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 understandable to focus on models with extremely high efficiency ratings.
Surely the most efficient equipment should deliver the most comfort and lowest energy bills, right?
Actually, that’s not always the case.
High efficiency isn't the only thing that matters when it comes to new air conditioner installation or replacing your furnace. Even though many focus only on efficiency ratings, proper HVAC system sizing is just as, if not more important for your home's comfort and your power bills.
Proper sizing directly impacts humidity control and long-term reliability. The best HVAC system for your home combines energy efficiency and proper 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 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), measures how effectively a cooling system cools your home over a standard cooling season. A SEER2 rating is the newer version of SEER, using testing methods that better simulate real-world operating conditions. Nearly all new air conditioners have a SEER2 efficiency rating, simply because this is the current rating system for cooling equipment.
Fuel-burning heating system efficiency is rated by an AFUE rating, which is 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.
Even so, high numbers don't necessarily guarantee lower utility bills. Actual heating and air conditioner efficiency depends on many factors, including the quality of the installation, the condition of your ductwork, your home's insulation, thermostat settings and, most importantly, HVAC system sizing. Even the most efficient system cannot operate at its best if it is bigger than necessary or undersized for the home.
Why HVAC System Size Matters More Than You Think
Many assume a larger 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 selected 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 selecting replacement equipment. A Manual J calculation evaluates many factors that affect your home's comfort needs, including:
- Overall square footage
- Room height
- Window size and direction
- Home insultation levels
- Drafts and air leakage
- Local 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 pulling out excess humidity. That means more consistent temperatures, better indoor comfort and improved indoor humidity management. This also allows the equipment to perform 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 Heating and Cooling Systems
You may be tempted to buy the most energy efficient, largest-capacity air conditioner or heating system on the market. In reality, that often isn't a smart choice.
heating and cooling systems that are too large or undersized can create comfort problems, increase utility costs and reduce efficiency regardless of their SEER rating.
Drawbacks of Oversized HVAC Systems
An oversized air conditioner or heating system may work quickly, but that doesn't mean it works well.
- Short cycling: An oversized HVAC system cycles repeatedly, reducing efficiency and increasing equipment strain.
- Reduced humidity control: Oversized air conditioners cool your home too quickly to remove indoor humidity from the air.
- Uneven temperatures: Some rooms feel too cool while others stay too warm.
- Increased wear and tear: Even though the system heats or cools your home fast, those repeated on-and-off cycles 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 stays on for extended 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 feel too cool during winter.
- Higher energy use: Running almost constantly can increase monthly energy expenses.
- Extra stress during severe weather: HVAC systems that are too small can run extremely hard in extreme temperatures, increasing wear and the risk of breakdowns.
Balancing Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, keep in mind that you don't automatically need the most efficient model on the market.
Often, a professionally sized, mid-efficiency heating and cooling system will outperform an oversized premium system because it operates the way it was designed to.
Thesmartest choice is an energy-efficient HVAC system that's matched 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 require a larger upfront investment than mid-range models but can reduce long-term energy costs.
- Local utility costs: Areas with more expensive electricity may see greater long-term savings from higher-efficiency units.
- Your local climate: It's crucial your heating or cooling system has enough capacity to handle areas with extremely cold winters or extremely hot summers.
- Time you plan to 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 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 Comparison: High Seer vs. Right System Size
How does this play out in a real world example?
Suppose there are two neighboring homes.
In one, the homeowner chooses a premium high-efficiency HVAC system has far more capacity than the home needs because the contractor simply matched the previous unit. The other homeowner installs a correctly sized, mid-SEER or AFUE system after completing a Manual J calculation.
While the second system has a more modest efficiency rating on paper, it may provide lower operating costs, better home comfort, improved humidity control and last longer because it's properly matched to the home's needs.
Choose the Local HVAC Professional Who Designs Solutions Tailored to Your Home
HVAC replacent or installation should involve more than selecting the unit with the top efficiency rating. An ideal system is one that meets your home’s heating and cooling requirements.
At Farnell Heating & Air Conditioning Inc, our skilled HVAC experts perform an HVAC load calculation. Our team will evaluate your home's layout and construction, your household's comfort needs 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 let you know about any available rebates or tax incentives 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 Farnell Heating & Air Conditioning Inc to get started. We'll evaluate your home, answer any questions and help you choose the correctly sized high-efficiency system that keeps your family comfortable for the long haul.