Shopping for a new air conditioner or furnace can be stressful. If you're trying to find the best HVAC system for your home, it's understandable to look for models with the highest efficiency ratings.
After all, the most efficient equipment should deliver the most comfort and lowest energy bills, right?
Actually, that’s not always the case.
Energy efficiency isn't the only thing to think about 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 just as, if not more important for your home's comfort and your utility bills.
Proper sizing also influences humidity control and lasting performance. The best HVAC system for your home combines 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 size is so important and why trusted HVAC experts consider both when helping you choose the best HVAC system for your home.
What Does it Mean if an AC Has a High SEER Rating?
A SEER rating, (Seasonal Energy Efficiency Ratio), measures how efficiently a cooling system cools your home over a typical cooling season. A SEER2 rating is the updated version of SEER, using evaluation methods that better represent real-world operating conditions. Most new air conditioners have a SEER2 efficiency rating, simply because this is the current rating system for cooling equipment.
Fuel-burning heating system efficiency is rated 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 keep you comfortable than lower-rated systems under standardized laboratory testing.
Even so, high numbers don't automatically guarantee lower utility bills. Actual heating and air conditioner efficiency depends on more than just efficiency ratings, including the installation quality, the state of your ductwork, your home's insulation, thermostat settings and, most importantly, HVAC system sizing. Even the highest-rated system cannot perform as intended if it is too large or smaller than needed for the home.
Why Proper HVAC Sizing Matters More Than You Probably Think
Many assume a bigger 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. The truth is, new heating system installation or air conditioner 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 companies perform an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation evaluates many details that impact your home's heating and cooling requirements, including:
- Overall square footage
- Room height
- Window size and orientation
- Insulation
- Air leakage
- Regional climate
- Number of occupants
- Heat generated by appliances and lighting
- Air duct condition
A properly sized air conditioner runs for enough time to cool your home consistently while pulling out excess humidity. That means steadier temperatures, better indoor comfort and improved moisture control. This also allows the equipment to perform more effciently, reducing excessive wear and tear that can reduce its service life or lead to more repairs and higher repair costs.
When HVAC equipment is correctly sized, you get better comfort and more dependable performance.
Problems with Oversized and Undersized HVAC Equipment
It might be tempting to buy the most energy efficient, largest-capacity air conditioner or heating system on the market. In reality, that often isn't a great idea.
HVAC systems that are bigger than necessary 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 and tear.
- High indoor humidity: Oversized air conditioners cool your home too quickly to remove indoor humidity from the air.
- Uneven temperatures: Some rooms become too cold while others never feel comfortable.
- Additional equipment wear: Even though the system works quickly, those frequent starts and stops can cause avoidable breakdowns due to the strain.
Drawbacks of Undersized HVAC Systems
An undersized HVAC system can have the opposite problem:
- Long run times: The system operates almost continuously trying to reach the thermostat setting, which also causes unnecessary wear and tear.
- Trouble reaching the thermostat setting: Your home may not feel comfortable during hot weather or never feel warm enough in cold weather.
- Increased energy consumption: Running almost constantly can increase monthly energy expenses.
- Extra stress during severe weather: HVAC systems that are too small can work harder in extreme temperatures, increasing wear and the likelihood of repairs.
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 most efficient model on the market.
In many cases, a correctly 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.
Theideal choice is an energy-efficient HVAC system that's matched for your home, your budget, your climate and your long-term goals.
As you think about how to choose a new air conditioner or furnace, consider:
- Energy savings: Higher-efficiency and right-sized systems can reduce electricity use.
- Upfront investment: High-efficiency AC and heating systems often cost more initially than mid-range models but can lower long-term energy costs.
- Local utility costs: Areas with higher electricity rates may see better long-term savings from higher-efficiency units.
- Climate: It's crucial your heating or cooling system has enough capacity to handle areas with extremely cold winters 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.
- Financial incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can reduce the overall cost of qualifying equipment.
Real-World Example: High Seer vs. Right System Size
How does this work in the real world?
Imagine two neighboring homes.
In the first, the homeowner chooses a premium high-efficiency HVAC system has far more capacity than the home needs because the contractor replaced it with the same size system as the previous unit. Next door, the second homeowner installs a properly sized, mid-SEER or AFUE 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 have a longer lifespan because it's properly matched to the home's needs.
Choose the Local HVAC Professional Who Designs Personalized Solutions
Replacing your HVAC system should involve more than selecting a system with the top efficiency rating. The right system is one that meets your heating and cooling requirements.
At Total Assurance AC & Heating, our skilled HVAC experts perform an HVAC load calculation. We'll carefully evaluate your home's layout and construction, 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 connect you with any available tax rebates and provide information about HVAC financing options that make energy-efficient HVAC systems more accessible for all budgets.
Schedule an HVAC consultation online with Total Assurance AC & Heating today. We'll evaluate your home, answer any questions and help you choose the correctly sized high-efficiency system that keeps your family comfortable for many years.
