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 understandable to focus on models with the highest efficiency ratings.
Surely the most efficient heating and cooling system will provide the most comfort and lowest energy bills, right?
Not necessarily.
High efficiency isn't the only thing you should consider when it comes to new air conditioner installation or furnace replacement. Even though many focus only on efficiency ratings, proper HVAC system sizing is equally, if not more important for your home's comfort and your power bills.
Proper sizing also influences humidity control and lasting performance. The best HVAC system for your home balances energy efficiency and proper sizing.
In this blog, 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 normal cooling season. A SEER2 rating is the updated version of SEER, using testing methods that better simulate real-world operating conditions. Today’s new air conditioners have a SEER2 designation, simply because this rating is the new rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by AFUE, which is for Annual Fuel Utilization Efficiency. As with SEER and SEER2 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 numbers don't necessarily guarantee lower utility bills. Everyday heating and air conditioner efficiency depends on several key factors, including the quality of the installation, the condition of your ductwork, how much insulation your home has, thermostat settings and, most importantly, HVAC system sizing. Even the highest-efficiency system cannot operate at its best if it is oversized or undersized for the home.
Why Correct HVAC System Sizing Matters More Than You Probably Think
Many assume a higher-capacity air conditioner or furnace will work the best 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 chosen 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 conduct an HVAC load calculation, also called a Manual J calculation, before recommending replacement equipment. A Manual J calculation evaluates many details that impact your home's comfort needs, including:
- Total square footage
- Ceiling height
- Window size and orientation
- Home insultation levels
- 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 eliminating excess humidity. That means steadier temperatures, better indoor comfort and improved humidity control. It also helps the equipment to operate more effciently, reducing strain that can reduce its service life or lead to frequent or expensive repairs.
When your heating or cooling system is correctly sized, you get better comfort and long-lasting performance.
Problems with Oversized and Undersized HVAC Equipment
Many homeowners are tempted to buy the most energy efficient, biggest air conditioner or heating system on the market. In reality, that's usually not a good investment.
HVAC systems that are too large or undersized can create comfort issues, increase operating costs and reduce efficiency regardless of their SEER rating.
Issues Created by 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 cycles repeatedly, reducing efficiency and increasing wear.
- Humidity problems: Oversized air conditioners cool your home too quickly to remove excess moisture from the air.
- Uneven temperatures: Some rooms feel too cool while others stay too warm.
- More wear and tear: Even though the system reaches the target temperature rapidly, those frequent starts and stops can cause avoidable breakdowns due to the strain.
Issues Created by Undersized HVAC Systems
An undersized HVAC system can have the opposite problem:
- 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 not feel comfortable during hot weather or always feel chilly in the winter.
- Higher energy use: Running for extended periods can increase utility bills.
- Greater strain on very hot or cold days: HVAC systems that are too small can run extremely hard in extreme temperatures, increasing wear and the chance of failure.
Why You Should Balance HVAC System Efficiency and Size
When trying to decide between a high SEER vs right-sized system, don't forget that you don't necessarily need the top-efficiency model on the market.
In many cases, a professionally sized, mid-efficiency heating and cooling system will outperform an overly large premium system because it operates 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 future plans.
As you think about how to choose a new air conditioner or furnace, consider:
- Energy savings: Higher-efficiency and right-sized systems can reduce electricity use.
- Upfront investment: High-efficiency AC and heating systems often cost more initially than mid-range models but can help reduce long-term energy costs.
- Energy prices: Areas with higher utility costs may see better long-term savings from higher-efficiency units.
- Seasonal weather conditions: It's important your heating or cooling system has adequate capacity to handle areas with extremely cold winters 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 high-efficiency HVAC equipment.
Real-World Example: High Seer vs. Right System Size
How does this work in a real world scenario?
Picture two neighboring homes.
At the first home, the homeowner chooses a premium high-efficiency HVAC system that's too big for the house because the contractor replaced it with the same size system as the previous unit. Next door, the second homeowner installs a properly sized, moderate-efficiency system after completing a Manual J calculation.
Although the second system has a lesser efficiency rating on paper, it may deliver lower operating costs, better home comfort, improved humidity control and last longer because it's correctly matched to the home's needs.
Choose the HVAC Professional Who Designs the Right Solution
Replacing your HVAC system should involve much more than selecting the unit with the top efficiency rating. The right system is one that meets your household heating and cooling requirements.
At Struven Heating & Cooling, 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 designed specifically 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 or tax incentives and provide information about HVAC financing options that make energy-efficient HVAC systems more accessible for all budgets.
Schedule an HVAC consultation online with Struven Heating & Cooling today. We'll evaluate your home, answer your questions and help you choose the right-sized energy-efficient system that keeps your family comfortable for years to come.
