Shopping for a new air conditioner or furnace can feel overwhelming. If you want to find the best HVAC system for your home, it's natural to focus on models with the highest efficiency ratings.
After all, the most efficient heating and cooling system should deliver the most comfort and lowest energy bills, right?
Not necessarily.
High 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 {energy efficiency|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 long-term reliability. The best HVAC system for your home delivers efficiency and proper sizing.
In thisarticle, 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.
What Does a High SEER Rating Actually Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), measures how efficiently an AC cools your home over a standard cooling season. A SEER2 rating is the updated version of SEER, using testing methods that better reflect real-world operating conditions. Nearly all new air conditioners have a SEER2 rating, simply because this is the new rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by an AFUE rating, 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 heat your home than lower-rated systems under standardized laboratory testing.
That said, high numbers don't by themselves guarantee lower utility bills. Actual heating and air conditioner efficiency depends on many factors, including the way the system is installed, the state of your ductwork, insulation levels, thermostat settings and, most importantly, system sizing. Even the highest-rated system cannot deliver peak performance if it is bigger than necessary or undersized for the home.
Why HVAC System Size 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 same-sized replacement. The truth is, 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 companies conduct an HVAC load calculation, also called a Manual J calculation, before selecting replacement equipment. A Manual J calculation analyzes many factors that affect your home's heating and cooling load, including:
- Home square footage
- Room height
- Window size and direction
- Home insultation levels
- Drafts and air leakage
- Regional 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 consistently while eliminating excess humidity. That means steadier temperatures, better indoor comfort and improved moisture control. This also allows the equipment to run more effciently, reducing unnecessary wear that can cause it to wear it out sooner or lead to frequent or expensive repairs.
When a furnace or AC is properly sized, you get better comfort and long-lasting performance.
Problems Caused by Oversized and Undersized HVAC Equipment
Many homeowners are tempted to buy the most energy efficient, highest-capacity air conditioner or heating system on the market. However, that's usually not a great idea.
HVAC 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 reach the thermostat setting fast, but that doesn't mean it works well.
- Short cycling: An oversized HVAC system starts and stops often, reducing efficiency and increasing equipment strain.
- Reduced humidity control: Oversized air conditioners cool your home too quickly to remove excess moisture from the air.
- Uneven temperatures: Some rooms become too cold while others stay too warm.
- More wear and tear: Even though the system works quickly, those constant 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 runs for long 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 always feel chilly in the winter.
- Greater energy usage: Running for extended periods can increase monthly energy expenses.
- Extra stress during severe weather: HVAC systems that are too small can struggle in extreme temperatures, increasing component strain and the risk of breakdowns.
Why You Should Balance HVAC System Efficiency and Size
When trying to decide between a high SEER vs right-sized system, remember that you don't necessarily need the top-efficiency model on the market.
Often, a properly sized, mid-efficiency heating and cooling system will deliver better performance than an oversized premium system because it functions the way it was designed to.
Thesmartest choice is an energy-efficient HVAC system that's correctly 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:
- Energy 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 lower long-term energy costs.
- Electricity rates: Areas with higher utility costs 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 harsh winter weather 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 offset the investment.
- Rebates and tax credits: 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 a real world example?
Picture two neighboring homes.
In the first, the homeowner chooses a premium high-efficiency HVAC system that's too big because the contractor simply matched the previous unit. The other homeowner installs a right-sized, moderate-efficiency system after completing a Manual J calculation.
Although 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.
Work With an HVAC Professional Who Designs Personalized Solutions
An HVAC replacement should involve more than selecting the unit with the top efficiency rating. The best system is one that meets your household heating and cooling requirements.
At Better Air, our knowledgeable technicians perform an HVAC load calculation. We'll evaluate your home's design, 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 heating and cooling specialists will help you identify any available rebates or tax incentives and provide information about HVAC financing options that make high-efficiency systems more accessible for all budgets.
Schedule an HVAC consultation online with Better Air to get started. Our team will evaluate your home, answer your questions and help you choose the correctly sized efficient system that keeps your family comfortable for the long haul.