Shopping for a new AC 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 the highest efficiency ratings.
Surely the most efficient equipment should deliver 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 has a major impact on humidity control and lasting performance. The best HVAC system for your home combines energy efficiency and proper sizing.
In thisguide, 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 helping you select the best HVAC system for your home.
What Does a High SEER Rating Actually Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), indicates how efficiently an air conditioner cools your home over a standard cooling season. A SEER2 rating is the updated version of SEER, using testing methods that better reflect real-world operating conditions. Most new air conditioners have a SEER2 designation, simply because that is the new rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by something called AFUE, which is for Annual Fuel Utilization Efficiency. Like 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.
Even so, high ratings don't necessarily guarantee lower utility bills. Actual heating and air conditioner efficiency depends on more than just efficiency ratings, including the way the system is installed, the quality of your ductwork, your home's insulation, thermostat settings and, most importantly, proper HVAC system sizing. Even the highest-efficiency system cannot deliver peak performance if it is bigger than necessary or undersized 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. The truth is, new heating system installation or AC replacement should be sized 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 companies conduct 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 requirements, including:
- Total square footage
- Room height
- Window size and placement
- Insulation
- Drafts and air leakage
- Regional climate
- Household occupants
- Heat produced from appliances and lighting
- Ductwork condition
A properly sized air conditioner runs for enough time to cool your home evenly while pulling out excess humidity. That means more consistent temperatures, better indoor comfort and improved humidity control. Proper sizing also helps the equipment to perform more effciently, reducing excessive wear and tear that can reduce its service life or lead to frequent or expensive repairs.
When your heating or cooling system is properly sized, you get better comfort and more reliable operation.
Problems with Oversized and Undersized Systems
Many homeowners are tempted to buy the most energy efficient, highest-capacity air conditioner or heating system on the market. However, that's usually not a good investment.
heating and cooling systems that are bigger than your home needs or smaller than your home requires can create indoor comfort challenges, increase energy expenses and reduce efficiency regardless of their SEER rating.
Drawbacks of Oversized HVAC Systems
An oversized air conditioner or heating system may reach the thermostat setting fast, but that doesn't mean it delivers the best comfort.
- Short cycling: An oversized HVAC system starts and stops often, reducing efficiency and increasing equipment strain.
- Reduced humidity control: Oversized air conditioners reach the set temperature too fast to remove indoor humidity from the air.
- Hot and cold spots: Some rooms become too cold while others never feel comfortable.
- Additional equipment wear: Even though the system reaches the target temperature rapidly, 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:
- Continuous operation: The system runs for long periods trying to reach the set temperature, which also causes additional wear.
- Difficulty maintaining the desired temperature: Your home may feel cool enough during hot weather or never feel warm enough in cold weather.
- Increased energy consumption: Running almost constantly can increase energy costs.
- Greater strain on very hot or cold days: HVAC systems that are too small can struggle in extreme temperatures, increasing 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, remember that you don't necessarily need the highest-efficiency model on the market.
In many cases, a professionally sized, mid-efficiency heating and cooling system will deliver better performance than an overly large premium system because it functions the way it was designed to.
Thesmartest choice is an energy-efficient HVAC system that's correctly sized for your home, your budget, your climate and your long-term needs.
As you consider how to choose a new air conditioner or furnace, keep these factors in mind:
- Lower energy costs: Higher-efficiency and right-sized systems can decrease electricity use.
- Upfront investment: High-efficiency AC and heating systems often require a larger upfront investment than mid-range models but can lower long-term energy costs.
- Energy prices: Areas with higher electricity rates may see more significant 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 extremely cold winters or extremely hot summers.
- Time you plan to 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 be worth the investment.
- Available rebates or tax incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can lower the overall cost of higher-efficiency systems.
Real-World Comparison: High Seer vs. Right System Size
How does this work in a real world example?
Imagine two neighboring homes.
In one, 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. 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 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
An HVAC replacement should involve much more than selecting the unit with the highest efficiency rating. An ideal system is one that meets your household heating and cooling requirements.
At Kapaun & Brown, our experienced professionals 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, fanciest 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 efficient heating and cooling systems more accessible for all budgets.
Schedule an HVAC consultation online with Kapaun & Brown to get started. Our team will evaluate your home, answer your questions and help you choose the correctly sized efficient system that keeps your family comfortable for many years.