Why Is My A/C Running Non-Stop in the Summer? The Benefits of Air Sealing Your Attic and Installing Better Insulation

Oct 02, 2024

 Why Is My A/C Running Non-Stop in the Summer? The Benefits of Air Sealing Your Attic and Installing Better Insulation

Introduction:
It's the middle of summer, and your air conditioner is running non-stop, struggling to keep your home cool. You might find yourself asking, “Why is my A/C working so hard?” The problem may not be your A/C unit at all—it could be your attic. An improperly air-sealed and under-insulated attic is one of the primary culprits behind rising energy bills and overworked HVAC systems during the hottest months.

Air sealing and upgrading insulation in your attic can have a profound impact on your home’s energy efficiency, comfort, and even the lifespan of your heating and cooling systems. The right insulation, particularly cellulose and spray foam, can also improve indoor air quality, prevent mold growth, and keep pests out of your home. In this comprehensive guide, we’ll explore how an unsealed, poorly insulated attic affects your home and the benefits of properly addressing this crucial space.

Why Your A/C Runs Non-Stop in the Summer

Your A/C is designed to cool your home by removing heat from the air. However, if your attic is poorly insulated and not air-sealed, it can act as a massive heat sponge, forcing your A/C to work overtime to compensate. Here’s why:

Heat Transfer: In the summer, attics can reach temperatures of 150°F or higher. If there isn’t a proper thermal barrier, this heat seeps into your home, making your A/C work harder to maintain comfortable indoor temperatures.
Air Leaks: If your attic isn't properly air-sealed, conditioned air from your living spaces escapes into the attic, while hot air infiltrates back in. This air exchange forces your HVAC system to run constantly to keep up with the cooling demands.
Lack of Insulation: The R-value (a measure of thermal resistance) of your attic insulation directly affects how well your home stays cool in summer. Older, builder-grade fiberglass insulation, often rated at an R-value much lower than what’s needed today, doesn’t provide adequate thermal protection.
 

The Role of Attic Air Sealing and Insulation


What is Air Sealing?
Air sealing involves closing off the small gaps, cracks, and penetrations in your attic that allow for unwanted airflow. These leaks often occur around recessed lighting, plumbing vents, electrical wiring, and attic access points.

Without air sealing, the energy efficiency of your home suffers drastically. During the summer, cool air produced by your A/C escapes through these gaps, and hot air enters your living space, leading to higher cooling costs and reduced comfort. Air sealing is the first and most crucial step toward creating an energy-efficient attic.

What is Attic Insulation?


Attic insulation is the material that creates a thermal barrier between your living space and the attic. It’s measured by its R-value, with a higher R-value indicating better insulation performance. Building codes today often recommend attic insulation with an R-value of R-49 or higher, depending on your climate zone.

Common insulation types include fiberglass batts, cellulose, and spray foam. However, not all insulation types perform equally. Below, we’ll discuss the advantages and disadvantages of the most common types of attic insulation.

 
Types of Insulation and Their Benefits
1. Cellulose Insulation
Cellulose insulation is becoming a popular choice for homeowners looking for a sustainable and effective insulation option. Made from recycled paper treated with chemicals to resist pests, fire, and mold, cellulose insulation offers significant advantages over traditional fiberglass insulation.

Benefits of Cellulose Insulation:
Energy Efficiency: Cellulose has a higher R-value per inch than fiberglass, providing superior energy savings. It is blown into the attic, filling in all gaps and voids, creating a continuous barrier against heat transfer.
Mold Resistance: One of the most significant advantages of cellulose insulation is its mold resistance. It is treated with borates, a chemical that repels moisture, preventing mold growth in damp conditions, which is particularly important in humid environments.
Fire Resistance: Cellulose insulation is also highly fire-resistant. It has been treated with fire retardants that slow down the spread of flames, providing an additional layer of protection in the event of a fire.
Pest Resistance: Cellulose is naturally pest-resistant. The borates used to treat cellulose are toxic to insects and rodents, keeping your attic free of pests that can cause damage to insulation and other parts of your home.
Sustainability: As a recycled product, cellulose is one of the most environmentally friendly insulation options available. Using it in your attic helps reduce your carbon footprint while improving your home’s energy efficiency.
 
2. Spray Foam Insulation
Spray foam insulation is widely considered the best insulation available for attics. It not only provides an excellent thermal barrier but also acts as an air sealant, effectively stopping all forms of air infiltration.

Benefits of Spray Foam Insulation:
Superior Insulation Value: Spray foam has the highest R-value per inch of any insulation material, typically ranging from R-6 to R-7 per inch. It expands to fill every crack and crevice in your attic, ensuring no gaps are left for heat to escape or enter.
Air Sealing Capabilities: Unlike other types of insulation, spray foam creates a complete air barrier. This eliminates the need for separate air sealing and ensures that no conditioned air escapes through the attic.
Moisture Barrier: Spray foam is impermeable to moisture, preventing condensation and the growth of mold and mildew in your attic. This helps to protect the structural integrity of your home and ensures your insulation remains effective over time.
Longevity: Spray foam insulation doesn’t sag, settle, or deteriorate over time, meaning it will last as long as your home. While the initial cost is higher than other forms of insulation, its durability and efficiency provide long-term savings.
Soundproofing: Spray foam also provides excellent soundproofing qualities, reducing noise from the outside and between different floors of your home.
 
3. Fiberglass Insulation
Fiberglass insulation is the most commonly used insulation in homes, but it’s often considered "builder-grade" because it is cheaper and less effective compared to cellulose and spray foam.

Benefits of Fiberglass Insulation:
Affordability: Fiberglass insulation is inexpensive, which is why it's often used in new construction. For homeowners on a tight budget, fiberglass may seem like an attractive option.
Availability: Fiberglass batts are widely available and can be installed relatively easily, making them a popular DIY option.
However, fiberglass insulation has significant limitations:

Lower R-Value: Fiberglass has a lower R-value per inch than both cellulose and spray foam, meaning it’s less effective at preventing heat transfer. This can result in higher energy bills and reduced comfort, especially in extreme climates.
Air Leakage: Fiberglass batts do not provide air sealing, meaning air leaks around the insulation, reducing its effectiveness.
Moisture Issues: Fiberglass is prone to absorbing moisture, which can lead to mold growth and the insulation losing its thermal properties over time.
 
How Poorly Insulated and Unsealed Attics Impact Your Home
An attic that isn’t properly insulated and air-sealed can cause several issues, including increased energy bills, reduced comfort, and potential damage to your home. Below are some of the major problems associated with an unsealed, under-insulated attic.

1. Higher Energy Bills
When your attic is poorly insulated, your HVAC system has to work overtime to keep your home cool in the summer and warm in the winter. This extra load leads to higher energy bills. The Department of Energy estimates that homeowners can save up to 20% on their heating and cooling costs by properly air-sealing and insulating their attics.

2. Reduced Comfort
Temperature fluctuations are one of the most common complaints from homeowners with under-insulated attics. In the summer, hot air from the attic seeps into your living spaces, making it harder to maintain a consistent, comfortable temperature. In the winter, heat escapes through the attic, making your home feel drafty and cold.

3. HVAC System Strain
Your HVAC system is designed to maintain a certain temperature in your home. When your attic is not properly insulated, your A/C or furnace must work much harder to compensate for the lost conditioned air. Over time, this extra strain shortens the lifespan of your HVAC system and can lead to costly repairs or replacements.

4. Indoor Air Quality
Air leaks in your attic can allow dust, allergens, and pollutants to enter your home. These contaminants can circulate through your HVAC system, leading to poor indoor air quality. Proper air sealing and insulation help create a healthier indoor environment by preventing these particles from entering your home.

5. Drafts and Cold Spots
An improperly insulated attic allows air to flow freely between your attic and your living space, causing uncomfortable drafts and cold spots. These drafts can make your home feel unevenly heated or cooled, leading to discomfort and higher energy usage as your HVAC system works harder to maintain consistent temperatures.

6. Moisture and Mold Growth
Attics that aren’t air-sealed and insulated can suffer from condensation problems. When warm, moist air from your home rises into the cooler attic, it can condense on surfaces, leading to mold growth, wood rot, and structural damage. Insulation materials like spray foam and cellulose are better at preventing moisture buildup compared to fiberglass, which can absorb moisture and lose its effectiveness over time.

 
Steps to Properly Insulate and Air Seal Your Attic
If your A/C is running non-stop in the summer, or you're experiencing high energy bills, it might be time to upgrade your attic insulation and air-seal any leaks. Here’s a step-by-step process for creating a more energy-efficient attic.

1. Inspect and Assess Your Attic
Begin by inspecting your attic for signs of poor insulation or air leaks. Look for gaps around light fixtures, plumbing vents, and any other penetrations in the ceiling. You should also check your current insulation to see if it's providing adequate coverage and has the right R-value for your region.

2. Air Seal the Attic
Before adding new insulation, it’s important to air-seal all gaps and cracks. Use spray foam or caulk to close off any leaks around attic penetrations. Don’t forget to seal around attic access doors and hatches as well, as these are common sources of air leakage.

3. Choose the Right Insulation
Consider the benefits of each type of insulation. If you’re looking for a cost-effective, eco-friendly option, cellulose insulation may be the best choice. For the highest level of energy efficiency, air-sealing, and moisture control, spray foam insulation is ideal. If you’re on a budget, fiberglass batts can still provide some improvement over an uninsulated attic, but they won’t deliver the same level of performance.

4. Install Insulation to Code
For most homes, current building codes require an R-value of at least R-49 in the attic. Ensure that your insulation is installed to meet or exceed this requirement for your region. Blown-in cellulose or spray foam insulation is often the easiest way to achieve the right R-value, as they fill in all the gaps and provide a continuous thermal barrier.

5. Consider Ventilation
Proper attic ventilation is key to preventing moisture buildup and ensuring that your insulation performs well over time. Ensure your attic has enough ventilation to allow for proper airflow, which helps regulate temperature and prevents condensation.

 
The Power of an Insulated and Sealed Attic


If your A/C is running non-stop in the summer, it’s time to take a closer look at your attic. Proper air sealing and insulation can drastically improve your home’s comfort, reduce energy bills, and extend the life of your HVAC system. Among the insulation options, spray foam and cellulose stand out for their superior performance, while builder-grade fiberglass lags behind.

By investing in the right attic upgrades, you’ll not only enjoy a cooler, more comfortable home in the summer, but you’ll also reap the benefits year-round with lower energy bills, improved indoor air quality, and a healthier living environment. Don't wait—take control of your attic today and experience the long-term benefits of a properly insulated home.