Shopping for a new air conditioner 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 the highest efficiency ratings.
Surely the most efficient system will provide the most comfort and lowest energy bills, right?
It’s not quite that simple.
High efficiency isn't the only thing that matters when it comes to new air conditioner installation or installing a new furnace. Even though many focus only on {energy efficiency|efficiency ratings, proper {HVAC system sizing is equally, if not more important for your home's comfort and your energy bills.
Proper sizing has a major impact on humidity control and system longevity. 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 recommending the best HVAC system for your home.
What Does a High SEER Rating Actually Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), indicates how efficiently a cooling system cools your home over a normal cooling season. A SEER2 rating is the current version of SEER, using evaluation methods that better simulate real-world operating conditions. Nearly all new air conditioners have a SEER2 efficiency rating, simply because that is the updated rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by AFUE, which stands for Annual Fuel Utilization Efficiency. Similar to cooling efficiency 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.
Even so, high ratings don't by themselves guarantee lower utility bills. Everyday heating and air conditioner efficiency depends on several key factors, including the quality of the installation, the quality of your ductwork, how much insulation your home has, thermostat settings and, most importantly, system sizing. Even the highest-rated system cannot perform as intended if it is bigger than necessary or too small for the home.
Why HVAC System Size Matters More Than You Think
Many assume a higher-capacity air conditioner or furnace will make their home the most comfortable or that they should just replace their old HVAC system with a unit of the same capacity. In reality, new heating system installation or AC replacement 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 contractors conduct an HVAC load calculation, also called a Manual J calculation, before recommending replacement equipment. A Manual J calculation considers many details that impact your home's heating and cooling load, including:
- Overall square footage
- Ceiling height
- Window size and placement
- Home insultation levels
- Air infiltration
- Local climate
- Number of occupants
- Heat produced from appliances and lighting
- Air duct condition
A properly sized air conditioner runs through longer cooling cycles to cool your home consistently while pulling out excess humidity. That means steadier temperatures, better indoor comfort and improved humidity control. This also allows the equipment to perform more effciently, reducing strain that can cause it to wear it out sooner or lead to frequent or expensive repairs.
When a furnace or AC is the right size for your home, you get better comfort and long-lasting performance.
Problems Caused by Oversized and Undersized Systems
You may be tempted to buy the most energy efficient, biggest air conditioner or heating system on the market. However, that's usually not a great idea.
HVAC systems that are bigger than your home needs or smaller than your home requires 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 reach the thermostat setting fast, but that doesn't mean it works well.
- Short cycling: An oversized HVAC system turns on and off frequently, reducing efficiency and increasing wear.
- Reduced humidity control: Oversized air conditioners finish cooling cycles too soon to remove enough moisture from the air.
- Uneven temperatures: Some rooms become too cold while others never feel comfortable.
- Additional equipment wear: Even though the system reaches the target temperature rapidly, those repeated on-and-off cycles can cause avoidable breakdowns due to the strain.
Drawbacks of 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 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 energy costs.
- Greater strain on very hot or cold days: HVAC systems that are too small can struggle in extreme temperatures, increasing component strain and the risk of breakdowns.
Finding the Right Balance Between Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, don't forget that you don't automatically need the top-efficiency model on the market.
In many cases, a professionally sized, mid-efficiency heating and cooling system will provide better results than an oversized premium system because it runs the way it was designed to.
Theideal choice is an energy-efficient HVAC system that's properly 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, consider:
- Energy savings: Higher-efficiency and right-sized systems can decrease electricity use.
- Purchase price: High-efficiency AC and heating systems often require a larger upfront investment than mid-range models but can reduce long-term energy costs.
- Electricity rates: Areas with higher utility costs may see greater long-term savings from higher-efficiency units.
- Your local climate: It's crucial your heating or cooling system has enough capacity to handle areas with harsh winter weather or extremely hot summers.
- Length of home ownership: If you plan to stay in your home for many years, the long-term energy savings of a higher-efficiency unit may offset the investment.
- Available rebates or tax incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can reduce the overall cost of high-efficiency HVAC equipment.
Real-World Comparison: High Seer vs. Right System Size
What does this look like in a real world example?
Suppose there are two neighboring homes.
In one, the homeowner chooses a premium high-efficiency HVAC system that's too big because the contractor replaced it with the same size system as the previous unit. At the neighboring home, an HVAC professional installs a correctly sized, mid-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, 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 more than selecting a system with the highest efficiency rating. An ideal system is one that meets your heating and cooling requirements.
At Taylor's Heating & Air Conditioning, our skilled HVAC experts perform an HVAC load calculation. We'll evaluate your home's layout and construction, your household's heating and cooling preferences and recommend equipment that's right for your home—not simply the biggest, fanciest 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 efficient heating and cooling systems more accessible for all budgets.
Schedule an HVAC consultation online with Taylor's Heating & Air Conditioning to get started. We'll evaluate your home, answer any questions and help you choose the right-sized energy-efficient system that keeps your family comfortable for many years.