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 natural to look for models with the highest efficiency ratings.
Surely the most efficient system provides the most comfort and lowest energy bills, right?
It’s not quite that simple.
Efficiency ratings aren’t the only thing that matters 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 utility bills.
Proper sizing directly impacts humidity control and lasting performance. 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 trusted HVAC experts 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), shows how effectively an AC cools your home over a typical 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 that is the current rating system for cooling equipment.
Fuel-burning heating system efficiency is measured by something called AFUE, which is short for Annual Fuel Utilization Efficiency. Similar to cooling efficiency 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 necessarily guarantee lower utility bills. Actual heating and air conditioner efficiency depends on more than just efficiency ratings, including the installation quality, 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 oversized or too small for the home.
Why HVAC System Size Matters More Than You Think
Many assume a bigger air conditioner or furnace will heat or cool a home better or that they should just replace their old HVAC system with a unit of the same capacity. Actually, new heating system installation or AC replacement should be selected 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 complete an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation considers many details that impact your home's heating and cooling load, including:
- Home square footage
- Room height
- Window size and orientation
- Insulation
- Drafts and air leakage
- Local climate
- Household occupants
- Heat generated by appliances and lighting
- Air duct condition
A properly sized air conditioner runs long enough to cool your home consistently while removing excess humidity. That means more consistent temperatures, better indoor comfort and improved humidity control. Proper sizing also helps the equipment to operate more effciently, reducing unnecessary wear that can reduce its service life 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 long-lasting performance.
Problems Caused by 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. In reality, that’s rarely a smart choice.
HVAC systems that are too large or too small can create comfort issues, increase utility costs and reduce efficiency regardless of their SEER rating.
Issues Created by 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 turns on and off frequently, reducing efficiency and increasing wear and tear.
- Humidity problems: Oversized air conditioners cool your home too quickly to remove excess moisture from the air.
- Inconsistent temperatures: Some rooms feel too cool while others never feel comfortable.
- More wear and tear: Even though the system works quickly, those repeated on-and-off cycles can cause avoidable breakdowns due to the strain.
Cons Associated with Undersized HVAC Systems
An undersized HVAC system has a different set of problems:
- Long run times: The system runs for long periods trying to reach the desired temperature, which also causes extra strain.
- Trouble reaching the thermostat setting: Your home may not feel comfortable during hot weather or feel too cool during winter.
- Increased energy consumption: Running nonstop can increase utility bills.
- Greater strain on very hot or cold days: HVAC systems that are too small can run extremely hard in extreme temperatures, increasing wear 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 necessarily need the highest-efficiency model on the market.
Often, a properly sized, mid-efficiency heating and cooling system will provide better results 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 long-term goals.
When deciding how to choose a new air conditioner or furnace, consider:
- Efficiency savings: Higher-efficiency and right-sized systems can decrease electricity use.
- Purchase price: High-efficiency AC and heating systems often cost more initially than mid-range models but can lower long-term energy costs.
- Local utility costs: Areas with more expensive electricity may see better long-term savings from higher-efficiency units.
- Your local climate: It's crucial your heating or cooling system has adequate capacity to handle areas with harsh winter weather or intense summer heat.
- Time you plan to own the home: 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.
- Rebates and tax credits: Manufacturer promotions, {utility|equipment rebates and tax credits can lower the overall cost of high-efficiency HVAC equipment.
Real-World Comparison: High Seer vs. Right System Size
How does this play out in a real world scenario?
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 replaced it with the same size system as the previous unit. At the neighboring home, an HVAC professional installs a right-sized, mid-efficiency system after completing a Manual J calculation.
Although the second system has a more modest efficiency rating on paper, it may provide lower operating costs, better home comfort, more effective humidity control and have a longer lifespan because it's correctly matched to the home's needs.
Choose the Local HVAC Professional Who Designs Solutions Tailored to Your Home
Replacing your HVAC system should involve 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 Western Mechanical, Inc., our experienced professionals perform an HVAC load calculation. Our team will evaluate your home's design, your household's comfort goals 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 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 Western Mechanical, Inc. today. We'll evaluate your home, answer your questions and help you choose the correctly sized energy-efficient system that keeps your family comfortable for years to come.