Choosing a new air conditioner or furnace can be intimidating. 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 heating and cooling system should deliver the most comfort and lowest energy bills, right?
Actually, that’s not always the case.
High efficiency isn't the only thing to think about when it comes to new air conditioner installation or installing a new furnace. Even though many 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 also influences humidity control and system longevity. The best HVAC system for your home combines energy 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 experienced HVAC professionals consider both when recommending the best HVAC system for your home.
What Does a High SEER Rating Actually Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), measures how effectively a cooling system cools your home over a typical cooling season. A SEER2 rating is the newer version of SEER, using test procedures that better reflect real-world operating conditions. Nearly all new air conditioners have a SEER2 efficiency rating, simply because that is the current rating system for cooling equipment.
Fuel-burning heating system efficiency is rated by an AFUE rating, which stands for Annual Fuel Utilization Efficiency. Similar to SEER and SEER2, 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 necessarily guarantee lower utility bills. Actual heating and air conditioner efficiency depends on several key factors, including the quality of the installation, the quality of your ductwork, how much insulation your home has, thermostat settings and, most importantly, system sizing. Even the highest-efficiency system cannot perform as intended if it is too large or smaller than needed for the home.
Why Proper HVAC Sizing Matters More Than You Probably Think
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. Actually, new heating system installation or a new air conditioner should be sized based on your home's current heating and cooling needs—not just square footage or the size of the previous unit.
That's why reputable technicians perform an HVAC load calculation, also called a Manual J calculation, before recommending replacement equipment. A Manual J calculation considers many factors that impact your home's comfort needs, including:
- Overall square footage
- Room height
- Window size and placement
- Insulation
- Air leakage
- Area climate
- Number of occupants
- Heat produced from appliances and lighting
- Air duct 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 humidity control. This also allows the equipment to run more effciently, reducing excessive wear and tear that can reduce its service life or lead to more repairs and higher repair costs.
When HVAC equipment is properly sized, you get greater comfort and more reliable operation.
Problems with Oversized and Undersized Systems
You may be tempted to buy the most energy efficient, biggest air conditioner or heating system on the market. In reality, that often isn't a good investment.
heating and cooling systems that are too large or too small can create comfort problems, increase energy expenses and reduce efficiency regardless of their SEER rating.
Issues Created by Oversized HVAC Systems
An oversized air conditioner or heating system may reach the thermostat setting fast, but that doesn't mean it performs efficiently.
- Short cycling: An oversized HVAC system cycles repeatedly, reducing efficiency and increasing wear and tear.
- Reduced humidity control: Oversized air conditioners reach the set temperature too fast to remove indoor humidity from the air.
- Hot and cold spots: Some rooms get too cold while others stay too warm.
- More wear and tear: Even though the system reaches the target temperature rapidly, those frequent starts and stops can cause avoidable breakdowns due to the strain.
Drawbacks of Undersized HVAC Systems
An undersized HVAC system also can struggle:
- Long run times: The system stays on for extended periods trying to reach the desired temperature, which also causes unnecessary wear and tear.
- Difficulty maintaining the desired temperature: Your home may feel cool enough during hot weather or never feel warm enough in cold weather.
- Greater energy usage: Running almost constantly can increase energy costs.
- Extra stress during severe weather: HVAC systems that are too small can run extremely hard in extreme temperatures, increasing wear and the likelihood of repairs.
Finding the Right Balance Between Efficiency and Size
When trying to decide between a high SEER vs right-sized system, remember that you don't necessarily need the highest-efficiency model on the market.
Often, a properly sized, mid-efficiency HVAC system will outperform an oversized 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, keep these factors in mind:
- Lower energy costs: Higher-efficiency and right-sized systems can lower electricity use.
- Purchase price: High-efficiency AC and heating systems often have a higher purchase price than mid-range models but can lower long-term energy costs.
- Energy prices: Areas with higher electricity rates may see more significant long-term savings from higher-efficiency units.
- Seasonal weather conditions: It's crucial your heating or cooling system has enough capacity to handle areas with very cold winters or extremely hot summers.
- 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 offset the investment.
- Available rebates or tax incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can lower the overall cost of higher-efficiency systems.
Real-World Example: High Seer vs. Right System Size
What does this look like in a real world example?
Imagine two neighboring homes.
In the first, the homeowner chooses a premium high-efficiency HVAC system that's too big because the contractor replaced it with the same size system as the previous unit. At the neighboring home, an HVAC professional installs a correctly sized, mid-efficiency system after completing a Manual J calculation.
Even though the second system has a more modest 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 Solutions Tailored to Your Home
Replacing your HVAC system should involve much more than selecting a system with the top efficiency rating. The best system is one that meets your household heating and cooling requirements.
At Rescue Heating & 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 largest, fanciest unit or the one with the highest AFUE or SEER2 rating.
Our team will connect you with 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 Rescue Heating & Air today. We'll gladly evaluate your home, answer any questions and help you choose the right-sized efficient system that keeps your family comfortable for many years.