Shopping for a new air conditioning system or furnace can be stressful. When you're looking to find the best HVAC system for your home, it's natural to focus on models with extremely high efficiency ratings.
After all, the most efficient heating and cooling system provides the most comfort and lowest energy bills, right?
Not necessarily.
Efficiency ratings aren’t the only thing to think about when it comes to new air conditioner installation or installing a new furnace. Although many people focus only on {energy efficiency|efficiency ratings, proper {HVAC system sizing is just as, if not more important for your home's comfort and your utility bills.
Proper sizing also influences humidity control and system longevity. The best HVAC system for your home balances energy efficiency and correct sizing.
In thisguide, 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 experienced HVAC professionals consider both when helping you choose the best HVAC system for your home.
What Does a High SEER Rating Actually Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), shows how efficiently 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 represent real-world operating conditions. Nearly all new air conditioners have a SEER2 efficiency rating, simply because that is the updated rating system for cooling equipment.
Fuel-burning heating system efficiency is measured by an AFUE rating, which stands for Annual Fuel Utilization Efficiency. As with 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.
Even so, high ratings don't necessarily guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on many factors, including the installation quality, the condition of your ductwork, your home's insulation, thermostat settings and, most importantly, proper HVAC system sizing. Even the most efficient system cannot operate at its best if it is too large or too small for the home.
Why HVAC System Size Matters More Than You Probably 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 unit of the same capacity. 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 contractors perform an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation evaluates many factors that impact your home's comfort needs, including:
- Home square footage
- Ceiling height
- Window size and placement
- Home insultation levels
- Drafts and air leakage
- Local climate
- Household occupants
- Heat produced from appliances and lighting
- Ductwork condition
A properly sized air conditioner runs long enough to cool your home consistently while pulling out excess humidity. That means steadier temperatures, better indoor comfort and improved indoor humidity management. Proper sizing also helps the equipment to operate more effciently, reducing excessive wear and tear that can reduce its service life or lead to costly breakdowns.
When HVAC equipment is the right size for your home, you get better comfort and long-lasting performance.
Problems with Oversized and Undersized Systems
You may be tempted to buy the most energy efficient, biggest air conditioner or heating system on the market. In reality, that’s rarely a smart choice.
heating and cooling systems that are bigger than necessary or smaller than your home requires can create indoor comfort challenges, 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 work quickly, but that doesn't mean it delivers the best comfort.
- Short cycling: An oversized HVAC system cycles repeatedly, reducing efficiency and increasing wear and tear.
- Reduced humidity control: Oversized air conditioners cool your home too quickly to remove indoor humidity from the air.
- Hot and cold spots: Some rooms get too cold while others stay too warm.
- More wear and tear: Even though the system works quickly, those constant cycles can cause avoidable breakdowns due to the strain.
Cons Associated with Undersized HVAC Systems
An undersized HVAC system also can struggle:
- Long run times: The system stays on for extended periods trying to reach the desired temperature, which also causes additional wear.
- Trouble reaching the thermostat setting: Your home may never feel as cool as you want during hot weather or always feel chilly in the winter.
- Increased energy consumption: Running almost constantly can increase energy costs.
- Greater strain on very hot or cold days: HVAC systems that are too small can work harder in extreme temperatures, increasing equipment wear and the risk of breakdowns.
Balancing Efficiency and Size
When trying to decide between a high SEER vs right-sized system, don't forget that you don't always need the most efficient model on the market.
Often, a properly sized, mid-efficiency heating and cooling system will outperform an oversized 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.
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 cost more initially than mid-range models but can help reduce long-term energy costs.
- Electricity rates: Areas with more expensive electricity may see greater long-term savings from higher-efficiency units.
- Climate: It's essential your heating or cooling system has adequate capacity to handle areas with very cold winters or intense summer heat.
- Time you plan to 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 offset 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?
Picture two neighboring homes.
In the first, 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 properly sized, moderate-efficiency 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, more effective humidity control and have a longer lifespan because it's correctly matched to the home's needs.
Choose the HVAC Professional Who Designs Solutions Tailored to Your Home
An HVAC replacement should involve much more than selecting a system with the highest efficiency rating. An ideal system is one that meets your household heating and cooling requirements.
At Farnell Mechanical, Inc., our knowledgeable technicians perform an HVAC load calculation. We'll carefully evaluate your home's layout and construction, your household's comfort goals and recommend equipment that's designed specifically for your home—not simply the largest, latest and greatest 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 efficient heating and cooling systems more accessible for all budgets.
Schedule an HVAC consultation online with Farnell Mechanical, Inc. to get started. We'll gladly 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.