Choosing a new air conditioner or furnace can be intimidating. When you're looking to find the best HVAC system for your home, it's common to focus on models with extremely high efficiency ratings.
Surely the most efficient equipment will provide the most comfort and lowest energy bills, right?
Actually, that’s not always the case.
Efficiency ratings aren’t the only thing to think about when it comes to new air conditioner installation or installing a new furnace. Although many people 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 has a major impact on humidity control and long-term reliability. The best HVAC system for your home balances 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 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 an air conditioner cools your home over a typical cooling season. A SEER2 rating is the updated version of SEER, using testing methods that better simulate real-world operating conditions. Most new air conditioners have a SEER2 rating, simply because that is the new rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by AFUE, which is for Annual Fuel Utilization Efficiency. Like SEER and SEER2, 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 necessarily guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on more than just efficiency ratings, including the quality of the installation, the quality of your ductwork, your home's insulation, thermostat settings and, most importantly, HVAC system sizing. Even the most efficient system cannot deliver peak performance if it is oversized or smaller than needed for the home.
Why Correct HVAC System Sizing Matters More Than You Think
Many assume a larger air conditioner or furnace will work the best 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 actual 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 recommending replacement equipment. A Manual J calculation evaluates many factors that affect your home's heating and cooling requirements, including:
- Home square footage
- Room height
- Window size and direction
- Insulation
- Air leakage
- Local climate
- Household 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 removing excess humidity. That means steadier temperatures, better indoor comfort and improved humidity control. This also allows the equipment to run more effciently, reducing unnecessary wear that can reduce its service life or lead to more repairs and higher repair costs.
When HVAC equipment is properly sized, you get better comfort and more dependable performance.
Problems with Oversized and Undersized Systems
It might be tempting to buy the most energy efficient, highest-capacity air conditioner or heating system on the market. However, that's usually not a smart choice.
heating and cooling systems that are bigger than necessary or too small can create comfort problems, 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 delivers the best comfort.
- Short cycling: An oversized HVAC system starts and stops often, reducing efficiency and increasing equipment strain.
- High indoor humidity: 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 never feel comfortable.
- Additional equipment wear: Even though the system heats or cools your home fast, those constant cycles can cause avoidable breakdowns due to the strain.
Drawbacks of Undersized HVAC Systems
An undersized HVAC system has a different set of problems:
- Continuous operation: The system operates almost continuously trying to reach the thermostat setting, which also causes additional wear.
- Difficulty maintaining the desired temperature: Your home may never feel as cool as you want during hot weather or never feel warm enough in cold weather.
- 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 chance of failure.
Why You Should Balance HVAC System Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, remember that you don't always need the most efficient model on the market.
More often than not, a correctly sized, mid-efficiency HVAC system will deliver better performance than an overly large premium system because it functions the way it was designed to.
Thesmartest choice is an energy-efficient HVAC system that's matched 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:
- 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 help reduce long-term energy costs.
- Electricity rates: Areas with higher electricity rates may see better long-term savings from higher-efficiency units.
- Climate: It's essential 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 intend to remain 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 high-efficiency HVAC equipment.
Real-World Situation: High Seer vs. Right System Size
How does this work in the real world?
Imagine two neighboring homes.
At the first home, the homeowner chooses a premium high-efficiency HVAC system that's too big because the contractor simply matched the previous unit. The other homeowner installs a correctly sized, mid-SEER or AFUE system after completing a Manual J calculation.
Although the second system has a lesser efficiency rating on paper, it may deliver lower operating costs, better home comfort, improved humidity control and last longer because it's correctly matched to the home's needs.
Choose the Local HVAC Professional Who Designs Solutions Tailored to Your Home
HVAC replacent or installation should involve much more than selecting the unit with the top efficiency rating. An ideal system is one that meets your household heating and cooling requirements.
At Covington Air Systems, our experienced professionals perform an HVAC load calculation. We'll evaluate your home's design, your household's comfort needs and recommend equipment that's right for your home—not simply the largest, latest and greatest unit or the one with the highest AFUE or SEER2 rating.
Our HVAC experts will help you identify any available rebates or tax incentives and provide information about HVAC financing options that make energy-efficient HVAC systems more accessible for all budgets.
Schedule an HVAC consultation online with Covington Air Systems today. We'll gladly evaluate your home, answer any questions and help you choose the right-sized efficient system that keeps your family comfortable for many years.