Choosing a new AC 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 extremely high efficiency ratings.
After all, the most efficient heating and cooling system should deliver the most comfort and lowest energy bills, right?
Actually, that’s not always the case.
Energy efficiency isn't the only thing that matters when it comes to new air conditioner installation or installing a new furnace. Although many people focus only on energy efficiency, proper HVAC system sizing is just as, if not more important for your home's comfort and your utility bills.
Proper sizing also influences humidity control and lasting performance. The best HVAC system for your home delivers 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 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 an AC cools your home over a normal cooling season. A SEER2 rating is the newer version of SEER, using testing methods that better simulate real-world operating conditions. Today’s new air conditioners have a SEER2 rating, simply because this is the current rating system for cooling equipment.
Fuel-burning heating system efficiency is rated by AFUE, which stands for Annual Fuel Utilization Efficiency. As with 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.
However, high numbers don't by themselves guarantee lower utility bills. Everyday heating and air conditioner efficiency depends on many factors, including the way the system is installed, the state of your ductwork, your home's insulation, thermostat settings and, most importantly, 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 You Probably Think
Many assume a larger air conditioner or furnace will work the best or that they should just replace their old HVAC system with a unit of the same capacity. In reality, new heating system installation or air conditioner replacement should be selected based on your home's true heating and cooling needs—not just square footage or the size of the previous unit.
That's why reputable companies conduct an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation analyzes many variables that affect your home's comfort needs, including:
- Overall square footage
- Ceiling height
- Window size and placement
- Insulation
- Air infiltration
- Local 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 pulling out excess humidity. That means more even 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 shorten its lifespan or lead to frequent or expensive repairs.
When HVAC equipment is properly sized, you get greater comfort and more dependable performance.
Problems Caused by Oversized and Undersized Heating and Cooling Systems
You may be tempted to buy the most energy efficient, highest-capacity air conditioner or heating system on the market. However, that often isn't a great idea.
heating and cooling systems that are bigger than your home needs or undersized can create comfort issues, increase utility costs and reduce efficiency regardless of their SEER rating.
Issues Created by Oversized HVAC Systems
An oversized air conditioner or heating system may work quickly, but that doesn't mean it performs efficiently.
- Short cycling: An oversized HVAC system starts and stops often, reducing efficiency and increasing wear and tear.
- Poor humidity removal: Oversized air conditioners reach the set temperature too fast to remove excess moisture from the air.
- Hot and cold spots: Some rooms get too cold while others never feel comfortable.
- Additional equipment wear: 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 set temperature, which also causes extra strain.
- Difficulty reaching thermostat settings: Your home may feel cool enough during hot weather or always feel chilly in the winter.
- Increased energy consumption: Running for extended periods can increase energy costs.
- Extra stress during severe weather: HVAC systems that are too small can struggle in extreme temperatures, increasing wear 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, keep in mind that you don't automatically need the most efficient model on the market.
More often than not, a professionally sized, mid-efficiency HVAC system will outperform an overly large premium system because it functions 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.
When deciding how to choose a new air conditioner or furnace, think about:
- Efficiency savings: Higher-efficiency and right-sized systems can reduce electricity use.
- Upfront investment: High-efficiency AC and heating systems often require a larger upfront investment than mid-range models but can reduce long-term energy costs.
- Energy prices: Areas with higher utility costs may see better long-term savings from higher-efficiency units.
- Your local climate: It's essential your heating or cooling system has enough capacity to handle areas with very cold winters or extremely hot summers.
- Length of home ownership: 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.
- Rebates and tax credits: Manufacturer promotions, {utility|equipment rebates and tax credits can lower the overall cost of high-efficiency HVAC equipment.
Real-World Comparison: High Seer vs. Right System Size
How does this play out in a real world scenario?
Picture two neighboring homes.
In one, the homeowner chooses a premium high-efficiency HVAC system that's too big because the contractor simply matched the previous unit. At the neighboring home, an HVAC professional installs a correctly sized, moderate-efficiency system after completing a Manual J calculation.
Although 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 correctly matched to the home's needs.
Choose the HVAC Professional Who Designs the Right Solution
HVAC replacent or installation should involve more than selecting a model with the top efficiency rating. An ideal system is one that meets your household heating and cooling requirements.
At Strine's, our skilled HVAC experts perform an HVAC load calculation. We'll evaluate your home's size and layout, your household's heating and cooling preferences 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 heating and cooling specialists will let you know about any available rebates and 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 Strine's today. Our team will evaluate your home, answer any questions and help you choose the properly sized high-efficiency system that keeps your family comfortable for the long haul.