Choosing a new AC or furnace can be intimidating. If you want 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 equipment will provide the most comfort and lowest energy bills, right?
Not necessarily.
Efficiency ratings aren’t the only thing to think about when it comes to new air conditioner installation or furnace replacement. Even though many focus only on energy efficiency, proper HVAC system sizing is equally, if not more important for your home's comfort and your energy bills.
Proper sizing has a major impact on humidity control and system longevity. 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 qualified HVAC contractors 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), shows how efficiently an AC cools your home over a normal cooling season. A SEER2 rating is the current version of SEER, using test procedures that better reflect real-world operating conditions. Nearly all new air conditioners have a SEER2 efficiency rating, simply because this rating is the current rating system for cooling equipment.
Fuel-burning heating system efficiency is rated by AFUE, which stands for Annual Fuel Utilization Efficiency. As with SEER and SEER2 ratings, 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.
Even so, high numbers don't necessarily guarantee lower utility bills. Everyday heating and air conditioner efficiency depends on many factors, including the installation quality, the condition 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 too small for the home.
Why Proper HVAC Sizing Matters More Than Most Homeowners Realize
Many assume a bigger air conditioner or furnace will work the best or that they should just 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 selected based on your home's current heating and cooling needs—not just square footage or the size of the previous unit.
That's why reputable contractors conduct an HVAC load calculation, also called a Manual J calculation, before selecting replacement equipment. A Manual J calculation considers many factors that affect your home's comfort needs, including:
- Total square footage
- Ceiling height
- Window size and direction
- Home insultation levels
- Air leakage
- Local climate
- Household occupants
- Heat generated by appliances and lighting
- Air duct condition
A properly sized air conditioner runs for enough time to cool your home more uniformly while pulling out excess humidity. That means more even temperatures, better indoor comfort and improved moisture control. Proper sizing also helps the equipment to run more effciently, reducing unnecessary wear that can cause it to wear it out sooner or lead to more repairs and higher repair costs.
When your heating or cooling system is the right size for your home, you get greater comfort and more dependable performance.
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 often isn't a good investment.
heating and cooling 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 delivers the best comfort.
- Short cycling: An oversized HVAC system starts and stops often, reducing efficiency and increasing wear.
- Poor humidity removal: Oversized air conditioners finish cooling cycles too soon to remove enough moisture from the air.
- Uneven temperatures: Some rooms feel too cool while others aren’t ever cool enough.
- More 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.
Issues Created by Undersized HVAC Systems
An undersized HVAC system has a different set of problems:
- Long run times: The system stays on for extended periods trying to reach the thermostat setting, which also causes unnecessary wear and tear.
- Trouble reaching the thermostat setting: Your home may never feel as cool as you want during hot weather or never feel warm enough in cold weather.
- Greater energy usage: Running for extended periods can increase energy costs.
- Added strain during extreme weather: HVAC systems that are too small can struggle in extreme temperatures, increasing wear and the chance of failure.
Finding the Right Balance Between Efficiency and Size
When trying to decide between a high SEER vs right-sized system, keep in mind that you don't automatically need the most efficient model on the market.
In many cases, a professionally sized, mid-efficiency HVAC system will deliver better performance than an overly large premium system because it runs 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.
As you think about 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 have a higher purchase price than mid-range models but can help reduce long-term energy costs.
- Energy prices: Areas with more expensive electricity may see more significant long-term savings from higher-efficiency units.
- Climate: It's crucial your heating or cooling system has adequate capacity to handle areas with harsh winter weather 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 justify the investment.
- Rebates and tax credits: Manufacturer promotions, {utility|equipment rebates and tax credits can reduce the overall cost of qualifying equipment.
Real-World Situation: High Seer vs. Right System Size
How does this play out in the real world?
Picture 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 simply matched the previous unit. The other homeowner installs a properly sized, mid-efficiency system after completing a Manual J calculation.
While the second system has a lower efficiency rating on paper, it may provide lower operating costs, better home comfort, improved humidity control and last longer because it's appropriately sized to the home's needs.
Work With an HVAC Professional Who Designs Personalized Solutions
Replacing your HVAC system should involve much more than selecting the unit with the top efficiency rating. The best system is one that meets your home’s heating and cooling requirements.
At Hix Air Conditioning Service, Inc., our skilled HVAC experts perform an HVAC load calculation. We'll evaluate your home's design, your household's comfort goals and recommend equipment that's right for your home—not simply the biggest, latest and greatest unit or the one with the highest AFUE or SEER2 rating.
Our HVAC experts will connect you with 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 Hix Air Conditioning Service, Inc. now. We'll gladly evaluate your home, answer any questions and help you choose the properly sized high-efficiency system that keeps your family comfortable for many years.