Contaminants from attached garages

Volume 17, Number 3, September 2012

The attached garage has become a common part of modern single-family homes and row houses. Garages are used not only for housing vehicles but for storing all kinds of tools, equipment, materials and products used in and around the home. Chemicals, fuels, cleaners, paints, as well as fuel-powered equipment such as lawnmowers and snow blowers and other hobby or professional activities, are also found in most garages. Often, fuel-powered vehicles, gasoline cans and chemical products emit pollutants into the air, which can in turn pass into the home where they can affect indoor air quality.

Figure 1: Attached garage under construction at IARL

Health Canada and the National Research Council have determined there is a need to provide sound technical solutions that will adequately decrease the transfer of pollutants from attached garages to living spaces, thus reducing the health risks to Canadians. These solutions will provide a significant opportunity for the building industry to identify the most appropriate way of retrofitting garages with sustainable, energy-efficient, and healthy technical options.

To provide guidance to industry, researchers will perform laboratory and field studies beginning with evaluating several solutions at the NRC Indoor Air Research Laboratory (IARL) later this fall (see box). The work will involve testing three technical alternatives prioritized by Health Canada and the NRC:

  • improved air sealing between garages and homes,
  • demand-controlled, sensor-triggered, energy-efficient exhaust fans, and
  • control of the air pressure difference between attached garage and living space.

NRC's Indoor Air Research Laboratory (IARL)

The IARL is a unique, residential-home-type, full-scale facility, which was recently used in support of a ground-breaking field study into healthy ventilation for asthmatic children. The IARL features the following capacities: electronically-controlled airtightness room by room, sophisticated tracer gas equipment to measure airflows under variable indoor and outdoor conditions, and a particle image velocimetry system to visualise and measure air movement. The IARL is set up for a wide range of experiments addressing indoor air quality and ventilation questions, and is now open for direct support to Canadian industry. The facility can accommodate the testing of a wide range of ventilation devices including HRVs and ERVs, air quality sensors, and air quality improvement devices.

To enable a realistic study, a two-car garage (see Figure 1) is being added to the IARL. The design of the garage was determined after a review of provisions in the National Building Code, covering editions from 1941 to 2010. The evaluations will be based on advanced modelling approaches and tracer-gas experiments, which will mimic the air flow and the transfer of gases and inhalable particles.

Using the results of the laboratory evaluation, researchers will validate the most promising and energy-efficient solutions in a number of single homes with attached garages. The efficacy of the solutions will be determined through ‘interventions’, whereby the concentrations of harmful contaminants in the attached garage and the living spaces will be determined before and after the implementation of each technological solution.

The research and dissemination of results are being performed together with Health Canada’s Air Health Science Division of the Water, Air and Climate Change Bureau. Its mandate is to contribute to the development of science-based policies related to the impact of air pollution on public health, to study sources and determinants of air pollution exposures, and to recommend actions Canadians can take to reduce exposures to air pollution.

Final results are expected by the end of 2013. Interested groups are invited to comment on the research approaches described.

For more information

Contact Iain Macdonald at or 613-993-9676.