Air leaks in your home are often easy to detect. Whenever you feel a cold draft in your home in the winter, outside air is infiltrating your home. Air leaks may occur in obvious places like that gap underneath your door, but they can also be harder to find. Often, it is a combination of both. According to the U.S. Environmental Protection Agency's (EPA) ENERGY STAR program, 25 to 40 percent of the energy used for heating and cooling your home is wasted through air leaks.
What Are Air Leaks?
Air leakage occurs when air enters or leaves your home uncontrollably through cracks, gaps, and openings in the building envelope. Air leaks are a sign that the walls, floors, and roof of your home are not well sealed.
Air leakage not only happens when outside air enters your home but also when conditioned air from the inside leaves your home. Typically, it is a combination of both. In the winter, the cold outside air cools down your home, and your heating system needs to work harder to heat it up to your preferred room temperature. In the summer, hot air entering your home will make the air conditioner work harder. In both cases, air leaks can cost you big time because your energy use will go up.
Air can leak into and out of your home in different ways. They're easy to detect in many cases, such as holes and gaps around doors and windows or openings in your floor. In other cases, air can escape or enter through joints between building materials in the walls, floors, or ceiling. Gaps in these joints can be caused by defects in construction or material or the holes cut for electrical outlets, piping, or recessed lights.
The Cost of Air Leaks in Your Home
Air leaks can increase the cost to heat and cool your home significantly. They account for up to 40 percent of the heat and cooling expenses of a typical American home. While this number varies based on your geographic location and local climate, it also varies with the type of home you live in. Air leaks are more common in single-family homes than apartments, while at the same time, single-family homes have a higher heating and cooling bill per square foot.
According to the U.S. Energy Information Administration, 51 percent of the energy used in the average American home was used for space heating and cooling in 2015. Accordingly, air leaks account for up to 20 percent of the total annual energy costs.
Air leakage can cause mold and lead to structural damage through moisture building up in the exterior walls. During the summer, air leaks can bring in humid air from outdoors, while in the winter, warm and humid indoor air can move into the walls. Condensation in the walls leads to mold, which can affect the indoor air quality and your health. Repairing mold damage and especially structural damage can also cost you big time.
Easy Ways to Reduce Air Leaks in Your Home
You can take various simple steps to reduce air leaks around your home, which are cost-effective and come with a quick return of investment on your energy bills. They also lead to an immediate improvement of comfort in your home.
During your normal daily routine, make it a habit to keep external doors locked so the door seals tightly against the weatherstripping on the door frame. When you're not using your fireplace, close the damper tightly. Keep your dryer door closed to keep the cold air from entering your home through the dryer vent. Cover exhaust fans when they're not in use to prevent outside air from entering. Though not considered air leaks, active fans such as your kitchen hood or bathroom fans move out warm air in the winter and cool air in the summer, which then must be replaced by your heating or air conditioning system. Remember to turn them off when they're not needed.
Do a visual inspection of your home and seal all the smaller cracks or gaps you find with caulking and install or replace the weatherstripping around your doors and windows to include your attic hatch or basement door. The EPA recommends inspecting all areas where two different building materials meet. These areas are typically where plumbing or electrical wiring penetrates walls, floors, and ceilings. Some areas that often get overlooked are electrical outlets, TV and phone lines entering your home, or mail slots.
Maximize Your Home's Air Sealing
Bigger gaps or holes can be sealed using a foam sealant from your local hardware store. Expanding spray foam sealants can be used to easily close openings behind baseboards or around openings in less visible areas. Make sure to use a fire-stop sealant around electrical equipment. If possible, uninstall any window air conditioning units and store them in a safe place over the winter. That way, you can close the window completely and reduce air leakage.
While air sealing your home is an easy way to reduce your energy bill, adding proper insulation can reduce the amount of heat escaping through your walls significantly. Insulation can be added with minimal effort in easily accessible areas such as your attic floor or basement ceiling. If possible, replace your old windows with more efficient double-pane windows or high-performance three-pane windows and old exterior doors with newer insulated doors, especially if air leaks through the door or window itself.
If you're planning on air sealing your entire home, it is a good idea to start off with a blower test for your home. The test depressurizes your home to locate more hidden leaks. It can be part of an energy assessment to capture more ways to save energy in your home, such as installing insulation. Many utilities offer discounts on blower door tests as part of their energy efficiency programs.
Other Benefits of Air Sealing Your Home
While air leaks in your home can cost you big time, fixing leaks and sealing walls, floors, and roof of your home can bring significant savings on your utility bills. Air sealing your house improves your home's comfort by reducing drafts and eliminating cold spots around the exterior walls and floors. It also increases the indoor air quality by reducing the amount of dust and air pollutants entering your home while keeping out insects and small animals.
Once your home is well-sealed, have a look at your next few energy bills and see how much your efforts have saved you. You may be surprised at the results! And even if you still think your energy bills are too high, there are still things you can do. You could look into more efficient appliances, read up on ways to save on natural gas and electric bills, or even shop around for a new energy provider if you live in a deregulated state. You've got options, so take advantage of them!