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 extremely high 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.
Energy efficiency isn't the only thing you should consider when it comes to new air conditioner installation or installing a new furnace. Even though many focus only on energy efficiency, proper HVAC system sizing is equally, if not more important for your home's comfort and your power bills.
Proper sizing has a major impact on humidity control and long-term reliability. The best HVAC system for your home balances energy efficiency and correct 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.
High Seer Ratings: What Do They Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), measures how effectively a cooling system cools your home over a standard 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 updated rating system for cooling equipment.
Fuel-burning heating system efficiency is measured by an AFUE rating, which stands for Annual Fuel Utilization Efficiency. Like SEER and SEER2 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.
However, high ratings don't by themselves guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on more than just efficiency ratings, including the quality of the installation, the condition of your ductwork, your home's insulation, thermostat settings and, most importantly, HVAC system sizing. Even the highest-efficiency system cannot operate at its best if it is oversized or smaller than needed for the home.
Why Proper HVAC Sizing 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 simply replace their old HVAC system with a same-sized replacement. In reality, new heating system installation or air conditioner replacement should be selected based on your home's true 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 considers many variables that impact your home's heating and cooling load, including:
- Overall square footage
- Room height
- Window size and placement
- Home insultation levels
- Air infiltration
- Regional climate
- Household 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 eliminating excess humidity. That means steadier temperatures, better indoor comfort and improved indoor humidity management. This also allows the equipment to perform more effciently, reducing excessive wear and tear that can reduce its service life or lead to costly breakdowns.
When HVAC equipment is correctly sized, you get improved comfort and more reliable operation.
Problems Caused by Oversized and Undersized Systems
It might be tempting to buy the most energy efficient, highest-capacity air conditioner or heating system on the market. However, that's usually not a good investment.
HVAC systems that are bigger than your home needs or smaller than your home requires can create comfort problems, increase energy expenses and reduce efficiency regardless of their SEER rating.
Issues Created by Oversized HVAC Systems
An oversized air conditioner or heating system may reach the thermostat setting fast, but that doesn't mean it performs efficiently.
- 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 excess moisture from the air.
- Inconsistent temperatures: Some rooms feel too cool 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.
Cons Associated with Undersized HVAC Systems
An undersized HVAC system can have the opposite problem:
- Continuous operation: The system operates almost continuously trying to reach the set temperature, which also causes additional wear.
- Trouble reaching the thermostat setting: Your home may not feel comfortable during hot weather or always feel chilly in the winter.
- Increased energy consumption: Running almost constantly can increase monthly energy expenses.
- Greater strain on very hot or cold days: HVAC systems that are too small can struggle 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 highest-efficiency model on the market.
Often, a professionally sized, mid-efficiency heating and cooling system will provide better results than an oversized premium system because it runs the way it was designed to.
Thebest choice is an energy-efficient HVAC system that's correctly sized for your home, your budget, your climate and your future plans.
When deciding how to choose a new air conditioner or furnace, consider:
- Energy savings: Higher-efficiency and right-sized systems can reduce electricity use.
- Initial cost: High-efficiency AC and heating systems often require a larger upfront investment than mid-range models but can help reduce long-term energy costs.
- Electricity rates: Areas with higher electricity rates may see more significant long-term savings from higher-efficiency units.
- Climate: It's important your heating or cooling system has the right capacity to handle areas with harsh winter weather or intense summer heat.
- Length of home ownership: 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.
- Financial incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can offset the overall cost of higher-efficiency systems.
Real-World Situation: High Seer vs. Right System Size
How does this work in a real world scenario?
Imagine two neighboring homes.
In one, the homeowner chooses a premium high-efficiency HVAC system that's too big for the house because the contractor replaced it with the same size system as 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 lower efficiency rating on paper, it may deliver lower operating costs, better home comfort, more effective humidity control and last longer because it's appropriately sized to the home's needs.
Work With an HVAC Professional Who Designs the Right Solution
An HVAC replacement should involve much more than selecting a model with the highest efficiency rating. The best system is one that meets your household heating and cooling requirements.
At Pepper AC & Heat, our knowledgeable technicians perform an HVAC load calculation. We'll carefully evaluate your home's layout and construction, your household's heating and cooling preferences and recommend equipment that's designed specifically for your home—not simply the largest, fanciest unit or the one with the highest AFUE or SEER2 rating.
Our HVAC experts will help you identify 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 Pepper AC & Heat now. Our team will evaluate your home, answer your questions and help you choose the right-sized high-efficiency system that keeps your family comfortable for years to come.
