Choosing a new AC or furnace can be stressful. If you want to find the best HVAC system for your home, it's understandable to look for models with the highest efficiency ratings.
After all, the most efficient system should deliver the most comfort and lowest energy bills, right?
It’s not quite that simple.
Efficiency ratings aren’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 equally, if not more important for your home's comfort and your power bills.
Proper sizing directly impacts humidity control and long-term reliability. The best HVAC system for your home delivers energy efficiency and correct sizing.
In this guide, we'll explain what an air conditioner's SEER rating or SEER2 rating actually measures, why correct HVAC size is so important and why trusted HVAC experts consider both when recommending the best HVAC system for your home.
High Seer Ratings: What Do They Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), indicates how effectively an AC cools your home over a typical cooling season. A SEER2 rating is the current version of SEER, using test procedures that better represent real-world operating conditions. Today’s new air conditioners have a SEER2 designation, simply because that is the updated rating system for cooling equipment.
Fuel-burning heating system efficiency is rated by something called AFUE, which is short for Annual Fuel Utilization Efficiency. Like cooling efficiency 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.
However, high ratings don't by themselves 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, your home's insulation, thermostat settings and, most importantly, HVAC system sizing. Even the highest-rated system cannot operate at its best 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 make their home the most comfortable or that they should simply replace their old HVAC system with a unit of the same capacity. In reality, new heating system installation or AC replacement should be sized based on your home's true heating and cooling needs—not just square footage or the size of your existing equipment.
That's why reputable technicians complete 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 comfort needs, including:
- Total square footage
- Room height
- Window size and orientation
- Home insultation levels
- Drafts and air leakage
- Area climate
- Number of occupants
- Heat produced from appliances and lighting
- Ductwork condition
A properly sized air conditioner runs long enough to cool your home more uniformly while removing excess humidity. That means more even temperatures, better indoor comfort and improved moisture control. This also allows the equipment to operate more effciently, reducing unnecessary wear that can cause it to wear it out sooner 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 Heating and Cooling Systems
You may be tempted to buy the most energy efficient, biggest air conditioner or heating system on the market. In reality, that's usually not a smart choice.
HVAC systems that are bigger than your home needs or undersized can create comfort issues, increase operating costs and reduce efficiency regardless of their SEER rating.
Common Problems With 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 cycles repeatedly, reducing efficiency and increasing equipment strain.
- Reduced humidity control: Oversized air conditioners reach the set temperature too fast to remove indoor humidity from the air.
- Inconsistent temperatures: Some rooms get too cold while others never feel comfortable.
- Increased wear and tear: Even though the system heats or cools your home fast, those constant cycles can cause avoidable breakdowns due to the strain.
Cons Associated with Undersized HVAC Systems
An undersized HVAC system also can struggle:
- Long run times: The system stays on for extended periods trying to reach the thermostat setting, which also causes unnecessary wear and tear.
- Difficulty maintaining the desired temperature: Your home may not feel comfortable during hot weather or always feel chilly in the winter.
- Greater energy usage: Running nonstop can increase utility bills.
- Extra stress during severe weather: HVAC systems that are too small can run extremely hard in extreme temperatures, increasing wear 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, don't forget that you don't automatically need the highest-efficiency model on the market.
Often, a correctly sized, mid-efficiency heating and cooling system will provide better results 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 needs.
When deciding how to choose a new air conditioner or furnace, think about:
- 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.
- Local utility costs: Areas with more expensive electricity may see better 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 intense summer heat.
- Time you plan to own the home: If you plan to stay in your home for many years, the long-term energy savings of a higher-efficiency unit may be worth the investment.
- Financial incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can reduce the overall cost of higher-efficiency systems.
Real-World Example: High Seer vs. Right System Size
How does this play out in the real world?
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 right-sized, mid-SEER or AFUE system after completing a Manual J calculation.
Even though the second system has a more modest efficiency rating on paper, it may deliver lower operating costs, better home comfort, more effective 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
An HVAC replacement should involve more than selecting a system with the top efficiency rating. The right system is one that meets your household heating and cooling requirements.
At Kirkfield Heating & Air Conditioning, our knowledgeable technicians perform an HVAC load calculation. Our team will evaluate your home's layout and construction, your household's comfort goals 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 HVAC experts will help you identify any available rebates and 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 Kirkfield Heating & Air Conditioning to get started. Our team will evaluate your home, answer any questions and help you choose the correctly sized efficient system that keeps your family comfortable for many years.
