Energy S.O.S.: Is Your Home Leaking Money in Plain Sight?
Are you constantly shocked by your soaring energy bills? The culprit might be right under your nose, or more accurately, all around you. Your home might be leaking precious warm or cool air, making your heating and cooling systems work overtime. Let's dive into the world of building airtightness and discover how a simple test can help you identify and rectify this issue.
Building Airtightness: What's the Big Deal?
In the simplest terms, building airtightness refers to a building’s resistance to air leakage—air flowing both in and out of the building—through areas of the building enclosure not intended to allow air flow.
The idea of air entering or exiting a building may not seem like cause for concern, but in reality, airtightness is an important aspect in building performance. Because the internal environments of buildings need to be carefully controlled to allow for proper ventilation, temperature, and moisture control, these unintended leakages, usually invisible to the naked eye, can cause major issues—issues that can be costly to both building owners and occupants.
Why is Airtightness Important for Energy Conservation?
Occupant Comfort: One of the most noticeable problems associated with poor building airtightness is occupant comfort. When a building’s airtightness has not been properly addressed, tenants often complain of temperature and humidity control issues. In the winter months, tenants experience dry and drafty spaces as heat escapes through openings in the building enclosures and cold air enters from outside. Similarly, in the warmer months of the year, it can be a challenge to keep spaces cool even when using air conditioning, and indoor spaces can begin to feel humid.
Cost Savings, Energy Bills and Energy Conservation: It should come as no surprise then that poor building airtightness also impacts a building’s energy usage—a costly effect for both the environment and those paying for utilities. Even in the most insulated of buildings, without proper airtightness, conditioned air (either heated or cooled air) from the interior of the building will escape through the enclosure while unconditioned air from outside will enter the building. The result is a never-ending battle between the interior and exterior environments as heating or cooling systems work frantically to try and stabilize the indoor conditions—a battle clearly reflected in the building’s skyrocketing energy bills.
Moisture Control: Air leaks can bring in moisture, which can lead to mold growth, structural damage, and reduced indoor air quality. By ensuring airtightness, we can prevent these issues and the potential health risks associated with them.
Building Durability: While it’s easy to see and feel the effects of poor airtightness on occupant comfort and energy costs, some of the most significant issues can be hidden from tenants or building owners. Cracks and gaps in the enclosure (or, more specifically, the air barrier) can also allow moisture to accumulate within walls and other enclosure assemblies, potentially causing damage and deterioration of the building and leading to costly investigations and repairs. When this happens, you’ll want to turn to a team of expert consultants who can properly assess the issues and help you develop a plan to get your building back to the way it should be performing.
Improved Indoor Air Quality: Airtight buildings can better control the quality of indoor air, as they prevent the infiltration of pollutants and allergens from the outside.
The Blower Door Test: Measuring Airtightness
To ensure that a building is airtight, we need a reliable method to measure its airtightness. This is where the blower door test comes into play.
What is the Blower Door Test?
The blower door test is a diagnostic tool used to measure the airtightness of buildings. It can also help locate air leakage sites, making it easier to address them.
image by Natural-Resources Canada
How Does It Work?
Setup: A powerful fan, known as a blower door, is mounted into the frame of an exterior door. All other openings, like windows and vents, are sealed off.
Depressurization: The fan starts to pull air out of the building, creating a pressure difference between the inside and outside.
Measurement: As the fan operates, it measures the amount of air required to maintain a certain pressure difference, giving an indication of the building's airtightness.
Detection: With the building depressurized, it becomes easier to detect air leaks using smoke pencils or infrared cameras.
Conclusion
Airtightness is a critical factor in creating energy-efficient buildings. Not only does it help in conserving energy and reducing utility bills, but it also ensures a healthier and more comfortable indoor environment. The blower door test, with its ability to accurately measure and locate air leaks, is an invaluable tool in the quest for more sustainable and energy-efficient buildings. As we continue to strive for a greener future, understanding and implementing these concepts becomes ever more essential.
Read more about blower door test - Determination of the airtightness of building envelopes by the fan depressurization method