NRC’s indoor air strategies and solutions

In Canada, much of what we do in a day takes place indoors — at home, at the office, inside schools, theatres, shopping malls, restaurants and other enclosed spaces. Good indoor air quality (IAQ), besides an appropriate lighting and acoustical environment, is important to the health and well-being of Canadians. Poor indoor air quality may cause sickness like asthma, allergies and cancer, and discomfort leading to absenteeism and loss of productivity. For example, 3000 Canadians lose their lives per year due to elevated radon concentrations in their homes, according to Health Canada.

In most buildings, the quality of the air we breathe depends on mechanical systems that are designed to ventilate and dilute pollutants, and also on the chemical emissions from the building materials and consumer products being used in the building. Providing technical and evaluated solutions and their effective usage are the keys to efficiently improve IAQ.

NRC’s role within the Clean Air Regulatory Agenda (CARA)

NRC has engaged in an initiative called Indoor Air Strategies and Solutions under the Canadian Government’s broader Clean Air Regulatory Agenda. NRC’s part of the initiative aims at reducing adverse health effects due to poor indoor air by increasing the availability and uptake of new and evaluated products and technological solutions that improve the IAQ. The created information will be provided to the Canadian industry, government decision makers and other stakeholders.

NRC’s role is to foster an innovative knowledge-based domestic economy through research and development, technology and commercialization support to industry, which will also open new opportunities for Canadian companies through increased competitiveness. The knowledge gaps NRC is addressing within this initiative were identified after consultation with stakeholders and collaborators.

The Government of Canada is looking for input from Canadians on the draft second cycle of the Federal Sustainable Development Strategy (FSDS), covering the period 2013 to 2016. Canadians are encouraged to submit comments before June 14, 2013 on the advancement of federal sustainable development initiatives by visiting Environment Canada’s website.

A multi-faceted approach to improve IAQ

Within the Federal Sustainable Development Strategy (2013-2016), NRC will focus on reducing pollutants in Canadian homes, either at the source or through secondary approaches like ventilation and air purification. Indoor air quality design tools and emission databases for building and consumer products will be enhanced, air purification solutions and technologies evaluated. The IAQ information is being disseminated to building operators, industry, government partners, decision makers, home owners and consumers. NRC’s activity will pave the way for better IAQ through increased knowledge, more reliable and effective best practices and technical solutions.

NRC has engaged in multi-pronged activities to improve IAQ through:

• Evaluating indoor air systems through field studies
• Managing harmful emissions at the source
• Evaluating innovative indoor air quality solutions
• Dissemination of knowledge and best practices through the Canadian Committee on Indoor Air Quality and Buildings
• Evaluating radon mitigation strategies
• Minimizing the transport of pollutants from attached garages into homes
• Helping homeowners chose and maintain indoor air devices

Evaluating indoor air systems through field studies

To maintain and improve the health of Canadians, NRC is developing strategies and evaluating technologies to improve indoor air quality in homes by reducing the exposure to harmful contaminants. Field intervention studies are the most powerful means to validate and quantify the positive impacts of strategies and technical solutions to improve the indoor air quality. As field studies mostly include the influence of occupants, they allow researchers to better demonstrate the benefits under real-life conditions.

Field study on IAQ and respiratory health

Recently NRC and its collaborators completed a field study investigating the impact of residential ventilation rates on indoor air quality and the respiratory health of asthmatic children. This three-year study included 83 homes with asthmatic children in Québec City. The Institut national de santé publique du Québec and the Université Laval, two of the main collaborators, studied the health of the asthmatic children throughout the project, while NRC assessed the impact on the air quality caused by the intervention.

The intervention was the introduction or adaptation of commercially available heat or energy recovery ventilators. Researchers looked into the positive effects of the increased ventilation on the indoor air quality and the respiratory health of the asthmatic children. Before the intervention, most of the homes were under-ventilated and a large number of them had formaldehyde concentrations exceeding Canada’s guide¬line.

Results

The study showed that heat or energy recovery ventilators are indeed effective and reliable at increasing ventilation to the desired rate, which significantly reduced the concentration of a number of indoor air contaminants such as carbon dioxide, formaldehyde and mould spores. In addition, energy recovery ventilators have the added benefit of being effective at preventing excessive dryness indoors during winter.

The information obtained from this study is being shared with homeowners, designers, contractors and regulators and can be used to help meeting the ventilation requirements in the applicable building codes, as well as potentially improving comfort by reducing excessive dryness in winter.

For this project, NRC increased the capacity of its analytical and mycological laboratories, and developed a suite of adaptable equipment for conducting field studies. Now NRC can analyze a broad spectrum of indoor parameters, from volatile organic compounds in air, to semi-volatile organic compounds, mould and bacterial bio-markers in dust. NRC also established knowledge and methods to characterize the ventilation in more detail. The increased capacity allows NRC to offer technical support to external clients to improve indoor air quality, ventilation and related systems and equipment.

New projects

NRC and Health Canada are conducting an intervention field study to reduce the transport of airborne contaminants from attached garages into the living spaces of residential houses. Health Canada and NRC’s field teams are testing several mitigation strategies, including improved sealing of the garage-house interface and introducing a garage exhaust fan, which are expected to prevent or at least reduce the transport of contaminants from the garage into the house. The objective of this study is to establish best practices and cost-effective and energy-efficient technological solutions to improve the air quality in Canadian homes. Results will be available by the end of 2013.

In 2014-2015, NRC along with several stakeholders will conduct an intervention study in childcare centers. This study will demonstrate the effectiveness of a technological solution aimed at improving indoor air quality for young children, a vulnerable part of the Canadian population.

The information obtained through field studies, especially those involving interventions, produce reliable, credible and useful data, which is valuable to stakeholders, standard organizations, builders, contractors as well as committees assessing regulatory requests. NRC reports availability of these data through its flagship magazine, Construction Innovation

Managing harmful emissions at the source

Indoor pollutants such as volatile organic compounds (VOCs) and formaldehyde can adversely affect indoor air quality. The main sources of chemical emissions in living spaces are building materials, furniture, electronic equipment and consumer products, so limiting emissions at the source is the most effective and energy-efficient way to reduce indoor chemical exposures. This can be achieved by identifying and selecting low-emitting products and improving products through collaboration with manufacturers.

This activity focuses on three aspects of source control

1. Identify key contaminants that can adversely affect health and are associated with Canadian building practices and building operations. This activity is performed in close collaboration with Health Canada and supports the government’s Chemicals Management Plan.
2. Identify key emitters by developing specific testing chambers for capturing a broad range of volatile and semi-volatile organic compounds, as well as by establishing and validating analytical methods that detect harmful emissions. With this broadened capacity of chamber testing and sophisticated analysis, data bases of emission results will be developed. This activity is being performed in collaboration with Health Canada and other collaborators.
3. Develop an advanced indoor air quality prediction tool that can forecast indoor concentrations of contaminants. Users will input information such as the type and usage of a product within a building, the surface area and their applicable ventilation rate to predict how much and which emissions to expect. This indoor air quality prediction tool will help architects, builders, contractors, retrofitters, building operators and homeowners to achieve the desired indoor air quality.

Results

Efforts on this project are ongoing and by mid-2013, NRC will have

• Compiled with collaborator Health Canada a list of 120 compounds, which are emitted from building materials in relevant amounts and might have a negative impact on indoor air quality
• Developed analytical methods to measure contaminants that are usually not measured, including
  • very volatile compounds causing cancer and/or irritation such as acrolein, ethylene oxide and propylene oxide
  • less volatile organic compounds such as phthalates and flame retardants
• Developed several chamber test methods including a fast screening method for semi-volatile organic compounds like naphthalene and phthalates, and a glass chamber method for contaminants from foam insulation materials.
• Established a number of data bases of VOCs and contaminants emitted from building materials, consumer products and do-it-yourself consumer products (for example construction and hobby glues, caulking, and insulating foam sealants).

Next steps

Once the knowledge has been gathered, a unique IAQ prediction tool will be developed in 2013 to enable

• Building managers to maintain or improve indoor air quality by selecting the most efficient control measures such as source control, ventilation and air cleaning
• Architects to design buildings with good indoor air by selecting low-emission materials and appropriate ventilation rates for pre- and post-occupancy
• Consumers to identify low- and high-emission products sources to improve their personal environment, as well as address their concerns and susceptibilities.

Studies will continue to identify and measure evaporative emission sources (for example contaminants from a garage to a home. Until 2016, the current NRC Indoor Air Quality Simulation Tool (IA-QUEST) will be continuously updated with new data acquired. Other functionalities such as simulation of the effects of ventilation, air cleaning devices and pollutant transport from e.g. attached spaces (e.g. garages) into living spaces will be also added to the tool.

Evaluating innovative indoor air quality solutions

Contaminated indoor or supply air can potentially cause adverse health effects, which can make it necessary to purify the indoor air. A number of solutions are available on the market with different capabilities and claims regarding the removal of airborne contaminants. To provide more clarity and support industry innovation, NRC’s aims at establishing useful protocols for the evaluation of the impact of those systems on the indoor air quality (IAQ). These protocols will help the industry assess and develop products that are highly acceptable in the market place, and to support stakeholders in the uptake of appropriate technologies.

As a first step, a review of current existing standards and protocols for all IAQ solutions and technologies was conducted. Based on the identified gaps and limitations, as well as the needs of consumers and industry, six IAQ solutions were identified for protocol development. NRC has successfully established protocols for portable room air cleaners, heat and energy recovery ventilators, and the cleaning of air ducts by professional services. NRC will focus in the next three years on in-duct air filtration systems, passive panel systems and the long-term performance of portable room air cleaners.

Portable air cleaners (PAC)

PACs are promoted as effective devices to remove particles and sometimes gaseous pollutants from the indoor residential environment. Although different types of PACs are already available in the market place, detailed guidance for manufacturers to improve, and for consumers to appropriately select them according to their needs does not exist. Existing evaluation protocols are based only on the removal of certain particles (Arizona road dust, tobacco smoke and some pollens), sound generated from these devices and energy efficiency. NRC’s protocol from 2011 allows a more meaningful evaluation, as it encompasses

• the evaluation of potential by-products and VOCs generated by the device,
• the effectiveness to remove nano and micro particles,
• the removal efficiency of limonene, toluene and formaldehyde as target volatile organic compounds (VOCs),
• the noise level (sound power) of the operating device, and
• the energy consumption of the device in relation to its removal efficiency. (Portable Air Cleaner Protocol Evaluation Report);

Heat and energy recovery ventilators

Mechanical ventilation of Canadian homes is mandatory under current building codes. Heat Recovery Ventilators (HRVs) or their moisture-transferring variants, the Energy Recovery Ventilators (ERVs), are increasingly integrated into forced air heating and cooling systems to reduce ventilation-associated heating costs in winter and cooling in summer. While the airflow delivery rates and heat transfer efficiency of these units can be well characterized by the use of existing standards, the actual impact of HRVs or ERVs on residential indoor air quality may depend on a number of factors, and a respective evaluation is not included in current certification practices. Using feedback from stakeholder workshops, a protocol was released in 2012 to evaluate HRV/ERV systems for

• the effectiveness to remove coarse and fine particulates from outdoor air, and return air if a recirculation option exists for the unit,
• the potential ozone formation, which could be generated by blower motors or filtration systems incorporated into the system, and
• the emissions of VOCs and aldehydes from the complete system or from individual system components (including filter assemblies, casing materials and flex duct).

The evaluation method will provide HRV/ERV manufacturers and their supply chain with a useful tool to assess and refine their products, opening market niches while achieving better indoor air quality for residential occupants.

Commercial air duct cleaning

Through the guidance of stakeholder and industry workshops NRC learnt that commercial building operators need specific information to obtain effective and cost-efficient air duct cleaning results. In response to this need, the NRC team developed a guide to evaluate air duct cleaning provided by commercial services for larger heating, ventilation and air conditioning (HVAC) systems.

This guide helps building operators to

• interact in an informed way with air duct cleaning companies in order to avoid issues related to pollutant emissions from duct cleaning activities and duct cleanliness assessment,
• focus the scope of proposed duct remediation to address both adequate cleaning and cost-effectiveness,
• assess potentially harmful effects and minimize exposure of occupants to particulates/biocontaminants resulting from improper cleaning procedures, and
• assess the potential adverse impacts associated with the use of chemical cleaning agents or biocides.

Next steps

Protocols are currently in development to assess the effectiveness of in-duct air purification solutions and indoor passive panel technologies. As well, over the next three years, we will establish a protocol to evaluate the long-term performance of portable air cleaners.

In-duct air purification solutions

As airborne particles can have a significant effect on health it is important to minimize their concentrations indoors. In-duct air purification solutions (I-DAPS) can be used to reduce particle concentrations of supply air as well as of return air into the indoor environment. It is also important to ensure that I-DAPS technologies do not generate ozone, which also may contribute to adverse health effects. NRC researchers are building a full-scale air handling unit, which is housed in a controlled environment, where scientists are able to

• assess the particle removal performance of air purification technologies,
• determine ozone emissions generated by electronic air cleaners, and
• assess the air purification performance of devices intended for aircraft.

The test air handling unit will be available to stakeholders by the end of 2013 for further research and testing to support the heat, ventilation and air conditioning (HVAC) industry.

Indoor passive panel technologies

Currently there are many building materials and coating products produced with the expectations that they can passively remove gaseous contaminants, are antimicrobial and self-cleaning. To validate indoor passive panel technologies, NRC will build a test chamber in 2013 to evaluate the contaminant removal effectiveness of various commercially available passive panel products advertised for the use in indoor environments. These panels will include modified gypsum board or specially coated building materials.

Outcomes

The developed protocols are aimed to support scientifically sound rating systems, manufacturers in their efforts to produce better and more energy-efficient choices for builders and end-users through technology innovation. It is also expected that these protocols will be used as the basis for adopting or revising standards under ISO (International Standardization Organization) and the Canadian Standards Association (CSA).

Acknowledgement for the Technical Advisory Committee

The protocols were developed under the assistance and guidance of a Technical Advisory Committee (TAC) comprised of participants representing federal, provincial and municipal agencies, industry and standards associations, and non-government organizations, who we thank for their invaluable contributions.

Dissemination of knowledge and best practices through the Canadian Committee on Indoor Air Quality and Buildings

The Canadian Committee on Indoor Air Quality and Buildings (CCIAQB) is an independent national forum and clearinghouse for best-of-knowledge information on the design and operation of buildings as they affect indoor air quality.

The Committee has identified the need for concise, user-friendly technical guides to assist building operators and facility managers in making informed decisions to maintain good air quality in buildings.

Results

Eight guides that address areas such as custodial activities, hygienic operation of air-handling systems and communications with tenants and occupants are in production. Starting in early 2013, the Committee plans to promote the documents through stakeholder organizations representing building and facility managers, and to establish a web-based distribution and feedback mechanism to improve the documents and respond to priorities. Members will also work with partner organizations to develop educational materials from the guide series.

Next activities

Future plans include the production of guides for assessment and accreditation methods, selection of low-emission building materials and furnishings, as well as mould detection and remediation. The Committee will address the needs of homeowners and tenants of multi-residential buildings at a later stage, using the existing guides as source-documents. CCIAQB will also provide a platform for online stakeholder discussions at its website IAQforum.ca blog.

Research into healthy and energy-efficient ventilation

The quality of indoor air can be negatively influenced by a number of pollutants such volatile organic compounds emitted by building materials and cleaning products, pesticides, CO2, bacteria and viruses, radon, and mould. To avoid adverse health effects from indoor pollutants, a ventilation system is required in all heated Canadian buildings. The ventilation system delivers outdoor air to occupants and removes pollutants which would otherwise accumulate in the indoor environment.

Ventilation systems have multiple constraints though. In addition to delivering a sufficient amount of outdoor air and distributing the air efficiently throughout the building, they need to avoid undesired drafts and excessive noise, not induce significant pressure differences between the inside and the outside of a building, and integrate themselves seamlessly with the heating and cooling system, and do this in an energy-efficient manner.

Outdoor air is also introduced into buildings through cracks and gaps in the building envelope and roof systems, despite substantial efforts to make buildings more airtight. This infiltration may result in increased energy consumption for heating and cooling, drafts, moisture damage and mould growth.

NRC’s researchers have designed and built a unique full scale laboratory, the Indoor Air Research Laboratory (IARL), and configured the facility's flexible modules to duplicate specific room sizes and designs in actual buildings, as well as different types/configurations of heating and air-conditioning systems, air cleaners, filters and heat-recovery ventilators. In this facility, researchers perform experiments to understand the air movement under realistic but controlled conditions. The comprehensive features of the IARL allow ventilation and air quality experts to work together and document the impact of different systems and strategies aiming at improving indoor air quality while considering energy-efficiency. The knowledge gained is important to develop solutions that efficiently remove particulates and gases without necessarily increasing ventilation rates, which would otherwise translate into increased energy consumption.

Support technological solutions

A number of projects have been undertaken using the Indoor Air Research Laboratory.

• Field Intervention Study to improve indoor air quality for asthmatic children.

  This three year field study was centred on the Québec City area, and involved the monitoring of indoor air quality and ventilation in 83 homes with asthmatic children. Over this period, NRC monitored the indoor air quality (IAQ) improvements, and our medical partners, the Institut national de santé publique du Québec, the respiratory health of the children. See Evaluating indoor air systems through field studies

• The IARL was used to test ventilation solutions for several room configurations.

  The results were coupled with computer simulations to further increase confidence that the proposed interventions in the field study homes would improve the indoor air quality. Results to date have shown that the use of heat or energy recovery ventilators reliably increased the effective ventilation rate, but also improved the indoor air quality in the field study homes.

• Protocols and Evaluations of Heat and Energy Recovery Systems (HRVs, ERVs).

  NRC researchers are supporting the industry by developing integrated test protocols for indoor air quality solutions and technology devices, as for most of those standards, which reliably improve IAQ, are currently not available. The IARL was used to recreate realistic environmental conditions needed for the development of a new protocol for the evaluation of HRV and ERV systems. See Managing harmful emissions at the source.

Ongoing activities

• Radon mitigation

  Radon is a naturally occurring radioactive gas that is present in indoor air of buildings across Canada. According to Health Canada’s Radiation Protection Bureau about 7% of residential properties have levels above Health Canada’s guideline. Radon mitigation strategies are often not validated, especially for the Canadian climatic conditions. The IARL is being used to investigate several approaches and risk factors for radon ingress or radon re-entrainment. Work started in 2011 and is continuing. See Evaluating radon mitigation strategies.

• Pollutants from attached garages

  Field studies have revealed that homes with attached garages have higher concentrations of pollutants due in part to automobiles and other gasoline powered equipment kept inside the attached garages. Other factors include leakage routes through the garage walls and ceiling to the home, and a driving pressure difference. In 2012 an attached garage was added to the IARL and several technologies to reduce “back-drafting” are presently being investigated. See Minimizing the transport of pollutants from attached garages into homes.

Evaluating radon mitigation strategies

Radon is a naturally occurring radioactive gas. Radon levels in indoor air of buildings vary quite significantly across Canada. According to Health Canada’s Radiation Protection Bureau about 7% of residential properties have levels above Health Canada’sir guideline. It is estimated that radon exposure results in 3000 deaths per year due to lung cancer, second behind smoking.

Although technologies exist to reduce radon levels in homes, several questions remain. To this end, NRC and Health Canada are collaborating to find and evaluate technical solutions to reduce the exposure of Canadians to radon.

As a first step, NRC and Health Canada held a stakeholder workshop to learn more about the needs of industry and to seek their guidance on different approaches. Participants highlighted that trustworthy information and validated technologies must be available to support an awareness campaign. The next stakeholder meeting will take place in Fall 2013.

Activities

Avoiding radon re-entering a house

NRC and Health Canada are collaborating to reduce the risk of radon re-entering (re-entrainment) the house when using of an active sub-soil depressurisation (ASD) system. These systems can be set up to exhaust at different locations. The research team explored the re-entrainment, when the ASD system is exhausting at ground level, first floor ceiling and second floor ceiling/roof. Initial results show that exhausting at ground level might lead to some re-entrainment of radon, whereas exhausting at higher levels would minimize or effectively eliminate re-entrainment. A first set of tests were completed during the winter of 2011-2012 and will be repeated in summer, fall and winter in 2013 to confirm the findings. A guide on appropriate exhaust locations will be available in 2014.

NRC and Health Canada are also looking into finding safe distances from an ASD exhaust to a building opening such as a ventilation intake or an operable window. Initial results show that the existing advice on locating exhausts might not be conservative enough. A first set of tests is completed and research will be repeated in 2013 to verify our findings. A final report on recommended separation distances between radon exhausts and fresh air intakes will be available by the end of 2013.

Is an ASD system a risk for neighbouring properties?

In densely built developments there might be a risk that the exhaust from ASD systems at ground level might not be sufficiently diluted and radon could enter neighbouring buildings. inkanswer this question, NRC is performing full-scale tests under real-world meteorological conditions in the Canadian Centre for Housing Technology (CCHT) twin houses is jointly operated by NRC, National Resources Canada and Canada Mortgage and the Housing Corporation. Results will be available in 2013.

Energy considerations for ASD systems

There are still questions on the overall energy consumption and performance of ASD systems. One of the concerns is that the basement floor temperatures could be lowered when ambient air is drawn under the slab during winter, which could increase the overall heating demand. While testing for re-entrainment, NRC is also monitoring the overall building energy performance. Results will be released in summer 2013.

Targeted ventilation

NRC has previously confirmed through testing that increasing ventilation rates in the whole house can reduce radon concentrations. However, an overall increase of the air exchange rate might also lead to excessive energy costs. An alternative approach NRC tested in 2012 was to install additional ventilation capacity in the basement where radon gas typically accumulates. The increased ventilation rate in the lab’s basement turned out to be sufficient in reducing the radon concentrations both in the basement as well as in the whole house.

NRC and Health Canada are continuing to investigate whether the combination of an additional basement air supply plus a radon-concentration controlled supply air flow will further decrease the energy demands and still be able to maintain radon concentrations below Health Canada’s guideline.

Improved passive barriers for reducing radon intrusion

New barrier materials are available in the marketplace with the claim of reduced radon intrusion into basements. These low-permeability barrier materials are typically metallised. Little is known about their performance; however, they hold the promise of alleviating the need for an active radon mitigation system such as an ASD, reducing installation and operation costs. In 2013-2014 NRC will build a dedicated new test facility to examine how these new materials compare to existing systems and constructions.

Interaction between fuel-fired appliances and ASD systems

Tests will take place in the winter of 2013-2014 to examine the interaction between combustion appliances, such as a wood-burning stove and a natural gas fire place, and the ASD system. Because the performance and safety of these appliances are directly linked to the building pressure, NRC will be specifically looking into the pressure differences created by the use of these systems, as well as back-drafting from wood burning stoves and natural fire places.

Minimizing the transport of pollutants from attached garages into homes

Canadians like to have an attached garage to their house, probably because of harsh winter conditions in many regions and the convenience that it provides. However, Health Canada's studies have consistently shown strong associations between the presence of an attached garage and higher concentrations of several indoor air pollutants in living areas within the house. This is potentially due to three conditions:

• The presence of gasoline-related pollutants caused by emissions from gas tanks of cars, gas-powered utility vehicles and tools, and gas storage canisters
• Air leakage routes through the garage wall and ceiling into the home
• A pressure difference between the garage and the house that drives air from the garage into the home

Suitable control mechanisms are required to minimize the pollutant transport and associated the risk posed to the health of Canadians.

In 2012 a two-car attached garage was added to the Indoor Air Research Laboratory (IARL) with the following features:

• A research wall between the IARL and the garage, which has been equipped with variable sized leakage routes allowing us to experiment with different leakage rates
• A dedicated tracer gas system to closely monitor air movement
• Meters to monitor the energy consumption of additional ventilation, heating and control systems to compare the costs of different solutions.

Activities

This IARL with an attached garage is a unique testing facility which allows an integrated assessment of solutions for reducing the transfer of pollutants into residential living spaces. The first solution tested is direct exhaust ventilation from the attached garage. The team will also look into the energy demands of various solutions as this may influence their adoption, as well as the long term use. In the winters of 2012-2014 the following scenarios will be evaluated:

• Constant and intermittent direct exhaust ventilation from the garage
• Timed ventilation triggered through garage door opening
• Improved control and limitation of the pressure difference between the garage and the house
• Garage exhaust ventilation triggered by sensing of characteristic gasoline contaminants

Initial experimental results will be available in summer 2013 with complete results after summer 2014.

Helping homeowners chose and maintain indoor air devices

Most people believe that indoor air problems can be solved through either changes to the building structures or the installation of adequate systems. However, the desired indoor air situation can only be effectively achieved if sufficient links exist between the appropriate design of systems, and the targeted selection and proper commissioning, operation and maintenance of all components. This becomes even more important when dealing with newer technologies and concepts. NRC will inform homeowners about the results of their research on validation and evaluation of products and systems that improve indoor air currently on the market through NRC’s websites and other outlets.

NRC’s researchers are exploring different ways to increase homeowners’ uptake and appropriate use of effective technologies. The first technology NRC will focus on is heat and energy recovery ventilators. NRC is currently using focus groups to understand the current use of these technologies in homes, the problems associated with them, and the actual and perceived barriers to their proper use and also obstacles to their uptake by new customers.

The information will be used to develop documents that will enable homeowners to make informed decisions on how to select and use products and systems for their homes. Using sound tailored information, they will be able to choose technologies according to the benefits most appropriate to their situation, such as expected health benefits, cost and possible side-effects on home comfort or energy consumption.

By 2014 NRC will be issuing additional guides to increase the uptake of these technical solutions and will focus on

• reducing the ingress of fine particulate matter into buildings,
• preventing the back-drafting of harmful gases from attached garages, and
• achieving and maintaining sufficient ventilation in homes.

These documents could also be used by provincial and municipal public health professionals to assist homeowners, and by industry to provide more targeted solutions.

More information on these guides will be available in Construction Innovation, NRC’s flagship construction research magazine.