When it comes to comfort in Mechanicsburg, PA, having a reliable air conditioning system isn’t just a luxury—it’s a necessity. While the area doesn’t experience scorching desert heat, Pennsylvania’s humid summers and unpredictable weather patterns can make indoor temperatures feel oppressive without effective cooling. Whether you’re upgrading an aging system or installing a unit for the first time, buying a new air conditioner is a significant decision—one that impacts your comfort, energy bills, and even your indoor air quality for years to come.

Yet, despite the importance of this investment, many homeowners unknowingly make costly mistakes during the buying process. These missteps can lead to higher expenses, inefficient performance, or premature system failures. To help you make a confident and informed choice, we’re breaking down the top five mistakes people make when buying a new AC unit in Mechanicsburg—and how to avoid them.

1. Choosing the Wrong Size AC Unit

One of the most common (and most costly) mistakes is selecting a system that is either too large or too small for your home.

Why Size Matters

Air conditioners are measured in “tons,” which refers to their cooling capacity. You might assume that bigger equals better, but that’s far from the truth. An oversized AC unit will cool your home quickly but shut off before completing a full cycle—this is known as “short cycling.” It leads to inconsistent temperatures, higher humidity levels, and excessive wear and tear. On the other hand, an undersized unit will run continuously, struggling to keep up with demand, and ultimately overworking itself.

How to Avoid It

An HVAC professional should perform a Manual J load calculation to determine the proper size for your home. This calculation considers square footage, insulation levels, window size, orientation, number of occupants, and even local climate patterns in Mechanicsburg. Skipping this step or relying on rough estimates is a shortcut that can cost you in the long run.

2. Ignoring Energy Efficiency Ratings

Not all AC units are created equal when it comes to energy consumption. Choosing a model without paying attention to its efficiency rating can result in unnecessarily high utility bills.

Understanding SEER Ratings

The Seasonal Energy Efficiency Ratio (SEER) measures the cooling output of an AC unit divided by the energy it uses over a typical cooling season. The higher the SEER rating, the more energy-efficient the unit is. Federal regulations now require all new air conditioners to meet minimum SEER standards, but you still have options that offer significantly higher efficiency.

The Long-Term Impact

While high-efficiency models might come with a higher upfront cost, they typically pay for themselves over time through lower operating costs. In fact, the U.S. Department of Energy reports that upgrading from a 10 SEER system to a 16 SEER unit can reduce air conditioning energy use by up to 40%. That adds up—especially during hot, humid Pennsylvania summers.

3. Overlooking Ductwork Condition and Design

Many homeowners focus solely on the AC unit itself, but your ductwork plays a critical role in system performance. Ignoring this part of the system is a mistake that can undermine even the most advanced equipment.

Why Ductwork Matters

According to Energy Star, 20% to 30% of the air that moves through the duct system is lost due to leaks, holes, and poorly connected ducts. If your ductwork is outdated or improperly designed, you could experience uneven cooling, longer run times, and wasted energy.

What to Do About It

Before installing a new unit, have your ductwork inspected for leaks, blockages, and sizing issues. Proper sealing and insulation, along with correctly sized ducts, ensure your AC unit works as intended and delivers cool air efficiently throughout your home.

4. Not Considering Indoor Air Quality

Another mistake people often make is focusing only on temperature control and forgetting about the air they breathe. Indoor air quality (IAQ) should be part of the conversation when buying a new AC system.

Why It’s Important

A well-functioning HVAC system does more than keep you cool. It can help filter airborne contaminants, manage humidity, and create a healthier living environment. Poor IAQ has been linked to allergies, asthma, and other respiratory problems.

Enhancing IAQ with the Right System

Modern AC systems can be paired with advanced filtration options, dehumidifiers, UV lights, and other add-ons that improve indoor air quality. In a place like Mechanicsburg, where pollen and humidity levels can fluctuate seasonally, these enhancements can make a noticeable difference in your overall comfort and health.

5. Failing to Hire a Qualified HVAC Contractor

Finally—and perhaps most importantly—many homeowners make the mistake of hiring the wrong contractor or trying to go the DIY route when replacing their AC.

Why Installation Matters

Even the best AC unit will perform poorly if it’s not installed correctly. Improper installation can reduce system efficiency by up to 30%, according to the U.S. Department of Energy. That translates into higher energy bills, more frequent repairs, and a shortened lifespan for your new equipment.

What to Look for in a Contractor

Make sure your HVAC contractor is licensed, insured, and experienced with the type of system you’re considering. They should also offer a comprehensive consultation, perform a Manual J load calculation, and take the time to explain your options clearly. Transparency, professionalism, and local knowledge—especially of climate-specific concerns in Mechanicsburg—are key indicators of a reputable company.

Working with a trusted contractor not only protects your investment but gives you peace of mind that the job will be done right the first time.

Other Considerations When Buying a New AC

While those are the top five mistakes, here are a few additional points to keep in mind during the decision-making process:

Don’t Rush the Decision

Replacing your AC often happens under pressure—usually when your old system breaks down. But taking time to research your options, get multiple estimates, and understand your long-term goals is crucial. If possible, plan ahead before your system fails completely.

Think About Future Needs

Are you planning to finish your basement? Add on a room? Install solar panels? Thinking about how your cooling needs might evolve can help you choose a system that continues to serve you well.

Ask About Maintenance Plans

Even the best AC systems require regular maintenance to perform at their best. Ask your contractor about maintenance programs that include seasonal tune-ups, inspections, and priority service. Routine care can prevent small issues from turning into costly repairs.

For AC Services in Mechanicsburg, PA, Contact Jeffrey A. Wilbur Plumbing, Heating & Air Inc. Today

Buying a new air conditioning system is a big decision—but it doesn’t have to be overwhelming. By understanding the common mistakes to avoid and working with experienced professionals, you can make a confident investment in your home’s comfort and efficiency.

At Jeffrey A. Wilbur Plumbing, Heating & Air Inc., we’re here to guide you through every step of the process—from evaluating your current system and performing accurate load calculations, to recommending the best equipment for your home and ensuring flawless installation. Our knowledgeable team has proudly served homeowners in Mechanicsburg, PA for years, and we take pride in delivering reliable, energy-efficient solutions tailored to your needs.

Whether you’re replacing an aging unit or installing AC for the first time, trust Jeffrey A. Wilbur Plumbing, Heating & Air Inc. to get the job done right. Let us help you enjoy cooler, cleaner air and lasting peace of mind.