Choosing a new air conditioner or furnace can be intimidating. If you're trying to find the best HVAC system for your home, it's common to focus on models with extremely high efficiency ratings.
Surely the most efficient equipment will provide the most comfort and lowest energy bills, right?
Not necessarily.
High efficiency isn't the only thing you should consider when it comes to new air conditioner installation or installing a new furnace. Although many people focus only on energy efficiency, 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 combines energy efficiency and correct sizing.
In this guide, 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 trusted HVAC experts consider both when recommending the best HVAC system for your home.
What Does a High SEER Rating Actually Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), shows how efficiently an air conditioner cools your home over a normal cooling season. A SEER2 rating is the current version of SEER, using test procedures that better represent real-world operating conditions. Nearly all new air conditioners have a SEER2 efficiency rating, simply because this rating is the updated rating system for cooling equipment.
Fuel-burning heating system efficiency is measured by something called AFUE, which is for Annual Fuel Utilization Efficiency. As with SEER and SEER2, 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 ratings don't necessarily guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on many factors, including the installation quality, the state of your ductwork, how much insulation your home has, thermostat settings and, most importantly, system sizing. Even the highest-rated system cannot deliver peak performance if it is too large or too small for the home.
Why HVAC System Size Matters More Than You Probably Think
Many assume a higher-capacity air conditioner or furnace will work the best or that they should just replace their old HVAC system with a same-sized replacement. Actually, new heating system installation or a new air conditioner 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 details that impact your home's heating and cooling load, including:
- Overall square footage
- Room height
- Window size and placement
- Home insultation levels
- Air infiltration
- Area climate
- Number of occupants
- Heat generated by appliances and lighting
- Ductwork condition
A properly sized air conditioner runs for enough time to cool your home consistently while pulling out excess humidity. That means steadier temperatures, better indoor comfort and improved moisture control. Proper sizing also helps the equipment to operate more effciently, reducing strain that can reduce its service life or lead to frequent or expensive repairs.
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
You may be tempted to buy the most energy efficient, largest-capacity air conditioner or heating system on the market. However, that’s rarely a smart choice.
HVAC systems that are bigger than your home needs or undersized can create indoor comfort challenges, increase operating costs and reduce efficiency regardless of their SEER rating.
Common Problems With Oversized HVAC Systems
An oversized air conditioner or heating system may reach the thermostat setting fast, but that doesn't mean it performs efficiently.
- Short cycling: An oversized HVAC system turns on and off frequently, reducing efficiency and increasing equipment strain.
- Poor humidity removal: Oversized air conditioners finish cooling cycles too soon to remove indoor humidity from the air.
- Inconsistent temperatures: Some rooms feel too cool while others never feel comfortable.
- Increased wear and tear: Even though the system heats or cools your home fast, those constant cycles can cause avoidable breakdowns due to the strain.
Cons Associated with 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 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 monthly energy expenses.
- Extra stress during severe weather: HVAC systems that are too small can work harder in extreme temperatures, increasing wear and the chance of failure.
Balancing 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 top-efficiency model on the market.
More often than not, a properly sized, mid-efficiency heating and cooling system will outperform an oversized premium system because it operates the way it was designed to.
Thesmartest choice is an energy-efficient HVAC system that's properly sized for your home, your budget, your climate and your long-term goals.
When deciding how to choose a new air conditioner or furnace, keep these factors in mind:
- Efficiency savings: Higher-efficiency and right-sized systems can decrease electricity use.
- Upfront investment: 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 higher electricity rates may see more significant long-term savings from higher-efficiency units.
- Your local climate: It's crucial your heating or cooling system has enough capacity to handle areas with extremely cold winters or extremely hot summers.
- 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.
- Rebates and tax credits: Manufacturer promotions, {utility|equipment rebates and tax credits can reduce the overall cost of qualifying equipment.
Real-World Comparison: High Seer vs. Right System Size
How does this play out in a real world example?
Imagine two neighboring homes.
At the first home, the homeowner chooses a premium high-efficiency HVAC system that's too big for the house because the contractor simply matched the previous unit. Next door, the second homeowner installs a right-sized, mid-efficiency 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 have a longer lifespan because it's appropriately sized to the home's needs.
Work With an HVAC Professional Who Designs Solutions Tailored to Your Home
An HVAC replacement should involve much more than selecting a system with the top efficiency rating. An ideal system is one that meets your home’s heating and cooling requirements.
At Herman Allen Plumbing, Heating & Cooling, our experienced professionals perform an HVAC load calculation. We'll carefully evaluate your home's design, your household's heating and cooling preferences and recommend equipment that's designed specifically for your home—not simply the biggest, latest and greatest unit or the one with the highest AFUE or SEER2 rating.
Our team will help you identify any available tax rebates 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 Herman Allen Plumbing, Heating & Cooling now. We'll gladly evaluate your home, answer your questions and help you choose the right-sized energy-efficient system that keeps your family comfortable for many years.