Air leaks are a major source of energy loss in homes. Learn how to find and fix them to reduce your utility bills.
Start by closing all the doors and windows. Turn off fans, humidifiers, and any other sources of moving air in the house. Walk around the house with a lighted stick of incense and pass it over doors, vents, and windows. If smoke is blown into the house or sucked out, there is a leak.
Hand Test
A basic approach to finding leaks is to listen for the hissing noise that leaking compressed air makes. This method is reliable but can be difficult to hear over the plant equipment noise and only works for large leaks located in easily accessible areas.
A more reliable method is to use a soapy water test on suspected areas of leakage. This requires direct physical access and is time consuming. It also does not provide information on the relative volume of each leak, which can make it challenging to prioritize leak repairs.
Finally, you can try to locate leaks visually by shining a flashlight at night over all potential gaps in your home and asking a friend to observe from outside. Leaks can be found around door and window frames, the top of basement walls, chimneys, recessed lighting, and wiring holes in wall and ceiling.
Another option is to use a blower door fan to depressurize the building and force outside air into leaky spots. A trained technician can use this tool to quickly and accurately pinpoint leaks and recommend the most cost effective repairs.
Candle Test
Similar to the hand test, this method uses a candle instead of your bare hands. Light a candle near the seams of your windows and doors, and carefully move it around the frames. If the flame moves a lot or flickers, you have air leaks that need to be fixed. You can also use a smoke pencil or incense stick to locate air leaks, but make sure you’re in a safe and controlled environment to avoid risk of burns or soot damage.
The smoke test can reveal leaking gaps in wall outlets, recessed lighting fixtures and other concealed areas. Close up all fans and shut down your furnace before you start testing for leaks on a windy day. Then, light a candle or incense and pass it around the edges of common leak sites like windows, vents and doors. Anywhere the smoke wavers or appears blown in or sucked out of the house indicates a leak.
If you’re a homemaker or small business owner, you can perform these tests to identify air leaks and prioritize repair projects. Just be sure to use the same wax, fragrance and container each time so you can compare results consistently. Ideally, you should perform each test in the same room to ensure accurate results. Clearly label each jar with information on the fragrance type, temperature of melting wax, size of wick and scent load to make it easier to keep track of your results.
Paper Test
Air leaks around doors and windows are a common source of energy waste. These small areas can be difficult to detect using traditional methods, but they can have a significant impact on your energy bills when left unchecked. This is why identifying them early on is so important – the sooner you address these leaks, the more money you stand to save.
The paper stiffness test is a property of a paper or paperboard that determines its ability to bend under certain conditions. There are several instruments for measuring this property like Bekk, Sheffield and Print-surf smoothness testers. The standard testing method followed is TAPPI T451.
Clarke stiffness measures the force that a strip of paper under normal pressure, requires to bend by 50% of its length and is reported as kN/m2. This property determines the strength of a paper under tensile conditions.
Paper ash content, also known as base weight is the measure of inorganic fillers and coating contents such as China clay and Titanium dioxide that are used in the production of paper. It is determined by completely combustion of the organic matter present in the sample and is calculated on the basis of oven-dried weight of the sample.
The bursting strength of paper refers to the maximum hydrostatic pressure that can be tolerated by a strip of paper under constant & increasing pressure. This property is determined by applying a continuous hydrostatic pressure to the specimen through a diaphragm of specific dimensions.
Seam Test
If you’re an advanced home weatherization worker, you may use a variety of tools to locate leaks, such as thermal imaging cameras that identify temperature differences. But even a homeowner can do some simple tests with a handful of items in his or her home improvement toolbox.
For example, a hissing sound produced by air moving through a leak may be detectable with the back of your hand (smoke pencil or stick of incense will also do the trick). A wet finger will feel cold against areas that are losing energy and therefore allowing drafts to enter. A sudden higher energy bill, or noticing a drafty feeling in certain rooms of the house are other indications that air is leaking in and heat is being lost.
Another quick test is to shut down the air conditioner, furnace and any fans in the house, then walk around with a lighted candle. Anywhere the candle blows out or flickers, there’s a potential leak. This is a good method to do in the winter when it’s cold and windy outside.
An even faster way to find leaks is with a device developed by Environmental Protection Inc. of Mancelona, Mich. This device allows the company to test a weld seam’s integrity within 5 minutes, rather than the 40 hours it takes to do so under ASTM and NSF standards.