Shopping for a new air conditioner or furnace can feel overwhelming. If you want to find the best HVAC system for your home, it's common 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?
It’s not quite that simple.
Efficiency ratings aren’t the only thing that matters when it comes to new air conditioner installation or furnace replacement. Even though many focus only on efficiency ratings, proper HVAC system sizing is often even more important for your home's comfort and your utility bills.
Proper sizing has a major impact on humidity control and system longevity. The best HVAC system for your home combines energy efficiency and proper sizing.
In this guide, we'll explain what an air conditioner's SEER rating or SEER2 rating actually measures, why correct HVAC size is so important and why qualified HVAC contractors consider both when helping you select the best HVAC system for your home.
High Seer Ratings: What Do They Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), shows how efficiently a cooling system cools your home over a typical cooling season. A SEER2 rating is the current version of SEER, using test procedures that better reflect real-world operating conditions. Nearly all new air conditioners have a SEER2 designation, simply because this is the new rating system for cooling equipment.
Fuel-burning heating system efficiency is rated by an AFUE rating, which is 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.
Even so, high ratings don't automatically guarantee lower utility bills. Everyday heating and air conditioner efficiency depends on many factors, including the installation quality, the condition 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 too large or too small for the home.
Why Correct HVAC System Sizing Matters More Than You Think
Many assume a larger air conditioner or furnace will work the best or that they should simply replace their old HVAC system with a unit of the same capacity. Actually, new heating system installation or a new air conditioner should be chosen based on your home's actual heating and cooling needs—not just square footage or the size of your existing equipment.
That's why reputable contractors perform an HVAC load calculation, also called a Manual J calculation, before selecting replacement equipment. A Manual J calculation analyzes many variables that impact your home's heating and cooling load, including:
- Total square footage
- Ceiling height
- Window size and placement
- Insulation
- Air leakage
- Regional climate
- Number of occupants
- Heat generated by appliances and lighting
- Ductwork condition
A properly sized air conditioner runs for enough time to cool your home consistently while pulling out 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 cause it to wear it out sooner or lead to frequent or expensive repairs.
When a furnace or AC is the right size for your home, you get better comfort and long-lasting performance.
Problems Caused by Oversized and Undersized Heating and Cooling Systems
Many homeowners are tempted to buy the most energy efficient, largest-capacity air conditioner or heating system on the market. In reality, that’s rarely a great idea.
heating and cooling systems that are too large or undersized can create comfort problems, increase operating costs and reduce efficiency regardless of their SEER rating.
Issues Created by 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 equipment strain.
- Reduced humidity control: Oversized air conditioners finish cooling cycles too soon to remove indoor humidity from the air.
- Uneven temperatures: Some rooms become too cold while others never feel comfortable.
- More wear and tear: Even though the system reaches the target temperature rapidly, those constant cycles can cause avoidable breakdowns due to the strain.
Cons Associated with Undersized HVAC Systems
An undersized HVAC system can have the opposite problem:
- Continuous operation: 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 feel cool enough during hot weather or never feel warm enough in cold weather.
- Higher energy use: Running nonstop can increase energy costs.
- Greater strain on very hot or cold days: HVAC systems that are too small can struggle in extreme temperatures, increasing component strain and the risk of breakdowns.
Balancing Efficiency and Size
When trying to decide between a high SEER vs right-sized system, don't forget that you don't always need the highest-efficiency model on the market.
Often, 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.
Thebest choice is an energy-efficient HVAC system that's matched 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.
- Upfront investment: High-efficiency AC and heating systems often require a larger upfront investment than mid-range models but can help reduce long-term energy costs.
- Local utility costs: Areas with more expensive electricity may see more significant long-term savings from higher-efficiency units.
- Your local climate: It's essential your heating or cooling system has adequate capacity to handle areas with very cold winters or intense summer heat.
- 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 offset the investment.
- Rebates and tax credits: Manufacturer promotions, {utility|equipment rebates and tax credits can reduce the overall cost of higher-efficiency systems.
Real-World Comparison: High Seer vs. Right System Size
How does this work in the real world?
Imagine 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 simply matched the previous unit. The other homeowner installs a correctly sized, mid-SEER or AFUE system after completing a Manual J calculation.
While 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 properly matched to the home's needs.
Work With an HVAC Professional Who Designs Personalized Solutions
Replacing your HVAC system should involve much more than selecting a model with the top efficiency rating. The best system is one that meets your home’s heating and cooling requirements.
At Kilbourne Heating & AC, our knowledgeable technicians perform an HVAC load calculation. We'll evaluate your home's design, your household's comfort needs and recommend equipment that's properly matched for your home—not simply the biggest, latest and greatest 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 Kilbourne Heating & AC now. We'll evaluate your home, answer any questions and help you choose the correctly sized energy-efficient system that keeps your family comfortable for the long haul.