Choosing a new air conditioning system or furnace can be intimidating. If you're trying to find the best HVAC system for your home, it's common to look for models with the highest efficiency ratings.
Surely the most efficient system will provide the most comfort and lowest energy bills, right?
It’s not quite that simple.
Energy efficiency isn't the only thing that matters 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 energy bills.
Proper sizing directly impacts humidity control and system longevity. The best HVAC system for your home delivers energy efficiency and correct sizing.
In thisblog, we'll explain what an air conditioner's SEER rating or SEER2 rating actually measures, why correct HVAC size is so important and why qualified HVAC contractors consider both when helping you select 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), indicates how efficiently a cooling system cools your home over a normal cooling season. A SEER2 rating is the newer version of SEER, using evaluation methods that better represent real-world operating conditions. Today’s new air conditioners have a SEER2 rating, simply because that is the new rating system for cooling equipment.
Fuel-burning heating system efficiency is rated by AFUE, which is short for Annual Fuel Utilization Efficiency. Like cooling efficiency 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.
However, high ratings don't necessarily guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on several key factors, including the quality of the installation, the state of your ductwork, insulation levels, thermostat settings and, most importantly, proper HVAC system sizing. Even the most efficient system cannot perform as intended if it is oversized or smaller than needed for the home.
Why Correct HVAC System Sizing 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 air conditioner replacement should be sized based on your home's actual heating and cooling needs—not just square footage or the size of the previous unit.
That's why reputable companies perform an HVAC load calculation, also called a Manual J calculation, before recommending replacement equipment. A Manual J calculation evaluates many factors that impact your home's comfort needs, including:
- Home square footage
- Room height
- Window size and direction
- Home insultation levels
- Drafts and air leakage
- Regional climate
- Number of occupants
- Heat generated by appliances and lighting
- Air duct condition
A properly sized air conditioner runs through longer cooling cycles 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 strain that can reduce its service life or lead to more repairs and higher repair costs.
When HVAC equipment is correctly sized, you get better comfort and long-lasting performance.
Problems Caused by Oversized and Undersized Systems
You may be tempted to buy the most energy efficient, highest-capacity air conditioner or heating system on the market. The truth is, that's usually not a great idea.
heating and cooling systems that are bigger than necessary or too small can create comfort issues, 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 performs efficiently.
- Short cycling: An oversized HVAC system starts and stops often, reducing efficiency and increasing wear and tear.
- Reduced humidity control: Oversized air conditioners finish cooling cycles too soon to remove enough moisture from the air.
- Inconsistent temperatures: Some rooms get too cold while others stay too warm.
- More 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.
Cons Associated with 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 always feel chilly in the winter.
- Greater energy usage: Running for extended periods can increase energy costs.
- Greater strain on very hot or cold days: HVAC systems that are too small can struggle in extreme temperatures, increasing wear and the risk of breakdowns.
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 automatically need the top-efficiency model on the market.
In many cases, a professionally sized, mid-efficiency HVAC system will provide better results than an overly large premium system because it runs the way it was designed to.
Thebest choice is an energy-efficient HVAC system that's correctly sized for your home, your budget, your climate and your long-term needs.
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.
- Upfront investment: High-efficiency AC and heating systems often have a higher purchase price than mid-range models but can reduce long-term energy costs.
- Local utility costs: Areas with higher utility costs may see greater long-term savings from higher-efficiency units.
- Seasonal weather conditions: It's essential your heating or cooling system has enough capacity to handle areas with very cold winters or extremely hot summers.
- How long you'll 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 offset the investment.
- Rebates and tax credits: Manufacturer promotions, {utility|equipment rebates and tax credits can offset the overall cost of qualifying equipment.
Real-World Example: High Seer vs. Right System Size
How does this work in a real world scenario?
Suppose there are two neighboring homes.
At the first home, the homeowner chooses a premium high-efficiency HVAC system that's too big because the contractor only matched the previous unit. The other homeowner installs a right-sized, mid-SEER or AFUE system after completing a Manual J calculation.
Although the second system has a more modest efficiency rating on paper, it may provide lower operating costs, better home comfort, improved humidity control and have a longer lifespan because it's properly matched to the home's needs.
Choose the HVAC Professional Who Designs the Right Solution
Replacing your HVAC system 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 Air Masters Heating & Cooling, our experienced professionals perform an HVAC load calculation. We'll carefully evaluate your home's size and layout, your household's heating and cooling preferences and recommend equipment that's properly matched for your home—not simply the biggest, most expensive unit or the one with the highest AFUE or SEER2 rating.
Our team will let you know about any available tax rebates and provide information about HVAC financing options that make high-efficiency systems more accessible for all budgets.
Schedule an HVAC consultation online with Air Masters Heating & Cooling to get started. We'll gladly evaluate your home, answer any questions and help you choose the properly sized efficient system that keeps your family comfortable for the long haul.