Choosing a new AC or furnace can feel overwhelming. When you're looking to find the best HVAC system for your home, it's natural to focus on models with extremely high efficiency ratings.
Surely the most efficient equipment should deliver the most comfort and lowest energy bills, right?
Actually, that’s not always the case.
Energy efficiency isn't the only thing to think about when it comes to new air conditioner installation or replacing your furnace. While many homeowners focus only on efficiency ratings, proper HVAC system sizing is just as, if not more important for your home's comfort and your energy bills.
Proper sizing directly impacts humidity control and lasting performance. The best HVAC system for your home balances efficiency and correct sizing.
In this blog, 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.
High Seer Ratings: What Do They Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), shows how effectively a cooling system cools your home over a standard cooling season. A SEER2 rating is the updated version of SEER, using evaluation methods that better reflect real-world operating conditions. Today’s new air conditioners have a SEER2 rating, simply because this rating is the current rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by AFUE, which is short for Annual Fuel Utilization Efficiency. Similar to SEER and SEER2 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 many factors, including the quality of the installation, the state of your ductwork, your home's insulation, thermostat settings and, most importantly, system sizing. Even the highest-efficiency system cannot deliver peak performance if it is bigger than necessary or smaller than needed for the home.
Why HVAC System Size Matters More Than You Think
Many assume a higher-capacity air conditioner or furnace will heat or cool a home better or that they should just replace their old HVAC system with a new one the same size. 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 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 details that impact your home's heating and cooling load, including:
- Total square footage
- Ceiling height
- Window size and direction
- Insulation
- Air infiltration
- Local climate
- Number of occupants
- Heat produced from appliances and lighting
- Ductwork condition
A properly sized air conditioner runs long enough to cool your home consistently while removing 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 shorten its lifespan or lead to costly breakdowns.
When your heating or cooling system is properly sized, you get greater comfort and long-lasting performance.
Problems with Oversized and Undersized Systems
You may be tempted to buy the most energy efficient, highest-capacity air conditioner or heating system on the market. The truth is, that often isn't a great idea.
HVAC systems that are too large or too small can create comfort problems, increase operating costs and reduce efficiency regardless of their SEER rating.
Drawbacks of Oversized HVAC Systems
An oversized air conditioner or heating system may heat or cool rapidly, but that doesn't mean it works well.
- Short cycling: An oversized HVAC system starts and stops often, reducing efficiency and increasing wear.
- Reduced humidity control: Oversized air conditioners cool your home too quickly to remove enough moisture from the air.
- Hot and cold spots: Some rooms get too cold while others aren’t ever cool enough.
- More 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.
Drawbacks of Undersized HVAC Systems
An undersized HVAC system can have the opposite problem:
- Continuous operation: The system operates almost continuously trying to reach the set temperature, which also causes unnecessary wear and tear.
- Difficulty maintaining the desired temperature: Your home may never feel as cool as you want during hot weather or feel too cool during winter.
- Higher energy use: Running nonstop can increase utility bills.
- Added strain during extreme weather: HVAC systems that are too small can run extremely hard in extreme temperatures, increasing equipment wear and the chance of failure.
Why You Should Balance HVAC System Efficiency and Size
When trying to decide between a high SEER vs right-sized system, remember that you don't necessarily need the top-efficiency model on the market.
Often, a correctly sized, mid-efficiency heating and cooling system will outperform an oversized premium system because it operates 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 future plans.
When deciding how to choose a new air conditioner or furnace, think about:
- Lower energy costs: Higher-efficiency and right-sized systems can decrease electricity use.
- Purchase price: High-efficiency AC and heating systems often require a larger upfront investment than mid-range models but can help reduce long-term energy costs.
- Energy prices: Areas with more expensive electricity may see better long-term savings from higher-efficiency units.
- Your local climate: It's important your heating or cooling system has adequate 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 offset the investment.
- Available rebates or tax incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can lower 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 scenario?
Picture two neighboring homes.
In one, 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-SEER or AFUE system after completing a Manual J calculation.
Even though the second system has a lower efficiency rating on paper, it may deliver lower operating costs, better home comfort, more effective humidity control and last longer because it's correctly matched 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. The best system is one that meets your household heating and cooling requirements.
At HCE Systems, our knowledgeable technicians perform an HVAC load calculation. Our team will evaluate your home's layout and construction, your household's heating and cooling preferences and recommend equipment that's designed specifically for your home—not simply the largest, latest and greatest unit or the one with the highest AFUE or SEER2 rating.
Our heating and cooling specialists will help you identify 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 HCE Systems to get started. We'll evaluate your home, answer your questions and help you choose the properly sized efficient system that keeps your family comfortable for years to come.