Choosing a new air conditioning system or furnace can feel overwhelming. If you're trying to find the best HVAC system for your home, it's natural to focus on models with the highest efficiency ratings.
After all, the most efficient system will provide 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 installing a new furnace. Although many people focus only on {energy efficiency|efficiency ratings, proper {HVAC system sizing is just as, if not more important for your home's comfort and your power 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 correct HVAC size is so important and why experienced HVAC professionals consider both when helping you choose 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 an AC cools your home over a normal cooling season. A SEER2 rating is the updated version of SEER, using evaluation methods that better reflect real-world operating conditions. Most new air conditioners have a SEER2 rating, simply because that is the new rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by AFUE, which stands 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.
Even so, high ratings don't necessarily guarantee lower utility bills. Everyday heating and air conditioner efficiency depends on several key factors, including the quality of the installation, the quality of your ductwork, insulation levels, thermostat settings and, most importantly, HVAC system sizing. Even the most efficient system cannot operate at its best if it is oversized or smaller than needed for the home.
Why Proper HVAC Sizing Matters More Than You Think
Many assume a bigger air conditioner or furnace will make their home the most comfortable or that they should simply replace their old HVAC system with a new one the same size. In reality, new heating system installation or a new air conditioner should be sized based on your home's true heating and cooling needs—not just square footage or the size of your existing equipment.
That's why reputable technicians conduct 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 heating and cooling load, including:
- Home square footage
- Ceiling height
- Window size and orientation
- Insulation
- Air leakage
- Area climate
- Number of occupants
- Heat generated by appliances and lighting
- Ductwork condition
A properly sized air conditioner runs long enough to cool your home more uniformly while eliminating excess humidity. That means more even temperatures, better indoor comfort and improved indoor humidity management. Proper sizing also helps the equipment to perform more effciently, reducing strain that can cause it to wear it out sooner or lead to more repairs and higher repair costs.
When HVAC equipment is correctly sized, you get better comfort and long-lasting performance.
Problems Caused by Oversized and Undersized HVAC Equipment
You may be tempted to buy the most energy efficient, highest-capacity air conditioner or heating system on the market. However, that's usually not a great idea.
HVAC systems that are bigger than your home needs or smaller than your home requires can create indoor comfort challenges, increase utility costs and reduce efficiency regardless of their SEER rating.
Common Problems With 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 and tear.
- Reduced humidity control: Oversized air conditioners finish cooling cycles too soon to remove excess moisture from the air.
- Hot and cold spots: Some rooms get too cold while others never feel comfortable.
- Additional equipment wear: Even though the system heats or cools your home fast, those constant cycles can cause avoidable breakdowns due to the strain.
Issues Created by Undersized HVAC Systems
An undersized HVAC system also can struggle:
- Long run times: The system operates almost continuously trying to reach the set temperature, which also causes unnecessary wear and tear.
- Trouble reaching the thermostat setting: Your home may feel cool enough during hot weather or always feel chilly in the winter.
- Increased energy consumption: Running for extended periods can increase utility bills.
- Greater strain on very hot or cold days: HVAC systems that are too small can run extremely hard in extreme temperatures, increasing component strain 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 always need the highest-efficiency model on the market.
More often than not, a correctly sized, mid-efficiency heating and cooling system will provide better results 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 future plans.
When deciding how to choose a new air conditioner or furnace, think about:
- Energy savings: Higher-efficiency and right-sized systems can reduce electricity use.
- Purchase price: High-efficiency AC and heating systems often require a larger upfront investment than mid-range models but can lower 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 extremely cold winters or intense summer heat.
- Time you plan to 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 lower the overall cost of higher-efficiency systems.
Real-World Comparison: High Seer vs. Right System Size
How does this work in a real world example?
Suppose there are 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-SEER or AFUE system after completing a Manual J calculation.
While 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 correctly matched to the home's needs.
Choose the Local HVAC Professional Who Designs Solutions Tailored to Your Home
An HVAC replacement should involve more than selecting a system with the top efficiency rating. The best system is one that meets your heating and cooling requirements.
At Balance Point Heating & Cooling, our knowledgeable technicians perform an HVAC load calculation. Our team will evaluate your home's size and layout, 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 let you know about any available rebates or tax incentives and provide information about HVAC financing options that make efficient heating and cooling systems more accessible for all budgets.
Schedule an HVAC consultation online with Balance Point Heating & Cooling to get started. Our team will evaluate your home, answer any questions and help you choose the properly sized energy-efficient system that keeps your family comfortable for the long haul.