Choosing a new air conditioning system or furnace can be intimidating. If you want to find the best HVAC system for your home, it's understandable to look for models with the highest efficiency ratings.
Surely the most efficient system provides the most comfort and lowest energy bills, right?
It’s not quite that simple.
Efficiency ratings aren’t the only thing to think about when it comes to new air conditioner installation or furnace replacement. Even though many focus only on energy efficiency, proper HVAC system sizing is equally, if not more important for your home's comfort and your power bills.
Proper sizing has a major impact on humidity control and lasting performance. The best HVAC system for your home balances efficiency and correct sizing.
In this blog, 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.
High Seer Ratings: What Do They Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), shows how effectively a cooling system cools your home over a normal cooling season. A SEER2 rating is the current version of SEER, using test procedures that better reflect real-world operating conditions. Most new air conditioners have a SEER2 rating, simply because this rating is the updated rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by AFUE, which is for Annual Fuel Utilization Efficiency. As with SEER and SEER2 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.
Even so, high numbers don't by themselves guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on more than just efficiency ratings, including the quality of the installation, the state of your ductwork, your home's insulation, thermostat settings and, most importantly, HVAC system sizing. Even the highest-efficiency system cannot deliver peak performance if it is oversized or smaller than needed for the home.
Why Correct HVAC System Sizing Matters More Than Most Homeowners Realize
Many assume a bigger air conditioner or furnace will work the best or that they should just replace their old HVAC system with a same-sized replacement. The truth is, new heating system installation or a new air conditioner should be sized based on your home's actual heating and cooling needs—not just square footage or the size of your existing equipment.
That's why reputable technicians conduct an HVAC load calculation, also called a Manual J calculation, before recommending replacement equipment. A Manual J calculation considers many factors that affect your home's heating and cooling load, including:
- Total square footage
- Ceiling height
- Window size and placement
- Insulation
- Air infiltration
- Area climate
- Household occupants
- Heat generated by appliances and lighting
- Air duct condition
A properly sized air conditioner runs for enough time to cool your home more uniformly while removing excess humidity. That means more even temperatures, better indoor comfort and improved humidity control. Proper sizing also helps the equipment to run more effciently, reducing unnecessary wear that can shorten its lifespan or lead to more repairs and higher repair costs.
When a furnace or AC is properly sized, you get greater comfort and long-lasting performance.
Problems with Oversized and Undersized HVAC Equipment
You may be tempted to buy the most energy efficient, highest-capacity air conditioner or heating system on the market. However, that’s rarely a great idea.
heating and cooling systems that are too large or smaller than your home requires can create comfort problems, 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 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 wear.
- Humidity problems: Oversized air conditioners finish cooling cycles too soon to remove indoor humidity from the air.
- Inconsistent temperatures: Some rooms feel too cool while others never feel comfortable.
- More wear and tear: Even though the system heats or cools your home fast, those constant cycles can cause avoidable breakdowns due to the strain.
Drawbacks of Undersized HVAC Systems
An undersized HVAC system can have the opposite problem:
- Continuous operation: The system runs for long periods trying to reach the thermostat setting, which also causes extra strain.
- Difficulty reaching thermostat settings: Your home may feel cool enough during hot weather or feel too cool during winter.
- Increased energy consumption: Running nonstop can increase monthly energy expenses.
- Extra stress during severe weather: HVAC systems that are too small can work harder in extreme temperatures, increasing equipment wear and the likelihood of repairs.
Balancing Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, don't forget that you don't always need the most efficient model on the market.
In many cases, a professionally sized, mid-efficiency heating and cooling system will deliver better performance than an overly large premium system because it operates 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 future plans.
When deciding how to choose a new air conditioner or furnace, keep these factors in mind:
- Energy savings: Higher-efficiency and right-sized systems can lower 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 electricity rates may see better long-term savings from higher-efficiency units.
- Seasonal weather conditions: It's important your heating or cooling system has the right capacity to handle areas with extremely 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 justify the investment.
- Available rebates or tax incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can offset the overall cost of high-efficiency HVAC equipment.
Real-World Comparison: High Seer vs. Right System Size
What does this look like 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 replaced it with the same size system as the previous unit. At the neighboring home, an HVAC professional installs a properly sized, mid-SEER or AFUE system after completing a Manual J calculation.
Although the second system has a lesser efficiency rating on paper, it may deliver 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.
Choose the Local HVAC Professional Who Designs Solutions Tailored to Your Home
An HVAC replacement should involve more than selecting the unit with the highest efficiency rating. An ideal system is one that meets your heating and cooling requirements.
At Temp Control of Vero Beach, our knowledgeable technicians perform an HVAC load calculation. We'll evaluate your home's layout and construction, your household's comfort goals and recommend equipment that's properly matched for your home—not simply the largest, most expensive unit or the one with the highest AFUE or SEER2 rating.
Our team will help you identify 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 Temp Control of Vero Beach today. We'll evaluate your home, answer your questions and help you choose the correctly sized efficient system that keeps your family comfortable for years to come.