Thinking about making your home more efficient? Here are the benefits and risks of an air tight home

Today, we see more and more home owners opt to enlist the services of building science experts, in order to ensure the homes’ maximum air tightness (The dwelling’s ability to retain its indoor air without it leaking through faulty breaks in the envelope) for their home. The hired professional will conduct specific tests inside the home to verify the levels of air leakage in the house (see article “Have a Blower Door Test and see how much you can save”), and determine the problematic areas in the construction of the building envelope.

The benefits of an air tight home are significant in the following areas; They are noticeably warmer, without the use of heating appliances, for a longer period of time. The air tight home provides a superior level of comfort due to its ability to retain a desired temperature, avoid moisture condensation problems, and control the entry of outdoor contaminants, pests, and odors. The noise transmission is significantly lower in the air tight home, due to the layering of the envelope’s construction, and the denser materials within its construction. Older homes that require new ducting systems will tend to have larger ducts, unless an upgrade to the construction is made. The air tight home will have a much smaller heat loss throughout the walls, ceilings, and floors, allowing the heating equipment to be of a smaller size and capacity, and ducting system to be sized much smaller than if the construction was less air tight, reducing the energy consumption of appliances.

With today’s minimum insulation levels, as outlined in the Ontario Building Code’s Supplementary standard SB-12 (click the button below this paragraph for more details), and up to date construction methods for air and vapour barrier systems, The air tightness of a home will reach a maximum of 3.5 ACH (Air changes per hour), and with home owners opting to use more air tight methods for their homes, we get increasingly lower air leakage rates of down to 0.5 ACH in the case of “Passive Homes” (See article “Help the environment – Live in The Passive Home”)

Upgrade your insulation

Potential health risks involved with air tight homes arise due to the enclosed or sealed character of the dwelling, which includes off-gassing from certain appliances such as a gas stove, poor ventilation, and pollution due to a lack in monitoring devices and proper exchange of air. Volatile Organic Compounds (VOC’s) can be found in many materials found throughout the home, like sprays (disinfectants, air purifiers, and bug sprays), Ethanol based detergents (dishwasher or laundry), or fuel and automotive products. Without the proper mechanical ventilation of an air-tight house, these VOCs could cause a number of health risks.

Finally, it is a strong recommendation to connect an HRV/ERV (Heat recovery ventilator / Energy or Enthalpy recovery ventilator) to your ducted heating system (see article ”Why you need an HRV/ERV for your home and quality of air“), as this device will reliably bring the required amounts of fresh air into the home by exchanging the stale air that is circulating in the house through the ducts, retaining the heat from said air, and introducing fresh air from the outside, to mitigate the associated health risks of an air tight home.