Choosing a new AC or furnace can feel overwhelming. If you want to find the best HVAC system for your home, it's common to look for models with extremely high efficiency ratings.
After all, the most efficient system will provide the most comfort and lowest energy bills, right?
Actually, that’s not always the case.
Efficiency ratings aren’t the only thing that matters when it comes to new air conditioner installation or installing a new furnace. Although many people focus only on {energy efficiency|efficiency ratings, proper {HVAC system sizing is equally, 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 balances energy efficiency and proper sizing.
In thisarticle, 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.
What Does it Mean if an AC Has a High SEER Rating?
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 current version of SEER, using evaluation methods that better reflect real-world operating conditions. Most 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 rated by AFUE, which stands for Annual Fuel Utilization Efficiency. Similar to SEER and SEER2 ratings, 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.
However, high numbers don't automatically guarantee lower utility bills. Everyday heating and air conditioner efficiency depends on more than just efficiency ratings, including the installation quality, the quality of your ductwork, insulation levels, thermostat settings and, most importantly, proper HVAC system sizing. Even the most efficient 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 just replace their old HVAC system with a same-sized replacement. The truth is, new heating system installation or air conditioner replacement should be sized based on your home's true heating and cooling needs—not just square footage or the size of the previous unit.
That's why reputable technicians perform an HVAC load calculation, also called a Manual J calculation, before recommending replacement equipment. A Manual J calculation considers many factors that impact your home's heating and cooling requirements, including:
- Total square footage
- Room height
- Window size and orientation
- Home insultation levels
- Drafts and air leakage
- Local climate
- Household occupants
- Heat produced from appliances and lighting
- Ductwork condition
A properly sized air conditioner runs for enough time to cool your home more uniformly while pulling out excess humidity. That means more even temperatures, better indoor comfort and improved moisture control. This also allows the equipment to run more effciently, reducing excessive wear and tear that can shorten its lifespan or lead to more repairs and higher repair costs.
When HVAC equipment is properly sized, you get greater comfort and long-lasting performance.
Problems with Oversized and Undersized Systems
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 smart choice.
heating and cooling systems that are bigger than necessary or smaller than your home requires can create comfort issues, increase operating costs and reduce efficiency regardless of their SEER rating.
Drawbacks of Oversized HVAC Systems
An oversized air conditioner or heating system may heat or cool rapidly, but that doesn't mean it delivers the best comfort.
- Short cycling: An oversized HVAC system starts and stops often, reducing efficiency and increasing wear and tear.
- Reduced humidity control: Oversized air conditioners reach the set temperature too fast to remove indoor humidity from the air.
- Hot and cold spots: Some rooms feel too cool while others aren’t ever cool enough.
- Additional equipment wear: Even though the system heats or cools your home fast, those frequent starts and stops can cause avoidable breakdowns due to the strain.
Cons Associated with Undersized HVAC Systems
An undersized HVAC system also can struggle:
- Long run times: The system runs for long periods trying to reach the desired temperature, which also causes unnecessary wear and tear.
- Difficulty maintaining the desired temperature: 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 work harder in extreme temperatures, increasing component strain and the likelihood of repairs.
Balancing Efficiency and Size
When trying to decide between a high SEER vs right-sized system, remember that you don't always need the top-efficiency model on the market.
More often than not, a properly sized, mid-efficiency HVAC system will outperform an oversized premium system because it operates 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 goals.
As you consider how to choose a new air conditioner or furnace, think about:
- Efficiency savings: Higher-efficiency and right-sized systems can reduce electricity use.
- Upfront investment: High-efficiency AC and heating systems often have a higher purchase price than mid-range models but can help reduce long-term energy costs.
- Local utility costs: Areas with more expensive electricity may see better long-term savings from higher-efficiency units.
- Climate: It's essential your heating or cooling system has enough capacity to handle areas with extremely cold winters or very hot summers.
- 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 offset the investment.
- Financial incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can offset the overall cost of high-efficiency HVAC equipment.
Real-World Example: High Seer vs. Right System Size
What does this look like in a real world example?
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 only matched the previous unit. Next door, the second homeowner installs a correctly sized, mid-SEER or AFUE system after completing a Manual J calculation.
Although 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 correctly matched to the home's needs.
Work With an HVAC Professional Who Designs Solutions Tailored to Your Home
Replacing your HVAC system should involve much more than selecting the unit with the top efficiency rating. The right system is one that meets your heating and cooling requirements.
At County Line Mechanical LLC, our skilled HVAC experts perform an HVAC load calculation. We'll evaluate your home's size and layout, your household's comfort goals and recommend equipment that's designed specifically for your home—not simply the highest-capacity, fanciest unit or the one with the highest AFUE or SEER2 rating.
Our HVAC experts 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 County Line Mechanical LLC now. We'll evaluate your home, answer any questions and help you choose the correctly sized energy-efficient system that keeps your family comfortable for many years.