Shopping for a new air conditioning system or furnace can feel overwhelming. If you're trying 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 will provide the most comfort and lowest energy bills, right?
It’s not quite that simple.
High efficiency isn'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 energy efficiency, 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 long-term reliability. The best HVAC system for your home combines energy 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 sizing 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), shows how effectively a cooling system cools your home over a standard cooling season. A SEER2 rating is the newer version of SEER, using test procedures that better represent 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 measured by AFUE, which is short for Annual Fuel Utilization Efficiency. As with 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 by themselves guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on several key factors, including the quality of the installation, the quality of your ductwork, how much insulation your home has, thermostat settings and, most importantly, proper HVAC system sizing. Even the highest-efficiency system cannot operate at its best if it is too large or undersized for the home.
Why Correct HVAC System Sizing Matters More Than You Think
Many assume a higher-capacity 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. The truth is, new heating system installation or AC replacement should be selected based on your home's actual heating and cooling needs—not just square footage or the size of the previous unit.
That's why reputable companies conduct an HVAC load calculation, also called a Manual J calculation, before recommending replacement equipment. A Manual J calculation evaluates many factors that impact your home's comfort needs, including:
- Total square footage
- Ceiling height
- Window size and direction
- Insulation
- Air leakage
- Area climate
- Number of occupants
- Heat produced from appliances and lighting
- Ductwork condition
A properly sized air conditioner runs for enough time to cool your home evenly while eliminating excess humidity. That means more consistent temperatures, better indoor comfort and improved moisture control. This also allows the equipment to run more effciently, reducing strain that can shorten its lifespan or lead to more repairs and higher repair costs.
When your heating or cooling system is correctly sized, you get improved comfort and more reliable operation.
Problems with Oversized and Undersized Heating and Cooling Systems
It might be tempting to buy the most energy efficient, largest-capacity air conditioner or heating system on the market. The truth is, that’s rarely a smart choice.
HVAC 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 heat or cool rapidly, but that doesn't mean it works well.
- Short cycling: An oversized HVAC system cycles repeatedly, reducing efficiency and increasing equipment strain.
- Reduced humidity control: Oversized air conditioners finish cooling cycles too soon to remove indoor humidity from the air.
- Hot and cold spots: Some rooms get too cold while others aren’t ever cool enough.
- Additional equipment wear: Even though the system reaches the target temperature rapidly, those constant cycles can cause avoidable breakdowns due to the strain.
Issues Created by Undersized HVAC Systems
An undersized HVAC system has a different set of problems:
- Continuous operation: The system runs for long periods trying to reach the set temperature, which also causes unnecessary wear and tear.
- Trouble reaching the thermostat setting: Your home may feel cool enough during hot weather or never feel warm enough in cold weather.
- Increased energy consumption: Running for extended periods can increase energy costs.
- Extra stress during severe weather: HVAC systems that are too small can run extremely hard in extreme temperatures, increasing equipment wear and the chance of failure.
Finding the Right Balance Between Efficiency and Size
When trying to decide between a high SEER vs right-sized system, remember that you don't always need the most efficient model on the market.
Often, a professionally sized, mid-efficiency heating and cooling system will outperform an overly large premium system because it functions 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 needs.
When deciding how to choose a new air conditioner or furnace, keep these factors in mind:
- Lower energy costs: Higher-efficiency and right-sized systems can lower 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.
- Energy prices: Areas with more expensive electricity may see greater long-term savings from higher-efficiency units.
- Climate: It's important your heating or cooling system has the right capacity to handle areas with very cold winters or extremely hot summers.
- How long you'll 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 justify the investment.
- Financial incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can offset the overall cost of higher-efficiency systems.
Real-World Example: High Seer vs. Right System Size
How does this work in a real world example?
Picture two neighboring homes.
In the first, the homeowner chooses a premium high-efficiency HVAC system that's too big for the house because the contractor replaced it with the same size system as the previous unit. At the neighboring home, an HVAC professional 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 have a longer lifespan because it's properly matched to the home's needs.
Choose the Local HVAC Professional Who Designs Solutions Tailored to Your Home
Replacing your HVAC system should involve much more than selecting a model with the top efficiency rating. The right system is one that meets your heating and cooling requirements.
At Olde Towne Heating & Air, our knowledgeable technicians perform an HVAC load calculation. Our team will evaluate your home's size and layout, your household's comfort goals and recommend equipment that's right for your home—not simply the highest-capacity, fanciest unit or the one with the highest AFUE or SEER2 rating.
Our HVAC experts will let you know about any available tax rebates 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 Olde Towne Heating & Air now. Our team will evaluate your home, answer your questions and help you choose the properly sized efficient system that keeps your family comfortable for many years.