Shopping for a new air conditioner or furnace can be intimidating. If you're trying to find the best HVAC system for your home, it's understandable to focus on models with extremely high efficiency ratings.
After all, the most efficient heating and cooling system will provide the most comfort and lowest energy bills, right?
Actually, that’s not always the case.
Efficiency ratings aren’t the only thing to think about when it comes to new air conditioner installation or furnace replacement. 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 also influences humidity control and system longevity. The best HVAC system for your home combines energy efficiency and correct 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 experienced HVAC professionals consider both when recommending 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), indicates how effectively an air conditioner cools your home over a normal cooling season. A SEER2 rating is the newer version of SEER, using testing methods that better reflect real-world operating conditions. Nearly all new air conditioners have a SEER2 rating, simply because this is the updated rating system for cooling equipment.
Fuel-burning heating system efficiency is measured by something called AFUE, which stands for Annual Fuel Utilization Efficiency. Like SEER and SEER2 ratings, 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. Everyday heating and air conditioner efficiency depends on more than just efficiency ratings, including the quality of the installation, the condition of your ductwork, how much insulation your home has, thermostat settings and, most importantly, proper HVAC system sizing. Even the highest-rated system cannot deliver peak performance if it is bigger than necessary or smaller than needed for the home.
Why Correct HVAC System Sizing Matters More Than You Probably Think
Many assume a bigger air conditioner or furnace will heat or cool a home better or that they should simply replace their old HVAC system with a new one the same size. In reality, new heating system installation or AC replacement should be chosen based on your home's actual heating and cooling needs—not just square footage or the capacity of the old system.
That's why reputable companies perform an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation analyzes many variables that affect your home's heating and cooling requirements, including:
- Overall square footage
- Room height
- Window size and placement
- Home insultation levels
- Air infiltration
- Local climate
- Household occupants
- Heat produced from appliances and lighting
- Air duct condition
A properly sized air conditioner runs through longer cooling cycles to cool your home evenly while pulling out excess humidity. That means more consistent temperatures, better indoor comfort and improved moisture control. This also allows the equipment to perform more effciently, reducing unnecessary wear that can reduce its service life or lead to frequent or expensive repairs.
When your heating or cooling system is the right size for your home, you get better comfort and long-lasting performance.
Problems with Oversized and Undersized Heating and Cooling Systems
You may be tempted to buy the most energy efficient, biggest air conditioner or heating system on the market. The truth is, that often isn't a good investment.
heating and cooling systems that are bigger than your home needs or smaller than your home requires can create comfort issues, 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 delivers the best comfort.
- 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 indoor humidity from the air.
- Hot and cold spots: Some rooms get too cold while others stay too warm.
- 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.
Drawbacks of Undersized HVAC Systems
An undersized HVAC system also can struggle:
- Continuous operation: The system operates almost continuously trying to reach the desired temperature, which also causes unnecessary wear and tear.
- Difficulty maintaining the desired temperature: Your home may feel cool enough during hot weather or feel too cool during winter.
- Higher energy use: Running nonstop can increase energy costs.
- Greater strain on very hot or cold days: HVAC systems that are too small can work harder in extreme temperatures, increasing equipment wear and the likelihood of repairs.
Finding the Right Balance Between Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, don't forget that you don't always need the highest-efficiency model on the market.
Often, a properly sized, mid-efficiency heating and cooling system will deliver better performance than an oversized premium system because it operates the way it was designed to.
Theideal choice is an energy-efficient HVAC system that's correctly sized for your home, your budget, your climate and your long-term goals.
As you think about how to choose a new air conditioner or furnace, keep these factors in mind:
- Energy savings: Higher-efficiency and right-sized systems can lower electricity use.
- Upfront investment: 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 better long-term savings from higher-efficiency units.
- Seasonal weather conditions: It's essential your heating or cooling system has enough capacity to handle areas with very cold winters or intense summer heat.
- Length of home ownership: 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 offset the overall cost of higher-efficiency systems.
Real-World Situation: High Seer vs. Right System Size
How does this work in a real world scenario?
Imagine 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. Next door, the second homeowner installs a correctly sized, mid-SEER or AFUE system after completing a Manual J calculation.
Even though the second system has a lesser 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.
Work With an HVAC Professional Who Designs Personalized Solutions
Replacing your HVAC system should involve much more than selecting a system with the top efficiency rating. The right system is one that meets your household heating and cooling requirements.
At Solar Air Inc., our knowledgeable technicians perform an HVAC load calculation. We'll 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, fanciest 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 Solar Air Inc. to get started. Our team will evaluate your home, answer your questions and help you choose the right-sized efficient system that keeps your family comfortable for years to come.
