Shopping for a new AC or furnace can be intimidating. If you're trying to find the best HVAC system for your home, it's natural to focus on models with the highest efficiency ratings.
After all, the most efficient heating and cooling system provides the most comfort and lowest energy bills, right?
It’s not quite that simple.
Efficiency ratings aren’t the only thing you should consider when it comes to new air conditioner installation or furnace replacement. Although many people focus only on efficiency ratings, proper HVAC system sizing is equally, if not more important for your home's comfort and your power bills.
Proper sizing also influences humidity control and lasting performance. The best HVAC system for your home combines energy efficiency and correct sizing.
In this article, we'll explain what an air conditioner's SEER rating or SEER2 rating actually measures, why proper HVAC system size is so important and why trusted HVAC experts consider both when helping you choose the best HVAC system for your home.
What Does a High SEER Rating Actually Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), indicates how effectively an AC cools your home over a normal cooling season. A SEER2 rating is the current version of SEER, using evaluation methods that better simulate real-world operating conditions. Today’s new air conditioners have a SEER2 rating, simply because that is the current rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by something called AFUE, which stands for Annual Fuel Utilization Efficiency. Similar to cooling efficiency ratings, higher AFUE ratings indicate a high-efficiency HVAC system that uses less electricity to keep you comfortable than lower-rated systems under standardized laboratory testing.
Even so, high numbers don't automatically guarantee lower utility bills. Everyday heating and air conditioner efficiency depends on several key factors, including the way the system is installed, the quality of your ductwork, your home's insulation, thermostat settings and, most importantly, HVAC system sizing. Even the highest-efficiency system cannot deliver peak performance if it is bigger than necessary or undersized for the home.
Why Correct HVAC System Sizing Matters More Than You Think
Many assume a higher-capacity air conditioner or furnace will make their home the most comfortable or that they should just replace their old HVAC system with a unit of the same capacity. The truth is, new heating system installation or a new air conditioner should be chosen based on your home's true heating and cooling needs—not just square footage or the size of the previous unit.
That's why reputable contractors perform an HVAC load calculation, also called a Manual J calculation, before recommending replacement equipment. A Manual J calculation considers many details that affect your home's heating and cooling requirements, including:
- Total square footage
- Ceiling height
- Window size and placement
- Insulation
- Drafts and air leakage
- Local climate
- Number of occupants
- Heat generated by appliances and lighting
- Ductwork condition
A properly sized air conditioner runs for enough time to cool your home more uniformly while eliminating excess humidity. That means steadier temperatures, better indoor comfort and improved moisture control. Proper sizing also helps the equipment to operate more effciently, reducing strain that can reduce its service life or lead to frequent or expensive repairs.
When a furnace or AC is correctly sized, you get greater comfort and more dependable performance.
Problems Caused by Oversized and Undersized HVAC Equipment
It might be tempting to buy the most energy efficient, biggest air conditioner or heating system on the market. In reality, that's usually not a good investment.
HVAC systems that are bigger than your home needs or undersized can create comfort issues, increase energy expenses and reduce efficiency regardless of their SEER rating.
Drawbacks of Oversized HVAC Systems
An oversized air conditioner or heating system may work quickly, but that doesn't mean it works well.
- Short cycling: An oversized HVAC system turns on and off frequently, reducing efficiency and increasing equipment strain.
- Humidity problems: Oversized air conditioners cool your home too quickly to remove enough moisture from the air.
- Uneven temperatures: Some rooms get too cold while others aren’t ever cool enough.
- Increased wear and tear: Even though the system heats or cools your home fast, those repeated on-and-off cycles can cause avoidable breakdowns due to the strain.
Cons Associated with Undersized HVAC Systems
An undersized HVAC system has a different set of problems:
- Long run times: The system stays on for extended periods trying to reach the set temperature, which also causes extra strain.
- Difficulty reaching thermostat settings: Your home may not feel comfortable during hot weather or feel too cool during winter.
- Increased energy consumption: Running almost constantly can increase monthly energy expenses.
- Greater strain on very hot or cold days: HVAC systems that are too small can run extremely hard in extreme temperatures, increasing wear and the likelihood of repairs.
Finding the Right Balance Between Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, keep in mind that you don't automatically need the top-efficiency model on the market.
More often than not, a properly sized, mid-efficiency heating and cooling system will provide better results than an overly large premium system because it runs the way it was designed to.
Thebest choice is an energy-efficient HVAC system that's matched for your home, your budget, your climate and your long-term goals.
As you think about how to choose a new air conditioner or furnace, think about:
- Efficiency savings: Higher-efficiency and right-sized systems can reduce electricity use.
- Initial cost: High-efficiency AC and heating systems often have a higher purchase price than mid-range models but can help reduce long-term energy costs.
- Electricity rates: Areas with more expensive electricity may see more significant long-term savings from higher-efficiency units.
- Your local climate: It's crucial your heating or cooling system has enough capacity to handle areas with harsh winter weather or very hot summers.
- Length of home ownership: If you intend to remain in your home for many years, the long-term energy savings of a higher-efficiency unit may justify the investment.
- Rebates and tax credits: Manufacturer promotions, {utility|equipment rebates and tax credits can lower the overall cost of qualifying equipment.
Real-World Example: High Seer vs. Right System Size
How does this play out in a real world example?
Picture two neighboring homes.
In the first, the homeowner chooses a premium high-efficiency HVAC system that's too big because the contractor only matched the previous unit. At the neighboring home, an HVAC professional installs a right-sized, mid-SEER or AFUE system after completing a Manual J calculation.
Although the second system has a lower efficiency rating on paper, it may deliver lower operating costs, better home comfort, improved humidity control and have a longer lifespan because it's correctly matched to the home's needs.
Choose the HVAC Professional Who Designs the Right Solution
An HVAC replacement should involve much more than selecting a model with the highest efficiency rating. The best system is one that meets your heating and cooling requirements.
At Superior Air Repair, our skilled HVAC experts perform an HVAC load calculation. Our team will evaluate your home's layout and construction, your household's comfort needs and recommend equipment that's right for your home—not simply the largest, latest and greatest unit or the one with the highest AFUE or SEER2 rating.
Our HVAC experts will let you know about any available tax rebates and provide information about HVAC financing options that make energy-efficient HVAC systems more accessible for all budgets.
Schedule an HVAC consultation online with Superior Air Repair today. We'll gladly evaluate your home, answer any questions and help you choose the right-sized high-efficiency system that keeps your family comfortable for many years.
