Shopping for a new air conditioner or furnace can feel overwhelming. If you're trying to find the best HVAC system for your home, it's understandable to focus on models with the highest efficiency ratings.
After all, the most efficient system will provide the most comfort and lowest energy bills, right?
Not necessarily.
Energy efficiency isn'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 often even more important for your home's comfort and your power bills.
Proper sizing directly impacts humidity control and system longevity. The best HVAC system for your home combines efficiency and correct sizing.
In thisarticle, 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 qualified HVAC contractors consider both when helping you choose the best HVAC system for your home.
High Seer Ratings: What Do They Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), measures how effectively an air conditioner cools your home over a normal cooling season. A SEER2 rating is the updated version of SEER, using evaluation methods that better simulate 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 evaluated by AFUE, which stands for Annual Fuel Utilization Efficiency. Similar to SEER and SEER2 ratings, 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 numbers don't by themselves guarantee lower utility bills. Actual heating and air conditioner efficiency depends on many factors, including the installation quality, the state of your ductwork, your home's insulation, thermostat settings and, most importantly, proper HVAC system sizing. Even the highest-rated system cannot perform as intended if it is too large or too small for the home.
Why Proper HVAC Sizing Matters More Than You Probably Think
Many assume a higher-capacity air conditioner or furnace will work the best or that they should simply replace their old HVAC system with a new one the same size. The truth is, 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 the previous unit.
That's why reputable technicians perform an HVAC load calculation, also called a Manual J calculation, before selecting replacement equipment. A Manual J calculation considers many factors that impact your home's heating and cooling requirements, including:
- Home square footage
- Ceiling height
- Window size and placement
- Insulation
- Air leakage
- Regional climate
- Household occupants
- Heat generated by appliances and lighting
- Ductwork condition
A properly sized air conditioner runs long enough to cool your home consistently while removing excess humidity. That means more even temperatures, better indoor comfort and improved moisture control. It also helps the equipment to run more effciently, reducing excessive wear and tear that can shorten its lifespan or lead to frequent or expensive repairs.
When your heating or cooling system is properly sized, you get better comfort and more reliable operation.
Problems with Oversized and Undersized HVAC Equipment
It might be tempting to buy the most energy efficient, largest-capacity air conditioner or heating system on the market. The truth is, that often isn't a great idea.
HVAC systems that are bigger than your home needs or undersized can create comfort problems, increase energy expenses 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 performs efficiently.
- Short cycling: An oversized HVAC system turns on and off frequently, reducing efficiency and increasing equipment strain.
- Humidity problems: Oversized air conditioners reach the set temperature too fast to remove enough moisture from the air.
- Hot and cold spots: Some rooms get too cold while others stay too warm.
- Increased wear and tear: Even though the system works quickly, those constant 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:
- Long run times: The system operates almost continuously trying to reach the set temperature, which also causes extra strain.
- Trouble reaching the thermostat setting: Your home may not feel comfortable during hot weather or never feel warm enough in cold weather.
- Increased energy consumption: Running for extended periods can increase utility bills.
- Extra stress during severe weather: HVAC systems that are too small can run extremely hard in extreme temperatures, increasing component strain and the likelihood of repairs.
Finding the Right Balance Between Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, keep in mind that you don't always need the top-efficiency model on the market.
In many cases, a correctly sized, mid-efficiency heating and cooling system will deliver better performance than an overly large premium system because it runs 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 goals.
As you consider how to choose a new air conditioner or furnace, keep these factors in mind:
- Efficiency savings: 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.
- Electricity rates: Areas with more expensive electricity may see more significant long-term savings from higher-efficiency units.
- Your local climate: It's crucial your heating or cooling system has the right capacity to handle areas with harsh winter weather or very hot summers.
- How long you'll 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 justify the investment.
- Available rebates or tax incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can lower the overall cost of qualifying equipment.
Real-World Situation: 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 for the house because the contractor only matched the previous unit. At the neighboring home, an HVAC professional installs a properly sized, mid-efficiency system after completing a Manual J calculation.
While the second system has a more modest efficiency rating on paper, it may deliver lower operating costs, better home comfort, improved humidity control and last longer because it's appropriately sized to the home's needs.
Choose the Local HVAC Professional Who Designs Personalized Solutions
An HVAC replacement should involve much more than selecting a model with the highest efficiency rating. The best system is one that meets your household heating and cooling requirements.
At Ohler & Holzhauer Inc., our knowledgeable technicians 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 right for your home—not simply the highest-capacity, fanciest unit or the one with the highest AFUE or SEER2 rating.
Our HVAC experts will let you know about any available rebates and 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 Ohler & Holzhauer Inc. today. We'll evaluate your home, answer your questions and help you choose the correctly sized efficient system that keeps your family comfortable for many years.