Shopping for a new air conditioning system or furnace can be intimidating. If you're trying to find the best HVAC system for your home, it's common to look for models with the highest efficiency ratings.
After all, the most efficient heating and cooling system will provide the most comfort and lowest energy bills, right?
Not necessarily.
Energy efficiency isn't the only thing that matters when it comes to new air conditioner installation or replacing your furnace. Even though many focus only on efficiency ratings, proper HVAC system sizing is equally, if not more important for your home's comfort and your power bills.
Proper sizing also influences humidity control and system longevity. The best HVAC system for your home delivers 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 sizing is so important and why qualified HVAC contractors consider both when helping you choose the best HVAC system for your home.
What Does a High SEER Rating Actually Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), indicates how effectively an air conditioner cools your home over a normal cooling season. A SEER2 rating is the newer version of SEER, using testing methods that better simulate real-world operating conditions. Nearly all new air conditioners have a SEER2 efficiency rating, simply because that is the new rating system for cooling equipment.
Fuel-burning heating system efficiency is measured by something called AFUE, which is short for Annual Fuel Utilization Efficiency. Like SEER and SEER2 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 numbers don't necessarily guarantee lower utility bills. Actual heating and air conditioner efficiency depends on many factors, including the installation quality, the quality of your ductwork, your home's insulation, thermostat settings and, most importantly, HVAC system sizing. Even the highest-rated system cannot deliver peak performance if it is too large or undersized for the home.
Why HVAC System Size Matters More Than Most Homeowners Realize
Many assume a larger 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. Actually, new heating system installation or a new air conditioner should be selected 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 complete an HVAC load calculation, also called a Manual J calculation, before selecting replacement equipment. A Manual J calculation considers many variables that affect your home's heating and cooling load, including:
- Total square footage
- Ceiling height
- Window size and orientation
- Insulation
- Drafts and air leakage
- Regional climate
- Household 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 more even temperatures, better indoor comfort and improved indoor humidity management. This also allows the equipment to run more effciently, reducing excessive wear and tear that can cause it to wear it out sooner or lead to frequent or expensive repairs.
When your heating or cooling system is properly sized, you get greater comfort and long-lasting performance.
Problems Caused by Oversized and Undersized Systems
It might be tempting 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 too large or too small can create comfort issues, increase operating costs and reduce efficiency regardless of their SEER rating.
Common Problems With 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 wear.
- High indoor humidity: Oversized air conditioners finish cooling cycles too soon to remove excess moisture from the air.
- Uneven temperatures: Some rooms become too cold while others never feel comfortable.
- Increased wear and tear: Even though the system works quickly, those constant 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:
- Continuous operation: The system stays on for extended periods trying to reach the thermostat setting, which also causes extra strain.
- 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 work harder in extreme temperatures, increasing equipment wear and the likelihood of repairs.
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 automatically need the top-efficiency model on the market.
More often than not, a professionally sized, mid-efficiency HVAC system will provide better results than an oversized premium system because it functions the way it was designed to.
Theideal choice is an energy-efficient HVAC system that's correctly sized for your home, your budget, your climate and your long-term needs.
As you think about how to choose a new air conditioner or furnace, think about:
- Efficiency savings: Higher-efficiency and right-sized systems can lower electricity use.
- Initial cost: High-efficiency AC and heating systems often cost more initially than mid-range models but can reduce long-term energy costs.
- Energy prices: Areas with more expensive electricity may see greater long-term savings from higher-efficiency units.
- Your local climate: It's crucial your heating or cooling system has adequate capacity to handle areas with harsh winter weather or very hot summers.
- Length of home ownership: 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 lower the overall cost of high-efficiency HVAC equipment.
Real-World Comparison: High Seer vs. Right System Size
How does this play out in a real world scenario?
Picture two neighboring homes.
In the first, 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, 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 correctly matched to the home's needs.
Work With an HVAC Professional Who Designs Personalized Solutions
An HVAC replacement should involve more than selecting a system with the highest efficiency rating. An ideal system is one that meets your heating and cooling requirements.
At Indoor Comfort Systems HVAC, our skilled HVAC experts perform an HVAC load calculation. We'll carefully evaluate your home's size and layout, your household's comfort needs and recommend equipment that's right for your home—not simply the largest, most expensive unit or the one with the highest AFUE or SEER2 rating.
Our heating and cooling specialists will help you identify any available rebates or tax incentives and provide information about HVAC financing options that make high-efficiency systems more accessible for all budgets.
Schedule an HVAC consultation online with Indoor Comfort Systems HVAC today. 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 the long haul.