Choosing a new air conditioning system or furnace can be intimidating. If you're trying to find the best HVAC system for your home, it's natural to focus on models with extremely high efficiency ratings.
Surely the most efficient equipment should deliver 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. Even though many 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 balances efficiency and correct sizing.
In this blog, we'll explain what an air conditioner's SEER rating or SEER2 rating actually measures, why correct HVAC size 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), indicates how effectively an AC cools your home over a standard cooling season. A SEER2 rating is the current version of SEER, using evaluation methods that better represent real-world operating conditions. Today’s new air conditioners have a SEER2 designation, simply because that 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. As with SEER and SEER2, 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.
However, high ratings don't necessarily guarantee lower utility bills. Actual heating and air conditioner efficiency depends on several key factors, including the way the system is installed, the quality of your ductwork, how much insulation your home has, thermostat settings and, most importantly, HVAC system sizing. Even the highest-efficiency system cannot perform as intended if it is bigger than necessary or undersized for the home.
Why Correct HVAC System Sizing Matters More Than You Probably Think
Many assume a bigger air conditioner or furnace will make their home the most comfortable or that they should just replace their old HVAC system with a new one the same size. Actually, 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 contractors complete an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation evaluates many factors that affect your home's heating and cooling requirements, including:
- Total square footage
- Ceiling height
- Window size and placement
- Home insultation levels
- Air infiltration
- Local climate
- Household occupants
- Heat generated by appliances and lighting
- Ductwork condition
A properly sized air conditioner runs through longer cooling cycles to cool your home consistently while pulling out excess humidity. That means more consistent temperatures, better indoor comfort and improved humidity control. This also allows the equipment to run 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 the right size for your home, you get improved comfort and more dependable performance.
Problems with Oversized and Undersized Heating and Cooling Systems
You may be tempted to buy the most energy efficient, highest-capacity air conditioner or heating system on the market. In reality, that's usually not a great idea.
HVAC systems that are too large or smaller than your home requires can create comfort problems, increase energy expenses and reduce efficiency regardless of their SEER rating.
Common Problems With Oversized HVAC Systems
An oversized air conditioner or heating system may work quickly, but that doesn't mean it performs efficiently.
- Short cycling: An oversized HVAC system cycles repeatedly, reducing efficiency and increasing wear and tear.
- High indoor humidity: Oversized air conditioners cool your home too quickly to remove excess moisture from the air.
- Hot and cold spots: Some rooms get too cold while others aren’t ever cool enough.
- Increased wear and tear: Even though the system heats or cools your home fast, those frequent starts and stops can cause avoidable breakdowns due to the strain.
Drawbacks of Undersized HVAC Systems
An undersized HVAC system has a different set of problems:
- Long run times: The system operates almost continuously trying to reach the set temperature, which also causes extra strain.
- Difficulty maintaining the desired temperature: Your home may not feel comfortable during hot weather or feel too cool during winter.
- Increased energy consumption: Running nonstop 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 trying to decide between a high SEER vs right-sized system, keep in mind that you don't always need the most efficient model on the market.
Often, a professionally sized, mid-efficiency heating and cooling system will provide better results than an oversized premium system because it runs the way it was designed to.
Thebest choice is an energy-efficient HVAC system that's matched 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 require a larger upfront investment than mid-range models but can reduce long-term energy costs.
- Energy prices: Areas with higher utility costs may see more significant long-term savings from higher-efficiency units.
- Climate: It's important your heating or cooling system has the right capacity to handle areas with extremely cold winters or intense summer heat.
- 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 be worth 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 Comparison: High Seer vs. Right System Size
What does this look like in a real world example?
Suppose there are two neighboring homes.
In the first, the homeowner chooses a premium high-efficiency HVAC system that's too big for the house because the contractor simply matched the previous unit. At the neighboring home, an HVAC professional installs a right-sized, moderate-efficiency system after completing a Manual J calculation.
Although the second system has a lesser 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
HVAC replacent or installation should involve more than selecting a system with the highest efficiency rating. An ideal system is one that meets your home’s heating and cooling requirements.
At Ameri-Tec, our skilled HVAC experts 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 properly matched for your home—not simply the biggest, most expensive 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 high-efficiency systems more accessible for all budgets.
Schedule an HVAC consultation online with Ameri-Tec to get started. We'll gladly evaluate your home, answer any questions and help you choose the right-sized efficient system that keeps your family comfortable for the long haul.