Choosing a new AC or furnace can be intimidating. If you're trying to find the best HVAC system for your home, it's understandable to focus on models with the highest efficiency ratings.
Surely the most efficient heating and cooling system will provide the most comfort and lowest energy bills, right?
It’s not quite that simple.
Energy efficiency isn't the only thing that matters when it comes to new air conditioner installation or replacing your furnace. While many homeowners focus only on energy efficiency, proper HVAC system sizing is just as, if not more important for your home's comfort and your utility bills.
Proper sizing has a major impact on humidity control and lasting performance. The best HVAC system for your home balances energy 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 trusted HVAC experts consider both when helping you select 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 efficiently an AC cools your home over a typical cooling season. A SEER2 rating is the updated version of SEER, using test procedures that better represent real-world operating conditions. Nearly all new air conditioners have a SEER2 designation, simply because this rating is the new rating system for cooling equipment.
Fuel-burning heating system efficiency is rated by something called AFUE, which is for Annual Fuel Utilization Efficiency. Like SEER and SEER2 ratings, 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.
Even so, high ratings don't automatically guarantee lower utility bills. Actual heating and air conditioner efficiency depends on many factors, including the way the system is installed, the condition 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 smaller than needed for the home.
Why Correct HVAC System Sizing Matters More Than You 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 same-sized replacement. Actually, new heating system installation or AC replacement should be chosen based on your home's actual heating and cooling needs—not just square footage or the size of the previous unit.
That's why reputable companies complete an HVAC load calculation, also called a Manual J calculation, before recommending replacement equipment. A Manual J calculation analyzes many factors that impact your home's heating and cooling requirements, including:
- Total square footage
- Room height
- Window size and orientation
- Insulation
- Air leakage
- Area climate
- Household occupants
- Heat produced from appliances and lighting
- Air duct condition
A properly sized air conditioner runs through longer cooling cycles to cool your home more uniformly while removing excess humidity. That means more consistent temperatures, better indoor comfort and improved moisture control. This also allows the equipment to run more effciently, reducing strain that can cause it to wear it out sooner or lead to costly breakdowns.
When a furnace or AC is properly sized, you get greater comfort and long-lasting performance.
Problems Caused by Oversized and Undersized Heating and Cooling Systems
You may be tempted to buy the most energy efficient, largest-capacity air conditioner or heating system on the market. The truth is, that often isn't a smart choice.
HVAC systems that are bigger than necessary or too small can create comfort issues, increase utility costs 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 performs efficiently.
- 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 indoor humidity from the air.
- Hot and cold spots: Some rooms get too cold while others stay too warm.
- Additional equipment wear: Even though the system reaches the target temperature rapidly, those repeated on-and-off cycles can cause avoidable breakdowns due to the strain.
Drawbacks of Undersized HVAC Systems
An undersized HVAC system also can struggle:
- Long run times: The system stays on for extended periods trying to reach the thermostat setting, which also causes extra strain.
- Trouble reaching the thermostat setting: Your home may not feel comfortable during hot weather or feel too cool during winter.
- Higher energy use: Running almost constantly can increase utility bills.
- Added strain during extreme weather: HVAC systems that are too small can work harder in extreme temperatures, increasing wear and the likelihood of repairs.
Balancing Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, don't forget that you don't necessarily need the top-efficiency model on the market.
More often than not, a properly sized, mid-efficiency HVAC system will deliver better performance than an oversized premium system because it functions the way it was designed to.
Thebest choice is an energy-efficient HVAC system that's correctly sized for your home, your budget, your climate and your long-term goals.
When deciding 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.
- 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.
- Local utility costs: Areas with higher electricity rates may see better long-term savings from higher-efficiency units.
- Your local climate: It's important your heating or cooling system has the right capacity to handle areas with very cold winters or intense summer heat.
- How long you'll own the home: If you plan to stay 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 reduce the overall cost of high-efficiency HVAC equipment.
Real-World Comparison: High Seer vs. Right System Size
How does this play out in a real world scenario?
Picture two neighboring homes.
In one, the homeowner chooses a premium high-efficiency HVAC system that's too big because the contractor simply matched the previous unit. Next door, the second homeowner installs a correctly sized, mid-efficiency system after completing a Manual J calculation.
Although 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 correctly matched to the home's needs.
Choose the Local HVAC Professional Who Designs Solutions Tailored to Your Home
An HVAC replacement should involve much more than selecting a system with the top efficiency rating. An ideal system is one that meets your household heating and cooling requirements.
At Allianz Heating & Air, our experienced professionals perform an HVAC load calculation. Our team will evaluate your home's size and layout, your household's heating and cooling preferences and recommend equipment that's right for your home—not simply the biggest, fanciest unit or the one with the highest AFUE or SEER2 rating.
Our team will help you identify 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 Allianz Heating & Air to get started. Our team will evaluate your home, answer any questions and help you choose the right-sized energy-efficient system that keeps your family comfortable for many years.
