How Important is Air Sealing? 5 Ways Air Leaks are Costing You Money

Indoor Air Quality, Saving Energy

When you imagine your home being comfortable, you might have seen it in your mind’s eye as being breezy where fresh air can come and go. And you are right about wanting adequate ventilation in your living space, free from stale odor or buildup of air pollutants.

But, air leaks are not equivalent to proper ventilation. Truth to told, you should NEVER underestimate the destructive power of air leaks. So how important is air sealing?

DP how important is air sealing

You might be surprised how air sealing is just as essential as proper ventilation and sufficient insulation to your overall home comfort and indoor air quality. Air sealing saves you from poor IAQ, discomfort due to uneven temperature, and overwhelmingly high electric bills due to air leakages.

What are you to gain from air sealing? And are air leaks that bad? Let’s find out.

Is Air Sealing Important?

Air sealing is the primary and most effective solution to air infiltration, or the uncontrolled leaking of air from the inside of the house to the outside and also the other way around. Dissimilar to proper ventilation, where needed fresh air can come in a regulated amount and consistency, leakages come in the form of gaps, small holes, and crevices that can only be prevented by air sealing.

In simpler terms, the cold air produced by your AC and the heat provided by your furnace or other kinds of heating systems will go to waste as they escape through air leaks around your house.

There are at least five ways air leakages are hurting you financially and impacting your family’s well-being:

  1. Compromised health and safety – If left untreated, air leaks can compromise the indoor air quality of your home by letting in harmful pollutants such as smoke, dust, pollen, and other small particle toxins. These can compromise your family’s breathing air and may even lead to severe allergies and serious respiratory problems. This will lead to expensive medical bills and additional stress for your family.
  2. Reduced comfort – Without an appropriate amount of air sealing, the performance of your cooling or heating systems will be reduced. Your desired level of coldness or amount of heat will take too long to be attained as the processed air kept evading the space. 
  3. Increased energy consumption – Your air conditioner or furnace is programmed to keep up with the thermostat temperature, but with chilled or heated air keep escaping, these HVAC systems will work twice as hard and consume more energy than necessary. This will cause you to have soaring electric bills monthly, especially in the summer and winter seasons.
  4. Diminished HVAC durability – Tremendous waste of precious energy is only one part of the consequences brought by air leaks. If your HVAC systems are constantly overused day in and day out, this would lead to premature wear and tear of the machines, costly repairs, or even an early replacement of your cooling and heating devices. 
  5. Additional carbon footprint – Excessive use of air conditioners and furnaces due to air leaks results in another problem: Immoderate greenhouse gas emissions such as carbon dioxide (CO2). Sealing air leaks partnered with adequate insulation are extremely helpful means to reduce homes’ carbon footprint.

Now that we are enlighted about how devastating air leaks are, you still might be hesitant about air sealing your home. Does sealing the air would make homes vapid, restrictive, or even suffocating? 

To help you ease up on the idea of air sealing, let us tackle a little more comprehensively one of the foremost enemies of efficient cooling or heating, and how appropriate and correctly done air sealing can combat each of these problems.

What Can Sealing Contribute to Your Home

A leak is never a good thing, especially in a structure you trusted to protect you and your family and made it fit for living. Additionally, air leaks can affect every room of a home, even if you just have a few gaps in some parts of the house.

Whether it is entering or escaping liquid or gas, a leak is rarely intentional and usually happens by fault or mistake. The result, on the other hand, is almost always undesirable.

How can air sealing solve the ugly effects of air infiltration or leaks? Will it offer quick returns on investment or will investing in sealing your home just be a money-waster?

Safe and Healthier House

When air leaks are present in a home, it can jeopardize your family’s health and well-being in two ways: 

1) Uncontrolled air coming from outside can bring in harmful pollutants such as smoke, dust, pollen, pet dander, and other unwanted particles. If you have children and older members of your household, they are more susceptible to developing allergies, asthma, and other respiratory issues. If you do have family members with current health problems, exposing them to these airborne toxins may aggravate their pre-existing conditions.

2) Cold drafts and hot spots may emerge due to unplanned openings and crevices around the house. Surfaces that should be otherwise dry may form condensation on them where mold and mildew would ideally thrive. Centers for Disease Control and Prevention CDC warns against the health effects of mold exposure to people. From mild reactions like stuffy nose, wheezing, and red or itchy eyes or skin, to severe responses such as fever and shortness of breath, mold is bad news for your family’s well-being.

Your Partner in Home Comfort

Ever felt a gust of cold air as you try to sit comfortably in a supposedly heated room? Or maybe found yourself sweating in certain places in the house despite having the air conditioner on?

These cold drafts and hot spots are not supposed to happen, yet nuisances were made possible by air leaks. Small holes and seemingly insignificant cracks if put together can cause your AC or heater to function poorly. Besides being hazardous to health, air leaks are a major detractor in your pursuit of having a comfy home.

Air sealing can make the temperature even throughout your living space. Your desired temperature set in your thermostat can be conveniently met by your cooling or heating systems without distractions.

Save More Energy

According to a paper published by the University of Nebraska-Lincoln, air leakage is one of the primary triggers of waste in energy and other resources in most residences in the country.

“Air leakage is often the least understood part of high energy usage. [It] contributes to unnecessary costs, less comfortable surroundings, and may have health risks,” says the research and case studies supported by the US Department of Agriculture.

How much waste are we talking about?

To put things in perspective, a regular utility bill is composed of energy consumed by heating and cooling systems, lighting and appliances, water heating, refrigeration, and other electricity-powered operations. Your air conditioner or furnace takes up 43% of that total utility bill!

Imagine if the precious energy dedicated to making the temperature in your house cozy and desirable is compromised because of some gaping holes and cracks! 

How do air leaks factor in? 

“Air infiltration or leaks can account for 30% or more of heating and cooling costs,” the study declared.

This is supported by the authority on energy savings, Energy Star. They strongly suggest finding and sealing air leaks around the house. Backed by the Environmental Protection Agency or EPA, the independent executive agency of the US responsible for environmental protection matters, it determines that you can save up to 15% on heating and cooling costs, or an average of 11% on total energy costs if you properly air seal your living space.

That’s $200 a year’s worth of savings! Or a $200 loss if you ignore air sealing completely. Your choice.

HVAC Durability

This is kind of a no-brainer. With sneaky air leaks as energy-wasters lurking around your house, your AC and heating systems will work twice as hard, if not more, to keep the temperature indoors at a comfortable level.

It’s like trying to fill a bucket with plenty of holes!

Relentless usage of your cooling or heating devices is a nightmare waiting to happen not only to your energy consumption but to the overall condition of the unit. 

An AC, for example, automatically starts as soon as it sensed that the temperature is warmer than the thermostat level. With air leaks sabotaging its goal to chill the room, it can either run continuously without stopping or start and stop abruptly without completing a full cycle.

Short cycling is one of the most common culprits of a worn-out AC unit and can inevitably contribute to early repairs or even replacement.

Proper Insulation, Less Carbon Footprint

Based on the report presented by the EPA, two of the largest source of greenhouse gas emissions from human activities is from burning of fossil fuels for electricity and heating commercial and residential spaces.

Imagine if your HVAC systems would not cease to run because the air leaks keep letting the processed and unprocessed air out. It is double jeopardy because the energy is used to generate heat and consumes a ton of electricity.

Sealing air leaks is an extremely helpful means to reduce our homes’ carbon footprint or the total amount of greenhouse gas emissions such as carbon dioxide (CO2) caused by excessive use of air conditioning or heating devices. This is especially true if you correctly seal your home and at the same time properly insulate it. 

If you want to start supporting green initiatives, properly air-sealed homes are a great way to go. As you improve your home’s air tightness and insulation, your HVAC systems will only run a minimal amount of time but still achieve your desired level of comfort.

How Do I Know If I Have Air Leaks?

Detecting where the problem lies is the first step to resolving it.  How do you know which parts of your home are leaking air, and how many? There are many practical measures you can do and some with the help of a professional.

The “Blower Door” Test

The most definitive test to ascertain how tightly sealed is your home is the “blower door” test. It is done during an energy audit by a qualified expert called a Home Energy Professionals (HEP) Certifications Energy Auditor.

The test got its name from the special fan fitted into the frame of one of your exterior doors. As it is turned on, it will suck out all the air from the inside of the house, making the air pressure indoors very low. The higher pressure from outside would naturally attempt to go into the house through whatever hole, gap, or crevice it could find.

With the use of a smoke pencil, the technician will be able to assess the airtightness of homes and identify the location of air leaks.

Building Pressurization Test

This test runs in the same vein as the blower door test but without the specialized machine or the help of a qualified technician.

To perform a building pressurization test, you must pick a very cool, windy weather day. After you turn off all combustion appliances and all exhaust fans that blow air outside, shut all your windows, exterior doors, and fireplace flues. 

Depressurize your home by using a large window fan to pull out air from all the rooms. Now, light an incense stick and hover it around known air leak locations. If the smoke in the incense flickered or blew, you found a leak. 

Another way is to use a damp hand and run it over the walls. If your hand feels unnaturally cool to the touch, you have an opening to seal.

Visual Inspection

Visually check for any openings where air might leak, especially in areas where two different building materials meet. The Department of Energy provided a list of typical spots where air leaks occur such as exterior corners, outdoor water faucets, where siding and chimneys meet, and areas where the foundation and the bottom of exterior brick or siding meet.

When you get to the inside, concentrate on finding leaks in and around electrical outlets, switch plates, door frames, window frames, gas service entrances, baseboards, fireplace dampers, attic hatches, wall-mounted ACs, or those installed on windows, cable TV lines, phone lines, dryer vents that go through walls, vents, and of course, fans.

What Air Sealing Techniques Can You Do?

Caulking and weatherstripping are the two most common and inexpensive ways of air sealing a residence. 

What exactly are caulking and weatherstripping and what products are available in the market to execute these air sealing techniques? 


Use a caulking gun loaded with caulk made of silicone or latex for holes, cracks, or joints that measure less than a quarter-inch wide between home components that are not moving.

Caulk is sometimes confused and used interchangeably with sealant, but the latter is more dedicated to structures’ components that are contracting and expanding, while caulking is more dedicated to preventing air, moisture, smoke, and dust leakage. 


If the building parts are movable such as doors, operable windows, and trunks, use weatherstripping made of rubber or metal to close up the leaks. 

Other kinds of weather stripping materials are foam tape, door sweeps, felt, vinyl, silicone, and V strip or tension seal. We published a complete guide in air sealing using caulking and weather stripping techniques in the article: Air Sealing 101: A Complete Guide on Sealing Your Home for Comfort. Read this in its entirety and seal your victory against air leaks once and for all!

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