Shopping for a new air conditioner or furnace can be intimidating. When you're looking to find the best HVAC system for your home, it's understandable to look for 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?
Not necessarily.
Energy efficiency isn't the only thing that matters when it comes to new air conditioner installation or furnace replacement. Although many people focus only on efficiency ratings, proper HVAC system sizing is equally, if not more important for your home's comfort and your utility bills.
Proper sizing directly impacts humidity control and system longevity. The best HVAC system for your home delivers 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 size is so important and why qualified HVAC contractors 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 newer version of SEER, using test procedures that better simulate real-world operating conditions. Today’s new air conditioners have a SEER2 designation, simply because this is the current rating system for cooling equipment.
Fuel-burning heating system efficiency is rated by an AFUE rating, which is short for Annual Fuel Utilization Efficiency. Like SEER and SEER2, 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 numbers don't by themselves guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on more than just efficiency ratings, including the way the system is installed, the condition of your ductwork, insulation levels, thermostat settings and, most importantly, proper HVAC system sizing. Even the highest-rated system cannot operate at its best if it is oversized or smaller than needed for the home.
Why HVAC System Size Matters More Than Most Homeowners Realize
Many assume a larger air conditioner or furnace will heat or cool a home better or that they should just replace their old HVAC system with a same-sized replacement. In reality, new heating system installation or AC replacement should be selected based on your home's true heating and cooling needs—not just square footage or the size of the previous unit.
That's why reputable technicians complete an HVAC load calculation, also called a Manual J calculation, before recommending replacement equipment. A Manual J calculation analyzes many details that affect your home's heating and cooling requirements, including:
- Overall square footage
- Room height
- Window size and placement
- Insulation
- Air infiltration
- Regional climate
- Number of occupants
- Heat generated by appliances and lighting
- Air duct condition
A properly sized air conditioner runs for enough time to cool your home more uniformly while removing excess humidity. That means more consistent temperatures, better indoor comfort and improved indoor humidity management. It also helps the equipment to run more effciently, reducing unnecessary wear that can cause it to wear it out sooner or lead to more repairs and higher repair costs.
When your heating or cooling system is correctly sized, you get improved comfort and more dependable performance.
Problems with Oversized and Undersized Systems
You may be tempted to buy the most energy efficient, highest-capacity air conditioner or heating system on the market. In reality, that often isn't a smart choice.
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.
Common Problems With 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.
- Reduced humidity control: Oversized air conditioners finish cooling cycles too soon to remove excess moisture from the air.
- Inconsistent temperatures: Some rooms become 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.
Issues Created by Undersized HVAC Systems
An undersized HVAC system can have the opposite problem:
- Long run times: The system stays on for extended periods trying to reach the desired temperature, which also causes additional wear.
- Difficulty reaching thermostat settings: Your home may not feel comfortable during hot weather or feel too cool during winter.
- Greater energy usage: Running almost constantly can increase utility bills.
- 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 risk of breakdowns.
Finding the Right Balance Between Efficiency and Size
When weighing the pros and cons of 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 professionally sized, mid-efficiency HVAC system will deliver better performance than an oversized premium system because it runs the way it was designed to.
Thebest choice is an energy-efficient HVAC system that's properly sized for your home, your budget, your climate and your future plans.
As you think about how to choose a new air conditioner or furnace, think about:
- Efficiency savings: Higher-efficiency and right-sized systems can decrease 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.
- Energy prices: Areas with higher utility costs may see greater long-term savings from higher-efficiency units.
- Seasonal weather conditions: It's crucial your heating or cooling system has the right capacity to handle areas with harsh winter weather or very hot summers.
- How long you'll 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 reduce the overall cost of high-efficiency HVAC equipment.
Real-World Example: High Seer vs. Right System Size
How does this play out in a real world example?
Picture two neighboring homes.
In the first, 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 properly sized, moderate-efficiency 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, improved 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
HVAC replacent or installation should involve much more than selecting the unit with the highest efficiency rating. The best system is one that meets your heating and cooling requirements.
At AW Heating & Air Conditioning, our knowledgeable technicians perform an HVAC load calculation. We'll evaluate your home's layout and construction, your household's comfort needs and recommend equipment that's properly matched for your home—not simply the largest, most expensive unit or the one with the highest AFUE or SEER2 rating.
Our HVAC experts will let you know about 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 AW Heating & Air Conditioning now. We'll evaluate your home, answer any questions and help you choose the right-sized high-efficiency system that keeps your family comfortable for the long haul.
