Shopping for a new air conditioner or furnace can be intimidating. If you want to find the best HVAC system for your home, it's common to focus on models with the highest efficiency ratings.
Surely the most efficient heating and cooling system should deliver the most comfort and lowest energy bills, right?
Actually, that’s not always the case.
High efficiency isn't the only thing you should consider when it comes to new air conditioner installation or installing a new furnace. Even though many focus only on {energy efficiency|efficiency ratings, proper {HVAC system sizing is equally, if not more important for your home's comfort and your energy bills.
Proper sizing also influences humidity control and system longevity. The best HVAC system for your home balances efficiency and proper sizing.
In thisguide, 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 a High SEER Rating Actually Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), measures how efficiently a cooling system cools your home over a normal cooling season. A SEER2 rating is the updated version of SEER, using testing methods that better simulate real-world operating conditions. Today’s new air conditioners have a SEER2 designation, simply because this is the new rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by something called AFUE, which is for Annual Fuel Utilization Efficiency. As with 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 ratings don't automatically guarantee lower utility bills. Actual heating and air conditioner efficiency depends on more than just efficiency ratings, including the installation quality, the condition of your ductwork, how much insulation your home has, thermostat settings and, most importantly, system sizing. Even the most efficient system cannot deliver peak performance if it is too large or smaller than needed for the home.
Why HVAC System Size Matters More Than Most Homeowners Realize
Many assume a larger air conditioner or furnace will work the best or that they should simply replace their old HVAC system with a same-sized replacement. The truth is, new heating system installation or air conditioner replacement should be selected based on your home's current heating and cooling needs—not just square footage or the size of your existing equipment.
That's why reputable technicians complete an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation considers many factors that affect your home's comfort needs, including:
- Total square footage
- Room height
- Window size and direction
- Home insultation levels
- Drafts and air leakage
- Local climate
- Household occupants
- Heat produced from appliances and lighting
- Air duct 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 perform more effciently, reducing strain that can cause it to wear it out sooner or lead to costly breakdowns.
When a furnace or AC is the right size for your home, you get improved comfort and more reliable operation.
Problems Caused by Oversized and Undersized HVAC Equipment
It might be tempting to buy the most energy efficient, highest-capacity air conditioner or heating system on the market. However, that's usually not a smart choice.
HVAC systems that are too large or smaller than your home requires can create indoor comfort challenges, 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 delivers the best comfort.
- Short cycling: An oversized HVAC system cycles repeatedly, reducing efficiency and increasing equipment strain.
- 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.
- Additional equipment wear: 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 runs for long periods trying to reach the desired temperature, which also causes extra strain.
- Difficulty maintaining the desired temperature: Your home may feel cool enough during hot weather or always feel chilly in the winter.
- Higher energy use: Running nonstop 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 equipment wear and the likelihood of repairs.
Balancing Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, remember that you don't automatically need the highest-efficiency model on the market.
Often, a properly 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 matched for your home, your budget, your climate and your long-term needs.
As you consider how to choose a new air conditioner or furnace, keep these factors in mind:
- Efficiency savings: Higher-efficiency and right-sized systems can lower electricity use.
- Initial cost: High-efficiency AC and heating systems often cost more initially than mid-range models but can lower long-term energy costs.
- Electricity rates: Areas with higher utility costs may see more significant 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 harsh winter weather or very hot summers.
- Length of home ownership: If you plan to stay in your home for many years, the long-term energy savings of a higher-efficiency unit may offset the investment.
- Rebates and tax credits: Manufacturer promotions, {utility|equipment rebates and tax credits can lower the overall cost of high-efficiency HVAC equipment.
Real-World Comparison: High Seer vs. Right System Size
How does this work in a real world example?
Picture two neighboring homes.
In one, the homeowner chooses a premium high-efficiency HVAC system that's too big because the contractor replaced it with the same size system as the previous unit. The other homeowner installs a correctly sized, moderate-efficiency system after completing a Manual J calculation.
Even though 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 appropriately sized to the home's needs.
Choose the HVAC Professional Who Designs Personalized Solutions
HVAC replacent or installation should involve much more than selecting the unit with the highest efficiency rating. An ideal system is one that meets your heating and cooling requirements.
At Pure Comfort Heating and 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 designed specifically for your home—not simply the biggest, most expensive unit or the one with the highest AFUE or SEER2 rating.
Our heating and cooling specialists will help you identify any available rebates and tax incentives and provide information about HVAC financing options that make high-efficiency systems more accessible for all budgets.
Schedule an HVAC consultation online with Pure Comfort Heating and Air Conditioning now. Our team will evaluate your home, answer your questions and help you choose the correctly sized efficient system that keeps your family comfortable for the long haul.