Why You Don’t Need a Bigger Air Conditioner (Probably)

You’ve probably noticed that you’re not getting the airflow out of your vents that you should be. Maybe you have rooms that are hotter than others. Therefore, the logical conclusion is that not enough air is being pushed through the ducts and into rooms further away from your unit. So, the next logical leap would be that you need a bigger, and more expensive, air conditioner so all that air gets pushed through, right? Well, most likely not. Sure, someone will sell one to you, and you may even notice a difference, but that’s kind of like pouring gas on top of your car to get it in the tank. Let’s first look into solving your air leakage issue before swapping out for something that could be overkill.

Understanding the Real Issue: Duct Leakage

A significant factor in uneven room temperatures is duct leakage. According to the Department of Energy, every home that has a duct system has duct leakage. On average, that leakage varies from 10% to 30%. So it’s possible that only 70% of your conditioned air is reaching the end of your ductwork, while the other 30% is escaping into unconditioned spaces such as inside the walls, into an attic, or in your crawlspace. Considering this, even if you paid up for a stronger air conditioner, you’re now paying for even more air to be lost. Therefore your air conditioner may already be the perfect size for your home, but you’re losing the air through duct leakage. Sealing your ductwork may be all you need to solve your problem.

The “Right Sizing” Philosophy

The concept of “right sizing” your air conditioning system is crucial in addressing inefficiencies. Rather than focusing on the size of the equipment, it’s crucial to consider the unique needs of your home. Factors such as the home’s insulation, the number and quality of windows, and the state of your ductwork play a significant role in determining the appropriate size of your air conditioning unit. Learn more here about getting the maximum efficiency out of your equipment.

In the case of windows, quality glazing can significantly reduce unwanted heat gain or loss. Similarly, superior insulation acts as a barrier to heat flow, maintaining desired indoor temperatures with less energy expenditure. It’s also important to consider the concept of Air Changes per Hour (ACH). ACH is a measure of how many times the air within a space is replaced in an hour, and it plays a pivotal role in understanding a home’s energy efficiency and comfort levels. Poorly sealed and drafty homes can have high ACH values, leading to significant energy losses and uneven temperatures.

The Misconception of Bigger Units

The misconception that a bigger air conditioner will solve all cooling issues leads to a cycle of inefficiency and increased energy costs. Oversized units not only consume more energy but can also lead to other problems such as increased humidity levels in the home and reduced life of the air conditioner overall. The key lies in optimizing the performance of your current system through measures like duct sealing and insulation improvements. By oversizing your equipment, you’re getting less efficiency out of that equipment, even if it’s rated very well.

Installing an oversized air conditioner can inadvertently create problems in your home, such as excessive condensation and mold growth. When an AC unit is too large, it cools the space quickly but doesn’t run long enough to effectively remove humidity from the air. This excess moisture can condense on cooler surfaces, fostering mold growth that can damage your home and affect air quality. Moreover, an oversized AC can lead to a phenomenon known as ‘choking,’ where the system’s return air flow is insufficient for its capacity. This restriction makes the air conditioner work harder than necessary, increasing wear and reducing its lifespan. Proper sizing and airflow management are critical to avoid these issues and ensure efficient, healthy cooling.

It’s also important to understand the role of return duct leakage. Return ducts bring conditioned air back to your furnace or air conditioner. Not only does this type of leakage pull in hot/humid or cold/dry air from unconditioned spaces, but it also introduces various contaminants into your living environment. A bigger air conditioner would only exacerbate these problems. Moreover, the imbalanced airflow caused by return duct leaks can lead to a buildup of positive pressure inside your home. This positive pressure forces conditioned air out through any openings in the building’s envelope, a process known as exfiltration, effectively wasting the cool air that your air conditioner works hard to produce. With more air being forced through the system, the positive pressure increases, leading to greater losses of conditioned air and higher infiltration of contaminants.

Leakage Causing positive pressure inside home

The Easiest, and Most-Effective Way to Seal Your Ducts.

You may be wondering how to even go about sealing your ducts. Using tape and a sticky sealant called mastic are a couple ways to stop the leaks that you can see. But what if you don’t know where the leaks are? That’s where Aeroseal comes in. Aeroseal is the only advanced duct sealing method that can reduce leakage by 90%-99% in one simple process. Even the leaks you can’t see, which are often behind drywall. Aeroseal’s non-toxic, water-based sealant efficiently seals air leaks in both ducts and the building envelope itself, ensuring that your air goes where you need it and not where you don’t. Imagine feeling comfortable, consistent temperatures in ALL rooms of your house. Aeroseal is by far the most effective, and efficient method to seal ductwork.

Learn more about how Aeroseal works.

Optimize Before You Maximize

Obtaining consistent room temperatures doesn’t necessarily mean buying a stronger air conditioner. By understanding the underlying issues and embracing the “right sizing” approach, you can achieve efficient cooling without falling into the trap of “bigger is better.” So, before you purchase a pricey upgrade, consider whether sealing your ducts and optimizing your current system might be the smarter, more efficient choice.