Shopping for a new air conditioning system or furnace can be stressful. 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 will provide the most comfort and lowest energy bills, right?
Actually, that’s not always the case.
Energy efficiency isn't the only thing that matters when it comes to new air conditioner installation or replacing your furnace. Although many people 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 system longevity. The best HVAC system for your home combines energy efficiency and correct sizing.
In this guide, we'll explain what an air conditioner's SEER rating or SEER2 rating actually measures, why correct HVAC size is so important and why qualified HVAC contractors 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 current version of SEER, using test procedures that better represent real-world operating conditions. Most new air conditioners have a SEER2 rating, simply because this is the new rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated 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 achieve indoor comfort than lower-rated systems under standardized laboratory testing.
However, high ratings don't by themselves guarantee lower utility bills. Actual heating and air conditioner efficiency depends on many factors, including the quality of the installation, the state of your ductwork, how much insulation your home has, thermostat settings and, most importantly, HVAC system sizing. Even the highest-efficiency system cannot deliver peak performance if it is oversized or smaller than needed for the home.
Why Proper HVAC Sizing Matters More Than You Think
Many assume a larger air conditioner or furnace will make their home the most comfortable or that they should simply replace their old HVAC system with a unit of the same capacity. Actually, 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 conduct an HVAC load calculation, also called a Manual J calculation, before selecting replacement equipment. A Manual J calculation considers many factors that impact your home's heating and cooling requirements, including:
- Total square footage
- Ceiling height
- Window size and placement
- Home insultation levels
- Air leakage
- Area climate
- Number of occupants
- Heat produced from appliances and lighting
- Air duct condition
A properly sized air conditioner runs for enough time to cool your home more uniformly while removing excess humidity. That means more consistent temperatures, better indoor comfort and improved humidity control. It also helps the equipment to run more effciently, reducing strain that can reduce its service life or lead to frequent or expensive repairs.
When a furnace or AC is correctly sized, you get improved comfort and more reliable operation.
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. The truth is, that's usually not a good investment.
HVAC systems that are too large or undersized can create indoor comfort challenges, 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 reach the thermostat setting fast, but that doesn't mean it performs efficiently.
- Short cycling: An oversized HVAC system cycles repeatedly, reducing efficiency and increasing wear.
- High indoor humidity: Oversized air conditioners cool your home too quickly to remove enough moisture from the air.
- Uneven temperatures: Some rooms feel too cool while others aren’t ever cool enough.
- Increased wear and tear: Even though the system reaches the target temperature rapidly, those frequent starts and stops can cause avoidable breakdowns due to the strain.
Drawbacks of Undersized HVAC Systems
An undersized HVAC system also can struggle:
- Continuous operation: The system stays on for extended periods trying to reach the desired temperature, which also causes unnecessary wear and tear.
- Difficulty reaching thermostat settings: Your home may feel cool enough during hot weather or always feel chilly in the winter.
- Increased energy consumption: Running for extended periods can increase utility bills.
- Added strain during extreme weather: HVAC systems that are too small can struggle in extreme temperatures, increasing component strain 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 always need the most efficient model on the market.
More often than not, a properly sized, mid-efficiency heating and cooling system will outperform an oversized premium system because it operates the way it was designed to.
Thesmartest choice is an energy-efficient HVAC system that's properly sized 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:
- Energy savings: Higher-efficiency and right-sized systems can decrease electricity use.
- Purchase price: High-efficiency AC and heating systems often cost more initially than mid-range models but can reduce long-term energy costs.
- Electricity rates: Areas with higher electricity rates may see more significant long-term savings from higher-efficiency units.
- Seasonal weather conditions: It's essential your heating or cooling system has enough capacity to handle areas with harsh winter weather or intense summer heat.
- 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 be worth the investment.
- Available rebates or tax incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can lower the overall cost of qualifying equipment.
Real-World Comparison: High Seer vs. Right System Size
How does this play out in the real world?
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. 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 deliver 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 the Right Solution
Replacing your HVAC system should involve much more than selecting a model with the top efficiency rating. The right system is one that meets your home’s heating and cooling requirements.
At Wallpe Heating & Cooling, our experienced professionals perform an HVAC load calculation. We'll evaluate your home's design, your household's comfort needs and recommend equipment that's designed specifically for your home—not simply the largest, latest and greatest unit or the one with the highest AFUE or SEER2 rating.
Our heating and cooling specialists will let you know about any available rebates and 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 Wallpe Heating & Cooling today. We'll gladly evaluate your home, answer any questions and help you choose the right-sized high-efficiency system that keeps your family comfortable for many years.