Choosing a new AC or furnace can feel overwhelming. If you're trying to find the best HVAC system for your home, it's common to look for models with the highest efficiency ratings.
Surely the most efficient equipment provides the most comfort and lowest energy bills, right?
Not necessarily.
Energy 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 energy efficiency, proper HVAC system sizing is equally, if not more important for your home's comfort and your utility bills.
Proper sizing also influences humidity control and long-term reliability. The best HVAC system for your home balances efficiency and proper 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 qualified HVAC contractors consider both when helping you choose the best HVAC system for your home.
High Seer Ratings: What Do They Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), indicates how efficiently a cooling system cools your home over a normal cooling season. A SEER2 rating is the newer version of SEER, using testing methods that better simulate real-world operating conditions. Nearly all new air conditioners have a SEER2 designation, simply because this rating is the current rating system for cooling equipment.
Fuel-burning heating system efficiency is measured by an AFUE rating, which is short for Annual Fuel Utilization Efficiency. As with cooling efficiency ratings, higher AFUE ratings indicate a high-efficiency HVAC system that uses less electricity to achieve indoor comfort than lower-rated systems under standardized laboratory testing.
That said, high ratings don't by themselves guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on more than just efficiency ratings, including the quality of the installation, the quality of your ductwork, insulation levels, thermostat settings and, most importantly, proper HVAC system sizing. Even the highest-efficiency system cannot perform as intended if it is oversized or undersized for the home.
Why Proper HVAC Sizing 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 new one the same size. In reality, new heating system installation or AC replacement should be selected based on your home's current heating and cooling needs—not just square footage or the size of the previous unit.
That's why reputable technicians perform an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation evaluates many details that affect your home's heating and cooling load, including:
- Total square footage
- Room height
- Window size and placement
- Home insultation levels
- Air leakage
- Local climate
- Number of occupants
- Heat produced from appliances and lighting
- Ductwork condition
A properly sized air conditioner runs for enough time to cool your home consistently while eliminating excess humidity. That means more consistent temperatures, better indoor comfort and improved indoor humidity management. 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 improved comfort and more dependable performance.
Problems Caused by Oversized and Undersized HVAC Equipment
You may be tempted to buy the most energy efficient, largest-capacity air conditioner or heating system on the market. In reality, that’s rarely a great idea.
HVAC systems that are bigger than necessary or too small can create comfort issues, increase energy expenses and reduce efficiency regardless of their SEER rating.
Issues Created by Oversized HVAC Systems
An oversized air conditioner or heating system may reach the thermostat setting fast, but that doesn't mean it works well.
- Short cycling: An oversized HVAC system turns on and off frequently, reducing efficiency and increasing wear and tear.
- Reduced humidity control: Oversized air conditioners cool your home too quickly to remove enough moisture from the air.
- Inconsistent temperatures: Some rooms get too cold while others never feel comfortable.
- Increased wear and tear: Even though the system reaches the target temperature rapidly, those constant cycles can cause avoidable breakdowns due to the strain.
Cons Associated with Undersized HVAC Systems
An undersized HVAC system also can struggle:
- Continuous operation: The system operates almost continuously trying to reach the set temperature, which also causes additional wear.
- Difficulty reaching thermostat settings: Your home may not feel comfortable during hot weather or always feel chilly in the winter.
- Higher energy use: Running almost constantly can increase utility bills.
- Greater strain on very hot or cold days: HVAC systems that are too small can work harder in extreme temperatures, increasing equipment wear and the likelihood of repairs.
Why You Should Balance HVAC System Efficiency and Size
When trying to decide between a high SEER vs right-sized system, don't forget that you don't automatically need the highest-efficiency model on the market.
Often, a correctly sized, mid-efficiency HVAC system will provide better results than an oversized premium system because it runs the way it was designed to.
Thesmartest choice is an energy-efficient HVAC system that's correctly sized 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, keep these factors in mind:
- Energy savings: Higher-efficiency and right-sized systems can reduce electricity use.
- Upfront investment: High-efficiency AC and heating systems often require a larger upfront investment than mid-range models but can reduce long-term energy costs.
- Local utility costs: Areas with higher utility costs may see more significant long-term savings from higher-efficiency units.
- Seasonal weather conditions: It's crucial your heating or cooling system has adequate capacity to handle areas with harsh winter weather or extremely 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 offset the investment.
- Available rebates or tax incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can reduce the overall cost of high-efficiency HVAC equipment.
Real-World Situation: High Seer vs. Right System Size
What does this look like in a real world example?
Picture two neighboring homes.
At the first home, the homeowner chooses a premium high-efficiency HVAC system has far more capacity than the home needs because the contractor replaced it with the same size system as the previous unit. The other homeowner installs a properly sized, mid-efficiency 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 last longer because it's properly matched to the home's needs.
Choose the HVAC Professional Who Designs the Right Solution
An HVAC replacement should involve more than selecting a system with the highest efficiency rating. The right system is one that meets your household heating and cooling requirements.
At Marios Air Conditioning, our skilled HVAC experts perform an HVAC load calculation. We'll evaluate your home's layout and construction, your household's comfort goals and recommend equipment that's properly matched for your home—not simply the largest, fanciest 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 energy-efficient HVAC systems more accessible for all budgets.
Schedule an HVAC consultation online with Marios Air Conditioning to get started. We'll evaluate your home, answer any questions and help you choose the properly sized high-efficiency system that keeps your family comfortable for the long haul.