What Is a SEER Rating & Why Does It Matter for Your HVAC System?

In Lancaster, PA air conditioning is essential for your family’s comfort and health, but it gets expensive to cool your home year after year. That’s pushing more homeowners to consider upgrading to higher-efficiency air conditioning systems. However, it’s often hard to decide how much of an efficiency upgrade is worth paying for. To do it, you must understand how AC manufacturers measure and rate the efficiency of their systems. Manufacturers measure efficiency using a scale called SEER.

What Does SEER Mean in HVAC?

Let’s begin with the question: What is SEER? SEER stands for Seasonal Energy Efficiency Ratio. It’s a system developed by the American Society of Heating, Refrigeration, and Air Conditioning Engineers and the Department of Energy. The original purpose of the SEER system was to give regulators a way to set efficiency minimums for new ACs. The system assigns numerical scores to every AC based on the outcome of standardized laboratory testing. The simplest way to understand the SEER system is to know that a higher SEER rating means a more efficient AC.

Even after hearing the basics of a SEER rating explained, there’s still more to learn. A SEER rating is calculated by dividing an air conditioner’s total cooling output in BTUs by the total energy it consumes, and the result is averaged over a typical cooling season. To simulate real-world usage, the SEER formula incorporates several assumptions about how often your AC runs at different capacities. These assumptions include:

• 1% of cooling season at 100% output
• 42% of cooling season at 75% output
• 45% of cooling season at 50% output
• 12% of cooling season at 25% output

Additionally, it’s worth noting that SEER testing takes place under controlled, steady-state conditions. Specifically, the indoor environment is set to 80°F with 50% relative humidity, while the outdoor environment is maintained at 82°F with 40% relative humidity. While that might not match the hotter, more variable conditions of a typical Lancaster summer, another detail helps balance things out.

During testing, both the indoor and outdoor environments use electric heaters to hold those precise temperatures. This setup forces the AC system to operate at full capacity for extended periods. While the ambient conditions are relatively mild, the constant high output helps simulate the stress an air conditioner would face during real-world summer use.

How SEER Ratings Affect Energy Efficiency

When you go shopping for a new AC, you should find a SEER rating listed on each unit’s EnergyGuide label. That can give you a decent idea of the efficiency of a given AC compared to its peers. Unfortunately, unlike other EnergyGuide labels, the ones on ACs will not contain an estimated yearly operating cost. That can make it challenging to judge whether a higher-SEER system is worth the price premium. Plus, there’s another thing you must know about the SEER scale: it isn’t linear. That means efficiency gains diminish as you move up the scale. In other words, the difference between a SEER of 14 and 15 isn’t the same as between a 15 and 16.

Fortunately, there’s a simple math formula you can use to calculate the efficiency difference between two ACs. However, it only works when you compare two systems of the same capacity. When it comes to central ACs, you’ll find capacity listed in tons. To use the formula, you begin by dividing the higher SEER value by the lower one. Then, subtract one from your result, and multiply the leftover decimal by 100. The answer you get is the efficiency difference between the two ACs as a percentage.

If you know the SEER rating of your existing AC, you can use this formula even more effectively. It can help you estimate how much your cooling bill might drop after installing a given AC. Although your answer won’t be precise, it should yield helpful results. First, start with the fact that AC use accounts for about 19% of the average home’s yearly electricity costs. That should let you calculate approximately how much you spent on cooling your home in the previous year. Using that number and your efficiency difference calculation, you can estimate how much any given AC will save you.

What’s the Best SEER Rating for Homes in Pennsylvania?

There’s no hard and fast rule specifying the best SEER rating for PA. However, it’s typically a good idea to purchase the highest-efficiency AC your budget allows. You should also know that you can’t legally buy a new AC with a SEER lower than 14 here in Lancaster. That’s the federal efficiency minimum as of 2023. As you shop, you may find that manufacturers group their systems into efficiency tiers, as follows:

• 14-15 SEER is standard efficiency
• 16-18 SEER is mid-range efficiency
• 19-21 SEER is high efficiency
• 22+ SEER is ultra-high efficiency

You should also know that purchasing a higher SEER AC can make more sense in certain situations. One is if your home’s electricity rate is relatively high. Here in Lancaster, PPL has raised electricity rates multiple times in recent memory. Third-party suppliers have all followed suit. If you expect that trend to continue, you should keep it in mind as you shop for a new AC. After all, you’ll depend on your new system for at least the next 10 to 15 years.

Higher SEER systems are also more beneficial in larger, rather than smaller homes. That’s because larger homes typically have higher cooling needs. So, each extra bit of efficiency you get from a new AC will have a bigger impact on reducing your cooling costs.

When Should You Upgrade to a Higher SEER System?

In most cases, upgrading to a higher SEER AC system comes down to homeowner preference. You might choose to make the switch to lower your long-term cooling costs. You could also be motivated by a desire to reduce your environmental impact through improved energy efficiency. Or, you may simply be replacing an aging unit that’s nearing the end of its usable life. If you need help deciding if an AC upgrade is the right choice, we are here to help.

Your Local AC Experts

When it comes to efficient air conditioners in Lancaster, nobody beats Lancaster Plumbing, Heating, Cooling & Electrical. We’ve proudly served Lancaster residents since 1904. We sell and install the latest energy-efficient HVAC systems from leading manufacturers like Bryant, Carrier, Rheem, and more! And you can count on a quality installation from our team of NATE-certified HVAC technicians. We even offer financing options on approved credit to help you afford the new AC you want.

When you’re ready for a new AC installation in Lancaster, contact Lancaster Plumbing, Heating, Cooling & Electrical to get the job done right the first time.

Frequently Asked Questions

Homeowners typically have plenty of questions about AC efficiency. Here are the answers to the most common ones we get.

Is a higher SEER always better?

A higher-SEER AC is always a more efficient option. However, a high SEER rating does not always justify the higher up-front cost. We can help you install a system that makes the most sense for your home.

Do SEER ratings apply to both AC and heat pumps?

Yes, SEER ratings apply to conventional ACs as well as heat pumps. However, with heat pumps, SEER only applies to their cooling function. They use a separate rating scale called HSPF for their heating efficiency.