Air leaks are gaps and cracks where different building materials meet. Typically they are around windows and doors. They can also be found where electrical outlets, piping and vents are installed.
This is a serious energy waste problem in homes and buildings. It’s critical to find and fix these leaks.
Hand Test
An airtight home requires a combination of building science know-how and a lot of gumption to get into the attic, crawl space and basement to seal leaky windows, doors and ductwork. Professionals use specialized equipment to perform blower door tests that depressurize the house, revealing hidden leaks and showing where the greatest improvement can be made.
One of the easiest ways to detect leaks is to simply feel for unwanted airflow with your hands. This works best on a cold day, and it’s important to close all doors and windows and turn off fans and humidifiers. Wet your hand before performing the test, and then move it around all edges of doors, windows, light switches, electrical outlets and vents. If you feel a draft or drastic change in temperature, there’s an air leak nearby.
Another easy test is to run a lit candle around common leak locations. Be careful to avoid flame burns. If the candle flickers or goes out, there’s an air leak in that area. For a more scientific test, we can use an ultrasonic acoustic detector that recognizes the high-frequency hissing sounds produced by air leaks and alerts you to their location. The device is portable and is especially useful when trying to find leaks that are hidden from sight. Professionals can also conduct a blower door test to depressurize the home, revealing large leaks and allowing them to be fixed.
Candle Test
The Candle Test is a simple but effective way to detect small air leaks. On a calm day, close all doors and windows, turn off the HVAC system and fans, and then hold a lit candle or stick of incense against the seams of your home’s exterior windows and doors. If the flame or smoke wavers, that’s a sign that air is leaking in through that area of your home. You can also use your hand to feel for drafts and drastic changes in temperature around window frames, doorframes, baseboards, and electrical outlets.
For the more advanced DIYer, you can also try a device called a leak detector or thermal detector. These are handheld devices that can be purchased at most hardware stores, and they work by detecting changes in room pressure. They’re usually used in conjunction with a hand-held tester or a stick of incense, which are both simple to operate and can be purchased at most hardware stores.
Burn testing your candles is a great way to ensure they’re safe for your customers to use and meet the required safety standards set by international organizations like RAL-GZ041 and ASTM. Using batch manufacturing software like Craftybase allows you to track all your ingredients, batches, and manufacturing processes so you can be confident that your candles are compliant.
Building Pressurization Test
Using a fan-powered blower door, this test applies the same pressures to the entire building and measures leakage between all spaces. This allows technicians to find leaks that would be harder to detect with a hand tester, a candle or smoke pen/pencil, and can be more accurate than a simple airflow reading.
While all buildings leak to some degree, excessive air loss can significantly reduce energy efficiency and increase operating costs. Leaks can also introduce moisture into walls and structures, causing damage, or contaminate conditioned space with pollutants from outside. Airtightness testing is a critical part of the energy analysis process, and can help ensure that your building is operating as efficiently as possible.
During the testing, the building will be pressurized and depressurized using the building HVAC system and a blower door assembly. Then, using tracer gas and/or thermal imaging, technicians can locate the source of air leaks.
This method is ideal for new construction, but can be used to measure the effectiveness of retrofits in existing buildings as well. It is also useful in locating specific details where a full depressurization of the building envelope is impractical, such as for testing penetrations and joints in air barrier materials that are supported by rigid substrates. When used with a thermal imaging camera, this test can provide additional information about the direction of leaks by identifying draughts as air is forced back into the building.
Smoke Stick Test
In the hands of a trained person, a smoke stick can help find air leaks that are too small to detect with the hand test. Light a stick of incense and carefully pass it around the edges of common leak sites like window seams and doors. Wherever the smoke wavers or is sucked in or out of the room indicates a draft that needs to be addressed.
You can also use a piece of toilet paper to locate leaks too large for the incense stick, but be sure to turn off any fans and depressurize your home before testing. Just move the piece of toilet paper slowly and methodically around the outside of your windows and doors. Where the paper sticks or slips suggests that the window isn’t closing tightly enough and letting air in.
Plumbing smoke tests are a quick and effective way to find the location of leaks, cracks, and loose fittings in drain pipes, sewer systems, and other underground infrastructure. During this process, workers blow artificial smoke through the pipes to show where there is air infiltration and where water and other contaminants are leaking. In many cases, this is done after a camera inspection has been performed so that workers can see where the leaks are located without entering the system. In addition to detecting leaks, these tests can also reveal areas of ground water infiltration.