Shopping for a new air conditioner or furnace can feel overwhelming. If you want to find the best HVAC system for your home, it's understandable to focus on models with extremely high efficiency ratings.
Surely the most efficient heating and cooling system should deliver the most comfort and lowest energy bills, right?
Not necessarily.
High efficiency isn't the only thing you should consider when it comes to new air conditioner installation or replacing your furnace. Although many people focus only on efficiency ratings, proper HVAC system sizing is often even 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 delivers energy efficiency and correct sizing.
In thisblog, 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 experienced HVAC professionals consider both when recommending 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 standard cooling season. A SEER2 rating is the updated version of SEER, using test procedures that better represent real-world operating conditions. Today’s new air conditioners have a SEER2 efficiency rating, simply because this rating is the new rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by something called AFUE, which stands for Annual Fuel Utilization Efficiency. As with cooling efficiency 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.
Even so, high numbers don't by themselves guarantee lower utility bills. Everyday heating and air conditioner efficiency depends on many factors, including the installation quality, the state of your ductwork, your home's insulation, thermostat settings and, most importantly, proper HVAC system sizing. Even the highest-efficiency system cannot perform as intended if it is bigger than necessary or too small for the home.
Why Proper HVAC Sizing Matters More Than You Probably Think
Many assume a bigger air conditioner or furnace will make their home the most comfortable or that they should simply replace their old HVAC system with a same-sized replacement. In reality, new heating system installation or air conditioner replacement should be chosen based on your home's actual 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 selecting replacement equipment. A Manual J calculation analyzes many variables that impact your home's comfort needs, including:
- Overall square footage
- Room height
- Window size and placement
- Home insultation levels
- Air leakage
- Area climate
- Number of occupants
- Heat generated by appliances and lighting
- Ductwork condition
A properly sized air conditioner runs through longer cooling cycles to cool your home consistently while eliminating excess humidity. That means more consistent temperatures, better indoor comfort and improved indoor humidity management. It also helps the equipment to operate more effciently, reducing unnecessary wear 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 more dependable performance.
Problems Caused by 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. The truth is, that often isn't a good investment.
heating and cooling systems that are bigger than your home needs or undersized can create indoor comfort challenges, increase energy expenses and reduce efficiency regardless of their SEER rating.
Issues Created by 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 equipment strain.
- High indoor humidity: Oversized air conditioners reach the set temperature too fast to remove excess moisture from the air.
- Uneven temperatures: Some rooms become too cold while others aren’t ever cool enough.
- Additional equipment wear: Even though the system works quickly, 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 runs for long periods trying to reach the desired temperature, which also causes extra strain.
- Difficulty reaching thermostat settings: Your home may not feel comfortable during hot weather or never feel warm enough in cold weather.
- Greater energy usage: Running for extended periods can increase monthly energy expenses.
- Added strain during extreme weather: HVAC systems that are too small can work harder in extreme temperatures, increasing equipment wear and the likelihood of repairs.
Balancing Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, don't forget that you don't necessarily need the highest-efficiency model on the market.
Often, a correctly sized, mid-efficiency heating and cooling system will deliver better performance than an oversized premium system because it operates the way it was designed to.
Thebest choice is an energy-efficient HVAC system that's correctly 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:
- Lower energy costs: Higher-efficiency and right-sized systems can decrease electricity use.
- Purchase price: High-efficiency AC and heating systems often have a higher purchase price than mid-range models but can help reduce long-term energy costs.
- Energy prices: Areas with more expensive electricity may see more significant long-term savings from higher-efficiency units.
- Your local climate: It's crucial your heating or cooling system has adequate capacity to handle areas with harsh winter weather or very hot summers.
- How long you'll own the home: If you plan to stay in your home for many years, the long-term energy savings of a higher-efficiency unit may justify the investment.
- Rebates and tax credits: 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 has far more capacity than the home needs because the contractor only matched the previous unit. At the neighboring home, an HVAC professional installs a right-sized, mid-efficiency system after completing a Manual J calculation.
While the second system has a lower efficiency rating on paper, it may provide lower operating costs, better home comfort, more effective humidity control and last longer because it's appropriately sized to the home's needs.
Choose the Local HVAC Professional Who Designs Solutions Tailored to Your Home
HVAC replacent or installation should involve more than selecting the unit with the top efficiency rating. An ideal system is one that meets your home’s heating and cooling requirements.
At Freed Heating & Air Conditioning, our knowledgeable technicians perform an HVAC load calculation. We'll carefully evaluate your home's size and layout, your household's comfort needs and recommend equipment that's properly matched for your home—not simply the highest-capacity, 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 Freed Heating & Air Conditioning to get started. We'll gladly evaluate your home, answer your questions and help you choose the right-sized efficient system that keeps your family comfortable for many years.