Shopping for a new AC or furnace can be intimidating. If you're trying 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 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 replacing your furnace. Even though many focus only on {energy efficiency|efficiency ratings, proper {HVAC system sizing is equally, if not more important for your home's comfort and your energy bills.
Proper sizing also influences humidity control and lasting performance. The best HVAC system for your home balances energy efficiency and correct sizing.
In thisblog, we'll explain what an air conditioner's SEER rating or SEER2 rating actually measures, why proper HVAC system size is so important and why trusted HVAC experts 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), indicates how effectively a cooling system cools your home over a typical cooling season. A SEER2 rating is the current version of SEER, using evaluation methods that better simulate real-world operating conditions. Nearly all new air conditioners have a SEER2 designation, simply because this rating is the updated 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 achieve indoor comfort than lower-rated systems under standardized laboratory testing.
Even so, high ratings don't automatically guarantee lower utility bills. Actual heating and air conditioner efficiency depends on many factors, including the installation quality, the state of your ductwork, insulation levels, thermostat settings and, most importantly, proper HVAC system sizing. Even the highest-efficiency system cannot operate at its best if it is bigger than necessary or too small for the home.
Why Proper HVAC Sizing Matters More Than Most Homeowners Realize
Many assume a higher-capacity air conditioner or furnace will heat or cool a home better or that they should just replace their old HVAC system with a same-sized replacement. Actually, new heating system installation or AC replacement should be chosen 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 companies complete an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation analyzes many details that impact your home's heating and cooling requirements, including:
- Home square footage
- Ceiling height
- Window size and orientation
- Home insultation levels
- Air leakage
- Regional climate
- Number of occupants
- Heat generated by 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 consistent temperatures, better indoor comfort and improved humidity control. This also allows the equipment to run more effciently, reducing strain that can reduce its service life or lead to costly breakdowns.
When a furnace or AC is the right size for your home, you get greater comfort and more reliable operation.
Problems with Oversized and Undersized HVAC Equipment
It might be tempting to buy the most energy efficient, biggest 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 too small can create comfort issues, increase energy expenses 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 delivers the best comfort.
- Short cycling: An oversized HVAC system starts and stops often, reducing efficiency and increasing wear.
- Poor humidity removal: Oversized air conditioners reach the set temperature too fast to remove indoor humidity from the air.
- Uneven temperatures: Some rooms feel too cool while others never feel comfortable.
- Increased wear and tear: Even though the system reaches the target temperature rapidly, those repeated on-and-off cycles can cause avoidable breakdowns due to the strain.
Issues Created by Undersized HVAC Systems
An undersized HVAC system has a different set of problems:
- Continuous operation: The system runs for long periods trying to reach the thermostat setting, which also causes additional wear.
- Trouble reaching the thermostat setting: 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 utility bills.
- Greater strain on very hot or cold days: HVAC systems that are too small can work harder in extreme temperatures, increasing component strain and the likelihood of repairs.
Balancing Efficiency and Size
When trying to decide between a high SEER vs right-sized system, don't forget that you don't necessarily need the most efficient model on the market.
More often than not, a properly sized, mid-efficiency heating and cooling system will deliver better performance than an oversized premium system because it functions the way it was designed to.
Theideal choice is an energy-efficient HVAC system that's correctly sized for your home, your budget, your climate and your long-term needs.
When deciding how to choose a new air conditioner or furnace, consider:
- Energy savings: Higher-efficiency and right-sized systems can decrease electricity use.
- Upfront investment: High-efficiency AC and heating systems often cost more initially than mid-range models but can reduce long-term energy costs.
- Energy prices: Areas with higher utility costs may see greater long-term savings from higher-efficiency units.
- Your local climate: It's crucial your heating or cooling system has adequate capacity to handle areas with harsh winter weather or intense summer heat.
- 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 be worth the investment.
- Rebates and tax credits: Manufacturer promotions, {utility|equipment rebates and tax credits can reduce the overall cost of higher-efficiency systems.
Real-World Example: High Seer vs. Right System Size
How does this work in the real world?
Suppose there are two neighboring homes.
In one, the homeowner chooses a premium high-efficiency HVAC system that's too big for the house because the contractor replaced it with the same size system as the previous unit. Next door, the second homeowner installs a right-sized, mid-SEER or AFUE system after completing a Manual J calculation.
Although the second system has a lower 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 Local HVAC Professional Who Designs Solutions Tailored to Your Home
HVAC replacent or installation should involve much more than selecting a system with the highest efficiency rating. The best system is one that meets your home’s heating and cooling requirements.
At MPC Heating & Cooling, our experienced professionals perform an HVAC load calculation. We'll evaluate your home's size and layout, your household's comfort needs and recommend equipment that's right for your home—not simply the highest-capacity, 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 MPC Heating & Cooling today. Our team will evaluate your home, answer any questions and help you choose the properly sized energy-efficient system that keeps your family comfortable for years to come.