Shopping for a new AC or furnace can feel overwhelming. When you're looking to find the best HVAC system for your home, it's common to look for models with extremely high efficiency ratings.
After all, the most efficient system should deliver the most comfort and lowest energy bills, right?
It’s not quite that simple.
High efficiency isn't the only thing to think about when it comes to new air conditioner installation or furnace replacement. Even though many focus only on efficiency ratings, proper HVAC system sizing is often even more important for your home's comfort and your utility bills.
Proper sizing has a major impact on humidity control and system longevity. The best HVAC system for your home combines efficiency and correct sizing.
In this blog, we'll explain what an air conditioner's SEER rating or SEER2 rating actually measures, why correct HVAC size is so important and why trusted HVAC experts consider both when helping you choose the best HVAC system for your home.
What Does it Mean if an AC Has a High SEER Rating?
A SEER rating, (Seasonal Energy Efficiency Ratio), indicates how effectively an air conditioner cools your home over a typical cooling season. A SEER2 rating is the newer version of SEER, using testing methods that better reflect real-world operating conditions. Nearly all new air conditioners have a SEER2 rating, simply because that is the updated rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by something called AFUE, which is for Annual Fuel Utilization Efficiency. Similar to SEER and SEER2, higher AFUE ratings indicate a high-efficiency HVAC system that uses less electricity to heat your home than lower-rated systems under standardized laboratory testing.
That said, high numbers don't necessarily guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on many factors, including the installation quality, the condition of your ductwork, how much insulation your home has, thermostat settings and, most importantly, HVAC system sizing. Even the most efficient system cannot deliver peak performance if it is bigger than necessary or undersized for the home.
Why HVAC System Size Matters More Than You Think
Many assume a larger air conditioner or furnace will work the best or that they should simply replace their old HVAC system with a unit of the same capacity. In reality, new heating system installation or air conditioner replacement should be sized based on your home's true heating and cooling needs—not just square footage or the size of your existing equipment.
That's why reputable technicians conduct an HVAC load calculation, also called a Manual J calculation, before selecting replacement equipment. A Manual J calculation analyzes many details that impact your home's comfort needs, including:
- Home square footage
- Ceiling height
- Window size and orientation
- Insulation
- Air leakage
- Regional climate
- Household occupants
- Heat generated by appliances and lighting
- Ductwork condition
A properly sized air conditioner runs through longer cooling cycles to cool your home more uniformly while removing excess humidity. That means more even temperatures, better indoor comfort and improved moisture control. It also helps the equipment to perform more effciently, reducing excessive wear and tear that can reduce its service life or lead to costly breakdowns.
When your heating or cooling system is the right size for your home, you get better comfort and more dependable performance.
Problems with Oversized and Undersized Heating and Cooling Systems
It might be tempting to buy the most energy efficient, biggest air conditioner or heating system on the market. However, that’s rarely a smart choice.
HVAC systems that are bigger than your home needs or smaller than your home requires can create comfort issues, increase operating costs and reduce efficiency regardless of their SEER rating.
Issues Created by 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 cycles repeatedly, reducing efficiency and increasing equipment strain.
- Humidity problems: Oversized air conditioners finish cooling cycles too soon to remove enough moisture from the air.
- Uneven temperatures: Some rooms feel too cool while others never feel comfortable.
- Increased wear and tear: Even though the system heats or cools your home fast, those frequent starts and stops 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 runs for long periods trying to reach the desired temperature, which also causes additional wear.
- Difficulty reaching thermostat settings: Your home may never feel as cool as you want during hot weather or always feel chilly in the winter.
- Higher energy use: Running almost constantly can increase energy costs.
- Added strain during extreme weather: HVAC systems that are too small can struggle in extreme temperatures, increasing wear and the likelihood of repairs.
Why You Should Balance HVAC System Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, remember that you don't always need the most efficient model on the market.
In many cases, a correctly sized, mid-efficiency HVAC system will provide better results than an overly large premium system because it functions the way it was designed to.
Theideal choice is an energy-efficient HVAC system that's correctly sized for your home, your budget, your climate and your future plans.
When deciding how to choose a new air conditioner or furnace, think about:
- Energy savings: Higher-efficiency and right-sized systems can reduce electricity use.
- Initial cost: High-efficiency AC and heating systems often cost more initially than mid-range models but can help reduce long-term energy costs.
- Energy prices: Areas with higher electricity rates may see greater long-term savings from higher-efficiency units.
- Your local climate: It's important your heating or cooling system has enough capacity to handle areas with very cold winters 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.
- Financial incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can offset the overall cost of high-efficiency HVAC equipment.
Real-World Situation: High Seer vs. Right System Size
How does this play out in a real world scenario?
Picture two neighboring homes.
At the first home, the homeowner chooses a premium high-efficiency HVAC system that's too big for the house because the contractor simply matched the previous unit. At the neighboring home, an HVAC professional installs a right-sized, mid-efficiency system after completing a Manual J calculation.
While the second system has a more modest efficiency rating on paper, it may deliver lower operating costs, better home comfort, more effective humidity control and have a longer lifespan because it's properly matched to the home's needs.
Choose the HVAC Professional Who Designs the Right Solution
Replacing your HVAC system should involve much more than selecting the unit with the top efficiency rating. The best system is one that meets your home’s heating and cooling requirements.
At Dearing's Service & Solutions, our skilled HVAC experts perform an HVAC load calculation. We'll carefully evaluate your home's design, your household's heating and cooling preferences and recommend equipment that's right for your home—not simply the highest-capacity, most expensive unit or the one with the highest AFUE or SEER2 rating.
Our team will connect you with any available rebates or tax incentives and provide information about HVAC financing options that make efficient heating and cooling systems more accessible for all budgets.
Schedule an HVAC consultation online with Dearing's Service & Solutions to get started. Our team will evaluate your home, answer any questions and help you choose the correctly sized energy-efficient system that keeps your family comfortable for many years.