Shopping for a new air conditioning system or furnace can be stressful. If you want to find the best HVAC system for your home, it's natural to look for models with extremely high efficiency ratings.
Surely the most efficient heating and cooling system will provide the most comfort and lowest energy bills, right?
It’s not quite that simple.
Energy efficiency isn't the only thing that matters when it comes to new air conditioner installation or installing a new furnace. While many homeowners focus only on energy efficiency, proper HVAC system sizing is often even more important for your home's comfort and your energy bills.
Proper sizing also influences humidity control and lasting performance. 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 proper HVAC system sizing is so important and why experienced HVAC professionals consider both when helping you choose the best HVAC system for your home.
High Seer Ratings: What Do They Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), measures how efficiently an AC cools your home over a standard cooling season. A SEER2 rating is the newer version of SEER, using evaluation methods that better represent real-world operating conditions. Today’s new air conditioners have a SEER2 rating, simply because this is the updated rating system for cooling equipment.
Fuel-burning heating system efficiency is rated by an AFUE rating, which is short 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.
Even so, high numbers don't automatically guarantee lower utility bills. Everyday 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 most efficient system cannot deliver peak performance if it is oversized or undersized for the home.
Why HVAC System Size Matters More Than Most Homeowners Realize
Many assume a bigger air conditioner or furnace will work the best or that they should just replace their old HVAC system with a new one the same size. In reality, new heating system installation or air conditioner replacement should be chosen based on your home's current heating and cooling needs—not just square footage or the size of the previous unit.
That's why reputable contractors conduct an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation analyzes many details that impact your home's comfort needs, including:
- Home square footage
- Room height
- Window size and placement
- Home insultation levels
- Drafts and air leakage
- Area climate
- Number of occupants
- Heat generated by appliances and lighting
- Ductwork condition
A properly sized air conditioner runs long enough to cool your home more uniformly while eliminating excess humidity. That means steadier temperatures, better indoor comfort and improved humidity control. This also allows the equipment to run 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 better comfort and more dependable performance.
Problems Caused by Oversized and Undersized Heating and Cooling Systems
You may be tempted to buy the most energy efficient, largest-capacity air conditioner or heating system on the market. In reality, that's usually not a smart choice.
heating and cooling systems that are bigger than necessary or too small can create comfort issues, increase operating costs 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 performs efficiently.
- Short cycling: An oversized HVAC system starts and stops often, reducing efficiency and increasing wear.
- Poor humidity removal: Oversized air conditioners finish cooling cycles too soon to remove indoor humidity from the air.
- Hot and cold spots: Some rooms feel too cool while others aren’t ever cool enough.
- Additional equipment wear: Even though the system reaches the target temperature rapidly, those constant cycles can cause avoidable breakdowns due to the strain.
Issues Created by Undersized HVAC Systems
An undersized HVAC system also can struggle:
- Continuous operation: The system stays on for extended periods trying to reach the set temperature, which also causes unnecessary wear and tear.
- Trouble reaching the thermostat setting: Your home may not feel comfortable during hot weather or always feel chilly in the winter.
- Greater energy usage: Running for extended periods can increase monthly energy expenses.
- Extra stress during severe weather: HVAC systems that are too small can run extremely hard in extreme temperatures, increasing component strain and the likelihood of repairs.
Why You Should Balance HVAC System Efficiency and Size
When trying to decide between a high SEER vs right-sized system, keep in mind that you don't necessarily need the most efficient model on the market.
In many cases, a correctly sized, mid-efficiency heating and cooling system will outperform an oversized premium system because it runs 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 future plans.
As you think about how to choose a new air conditioner or furnace, keep these factors in mind:
- Lower energy costs: Higher-efficiency and right-sized systems can reduce 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.
- Local utility costs: Areas with higher utility costs may see better long-term savings from higher-efficiency units.
- Your local climate: It's essential your heating or cooling system has the right capacity to handle areas with harsh winter weather or very hot summers.
- Time you plan to own the home: If you expect to live in your home for many years, the long-term energy savings of a higher-efficiency unit may justify the investment.
- Financial 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?
Suppose there are two neighboring homes.
At the first home, the homeowner chooses a premium high-efficiency HVAC system that's too big for the house because the contractor only matched the previous unit. At the neighboring home, an HVAC professional installs a properly sized, mid-SEER or AFUE system after completing a Manual J calculation.
Even though 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 properly matched to the home's needs.
Work With an HVAC Professional Who Designs Solutions Tailored to Your Home
Replacing your HVAC system should involve much more than selecting a model with the highest efficiency rating. The right system is one that meets your household heating and cooling requirements.
At J.L. Brady Company LLC, our experienced professionals perform an HVAC load calculation. We'll evaluate your home's size and layout, your household's heating and cooling preferences and recommend equipment that's designed specifically for your home—not simply the highest-capacity, 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 energy-efficient HVAC systems more accessible for all budgets.
Schedule an HVAC consultation online with J.L. Brady Company LLC today. 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.
