Shopping for a new air conditioner or furnace can feel overwhelming. If you want to find the best HVAC system for your home, it's natural to look for models with the highest efficiency ratings.
Surely the most efficient heating and cooling system will provide the most comfort and lowest energy bills, right?
Not necessarily.
Efficiency ratings aren’t the only thing you should consider when it comes to new air conditioner installation or replacing your furnace. Even though many focus only on {energy efficiency|efficiency ratings, proper {HVAC system sizing is often even more important for your home's comfort and your energy bills.
Proper sizing also influences humidity control and long-term reliability. The best HVAC system for your home delivers efficiency and proper sizing.
In thisguide, we'll explain what an air conditioner's SEER rating or SEER2 rating actually measures, why correct HVAC size is so important and why experienced HVAC professionals consider both when helping you select 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 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 designation, simply because this rating is the updated rating system for cooling equipment.
Fuel-burning heating system efficiency is rated by AFUE, which is for Annual Fuel Utilization Efficiency. Like SEER and SEER2, 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.
That said, high ratings don't automatically guarantee lower utility bills. Actual heating and air conditioner efficiency depends on many factors, including the installation quality, the quality of your ductwork, how much insulation your home has, thermostat settings and, most importantly, system sizing. Even the most efficient system cannot operate at its best if it is too large or undersized for the home.
Why Correct HVAC System Sizing Matters More Than You Probably Think
Many assume a bigger 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 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 technicians complete an HVAC load calculation, also called a Manual J calculation, before selecting replacement equipment. A Manual J calculation considers many factors that impact your home's heating and cooling requirements, including:
- Overall square footage
- Room height
- Window size and placement
- Insulation
- Air infiltration
- Regional climate
- Household occupants
- Heat generated by appliances and lighting
- Ductwork condition
A properly sized air conditioner runs long enough to cool your home evenly while pulling out excess humidity. That means steadier temperatures, better indoor comfort and improved humidity control. It also helps the equipment to operate more effciently, reducing unnecessary wear that can cause it to wear it out sooner or lead to costly breakdowns.
When your heating or cooling system is the right size for your home, you get greater comfort and long-lasting performance.
Problems Caused by Oversized and Undersized Systems
You may be tempted to buy the most energy efficient, biggest air conditioner or heating system on the market. In reality, that's usually not a good investment.
heating and cooling systems that are bigger than necessary or too small can create comfort issues, increase energy expenses and reduce efficiency regardless of their SEER rating.
Common Problems With Oversized HVAC Systems
An oversized air conditioner or heating system may reach the thermostat setting fast, but that doesn't mean it delivers the best comfort.
- Short cycling: An oversized HVAC system starts and stops often, reducing efficiency and increasing equipment strain.
- Reduced humidity control: Oversized air conditioners cool your home too quickly to remove excess moisture from the air.
- Inconsistent temperatures: Some rooms get too cold while others stay too warm.
- Increased wear and tear: Even though the system reaches the target temperature rapidly, those repeated on-and-off cycles can cause avoidable breakdowns due to the strain.
Cons Associated with Undersized HVAC Systems
An undersized HVAC system can have the opposite problem:
- Continuous operation: The system runs for long periods trying to reach the set temperature, which also causes extra strain.
- Difficulty reaching thermostat settings: Your home may never feel as cool as you want during hot weather or always feel chilly in the winter.
- Increased energy consumption: Running almost constantly can increase energy costs.
- Extra stress during severe weather: HVAC systems that are too small can run extremely hard in extreme temperatures, increasing equipment wear and the likelihood of repairs.
Balancing Efficiency and Size
When trying to decide between a high SEER vs right-sized system, remember that you don't necessarily need the most efficient model on the market.
Often, a professionally sized, mid-efficiency heating and cooling system will provide better results than an overly large premium system because it functions 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 consider 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 require a larger upfront investment than mid-range models but can help reduce long-term energy costs.
- Electricity rates: Areas with higher utility costs may see greater long-term savings from higher-efficiency units.
- Seasonal weather conditions: It's crucial your heating or cooling system has enough capacity to handle areas with extremely cold winters or extremely hot summers.
- How long you'll own the home: If you expect to live in your home for many years, the long-term energy savings of a higher-efficiency unit may be worth the investment.
- Rebates and tax credits: Manufacturer promotions, {utility|equipment rebates and tax credits can offset the overall cost of qualifying equipment.
Real-World Example: High Seer vs. Right System Size
How does this work in the real world?
Picture two neighboring homes.
In one, the homeowner chooses a premium high-efficiency HVAC system has far more capacity than the home needs because the contractor only matched the previous unit. Next door, the second homeowner installs a correctly sized, moderate-efficiency system after completing a Manual J calculation.
Even though the second system has a lesser efficiency rating on paper, it may deliver lower operating costs, better home comfort, improved humidity control and have a longer lifespan because it's properly matched to the home's needs.
Choose the Local HVAC Professional Who Designs the Right Solution
An HVAC replacement should involve more than selecting the unit with the highest efficiency rating. The best system is one that meets your home’s heating and cooling requirements.
At AW Heating & Air Conditioning, our experienced professionals perform an HVAC load calculation. We'll carefully evaluate your home's layout and construction, your household's comfort needs 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 let you know about any available rebates and 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 AW Heating & Air Conditioning 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.
