Shopping for a new air conditioning system or furnace can feel overwhelming. If you want to find the best HVAC system for your home, it's natural to look for models with extremely high efficiency ratings.
Surely the most efficient system provides the most comfort and lowest energy bills, right?
Not necessarily.
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, 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 balances energy efficiency and proper sizing.
In this blog, 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 qualified HVAC contractors consider both when helping you select the best HVAC system for your home.
High Seer Ratings: What Do They Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), indicates how efficiently a cooling system cools your home over a typical cooling season. A SEER2 rating is the updated version of SEER, using testing methods that better reflect real-world operating conditions. Most 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 measured by something called AFUE, which is short for Annual Fuel Utilization Efficiency. As with SEER and SEER2, 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 automatically guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on more than just efficiency ratings, including the installation quality, the quality of your ductwork, your home's insulation, thermostat settings and, most importantly, HVAC system sizing. Even the highest-efficiency system cannot deliver peak performance if it is bigger than necessary or smaller than needed for the home.
Why HVAC System Size Matters More Than You Think
Many assume a larger air conditioner or furnace will make their home the most comfortable or that they should just replace their old HVAC system with a same-sized replacement. Actually, new heating system installation or air conditioner replacement should be sized 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 complete an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation evaluates many variables that affect your home's comfort needs, including:
- Home square footage
- Room height
- Window size and direction
- Insulation
- Air infiltration
- Regional climate
- Number of occupants
- Heat produced from appliances and lighting
- Ductwork condition
A properly sized air conditioner runs long enough to cool your home evenly while removing excess humidity. That means steadier temperatures, better indoor comfort and improved humidity control. Proper sizing also helps the equipment to run more effciently, reducing strain that can reduce its service life or lead to costly breakdowns.
When HVAC equipment is the right size for your home, you get better comfort and long-lasting performance.
Problems with Oversized and Undersized Heating and Cooling Systems
You may be tempted to buy the most energy efficient, biggest air conditioner or heating system on the market. The truth is, that’s rarely a good investment.
heating and cooling systems that are bigger than necessary or undersized can create comfort problems, 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 works well.
- Short cycling: An oversized HVAC system starts and stops often, reducing efficiency and increasing wear.
- Humidity problems: Oversized air conditioners finish cooling cycles too soon to remove excess moisture from the air.
- Hot and cold spots: Some rooms get too cold 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.
Issues Created by Undersized HVAC Systems
An undersized HVAC system can have the opposite problem:
- Long run times: The system stays on for extended periods trying to reach the thermostat setting, which also causes extra strain.
- 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.
- Greater strain on very hot or cold days: HVAC systems that are too small can run extremely hard in extreme temperatures, increasing wear and the likelihood of repairs.
Why You Should Balance HVAC System Efficiency and Size
When trying to decide between a high SEER vs right-sized system, keep in mind that you don't always need the highest-efficiency model on the market.
Often, a properly 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.
Thebest choice is an energy-efficient HVAC system that's matched for your home, your budget, your climate and your future plans.
As you think about how to choose a new air conditioner or furnace, consider:
- Efficiency 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.
- Energy prices: Areas with higher electricity rates may see greater long-term savings from higher-efficiency units.
- Climate: It's important your heating or cooling system has adequate capacity to handle areas with extremely cold winters 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 lower the overall cost of higher-efficiency systems.
Real-World Situation: High Seer vs. Right System Size
What does this look like in the real world?
Imagine two neighboring homes.
In one, the homeowner chooses a premium high-efficiency HVAC system has far more capacity than the home needs because the contractor only matched the previous unit. Next door, the second homeowner installs a right-sized, moderate-efficiency system after completing a Manual J calculation.
While the second system has a lower efficiency rating on paper, it may deliver 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 HVAC Professional Who Designs the Right Solution
Replacing your HVAC system should involve more than selecting a system with the highest efficiency rating. An ideal system is one that meets your household heating and cooling requirements.
At J & J Air Conditioning, our knowledgeable technicians perform an HVAC load calculation. We'll carefully evaluate your home's layout and construction, your household's comfort goals and recommend equipment that's properly matched for your home—not simply the biggest, most expensive unit or the one with the highest AFUE or SEER2 rating.
Our heating and cooling specialists will connect you with 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 J & J Air Conditioning to get started. 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 the long haul.
