Choosing a new air conditioner or furnace can feel overwhelming. When you're looking to find the best HVAC system for your home, it's understandable to focus on models with the highest efficiency ratings.
Surely the most efficient equipment should deliver 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. Even though many focus only on energy efficiency, proper HVAC system sizing is just as, if not 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 balances efficiency and correct sizing.
In this article, 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 choose the best HVAC system for your home.
High Seer Ratings: What Do They Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), indicates how efficiently an AC cools your home over a typical cooling season. A SEER2 rating is the newer version of SEER, using test procedures that better simulate real-world operating conditions. Nearly all new air conditioners have a SEER2 efficiency rating, simply because this is the updated rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by an AFUE rating, which is for Annual Fuel Utilization Efficiency. As with 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.
Even so, high ratings don't automatically guarantee lower utility bills. Everyday heating and air conditioner efficiency depends on several key factors, including the installation quality, the state of your ductwork, your home's insulation, thermostat settings and, most importantly, system sizing. Even the highest-rated system cannot perform as intended if it is too large or too small for the home.
Why HVAC System Size Matters More Than You Think
Many assume a bigger air conditioner or furnace will heat or cool a home better or that they should just replace their old HVAC system with a new one the same size. The truth is, new heating system installation or air conditioner 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 complete an HVAC load calculation, also called a Manual J calculation, before recommending replacement equipment. A Manual J calculation analyzes many factors that affect your home's heating and cooling requirements, including:
- Overall square footage
- Room height
- Window size and orientation
- Home insultation levels
- Drafts and air leakage
- Local climate
- Household 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 indoor humidity management. It also helps the equipment to run more effciently, reducing excessive wear and tear that can cause it to wear it out sooner or lead to frequent or expensive repairs.
When HVAC equipment is properly sized, you get improved comfort and long-lasting performance.
Problems Caused by Oversized and Undersized Systems
You may be tempted to buy the most energy efficient, highest-capacity air conditioner or heating system on the market. However, that's usually not a good investment.
HVAC 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 starts and stops often, 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 get too cold while others aren’t ever cool enough.
- Increased wear and tear: Even though the system reaches the target temperature rapidly, those constant cycles can cause avoidable breakdowns due to the strain.
Cons Associated with Undersized HVAC Systems
An undersized HVAC system has a different set of problems:
- Long run times: The system stays on for extended periods trying to reach the thermostat setting, which also causes extra strain.
- Trouble reaching the thermostat setting: Your home may feel cool enough during hot weather or always feel chilly in the winter.
- Greater energy usage: Running for extended periods can increase utility bills.
- Greater strain on very hot or cold days: HVAC systems that are too small can work harder 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 necessarily need the top-efficiency model on the market.
Often, a professionally sized, mid-efficiency HVAC system will outperform an oversized premium system because it operates the way it was designed to.
Thebest choice is an energy-efficient HVAC system that's correctly sized for your home, your budget, your climate and your future plans.
As you think about how to choose a new air conditioner or furnace, think about:
- Energy savings: Higher-efficiency and right-sized systems can reduce electricity use.
- Purchase price: High-efficiency AC and heating systems often require a larger upfront investment than mid-range models but can reduce long-term energy costs.
- Electricity rates: Areas with more expensive electricity may see greater long-term savings from higher-efficiency units.
- Climate: It's crucial your heating or cooling system has enough capacity to handle areas with very cold winters or very 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.
- Available rebates or tax incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can reduce the overall cost of qualifying equipment.
Real-World Comparison: High Seer vs. Right System Size
How does this play out in a real world scenario?
Imagine two neighboring homes.
At the first home, the homeowner chooses a premium high-efficiency HVAC system that's too big because the contractor only matched the previous unit. At the neighboring home, an HVAC professional installs a right-sized, mid-efficiency system after completing a Manual J calculation.
Although the second system has a lesser efficiency rating on paper, it may provide lower operating costs, better home comfort, improved humidity control and have a longer lifespan because it's properly matched to the home's needs.
Work With an HVAC Professional Who Designs Personalized Solutions
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 Assured Appliance & Heating & Air, our knowledgeable technicians perform an HVAC load calculation. We'll 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 largest, fanciest 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 efficient heating and cooling systems more accessible for all budgets.
Schedule an HVAC consultation online with Assured Appliance & Heating & Air today. We'll evaluate your home, answer any questions and help you choose the right-sized efficient system that keeps your family comfortable for many years.
