Shopping for a new air conditioning system or furnace can be intimidating. When you're looking 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?
Not necessarily.
Efficiency ratings aren’t the only thing you should consider when it comes to new air conditioner installation or replacing your furnace. While many homeowners 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 energy bills.
Proper sizing directly impacts humidity control and long-term reliability. The best HVAC system for your home delivers energy efficiency and correct sizing.
In thisarticle, we'll explain what an air conditioner's SEER rating or SEER2 rating actually measures, why correct HVAC size is so important and why experienced HVAC professionals consider both when helping you select the best HVAC system for your home.
What Does a High SEER Rating Actually Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), shows how effectively a cooling system cools your home over a normal cooling season. A SEER2 rating is the updated version of SEER, using evaluation methods that better simulate real-world operating conditions. Most new air conditioners have a SEER2 designation, simply because this is the current rating system for cooling equipment.
Fuel-burning heating system efficiency is rated by AFUE, which is short for Annual Fuel Utilization Efficiency. As with 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 necessarily guarantee lower utility bills. Everyday heating and air conditioner efficiency depends on more than just efficiency ratings, including the way the system is installed, the quality of your ductwork, your home's insulation, thermostat settings and, most importantly, system sizing. Even the most efficient system cannot operate at its best if it is bigger than necessary or smaller than needed for the home.
Why Correct HVAC System Sizing 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 just replace their old HVAC system with a new one the same size. In reality, new heating system installation or a new air conditioner should be chosen 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 conduct an HVAC load calculation, also called a Manual J calculation, before recommending replacement equipment. A Manual J calculation evaluates many factors that impact your home's comfort needs, including:
- Home square footage
- Ceiling height
- Window size and orientation
- Home insultation levels
- Air leakage
- Local climate
- Household occupants
- Heat produced from appliances and lighting
- Air duct condition
A properly sized air conditioner runs through longer cooling cycles to cool your home more uniformly while eliminating excess humidity. That means steadier temperatures, better indoor comfort and improved humidity control. It also helps the equipment to operate more effciently, reducing strain 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 better comfort and long-lasting performance.
Problems Caused by Oversized and Undersized HVAC Equipment
Many homeowners are tempted to buy the most energy efficient, biggest air conditioner or heating system on the market. However, that's usually not a smart choice.
HVAC systems that are too large or undersized can create comfort problems, increase operating costs 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 delivers the best comfort.
- Short cycling: An oversized HVAC system starts and stops often, reducing efficiency and increasing equipment strain.
- High indoor humidity: Oversized air conditioners cool your home too quickly to remove enough moisture from the air.
- Hot and cold spots: Some rooms become too cold while others stay too warm.
- Additional equipment wear: Even though the system heats or cools your home fast, those frequent starts and stops can cause avoidable breakdowns due to the strain.
Cons Associated with Undersized HVAC Systems
An undersized HVAC system has a different set of problems:
- Continuous operation: The system runs for long periods trying to reach the desired temperature, which also causes unnecessary wear and tear.
- Trouble reaching the thermostat setting: Your home may feel cool enough during hot weather or feel too cool during winter.
- Greater energy usage: Running for extended periods can increase energy costs.
- 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 trying to decide between a high SEER vs right-sized system, don't forget that you don't necessarily need the top-efficiency model on the market.
More often than not, a properly sized, mid-efficiency heating and cooling system will provide better results than an oversized premium system because it operates the way it was designed to.
Thebest choice is an energy-efficient HVAC system that's properly sized for your home, your budget, your climate and your future plans.
When deciding how to choose a new air conditioner or furnace, think about:
- Energy 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 help reduce long-term energy costs.
- Local utility costs: Areas with higher electricity rates may see greater 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 harsh winter weather or very hot summers.
- How long you'll 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 higher-efficiency systems.
Real-World Comparison: High Seer vs. Right System Size
How does this play out in a real world scenario?
Suppose there are two neighboring homes.
At the first home, the homeowner chooses a premium high-efficiency HVAC system that's too big because the contractor only matched the previous unit. The other homeowner installs a properly sized, moderate-efficiency 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, improved humidity control and last longer because it's properly matched to the home's needs.
Choose the Local HVAC Professional Who Designs Solutions Tailored to Your Home
An HVAC replacement should involve more than selecting a system with the top efficiency rating. The best system is one that meets your household heating and cooling requirements.
At Air Current AC & Heat, our experienced professionals perform an HVAC load calculation. We'll carefully evaluate your home's design, your household's comfort goals and recommend equipment that's right for your home—not simply the largest, latest and greatest unit or the one with the highest AFUE or SEER2 rating.
Our team 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 Air Current AC & Heat to get started. Our team will evaluate your home, answer any questions and help you choose the correctly sized energy-efficient system that keeps your family comfortable for the long haul.