Choosing a new air conditioner or furnace can feel overwhelming. If you're trying to find the best HVAC system for your home, it's understandable to look for models with extremely high efficiency ratings.
After all, 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 you should consider when it comes to new air conditioner installation or furnace replacement. Even though many focus only on efficiency ratings, proper HVAC system sizing is just as, if not more important for your home's comfort and your energy bills.
Proper sizing also influences humidity control and long-term reliability. The best HVAC system for your home combines 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 qualified HVAC contractors consider both when helping you select the best HVAC system for your home.
High Seer Ratings: What Do They Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), indicates how effectively a cooling system cools your home over a normal cooling season. A SEER2 rating is the updated 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 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. Like cooling efficiency ratings, higher AFUE ratings indicate a high-efficiency HVAC system that uses less electricity to keep you comfortable than lower-rated systems under standardized laboratory testing.
Even so, high ratings don't automatically guarantee lower utility bills. Actual heating and air conditioner efficiency depends on many factors, including the installation quality, the condition of your ductwork, your home's insulation, thermostat settings and, most importantly, 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 Probably Think
Many assume a bigger air conditioner or furnace will work the best 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 current heating and cooling needs—not just square footage or the size of your existing equipment.
That's why reputable technicians conduct an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation analyzes many factors that impact your home's heating and cooling requirements, including:
- Overall square footage
- Ceiling height
- Window size and placement
- Insulation
- Drafts and air leakage
- Area climate
- Household occupants
- Heat generated by appliances and lighting
- Air duct condition
A properly sized air conditioner runs through longer cooling cycles to cool your home evenly while pulling out excess humidity. That means steadier temperatures, better indoor comfort and improved moisture control. Proper sizing also helps the equipment to operate more effciently, reducing strain that can reduce its service life or lead to costly breakdowns.
When a furnace or AC is the right size for your home, you get greater comfort and more reliable operation.
Problems Caused by Oversized and Undersized Systems
Many homeowners are tempted to buy the most energy efficient, biggest air conditioner or heating system on the market. However, that often isn't a good investment.
HVAC systems that are bigger than your home needs or too small can create comfort problems, increase operating costs 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 works well.
- Short cycling: An oversized HVAC system cycles repeatedly, reducing efficiency and increasing equipment strain.
- Humidity problems: Oversized air conditioners finish cooling cycles too soon to remove enough moisture from the air.
- Inconsistent temperatures: Some rooms feel too cool while others stay too warm.
- Increased wear and tear: Even though the system reaches the target temperature rapidly, those repeated on-and-off cycles can cause avoidable breakdowns due to the strain.
Cons Associated with Undersized HVAC Systems
An undersized HVAC system can have the opposite problem:
- Long run times: The system operates almost continuously trying to reach the set temperature, which also causes extra strain.
- Difficulty reaching thermostat settings: Your home may never feel as cool as you want during hot weather or never feel warm enough in cold weather.
- Greater energy usage: Running nonstop can increase energy costs.
- Extra stress during severe weather: HVAC systems that are too small can work harder in extreme temperatures, increasing component strain and the risk of breakdowns.
Finding the Right Balance Between Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, keep in mind that you don't automatically need the highest-efficiency model on the market.
In many cases, a correctly sized, mid-efficiency HVAC system will outperform an overly large premium system because it runs the way it was designed to.
Thesmartest choice is an energy-efficient HVAC system that's properly sized 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:
- Energy savings: Higher-efficiency and right-sized systems can lower electricity use.
- Initial cost: High-efficiency AC and heating systems often require a larger upfront investment than mid-range models but can lower long-term energy costs.
- Energy prices: Areas with higher electricity rates may see better long-term savings from higher-efficiency units.
- Seasonal weather conditions: It's essential your heating or cooling system has enough capacity to handle areas with harsh winter weather or intense summer heat.
- 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 be worth the investment.
- Available rebates or tax incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can offset the overall cost of qualifying equipment.
Real-World Comparison: High Seer vs. Right System Size
What does this look like in a real world example?
Imagine two neighboring homes.
In one, 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. Next door, the second homeowner installs a properly sized, moderate-efficiency system after completing a Manual J calculation.
While the second system has a lesser efficiency rating on paper, it may provide lower operating costs, better home comfort, improved humidity control and last longer because it's appropriately sized to the home's needs.
Work With an HVAC Professional Who Designs the Right Solution
HVAC replacent or installation should involve more than selecting a system with the top efficiency rating. The best system is one that meets your heating and cooling requirements.
At Prestige Plumbing and Air, our experienced professionals perform an HVAC load calculation. We'll carefully evaluate your home's layout and construction, your household's comfort needs and recommend equipment that's properly matched for your home—not simply the highest-capacity, most expensive unit or the one with the highest AFUE or SEER2 rating.
Our team will let you know about any available tax rebates and provide information about HVAC financing options that make energy-efficient HVAC systems more accessible for all budgets.
Schedule an HVAC consultation online with Prestige Plumbing and Air now. Our team will evaluate your home, answer any questions and help you choose the properly sized energy-efficient system that keeps your family comfortable for many years.