongst computer operators."

Cutting costs and saving energy

Peter Costa, winner of the 1994 Heating and Ventilation Award, who is now working in his native Australia, demonstrated the value of using plants for energy conservation.

Costa finds that using plants in and on buildings for cooling purposes can reduce the necessary required size of traditional air-conditioning systems, thereby reducing energy consumption.

Costa has also found that houseplants can be used to raise the humidity levels without an energy penalty. In this case, they will need either daylight or artificial lighting to ensure photosynthesis takes place.

His research also finds that houseplants can also be used to absorb noise by diffraction and reflection of sound.

Costa does not see his solutions replacing mainstream building engineering services but working in harmony with them. Two examples where this is in practice can be found at the Horniman Museum's Centre for Understanding the Environment (CUE) in South East London and at Watford New Hope Trust's "Day Centre" in North London.

Costa's philosophy is shared by Fjeld and Wood. Houseplants can work with traditional methods to improve air quality and reduce discomfort for occupants. At the same time, there are obvious psychological benefits.

Houseplants not only add an aesthetic quality but have the added value of reducing the discomfort of occupants and can be a good source of saving energy. Not only do these dovetail nicely with the growing trend towards the use of sustainable materials in our buildings, but they also add to the health and well-being of the occupants.

For further information, please contact Colleen Smith at Plants for People, Jervis Communications, 6-8 Catherine Street, Salisbury, Wiltshire SP1 2DA. Tel: +44 (0) 1722 335858; E-mail:; Website:

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