Most homes in Canada are polluted. Breathing dirty indoor air and being oblivious to it

MOST HOUSES I INSPECT HAVE POLLUTED INDOOR AIR but the occupants aren’t aware or choose not to be aware of it. It’s not visible. While you have your health you turn to other priorities. It’s only when you are older or get sick that it becomes a crisis.

No one checks air quality: not the pre-purchase building inspector- that sector of work got deregulated and checking air quality takes expertise, not the mechanical contractor who last participated in some renovation, they make their money marking up the installation of new mechanical equipment, they never measure air quality, they don’t have the equipment to do it. Doctors treat patients who are already sick. Preventative medicine is another domain and architects need to take on that responsibility. As a result, most houses have polluted indoor air.

You can’t create a healthy environment without knowing what it takes, and what has to be done. You can’t just buy a heat pump even if there are subsidies and hope for the best. You have to appreciate that you cannot achieve good quality air if you have a wood-burning fireplace [even if you are not using it –because of chemically laden down draughts] or a gas stove in the kitchen [without a proper exhaust hood which should continue to work 24/7]. You may even have invested in an air exchanger/heat recovery ventilator, but most of those machines are incapable of delivering fresh outside air to all the inhabited rooms in the house–the volume of air being moved is insufficient.

If there are children living in the house, their lungs are smaller compared to adults, they become sick more easily and go on to develop allergies or more serious respiratory problems like asthma. They need fresh air/oxygen to help their developing brains. In winter it gets too dry in the house especially if you rely on electric baseboards. Heat will result in dehumidification, so the air has to be humidified and kept above 30% RH [relative humidity].

One of the most common defects in houses with a forced air system is the use of “in-wall” returns. They are still being installed even in new construction despite the fact that the matter has been researched for decades and the best advice coming from the National Research Council is “that it could be made to work” – which is rather meaningless. In all mechanical forced air systems, at least 90% of the air that is pushed out from the air handler has to be returned to it, the remaining 10% represents makeup air, the fresh air being brought in and a more or less equal amount that is being exhausted. The problem with in-wall return air pathways is that they are not fully ducted and the air moves within the wall cavity between wall studs or under the floor between floor joists. It results in significant heat loss-usually going up to the roof entretoit [where it can condense]. Furthermore, those passageways cannot be properly cleaned because the spaces are not aerodynamic, and the surfaces are too rough so that dust clings to them. Despite that there is a lucrative industry that will offer to clean those areas with an industrial vacuum cleaner, thereby increasing pollution levels inside the house.

It is difficult to know how to clean a house especially when it contains wall-to-wall carpets that absorb microparticles suspended in the air containing viruses, bacteria and mould spores. Even those microparticles eventually fall to the ground by virtue of gravity but some viruses and bacteria can linger for months suspended in the air. You cannot use an ordinary vacuum cleaner. They scoop up the microparticles that have fallen to the floor and then recontaminate the air rendering the particles airborne once again because they pass right through the machine. It is the same even if the machine has a HEPA filter. HEPA is a generic word and the small filters in vacuum cleaners become contaminated within 20 minutes of use. So the only safe way to clean a house is with the use of a central VAC providing the “used air” is exhausted to the outside. That “used air” will contain all the microparticles that can make you sick. The visible dust that collects in the canister will not harm you or your children.

In 1990 and more explicitly in 1995, the National Building Code of Canada came out with new mechanical air quality recommendations. At the time it was considered to be the most progressive in the world. The objectives are stated very clearly and very succinctly. A healthy environment requires a complete air change with fresh filtered outside air delivered to all the inhabited rooms of the house and it has to be achieved within 3 to 4 hours. It explained how one cannot be dependent on opening windows. Research has shown that it is a Canadian myth – windows are hardly ever left open in winter, or during inclement weather such as in wind-driven rain or snow storms, or in summer when there are heat waves. They are not left open when one is not home. The required air change has to be continuous 24/7 year-round. One has to be able to evacuate as much used stale air as the amount of fresh air being brought in.

The Canadian building code is upgraded every 5 years to establish minimum standards for health and safety. The pandemic made most consumers somewhat aware of the importance of ventilation in creating a healthy environment. Unfortunately, matters have not changed very much. Most houses, even luxury ones, still have polluted indoor air.

You can have an excellent building code but then enforcement or implementation is another matter. The National Building Code of Canada has to be adopted by each of the provinces and they have a right to make modifications provided the original objectives are met. That process can take a decade. In Québec, the government decided that the ’95 mechanical objectives were too difficult to implement, and they chose to partner with industry and come up with a suitable mechanical unit. The resulting Québec Construction Code refers to the necessity of installing an air exchanger/heat recovery ventilator. Unfortunately, those units are inadequate [insufficient volume of air circulated] and they become easily contaminated which makes them counterproductive [no filter at the point of entry of the outside air].

The final arbiters are the municipalities because they have jurisdiction over what actually gets built within their territory. It can also take up to a decade to adopt or modify the original objectives of the National Building Code or not adopt them at all. Unfortunately, implementation is very lax at the municipal level. The municipality of Westmount as an example is particularly conservative and decided not to adopt the mechanical air quality requirements of the ‘95 code. Whereas there are no acquired rights in regard to matters of health and safety, if one chooses not to renovate, not to upgrade, one is not forced to do so [provided it does not harm your neighbours well being]. Proper or inadequate maintenance is not being done for a multitude of reasons. Proper maintenance includes not only changing worn component parts of a house but also upgrading according to the current building code which sets a minimal standard for health and safety.

If the objective is to create a healthy environment, then one has to look elsewhere beyond the 1995 mechanical requirements of the National Building Code of Canada. Because factors other than fresh air changes are involved. There are standards now that are well established regarding the dangers of contamination from fine microscopic particles suspended in the air. In 1997 the Environmental Protection Agency in the US [EPA] and the World Health Organization [WHO] adopted a standard referred to as PM 2.5. The PM stands for particulate matter also referred to as micro particles and 2.5 represents the size [diameter] in microns [µm] of those particles. All particles of 2.5 µm or less are dangerous to one’s health because they are small enough to get into one’s lungs and even continue beyond to one’s bloodstream. It is especially dangerous for people with existing respiratory [breathing] problems such as asthma and it is the source or the cause/the trigger for allergic reactions. Children are the most vulnerable because their immune systems are developing.

We also have international standards regarding air filters referred to as MERV. The ratings run from 1 to 16. The highest level is referred to as perfect 16. It is capable of capturing microparticles that are less than 2.5 µm. It includes particles such as viruses, smog, bacteria and mould spores. Air purifiers with large HEPA filters can capture microparticles of that size and smaller. For a full-size house, one needs a central system to do the job. One of the objectives of having air changes is to diminish the level of indoor contamination. When there are minimal or no air changes microparticle contaminants will accumulate over time. One requires a minimum-sized pleated filter of at least MERV 11 [5.25” thick] in a central system to capture the microparticles mentioned above.

Architects are also guilty of ignoring air pollution levels in housing. They are accepting the diminished role of only providing a design image for a building leaving the engineering to others. Traditionally they had the role of le maître de l’ouvrage, master of the works. Those few who accept to do pre-purchase building inspections in Quebec will do it exactly the way the OACIQ recommends it be done, leaving the engineering components such as air quality for others to assess, producing superficial and meaningless inspection reports which are now standard throughout North America.

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