Choosing a new AC or furnace can be intimidating. If you're trying to find the best HVAC system for your home, it's common to look for models with the highest efficiency ratings.
Surely the most efficient equipment provides the most comfort and lowest energy bills, right?
It’s not quite that simple.
Energy efficiency isn't the only thing you should consider when it comes to new air conditioner installation or replacing your furnace. While many homeowners focus only on efficiency ratings, proper HVAC system sizing is often even more important for your home's comfort and your utility bills.
Proper sizing directly impacts humidity control and lasting performance. The best HVAC system for your home combines 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 sizing is so important and why experienced HVAC professionals 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), shows how efficiently a cooling system cools your home over a typical cooling season. A SEER2 rating is the updated version of SEER, using testing methods that better represent real-world operating conditions. Nearly all new air conditioners have a SEER2 rating, simply because this rating is the current rating system for cooling equipment.
Fuel-burning heating system efficiency is rated by AFUE, which is short 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 achieve indoor comfort than lower-rated systems under standardized laboratory testing.
That said, high ratings don't automatically guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on many factors, including the quality of the installation, 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 undersized for the home.
Why Correct HVAC System Sizing Matters More Than Most Homeowners Realize
Many assume a higher-capacity air conditioner or furnace will heat or cool a home better or that they should simply replace their old HVAC system with a unit of the same capacity. The truth is, new heating system installation or AC replacement should be sized 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 technicians conduct an HVAC load calculation, also called a Manual J calculation, before selecting replacement equipment. A Manual J calculation evaluates many details that affect your home's heating and cooling load, including:
- Home square footage
- Ceiling height
- Window size and orientation
- Home insultation levels
- Drafts and air leakage
- Area climate
- Number of occupants
- Heat generated by appliances and lighting
- Ductwork condition
A properly sized air conditioner runs through longer cooling cycles to cool your home evenly while pulling out excess humidity. That means more even temperatures, better indoor comfort and improved moisture control. Proper sizing also helps 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 a furnace or AC is the right size for your home, you get improved comfort and more dependable performance.
Problems Caused by 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. However, that’s rarely a great idea.
heating and cooling systems that are too large or smaller than your home requires can create indoor comfort challenges, increase utility 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 works well.
- Short cycling: An oversized HVAC system turns on and off frequently, reducing efficiency and increasing wear.
- High indoor humidity: Oversized air conditioners finish cooling cycles too soon to remove excess moisture from the air.
- Uneven temperatures: Some rooms feel too cool while others aren’t ever cool enough.
- Additional equipment wear: Even though the system works quickly, those repeated on-and-off cycles can cause avoidable breakdowns due to the strain.
Drawbacks of 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 set temperature, which also causes extra strain.
- Trouble reaching the thermostat setting: Your home may not feel comfortable during hot weather or never feel warm enough in cold weather.
- Increased energy consumption: Running almost constantly 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 equipment wear and the risk of breakdowns.
Balancing Efficiency and Size
When trying to decide between a high SEER vs right-sized system, don't forget that you don't automatically need the top-efficiency model on the market.
Often, a professionally sized, mid-efficiency heating and cooling system will deliver better performance than an overly large premium system because it runs the way it was designed to.
Thebest 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, consider:
- Lower energy costs: 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.
- Electricity rates: Areas with higher electricity rates may see better long-term savings from higher-efficiency units.
- Your local climate: It's crucial your heating or cooling system has adequate capacity to handle areas with very cold winters or extremely hot summers.
- Time you plan to 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 offset the investment.
- Rebates and tax credits: Manufacturer promotions, {utility|equipment rebates and tax credits can offset the overall cost of higher-efficiency systems.
Real-World Comparison: High Seer vs. Right System Size
How does this play out in a real world scenario?
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 only matched the previous unit. Next door, the second homeowner installs a right-sized, moderate-efficiency system after completing a Manual J calculation.
Even though the second system has a lower efficiency rating on paper, it may provide lower operating costs, better home comfort, more effective humidity control and have a longer lifespan because it's appropriately sized to the home's needs.
Choose the Local HVAC Professional Who Designs Solutions Tailored to Your Home
An HVAC replacement should involve much more than selecting a system with the top efficiency rating. The right system is one that meets your heating and cooling requirements.
At GV Heating & Air, our skilled HVAC experts perform an HVAC load calculation. Our team will evaluate your home's layout and construction, your household's heating and cooling preferences and recommend equipment that's properly matched for your home—not simply the biggest, latest and greatest unit or the one with the highest AFUE or SEER2 rating.
Our HVAC experts will connect you with any available rebates or tax incentives 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 GV Heating & Air now. Our team will evaluate your home, answer your questions and help you choose the correctly sized high-efficiency system that keeps your family comfortable for many years.
