Biofilter FAQs
Q. Do potted plants provide the same benefit as BioFilters?
A. No - while potted plants do provide numerous benefits, they do not remove indoor air pollutants like BioFilters because it is not the plants themselves, but rather the microbes inhabiting the rhizosphere surrounding the roots of the plants that do the work. The method of planting plants a Naturaire® biofilter system increases microbial populations over that found in bare soil, and the mechanical design of the system brings indoor air in contact with these microbes in order to achieve biofiltration and phyto-remediation. Also, the plants species affects the composition of its associated microbial population, and therefore careful selection of plants species promotes desirable VOC-degraders. Many plants produce antibiotic compounds that may actually inhibit biological activity. [back to top]
Q. Does the biofilter create economic benefit?
A. Estimates have placed the annual impact of poor indoor air quality on worker productivity in the USA to be between 20 and 200 billion dollars. Twenty percent of all absenteeism is directly related to poor indoor air quality. Sick building syndrome alone has been quoted as costing the American economy between $15 and $40 billion dollars per year. The biofilter will reduce indoor VOCs and other compounds that are linked to poor air quality and sick building syndrome. [back to top]
Q. Are there other benefits even if hard to quantify?
A. The biofilter will have the general impact of greening the indoor space. Greening the indoor space has a substantial impact on the psychological well-being of the building occupants. Although difficult to quantify, several studies indicate that plants reduce the stress levels of occupants. Professor Lohr at Washington State University demonstrated that the inclusion of plants in computer classrooms reduced the stress levels and led to a 12% increase in the productivity of the students. Professor Fjeld demonstrated that the inclusion of green plants in a Radiology Unit in Oslo, Norway led to a measurable improvement in the work environment which manifested itself as a 5 to 15% reduction in absenteeism. In another two year study at an Oslo office building, Professor Fjeld found a 20% reduction in fatigue levels and a 30% reduction in occurrence of headaches after the greening of the indoor space. [back to top]
Q. Why filter indoor air beyond whatever filtration my HVAC provides?
A. The indoor environment is a complex soup of over two hundred different chemicals. These compounds arise from the off-gassing from the furniture, building materials (fabrics, plywood, paints and rugs), and the activities within the space. Many of these chemicals (commonly referred to as volatile organic compounds or 'VOCs') are known to cause cancer. All will greatly reduce the well-being of the occupants if allowed to accumulate unchecked. The quality of the indoor environment has been identified by the EPA as one of the five top health issues currently being faced. [back to top]
Q. What pollutants will a biofilter remove?
A. The indoor environment is a complex soup of over two hundred different chemicals. These compounds arise from the off-gassing from the furniture, building materials (fabrics, plywood, paints and rugs), and the activities within the space. Many of these chemicals (commonly referred to as volatile organic compounds or ‘VOCs’) are known to cause cancer. All will greatly reduce the well-being of the occupants if allowed to accumulate unchecked. The quality of the indoor environment has been identified by the EPA as one of the five top health issues currently being faced. [back to top]
Q. What about mold or pollen?
A. Similar to VOCs , biofilters sequester mold and virusesfrom the air. Removal of pollen is similar to removing any airborne particulate. The biofilter is moderately effective in this regard, but the standard air filters within the HVAC system is probably more effective for airborne particulate. [back to top]
Q. Can BioFilter earn LEED™ credits?
A. Biofilters have earned LEED™ innovation credits on a number of projects in which they have been installed. ASHRAE is just beginning to consider the potential benefits of biofilters. When credit is recognized for the air quality improvements delivered by Nedlaw Living Wall biofilters, we expect additional credit toward LEED points related to air quality and energy reductions to be likely. [back to top]
Q. Does the biofilter consume a lot of energy?
A. Traditionally, the build-up of VOCs is avoided through ventilation. This is achieved with energy recovery ventilation systems (ERVs) that introduce new 'fresh' outside air into the building to dilute the accumulating indoor contaminants. The conditioning of this additional flow of air can be very expense. It must be heated or cooled (depending on the season) prior to distribution in the building. The cost of operating the biofilter is more than offset by the energy savings of reduced air exchanges to the outdoors. Further, ventilation does not solve the problem of the pollutants; instead it simply releases the pollutants to the outdoor where they become "someone else's problem". [back to top]
Q. Can the system be retrofitted into an existing HVAC system?
A. Yes, we can integrate the biofilter into existing HVAC systems. Coordination with mechanical engineers is required to maintain appropriate balancing of air flows within the existing infrastructure. The biofilter can also be installed as retrofit with its own ductwork to distribute filtered air throughout a building without direct integration to existing systems. And the simplest retrofit system will discharge filtered air out the top of the biofilter to diffuse naturally in the room without any ductwork at all. [back to top]
Q. Does the wall require direct Sunlight?
A. No, but direct sunlight is preferred. The plants are growing hydroponically with air being drawn across their root mass. The plants compensate for this stressful environment by seeking plentiful light. At a minimum, the wall requires 12 hours of light. We prefer natural light, but if not provided through skylights and windows, supplemental light can be provided with appropriate fixtures and scheduled routines for flooding the plants regularly. [back to top]
Q. Does the system provide for cooling or humidification?
A. Not currently, but this appears potentially feasible. The plants are very tolerant of wide fluctuations in water temperature. Thus, if the water is chilled below the dew point in summer use, humidity in the air will condense when passing through the wall enabling the wall to provide dehumidification when in cooling mode. The reverse is possible in the heating mode. It is conceivable that the biofilter could provide either humidification or dehumidification as needed. [back to top]
Q. Does the system generate any Noise?
A. Little to none, depending on how it is configured. The airflow through the system is very quiet. The water circulation pump may emit some audible sounds depending on how it is configured (submerged versus in-line). [back to top]
Q. How big a system do I need?
A. One square foot of biofilter will treat 100 square feet of floor space, given typical pollution loads generated in most residential and office conditions. This will generate an appropriate ventilation rate and give the desired improvement to the indoor environment. considering that standard ventilation rates range from 2 to 15 air changes per hour, an indoor air biofilter has to handle large air volumes. [back to top]
Q. Who is Air Quality Solutions?
A. The Controlled Environment Systems Research Facility of the Department of Environmental Biology at the University of Guelph is an essential part of Canada's contributions to plant research and development for space and closed environment related activities. Since 1994, the research team through the Center for Earth and Space Technologies (CRESTech) have gained world recognition for the use of biological systems to improve indoor air quality. In 2001, Dr. Alan Darlington received the Martin Walmsley Fellowship sponsored by the Ontario Centres of Excellence. This allowed Dr. Darlington, along with other researchers on the team to spin-off Air Quality Solutions Ltd. a technology company that markets the Naturaire® System . [back to top]
Q. What is Naturaire®?
A. Naturaire® is the registered trademark for Air Quality Solution's biofilter product line. It is an interior plantscape that effectively removes contaminants and improves the living environment. [back to top]
|
