air sealing, ventilation and air quality

Some people are often concerned about air sealing their homes too tightly, due to ventilation and security problems.

But, in cold and other harsh climates, there is no alternative: an air-tight home is the only good solution in terms of energy efficiency and savings and you should bet on it and in natural or mechanical ventilation (a HVAC system) – and never in air leakage.

Air Leaks and Ventilation

Air leaks may help to dilute indoor carbon dioxide or chemicals like formaldehyde from building materials. But since air leaks are largely driven by the weather - and particularly by the wind - it easily provides too much fresh air when it isn’t necessary (in cold and windy weather) and too little during the hot and mild weather conditions.

Air leakage & Unhealthy air

Besides, instead of being a source of fresh air, air infiltration can be a source of problems like moisture and dusty air, entering into the house through foundations, crawlspace, walls, etc.

And since the penetrations and the cavities of foundations, crawlspaces or basements can also be contaminated with chemicals, radon, etc., air leaks can be the inverse of fresh and healthy air.

Fresh air

Good indoor air quality demands a certain amount of fresh air, and there are technical specifications setting the amounts of it.

You can hire a professional, who will use diagnostic tools to measure your actual leakage and will advise you on HVAC and natural ventilation.

But never expect to get sufficient and good fresh air through air leaks. You can get it through natural ventilation, in many climates or in some periods of the year. But you can’t have it via air leakage. That’s why a mechanical ventilation (HVAV) system is the only way to get healthy fresh air, namely in harsh climates.

Sealing, ventilation

Obviously, sealing a home - making it highly air-tight - may indeed demand the modification of existent ventilation systems. A high-quality exhaust fan in each bathroom and kitchen, ducted to outdoors, is crucial in any house, well sealed or not.

And in cold climates, where homes can’t be naturally ventilated during most of the year, mechanical ventilation (a Heat Recovery Ventilation System (HRV) or a Energy Recovery Ventilator system (ERV)) is mandatory. That’s the only way to get healthy indoor air.

Air Sealing and combustion appliances

Independently of the fresh and healthy air issues, any air sealing project should be accompanied by a revision of the heating and cooling system. Ask a heating and cooling technician to check your gas/oil-fired units, and namely if they are venting properly.