Shopping for a new AC or furnace can feel overwhelming. When you're looking to find the best HVAC system for your home, it's natural to look for 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?
Not necessarily.
Efficiency ratings aren’t the only thing to think about when it comes to new air conditioner installation or replacing your furnace. Although many people focus only on {energy efficiency|efficiency ratings, proper {HVAC system sizing is often even more important for your home's comfort and your utility bills.
Proper sizing directly impacts humidity control and lasting performance. The best HVAC system for your home combines energy efficiency and proper sizing.
In thisarticle, we'll explain what an air conditioner's SEER rating or SEER2 rating actually measures, why correct HVAC size is so important and why trusted HVAC experts consider both when recommending 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), measures how efficiently an AC cools your home over a normal cooling season. A SEER2 rating is the current version of SEER, using testing methods that better simulate real-world operating conditions. Nearly all new air conditioners have a SEER2 designation, simply because this rating is the current rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by AFUE, which is for Annual Fuel Utilization Efficiency. Like SEER and SEER2, 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.
However, high ratings don't necessarily guarantee lower utility bills. Actual heating and air conditioner efficiency depends on several key factors, including the way the system is installed, the quality of your ductwork, how much insulation your home has, thermostat settings and, most importantly, system sizing. Even the highest-rated system cannot operate at its best if it is bigger than necessary or smaller than needed for the home.
Why Proper HVAC Sizing Matters More Than You Think
Many assume a larger 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. In reality, new heating system installation or AC replacement should be chosen based on your home's actual heating and cooling needs—not just square footage or the capacity of the old system.
That's why reputable companies complete an HVAC load calculation, also called a Manual J calculation, before recommending replacement equipment. A Manual J calculation considers many details that impact your home's comfort needs, including:
- Total square footage
- Room height
- Window size and direction
- Insulation
- Drafts and air leakage
- Local climate
- Number of occupants
- Heat generated by appliances and lighting
- Air duct condition
A properly sized air conditioner runs long enough to cool your home evenly while eliminating excess humidity. That means more even temperatures, better indoor comfort and improved humidity control. Proper sizing also helps the equipment to operate more effciently, reducing excessive wear and tear that can reduce its service life or lead to more repairs and higher repair costs.
When a furnace or AC is correctly sized, you get improved comfort and more reliable operation.
Problems Caused by Oversized and Undersized Heating and Cooling Systems
Many homeowners are tempted to buy the most energy efficient, largest-capacity air conditioner or heating system on the market. In reality, that's usually not a good investment.
HVAC systems that are bigger than necessary or smaller than your home requires can create indoor comfort challenges, increase operating costs 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 starts and stops often, reducing efficiency and increasing equipment strain.
- Humidity problems: Oversized air conditioners cool your home too quickly to remove excess moisture from the air.
- Inconsistent temperatures: Some rooms feel too cool while others never feel comfortable.
- 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.
Issues Created by Undersized HVAC Systems
An undersized HVAC system also can struggle:
- Continuous operation: The system operates almost continuously trying to reach the thermostat setting, which also causes unnecessary wear and tear.
- Difficulty reaching thermostat settings: Your home may never feel as cool as you want during hot weather or feel too cool during winter.
- Increased energy consumption: Running nonstop can increase utility bills.
- Added strain during extreme weather: HVAC systems that are too small can struggle in extreme temperatures, increasing equipment wear and the chance of failure.
Why You Should Balance HVAC System Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, remember that you don't always need the top-efficiency model on the market.
Often, a properly sized, mid-efficiency HVAC system will deliver better performance than 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 future plans.
When deciding how to choose a new air conditioner or furnace, keep these factors in mind:
- Efficiency savings: Higher-efficiency and right-sized systems can decrease electricity use.
- Initial cost: 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 more expensive electricity may see more significant long-term savings from higher-efficiency units.
- Climate: It's crucial your heating or cooling system has enough capacity to handle areas with extremely cold winters 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 justify the investment.
- Rebates and tax credits: Manufacturer promotions, {utility|equipment rebates and tax credits can lower the overall cost of qualifying equipment.
Real-World Comparison: High Seer vs. Right System Size
What does this look like in the real world?
Imagine two neighboring homes.
At the first home, 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. The other homeowner installs a right-sized, moderate-efficiency system after completing a Manual J calculation.
Even though the second system has a lesser efficiency rating on paper, it may deliver lower operating costs, better home comfort, improved humidity control and have a longer lifespan because it's appropriately sized to the home's needs.
Choose the HVAC Professional Who Designs the Right Solution
An HVAC replacement should involve more than selecting a model with the highest efficiency rating. An ideal system is one that meets your heating and cooling requirements.
At Mechanical Air Systems Co, our experienced professionals perform an HVAC load calculation. We'll carefully evaluate your home's layout and construction, your household's heating and cooling preferences and recommend equipment that's properly matched for your home—not simply the biggest, latest and greatest unit or the one with the highest AFUE or SEER2 rating.
Our HVAC experts 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 Mechanical Air Systems Co to get started. We'll gladly evaluate your home, answer your questions and help you choose the properly sized energy-efficient system that keeps your family comfortable for years to come.