Shopping for a new AC or furnace can feel overwhelming. If you want 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 heating and cooling system provides the most comfort and lowest energy bills, right?
Actually, that’s not always the case.
High efficiency isn't the only thing you should consider when it comes to new air conditioner installation or furnace replacement. Although many people focus only on {energy efficiency|efficiency ratings, proper {HVAC system sizing is just as, if not more important for your home's comfort and your power bills.
Proper sizing directly impacts humidity control and lasting performance. The best HVAC system for your home combines energy efficiency and proper sizing.
In thisarticle, 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 it Mean if an AC Has a High SEER Rating?
A SEER rating, (Seasonal Energy Efficiency Ratio), shows how effectively an air conditioner cools your home over a typical cooling season. A SEER2 rating is the updated version of SEER, using test procedures that better represent real-world operating conditions. Today’s new air conditioners have a SEER2 efficiency rating, simply because this is the current rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by AFUE, which stands for Annual Fuel Utilization Efficiency. Like SEER and SEER2, higher AFUE ratings indicate a high-efficiency HVAC system that uses less electricity to achieve indoor comfort than lower-rated systems under standardized laboratory testing.
However, high ratings don't automatically guarantee lower utility bills. Everyday heating and air conditioner efficiency depends on several key factors, including the quality of the installation, 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 operate at its best if it is too large or undersized for the home.
Why HVAC System Size Matters More Than You Think
Many assume a bigger air conditioner or furnace will make their home the most comfortable or that they should just replace their old HVAC system with a unit of the same capacity. The truth is, new heating system installation or a new air conditioner should be sized based on your home's current heating and cooling needs—not just square footage or the capacity of the old system.
That's why reputable technicians perform an HVAC load calculation, also called a Manual J calculation, before recommending replacement equipment. A Manual J calculation analyzes many factors that impact your home's heating and cooling requirements, including:
- Home square footage
- Room height
- Window size and direction
- Insulation
- Air infiltration
- 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 evenly while removing excess humidity. That means steadier temperatures, better indoor comfort and improved indoor humidity management. This also allows the equipment to perform more effciently, reducing strain that can shorten its lifespan or lead to costly breakdowns.
When a furnace or AC is correctly sized, you get better comfort and long-lasting performance.
Problems with Oversized and Undersized HVAC Equipment
You may be tempted to buy the most energy efficient, largest-capacity air conditioner or heating system on the market. The truth is, that’s rarely a smart choice.
HVAC systems that are bigger than your home needs or undersized can create comfort problems, increase utility costs and reduce efficiency regardless of their SEER rating.
Drawbacks of 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 cycles repeatedly, reducing efficiency and increasing wear and tear.
- Poor humidity removal: Oversized air conditioners reach the set temperature too fast to remove excess moisture from the air.
- Uneven temperatures: Some rooms feel too cool while others stay too warm.
- Increased wear and tear: 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 operates almost continuously trying to reach the thermostat setting, which also causes unnecessary wear and tear.
- Difficulty reaching thermostat settings: Your home may feel cool enough during hot weather or feel too cool during winter.
- Greater energy usage: Running for extended periods can increase utility bills.
- Added strain during extreme weather: HVAC systems that are too small can work harder in extreme temperatures, increasing wear and the risk of breakdowns.
Balancing Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, keep in mind that you don't automatically need the most efficient model on the market.
More often than not, a professionally sized, mid-efficiency HVAC system will outperform an overly large premium system because it functions the way it was designed to.
Thesmartest choice is an energy-efficient HVAC system that's properly sized for your home, your budget, your climate and your long-term needs.
When deciding 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.
- Purchase price: High-efficiency AC and heating systems often have a higher purchase price than mid-range models but can reduce long-term energy costs.
- Electricity rates: Areas with higher electricity rates may see more significant long-term savings from higher-efficiency units.
- Your local climate: It's important your heating or cooling system has the right capacity to handle areas with very cold winters 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 be worth the investment.
- Available rebates or tax incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can offset the overall cost of qualifying equipment.
Real-World Comparison: High Seer vs. Right System Size
How does this work in the real world?
Suppose there are 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. The other homeowner installs a properly sized, moderate-efficiency system after completing a Manual J calculation.
Although the second system has a more modest efficiency rating on paper, it may deliver lower operating costs, better home comfort, more effective humidity control and have a longer lifespan because it's properly matched to the home's needs.
Work With an HVAC Professional Who Designs the Right Solution
HVAC replacent or installation should involve much more than selecting a system with the top efficiency rating. The best system is one that meets your household heating and cooling requirements.
At Airtech Cooling & Heating, our experienced professionals perform an HVAC load calculation. We'll evaluate your home's design, your household's comfort goals 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 team will connect you with any available rebates or tax incentives and provide information about HVAC financing options that make energy-efficient HVAC systems more accessible for all budgets.
Schedule an HVAC consultation online with Airtech Cooling & Heating now. Our team will 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.