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 look for models with extremely high efficiency ratings.
After all, the most efficient system will provide the most comfort and lowest energy bills, right?
Actually, that’s not always the case.
High 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 equally, if not more important for your home's comfort and your power 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 blog, we'll explain what an air conditioner's SEER rating or SEER2 rating actually measures, why proper HVAC system sizing is so important and why experienced HVAC professionals consider both when helping you choose the best HVAC system for your home.
High Seer Ratings: What Do They Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), shows how efficiently an AC cools your home over a standard cooling season. A SEER2 rating is the current version of SEER, using testing methods that better represent real-world operating conditions. Most new air conditioners have a SEER2 efficiency rating, simply because this rating is the new rating system for cooling equipment.
Fuel-burning heating system efficiency is measured by an AFUE rating, 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 keep you comfortable than lower-rated systems under standardized laboratory testing.
However, high numbers don't automatically guarantee lower utility bills. Actual heating and air conditioner efficiency depends on many factors, including the quality of the installation, the condition of your ductwork, insulation levels, thermostat settings and, most importantly, system sizing. Even the most efficient system cannot deliver peak performance if it is too large or too small for the home.
Why Correct HVAC System Sizing Matters More Than Most Homeowners Realize
Many assume a higher-capacity air conditioner or furnace will heat or cool a home better 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 sized 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 conduct an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation evaluates many variables that affect your home's comfort needs, including:
- Overall square footage
- Room height
- Window size and placement
- Insulation
- Air infiltration
- Area climate
- Household occupants
- Heat generated by appliances and lighting
- Air duct condition
A properly sized air conditioner runs through longer cooling cycles to cool your home consistently while pulling out excess humidity. That means more even temperatures, better indoor comfort and improved moisture control. Proper sizing also helps the equipment to operate more effciently, reducing excessive wear and tear that can shorten its lifespan or lead to more repairs and higher repair costs.
When your heating or cooling system is correctly sized, you get greater comfort and more reliable operation.
Problems with Oversized and Undersized Heating and Cooling Systems
It might be tempting 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.
heating and cooling systems that are bigger than necessary or undersized can create comfort problems, increase energy expenses and reduce efficiency regardless of their SEER rating.
Issues Created by 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 turns on and off frequently, reducing efficiency and increasing wear and tear.
- High indoor humidity: Oversized air conditioners finish cooling cycles too soon to remove excess moisture from the air.
- Inconsistent temperatures: Some rooms feel too cool while others stay too warm.
- Increased 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.
Drawbacks of Undersized HVAC Systems
An undersized HVAC system can have the opposite problem:
- Continuous operation: The system stays on for extended periods trying to reach the set temperature, which also causes extra strain.
- Trouble reaching the thermostat setting: Your home may never feel as cool as you want during hot weather or feel too cool during winter.
- Higher energy use: Running for extended periods can increase utility bills.
- Extra stress during severe weather: HVAC systems that are too small can work harder in extreme temperatures, increasing component strain and the chance of failure.
Why You Should Balance HVAC System Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, keep in mind that you don't automatically need the highest-efficiency model on the market.
More often than not, a correctly sized, mid-efficiency HVAC system will outperform an overly large premium system because it runs 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 goals.
As you consider how to choose a new air conditioner or furnace, consider:
- Energy savings: Higher-efficiency and right-sized systems can lower electricity use.
- Purchase price: High-efficiency AC and heating systems often require a larger upfront investment than mid-range models but can reduce long-term energy costs.
- Local utility costs: Areas with more expensive electricity may see greater long-term savings from higher-efficiency units.
- Seasonal weather conditions: It's important your heating or cooling system has enough capacity to handle areas with extremely cold winters or extremely hot summers.
- Length of home ownership: If you intend to remain 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 higher-efficiency systems.
Real-World Comparison: High Seer vs. Right System Size
How does this work in the real world?
Imagine two neighboring homes.
In one, the homeowner chooses a premium high-efficiency HVAC system has far more capacity than the home needs because the contractor only matched the previous unit. Next door, the second homeowner installs a correctly sized, moderate-efficiency system after completing a Manual J calculation.
While the second system has a lesser 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.
Work With an HVAC Professional Who Designs Solutions Tailored to Your Home
Replacing your HVAC system should involve much more than selecting a model with the top efficiency rating. An ideal system is one that meets your heating and cooling requirements.
At Freed Heating & Air Conditioning, our knowledgeable technicians perform an HVAC load calculation. We'll carefully evaluate your home's size and layout, your household's comfort needs and recommend equipment that's right for your home—not simply the highest-capacity, 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 Freed Heating & Air Conditioning today. 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.