Shopping for a new air conditioner or furnace can be intimidating. When you're looking to find the best HVAC system for your home, it's natural to look for models with the highest efficiency ratings.
After all, the most efficient equipment will provide the most comfort and lowest energy bills, right?
Actually, that’s not always the case.
Energy efficiency isn't the only thing to think about when it comes to new air conditioner installation or furnace replacement. While many homeowners focus only on efficiency ratings, proper HVAC system sizing is equally, if not more important for your home's comfort and your utility bills.
Proper sizing has a major impact on humidity control and long-term reliability. The best HVAC system for your home combines energy efficiency and proper sizing.
In this article, 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 choose 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 typical cooling season. A SEER2 rating is the newer version of SEER, using testing methods that better represent real-world operating conditions. Today’s new air conditioners have a SEER2 rating, simply because this rating is the new rating system for cooling equipment.
Fuel-burning heating system efficiency is rated by AFUE, which is for Annual Fuel Utilization Efficiency. Similar to 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 ratings don't automatically guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on many factors, including the installation quality, the quality of your ductwork, how much insulation your home has, thermostat settings and, most importantly, HVAC system sizing. Even the most efficient system cannot operate at its best if it is too large or smaller than needed for the home.
Why HVAC System Size Matters More Than Most Homeowners Realize
Many assume a higher-capacity air conditioner or furnace will heat or cool a home better or that they should simply replace their old HVAC system with a same-sized replacement. The truth is, 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 complete 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
- Ceiling height
- Window size and orientation
- Home insultation levels
- Air infiltration
- Local climate
- Number of occupants
- Heat generated by appliances and lighting
- Ductwork condition
A properly sized air conditioner runs long enough to cool your home evenly while pulling out excess humidity. That means steadier temperatures, better indoor comfort and improved moisture control. It also helps the equipment to perform more effciently, reducing excessive wear and tear that can cause it to wear it out sooner or lead to costly breakdowns.
When HVAC equipment is the right size for your home, you get greater comfort and long-lasting performance.
Problems Caused by Oversized and Undersized Systems
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 great idea.
heating and cooling systems that are too large or too small can create indoor comfort challenges, increase energy expenses and reduce efficiency regardless of their SEER rating.
Drawbacks of Oversized HVAC Systems
An oversized air conditioner or heating system may heat or cool rapidly, but that doesn't mean it performs efficiently.
- Short cycling: An oversized HVAC system starts and stops often, reducing efficiency and increasing equipment strain.
- Reduced humidity control: Oversized air conditioners reach the set temperature too fast to remove enough moisture from the air.
- Hot and cold spots: Some rooms feel too cool while others never feel comfortable.
- More wear and tear: Even though the system works quickly, those repeated on-and-off cycles can cause avoidable breakdowns due to the strain.
Issues Created by Undersized HVAC Systems
An undersized HVAC system has a different set of problems:
- Long run times: The system stays on for extended periods trying to reach the desired temperature, which also causes additional wear.
- Difficulty maintaining the desired temperature: Your home may feel cool enough during hot weather or feel too cool during winter.
- Increased energy consumption: Running for extended periods can increase energy costs.
- Extra stress during severe weather: HVAC systems that are too small can struggle in extreme temperatures, increasing wear and the risk of breakdowns.
Balancing Efficiency and Size
When trying to decide between a high SEER vs right-sized system, remember that you don't always need the most efficient model on the market.
In many cases, a correctly sized, mid-efficiency heating and cooling 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 matched 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:
- Energy savings: 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 help reduce long-term energy costs.
- Electricity rates: Areas with higher electricity rates may see better long-term savings from higher-efficiency units.
- Your local climate: It's important your heating or cooling system has adequate capacity to handle areas with extremely cold winters or very hot summers.
- Length of home ownership: If you expect to live 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 lower the overall cost of high-efficiency HVAC equipment.
Real-World Example: 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 simply matched 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 more modest 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 appropriately sized to the home's needs.
Choose the Local HVAC Professional Who Designs Solutions Tailored to Your Home
An HVAC replacement should involve much more than selecting the unit with the top efficiency rating. An ideal system is one that meets your home’s heating and cooling requirements.
At Lakeside Heating & Air, our skilled HVAC experts perform an HVAC load calculation. Our team will 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 highest-capacity, fanciest unit or the one with the highest AFUE or SEER2 rating.
Our team will help you identify 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 Lakeside Heating & Air to get started. Our team will evaluate your home, answer your questions and help you choose the right-sized energy-efficient system that keeps your family comfortable for many years.
