Shopping for a new air conditioning system or furnace can be intimidating. If you want to find the best HVAC system for your home, it's common to look for models with the highest efficiency ratings.
After all, the most efficient equipment will provide the most comfort and lowest energy bills, right?
It’s not quite that simple.
High efficiency isn't the only thing that matters when it comes to new air conditioner installation or furnace replacement. While many homeowners focus only on efficiency ratings, proper HVAC system sizing is often even more important for your home's comfort and your energy bills.
Proper sizing directly impacts humidity control and system longevity. The best HVAC system for your home combines efficiency and correct sizing.
In this article, we'll explain what an air conditioner's SEER rating or SEER2 rating actually measures, why correct HVAC size is so important and why experienced HVAC professionals 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 efficiently a cooling system cools your home over a standard cooling season. A SEER2 rating is the current version of SEER, using testing methods that better simulate real-world operating conditions. Nearly all new air conditioners have a SEER2 designation, simply because this is the new rating system for cooling equipment.
Fuel-burning heating system efficiency is measured by something called AFUE, which is short for Annual Fuel Utilization Efficiency. Similar to SEER and SEER2, 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 ratings don't by themselves guarantee lower utility bills. Everyday heating and air conditioner efficiency depends on more than just efficiency ratings, including the way the system is installed, the condition of your ductwork, how much insulation your home has, thermostat settings and, most importantly, HVAC system sizing. Even the highest-rated system cannot operate at its best if it is oversized or smaller than needed for the home.
Why Proper HVAC Sizing Matters More Than You Think
Many assume a higher-capacity air conditioner or furnace will heat or cool a home better or that they should just replace their old HVAC system with a same-sized replacement. Actually, 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 your existing equipment.
That's why reputable companies conduct an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation analyzes many factors that affect your home's comfort needs, including:
- Total square footage
- Ceiling height
- Window size and orientation
- Insulation
- Air leakage
- Local climate
- Household occupants
- Heat produced from appliances and lighting
- Ductwork condition
A properly sized air conditioner runs through longer cooling cycles to cool your home evenly while eliminating excess humidity. That means more consistent temperatures, better indoor comfort and improved moisture control. Proper sizing also helps the equipment to operate more effciently, reducing excessive wear and tear that can shorten its lifespan or lead to costly breakdowns.
When HVAC equipment is the right size for your home, you get improved comfort and more dependable performance.
Problems with Oversized and Undersized HVAC Equipment
You may be tempted to buy the most energy efficient, largest-capacity air conditioner or heating system on the market. In reality, that often isn't a good investment.
heating and cooling systems that are bigger than your home needs or smaller than your home requires can create indoor comfort challenges, increase utility 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 cycles repeatedly, reducing efficiency and increasing equipment strain.
- Reduced humidity control: Oversized air conditioners reach the set temperature too fast to remove enough moisture from the air.
- Uneven temperatures: Some rooms get too cold while others aren’t ever cool enough.
- Additional equipment wear: Even though the system works quickly, those frequent starts and stops can cause avoidable breakdowns due to the strain.
Issues Created by Undersized HVAC Systems
An undersized HVAC system can have the opposite problem:
- Continuous operation: The system stays on for extended periods trying to reach the desired temperature, which also causes unnecessary wear and tear.
- Trouble reaching the thermostat setting: Your home may never feel as cool as you want during hot weather or always feel chilly in the winter.
- Higher energy use: Running for extended periods can increase utility bills.
- Extra stress during severe weather: HVAC systems that are too small can work harder in extreme temperatures, increasing equipment wear and the likelihood of repairs.
Finding the Right Balance Between Efficiency and Size
When trying to decide between a high SEER vs right-sized system, keep in mind that you don't always need the highest-efficiency model on the market.
More often than not, a correctly sized, mid-efficiency heating and cooling system will deliver better performance than an overly large premium system because it operates 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 needs.
As you consider how to choose a new air conditioner or furnace, keep these factors in mind:
- Efficiency savings: Higher-efficiency and right-sized systems can decrease electricity use.
- Purchase price: High-efficiency AC and heating systems often cost more initially than mid-range models but can reduce long-term energy costs.
- Local utility costs: Areas with higher electricity rates may see greater long-term savings from higher-efficiency units.
- Your local climate: It's crucial your heating or cooling system has enough capacity to handle areas with harsh winter weather or intense summer heat.
- 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 Comparison: High Seer vs. Right System Size
How does this work in a real world scenario?
Suppose there are 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 only matched the previous unit. Next door, the second homeowner installs a properly sized, moderate-efficiency system after completing a Manual J calculation.
Although the second system has a more modest efficiency rating on paper, it may provide lower operating costs, better home comfort, improved humidity control and have a longer lifespan because it's correctly matched to the home's needs.
Choose the Local HVAC Professional Who Designs Personalized Solutions
HVAC replacent or installation should involve much more than selecting a system with the top efficiency rating. The right system is one that meets your home’s heating and cooling requirements.
At Stephen Hurst Pack Heating and Cooling, our knowledgeable technicians perform an HVAC load calculation. We'll carefully evaluate your home's design, 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 high-efficiency systems more accessible for all budgets.
Schedule an HVAC consultation online with Stephen Hurst Pack Heating and Cooling today. We'll gladly evaluate your home, answer any questions and help you choose the right-sized energy-efficient system that keeps your family comfortable for years to come.