Choosing a new AC or furnace can be intimidating. If you want to find the best HVAC system for your home, it's common to look for models with the highest efficiency ratings.
After all, the most efficient equipment should deliver the most comfort and lowest energy bills, right?
Actually, that’s not always the case.
Energy efficiency isn't the only thing you should consider when it comes to new air conditioner installation or replacing your furnace. Although many people focus only on {energy efficiency|efficiency ratings, proper {HVAC system sizing is equally, if not more important for your home's comfort and your energy bills.
Proper sizing has a major impact on humidity control and lasting performance. The best HVAC system for your home balances 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 experienced HVAC professionals 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 AC cools your home over a normal cooling season. A SEER2 rating is the newer version of SEER, using test procedures that better represent real-world operating conditions. Most new air conditioners have a SEER2 efficiency rating, simply because this 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 cooling efficiency ratings, 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.
However, high numbers 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, your home's insulation, thermostat settings and, most importantly, HVAC system sizing. Even the highest-rated system cannot perform as intended if it is bigger than necessary or too small for the home.
Why HVAC System Size Matters More Than Most Homeowners Realize
Many assume a higher-capacity air conditioner or furnace will make their home the most comfortable or that they should just replace their old HVAC system with a same-sized replacement. In reality, new heating system installation or air conditioner replacement should be chosen 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 complete an HVAC load calculation, also called a Manual J calculation, before selecting replacement equipment. A Manual J calculation analyzes many details that impact your home's heating and cooling load, including:
- Home square footage
- Room height
- Window size and orientation
- Home insultation levels
- Air infiltration
- Regional 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 pulling out excess humidity. That means more even temperatures, better indoor comfort and improved humidity control. It also helps the equipment to operate more effciently, reducing excessive wear and tear that can shorten its lifespan or lead to more repairs and higher repair costs.
When HVAC equipment is correctly sized, you get improved comfort and long-lasting performance.
Problems Caused by Oversized and Undersized HVAC Equipment
Many homeowners are tempted to buy the most energy efficient, highest-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 indoor comfort challenges, increase utility 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 delivers the best comfort.
- Short cycling: An oversized HVAC system turns on and off frequently, reducing efficiency and increasing wear.
- Reduced humidity control: Oversized air conditioners cool your home too quickly to remove indoor humidity from the air.
- Uneven temperatures: Some rooms get too cold while others never feel comfortable.
- Additional equipment wear: Even though the system reaches the target temperature rapidly, those constant cycles 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 extra strain.
- Trouble reaching the thermostat setting: Your home may feel cool enough during hot weather or always feel chilly in the winter.
- Higher energy use: Running nonstop 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 component strain and the chance of failure.
Why You Should Balance HVAC System Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, keep in mind that you don't always need the top-efficiency model on the market.
Often, a professionally sized, mid-efficiency HVAC system will provide better results than an overly large premium system because it functions the way it was designed to.
Theideal choice is an energy-efficient HVAC system that's properly sized for your home, your budget, your climate and your future plans.
As you consider how to choose a new air conditioner or furnace, consider:
- Efficiency savings: Higher-efficiency and right-sized systems can reduce electricity use.
- Upfront investment: High-efficiency AC and heating systems often have a higher purchase price than mid-range models but can lower long-term energy costs.
- Electricity rates: Areas with more expensive electricity may see better 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 very 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 justify 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 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 that's too big because the contractor replaced it with the same size system as the previous unit. Next door, the second homeowner installs a correctly sized, mid-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 Personalized Solutions
HVAC replacent or installation should involve more than selecting a model with the highest efficiency rating. The best system is one that meets your household heating and cooling requirements.
At Kohles & Bach Heating & Cooling, our skilled HVAC experts perform an HVAC load calculation. We'll evaluate your home's design, your household's heating and cooling preferences and recommend equipment that's properly matched for your home—not simply the biggest, fanciest unit or the one with the highest AFUE or SEER2 rating.
Our heating and cooling specialists will connect you with 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 Kohles & Bach Heating & Cooling to get started. We'll gladly evaluate your home, answer your questions and help you choose the properly sized high-efficiency system that keeps your family comfortable for years to come.