Air conditioning is a significant aspect of your home’s carbon footprint, as much as 20% on average. The Department of Energy estimates that the average household wastes a large portion of what it spends on cooling each year. That waste isn’t due to the efficiency of the AC unit alone. Let’s explore the other notable factors.

Central Ductwork

If you have a central AC or heat pump, the system forces air through a network of ducts. There’s great potential for energy loss in those ducts. In fact, the DOE estimates that the average home loses between 30% and 40% of its cooling that way. That is a staggering amount.

The good news is that there are solutions. You should have your ducts inspected once a year. You can schedule this service at the same time you book your spring cooling tune-up. The main cause of cooling loss in ducts is air leakage due to bad seals. If you have this problem, our HVAC technicians can correct it through the EPA-approved aerosol sealing method. It can reduce loss down to just 5%.

Crawl Space Insulation and Encapsulation

Crawl spaces can undermine cooling efficiency due to the stack effect. This is where your home draws in hot and humid air from the crawl space through convection. Insulating your crawl space can prevent the stack effect entirely. If you have excess moisture in your crawl space, you may also need to encapsulate it and, potentially, install a crawl space dehumidifier. This will prevent your crawl space from increasing humidity levels in your home.

Ceiling Fans

You should consider installing ceiling fans in any room where it’s practical and you use the space often. A ceiling fan serves two purposes when it comes to your air conditioner. It helps to distribute the cooling more evenly throughout the room. It also makes you feel cooler as the air blows on you. This may allow you to increase your comfortable temperature by as much as several degrees.

HVAC Air Filter

Central AC systems have one or more supply vents that require an air filter. Never use a filter with a higher minimum efficiency reporting value (MERV) than your AC supports. You should also check your filter each month and replace it when it’s visibly clogged. If you have a ductless AC, clean the filter every two weeks, and replace it annually. It may seem like a simple thing, but a clogged HVAC filter affects static air pressure. It will often lead to warm spots and even entire rooms that feel too warm.

Programmable and Smart Thermostats

If you haven’t yet, you should consider investing in a programmable or smart thermostat. These let you program your AC to increase the temperature while you’re sleeping and away from home. According to the DOE, a change of just 7 degrees over eight hours can lower your cooling costs by 10%. Many homeowners can save even more than that. Smart thermostats are Wi-Fi-capable programmable thermostats that provide additional features through which you can save.

Whole-House Ventilation Fans

Housebuilders build modern homes with energy efficiency in mind. That means that they have a tight seal, which is great for cooling efficiency. It often means little to no natural ventilation, which can result in greater reliance on your AC. With a whole-house fan, you’ll often be able to wait until later in the year to begin using your AC.

Avoid Overuse of Non-HVAC Ventilation

Non-HVAC ventilation is often necessary, such as kitchen and bathroom exhausts. Still, be mindful that these exhausts are venting your conditioned air directly out of the home. Run them only as long as you need to. For the bathroom, that’s when all moisture is gone. For the kitchen, that’s 10 minutes after you’ve finished cooking.

Fix Too Much Natural Ventilation

If you live in an older home, you may have the exact opposite problem in a newer home. Older homes often have too much natural ventilation. You can lose your cooling through cracks and other imperfections in the walls, ceilings, floors and foundation. If this is a potential issue for you, look into having a home energy audit performed and possibly resealing your house.

Whole-House Dehumidification

Relative humidity is the measure of airborne water vapor in relation to temperature. You should avoid an RH above 60%, and ideally, it should be somewhere between 30% and 50%. When the RH is lower, you’re going to be more comfortable in general and more comfortable at a higher temperature. If you struggle to maintain an optimal RH with your AC alone, a whole-house dehumidifier is the solution. Our HVAC technicians can install it on the supply side of your HVAC system. That means that it will extract moisture from the air before it gets to your AC. That has the added benefit of making your AC more efficient.


How good your home’s insulation is largely dictates its thermal efficiency. If your insulation is inadequate, you can lose a lot of cold air that way. The DOE recommends annual insulation inspections. Replace and add insulation as needed. Spray foam is a great option when the time comes because it’s relatively affordable and lasts between 80 and 100 years.

Energy-Efficient Windows and Doors

Windows and doors are other common reasons building envelopes are inefficient. When you need to replace them, consider investing in energy-efficient products. According to the EPA, Energy Star windows and doors can reduce AC costs by 13% on average. They may also let you claim a tax credit and energy rebates that help offset the initial investment.

Energy-Efficient Window Treatments

According to the DOE, about 75% of sunlight that falls on a window enters the home as heat. That causes your AC to work harder and your electricity bill to go up. Energy-efficient window treatments can reduce that unwanted solar heat by as much as 60%.

Zoned HVAC System

Traditional central HVAC systems provide a consistent temperature throughout a home. The downside to that is that you’re likely cooling some aspects of your home unnecessarily. There are two main solutions to avoid that.

Integrated HVAC Zoning

When you upgrade your central HVAC system, you may want to consider a zoned system. A zoned HVAC system lets you set different temperatures for distinct zones. While you can add zoning to an existing system, it can be quite complicated and expensive.

Ductless Mini-Split System As an Add-On

An alternative available to you right now is to add a ductless AC system to your home. A mini-split system would, for instance, let you maintain a very cool sleeping temperature in the bedroom. The rest of the home could have a much more energy-efficient setting.

Local Energy Efficiency Pros in Raleigh

If you’d like to make your Raleigh home’s cooling more efficient beyond just the AC, Thermo Direct can help. Our HVAC technicians specialize in furnaces, air conditioners, heat pumps, smart thermostats, dehumidifiers and humidifiers. We also repair, reseal and replace ductwork, install spray foam insulation and insulate and encapsulate crawl spaces. Ask us about our AC maintenance!

Thermo Direct has licensed electricians too. We perform inspections and upgrade electrical panels. Our electricians also install and repair outlets, switches, lighting, ceiling fans, surge protection, EV charging stations and generators. If you’d like to schedule a service appointment or in-home consultation, call today, or contact us online.

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