Some 80 percent of Australians live in urban areas and spend up to 90 percent of time indoors, so it is particularly important that air quality of a high standard be provided in ofﬁce buildings. HARTLEY HENDERSON reports.
Our heavy use of office buildings presents a significant challenge, as research has shown that indoor air pollution is generally higher than outdoors because air containing pollutants from burning fossil fuels is drawn into buildings and mixed with a range of indoor pollutants, particularly volatile organic compounds (VOCs).
VOCs, which can be released into the indoor air from a range of sources, including synthetic furnishings, paints, carpets and detergents, may potentially seriously affect the health, comfort and productivity of workers. Clearly, this is an area where facility managers can make a major contribution to the wellbeing and productivity of building occupants, which in turn can be reflected in reduced absenteeism and staff turnover, and improved business profitability.
According to Professor Margaret Burchett at the University of Technology Sydney (UTS), more than 900 different VOCs have been identified in office air (often in mixtures of 15 to 20 different substances), and exposure to these pollutants, even at unnoticeable levels, has been linked with headaches, lethargy, sore eyes and respiratory problems.
Burchett has been involved in studies that have shown that the use of suitable indoor plants can significantly reduce concentrations of VOCs.
“Our laboratory studies with 11 indoor plant species, and our field studies in 60 offices, show that potted plants can reliably reduce total VOC loads by 75 percent, with or without air-conditioning, and in light or dark conditions. It was also found that the primary removal agents are the normal potting mix microorganisms in the root zone of the plants,” she says.
“Indoor air quality problems can occur even when HVAC systems are well-designed and maintained. Maximum permitted occupational indoor air concentrations in Australia for VOCs are specified by Safe Work Australia. In office environments, maximum recommended levels are much lower, but air-conditioning systems are rarely designed to remove gaseous pollutants, apart from increasing ventilation rates when carbon dioxide concentrations rise above 1000ppm.
“Our laboratory test chamber studies have indicated that three to 10 times the occupational maximum concentrations of VOCs can be removed by potted plants in about 24 hours. This demonstrates that potted plants can provide an efficient, self-regulating, low-cost, sustainable bioremediation system for indoor air pollution that can effectively complement engineering measures.”
GREEN ON THE INSIDE
Ray Borg, regional director for the Asia Pacific Region at interior landscaping provider Ambius, says there is increasing recognition of the role of potted plants in improving indoor air quality. “There’s a collection of research from around the world which shows clearly that indoor plants have a positive effect on people and therefore can impact the bottom line of a business,” he says. “Research from the US, Netherlands and the UK has shown positive effects in reducing stress and sickness absence, increasing productivity and improving wellbeing. In Australia, the research undertaken by UTS is helping to raise awareness by demonstrating the benefits of indoor plants.
“In past tough economic times, indoor plants were often the first items to go in cost-cutting measures, but now the research shows us that indoor plants can have a direct impact on business performance. The Green Building Council of Australia (GBCA) now awards two points towards Green Star ratings for indoor plant installations that meet certain specifications – clear evidence of the increasing recognition of the role of indoor plants.
“Our laboratory studies… show that potted plants can reliably reduce total VOC loads by 75 percent, with or without air-conditioning, and in light or dark conditions.” PROF. MARGARET BURCHETT
“Indeed, Ambius has helped the GBCA to green-up the interior of its inner-city Sydney office. Indoor plants were selected for their suitability to the office environmental conditions and for their aesthetic qualities, and custom-designed trellises were designed to create a green wall effect.”
HVAC AND INDOOR AIR QUALITY AUDITS
According to Clean Air Technologies (Aust) Canberra branch manager, Greg Ible, HVAC and indoor air quality audits of commercial buildings should be processes that are undertaken on a periodic basis to identify a potential or existing air quality issue.
“There are many examples of why HVAC hygiene assessments and/or indoor air quality assessments are requested, including contamination of the air-conditioning system due to a failed air filtration system, poor maintenance of the HVAC system, and vehicle exhaust fumes entering via an outside air intake,” Ible says.
“There is also a federal requirement. Duty holders under Comcare who have a regular air quality monitoring regime in place are ensuring that building owners, tenants and facilities managers are satisfying the Occupational Health and Safety Code of Practice 2008 (under OH&S Act 1991) in the area of indoor air quality.
“There is a range of filtration products such as synthetic and electrostatically charged media, air filters coated with anti-microbial treatments and activated carbon filters that are available to improve the cleanliness of a building’s air delivery systems and the indoor environment.”
Melbourne-based company Air-Iononics Australia distributes a range of commercial air cleaners, including IQ Air systems from Switzerland. These are suitable for applications such as hospitals, office buildings and the hospitality industry. Managing director Paul Beers says air filtration systems, including stand-alone and in-duct systems, continue to be the leading means of professional air cleaning.
“Many manufacturers have moved away from ionisers and UV (ultraviolet) systems, largely due to the international debate relating to the production of ozone and the overall effectiveness of these systems. At the same time, technological developments have resulted in many air filtration brands now going well beyond the High Efficiency Particle Arrestor (HEPA) international standard, which is now the absolute lowest point for this type of equipment,” Beers explains.
“IQ Air modular stand-alone air purifiers (which are hospital grade) are configured to provide targeted air cleaning and actually improve HVAC performance. In addition, IQ Air has designed a range of in-duct air filter products that are integrated into the central HVAC system and therefore provide an economical means of air purification throughout the entire location.”
Hartley Henderson is a Melbourne-based freelance journalist specialising
in property and construction issues.