Shopping for a new AC or furnace can be stressful. 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.
Surely the most efficient equipment provides the most comfort and lowest energy bills, right?
It’s not quite that simple.
High efficiency isn't the only thing that matters when it comes to new air conditioner installation or furnace replacement. 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 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 helping you select the best HVAC system for your home.
High Seer Ratings: What Do They Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), measures how efficiently a cooling system cools your home over a normal cooling season. A SEER2 rating is the current version of SEER, using testing methods that better reflect real-world operating conditions. Most new air conditioners have a SEER2 rating, simply because this rating is the current rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by something called AFUE, which is short 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.
That said, high numbers don't automatically guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on several key factors, including the way the system is installed, the condition of your ductwork, how much insulation your home has, thermostat settings and, most importantly, proper HVAC system sizing. Even the highest-efficiency system cannot deliver peak performance if it is oversized or too small for the home.
Why HVAC System Size Matters More Than Most Homeowners Realize
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 air conditioner replacement should be sized based on your home's true 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 selecting replacement equipment. A Manual J calculation considers many details that impact your home's heating and cooling load, including:
- Home square footage
- Room height
- Window size and direction
- Insulation
- Air infiltration
- Area climate
- Household 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 consistent temperatures, better indoor comfort and improved humidity control. Proper sizing also helps the equipment to operate more effciently, reducing unnecessary wear that can cause it to wear it out sooner or lead to costly breakdowns.
When your heating or cooling system is properly sized, 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, highest-capacity air conditioner or heating system on the market. In reality, that’s rarely a smart choice.
HVAC systems that are bigger than your home needs or smaller than your home requires can create comfort problems, increase operating costs and reduce efficiency regardless of their SEER rating.
Drawbacks of Oversized HVAC Systems
An oversized air conditioner or heating system may heat or cool rapidly, but that doesn't mean it works well.
- Short cycling: An oversized HVAC system turns on and off frequently, reducing efficiency and increasing wear and tear.
- High indoor humidity: Oversized air conditioners finish cooling cycles too soon to remove enough moisture from the air.
- Hot and cold spots: Some rooms get too cold while others aren’t ever cool enough.
- Increased wear and tear: Even though the system works quickly, those repeated on-and-off cycles can cause avoidable breakdowns due to the strain.
Cons Associated with Undersized HVAC Systems
An undersized HVAC system has a different set of problems:
- Continuous operation: The system stays on for extended periods trying to reach the desired temperature, which also causes additional wear.
- Difficulty maintaining the desired temperature: Your home may not feel comfortable during hot weather or always feel chilly in the winter.
- Higher energy use: Running almost constantly can increase monthly energy expenses.
- Extra stress during severe weather: HVAC systems that are too small can struggle in extreme temperatures, increasing component strain and the risk of breakdowns.
Balancing Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, remember that you don't necessarily need the highest-efficiency model on the market.
More often than not, a professionally sized, mid-efficiency heating and cooling 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 properly sized for your home, your budget, your climate and your future plans.
When deciding how to choose a new air conditioner or furnace, think about:
- Energy savings: Higher-efficiency and right-sized systems can reduce electricity use.
- Initial cost: High-efficiency AC and heating systems often require a larger upfront investment than mid-range models but can lower 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 crucial your heating or cooling system has the right capacity to handle areas with very cold winters or intense summer heat.
- 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 offset the investment.
- Available rebates or tax incentives: 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 play out in a real world scenario?
Imagine two neighboring homes.
At the first home, the homeowner chooses a premium high-efficiency HVAC system that's too big because the contractor simply matched the previous unit. The other homeowner installs a properly sized, mid-efficiency system after completing a Manual J calculation.
While 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 properly matched to the home's needs.
Work With an HVAC Professional Who Designs the Right Solution
HVAC replacent or installation should involve more than selecting a system with the top efficiency rating. An ideal system is one that meets your heating and cooling requirements.
At Prudhom Mechanical, our experienced professionals perform an HVAC load calculation. We'll evaluate your home's design, your household's comfort goals and recommend equipment that's designed specifically for your home—not simply the highest-capacity, most expensive unit or the one with the highest AFUE or SEER2 rating.
Our HVAC experts will let you know about any available tax rebates and provide information about HVAC financing options that make energy-efficient HVAC systems more accessible for all budgets.
Schedule an HVAC consultation online with Prudhom Mechanical now. We'll gladly evaluate your home, answer any questions and help you choose the right-sized high-efficiency system that keeps your family comfortable for the long haul.