Selecting a new air conditioning system for your home can be confusing due to the many available options. The fact that an AC installation will always cost at least a few thousand dollars means the last thing you want to do is choose the wrong one. This guide will help you understand what you should focus on when finding the right AC system for your home.
Standard AC vs. Heat Pump
The first thing you should do is decide whether you want to install a standard central AC or a heat pump. Either option will cool just as effectively, as long as it’s the proper size for your house.
The major difference is that heat pumps can also be used to heat your home in winter. If you have an aging furnace or are installing a heating and cooling system for a new home, it may be worth the extra money it will cost to purchase a heat pump. Along with cooling just as effectively as dedicated air conditioners, heat pumps are more energy efficient when it comes to heating. This is because they transfer heat from the outside rather than create it by burning fossil fuels like a furnace.
Energy-Efficiency Ratings
When installing a new air conditioner, understanding energy-efficiency ratings is key to making a smart long-term investment. In particular, SEER2 ratings, the updated version of the original SEER (seasonal energy efficiency ratio), give you a clearer picture of how efficiently a unit will operate throughout the cooling season. The higher the SEER2 rating, the less energy the system uses to maintain a comfortable temperature in your home.
The U.S. Department of Energy sets minimum SEER2 standards based on system size and regional climate zones. In North Carolina, those minimums are as follows:
- 14.3 SEER2 for all new heat pumps
- 14.3 SEER2 for central air conditioners under 45,000 BTUs
- 13.8 SEER2 for central air conditioners 45,000 BTUs and over
Choosing a unit that only meets the minimum can be cost-effective upfront, but a system with a higher SEER2 rating will typically lead to lower electricity bills. On average, every one-point increase in SEER2 corresponds to about a 7% gain in energy efficiency.
For example, upgrading from a 15 SEER2 unit to an 18 SEER2 model could reduce your cooling costs by roughly 20% per year. For many North Carolina homeowners, this can mean annual savings of $50 to $150, depending on the size of the system and usage patterns.
Over the typical 15-year lifespan of a central AC unit, these savings add up. An 18 SEER2 system may save you $1,000 to $2,000 compared to a lower-rated system. Going even higher on the efficiency scale could potentially double those savings. However, it’s important to weigh that against the increased installation cost.
Another advantage to choosing a more efficient system is eligibility for tax incentives. Homeowners who install a central air conditioner or heat pump that’s ENERGY STAR certified and rated 16 SEER2 or higher may qualify for a federal tax credit of up to $600. This credit can help offset the initial investment and make high-efficiency systems even more attractive.
Type of System
There are three different types of central cooling systems: single-stage, two-stage, and variable-speed. Single-stage systems are the most basic and, thus, the least expensive. At the same time, they’re also the least efficient and cost the most to run. A single-stage system always runs at full speed.
Two-stage systems have a full power setting and a medium setting. On the medium setting, the system only runs at around 60%-70% of its full capacity. While that means it cools more slowly, it also uses 30%-40% less electricity when on this setting. This type of system will always start running on the medium setting and only then switch to full power if the temperature in the house doesn’t start to drop after a set period.
Even though a two-stage system will always stay on for longer than a single-stage system, it will still use quite a bit less electricity overall. The longer cooling cycles you get with a two-stage system also result in the house getting cooled more evenly, helping to prevent hot spots. One other advantage is that the system makes much less noise when running on the medium setting.
Variable-speed systems are designed to run almost constantly at a much lower speed. The system will shut off once it cools down enough in the evening that you no longer need your AC running, but otherwise, it will be on most of the time. This type of system has a variable-speed compressor that can run anywhere from around 25%-30% up to 100% capacity. The system also has a variable-speed blower that can automatically adjust its speed to regulate how quickly it circulates air through the system.
While variable-speed systems are the most efficient and use quite a bit less electricity, the cost savings still aren’t always enough to cover the much higher upfront price. That’s why many people end up choosing a two-stage system, as it is less expensive to install while still providing significant energy savings.
AC Sizing
While all of the above factors are important when choosing a new cooling system, making sure the system is correctly sized is also critical. Installing a system that’s either too small or too large for your home’s specific cooling needs is asking for trouble.
If the system isn’t big enough, it will often have difficulty keeping your house as cool as you want, especially on hot and humid days. While an oversized system won’t have issues keeping your home cool, it will make your electricity bills much higher than they need to be. You also end up paying more than necessary to install an oversized system. Another concern is that it will often short cycle, meaning it turns on and off every few minutes. Short cycling greatly increases the strain on the system’s motors, which is why oversized systems usually have a much shorter lifespan. Undersized systems also typically don’t last nearly as long simply because they have to run so much more.
Correctly sizing a central cooling system requires using a complex formula that takes numerous factors into account. This includes where you live, the size of your house, how well-insulated your home is, and even things like how many windows and exterior doors you have. The fact that so many different factors are involved is one reason why you should hire an experienced HVAC contractor for the installation.
If you’re looking to install a new AC system or need any other assistance with your cooling services or heating needs, Dawson's Electric & Air is here to help. We’ve been serving Raleigh and the Triangle Area for the past 20 years and will work to make sure your home is always comfortable.
We offer a range of quality AC and heat pump systems and will assist you with finding the perfect option. Contact us today to schedule an appointment with one of our experienced technicians.
