Shopping for a new air conditioner or furnace can feel overwhelming. If you want to find the best HVAC system for your home, it's common to focus on models with extremely high efficiency ratings.
After all, the most efficient equipment will provide the most comfort and lowest energy bills, right?
Not necessarily.
High efficiency isn't the only thing that matters when it comes to new air conditioner installation or replacing your furnace. While many homeowners focus only on energy efficiency, proper HVAC system sizing is equally, if not more important for your home's comfort and your utility bills.
Proper sizing has a major impact on humidity control and long-term reliability. The best HVAC system for your home combines efficiency and correct sizing.
In this guide, we'll explain what an air conditioner's SEER rating or SEER2 rating actually measures, why proper HVAC system size is so important and why qualified HVAC contractors consider both when recommending 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 an AC cools your home over a standard cooling season. A SEER2 rating is the newer 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 updated rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by an AFUE rating, which is for Annual Fuel Utilization Efficiency. Like 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 ratings don't automatically guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on several key factors, including the installation quality, the quality of your ductwork, insulation levels, thermostat settings and, most importantly, proper HVAC system sizing. Even the highest-rated system cannot operate at its best if it is too large or too small for the home.
Why Correct HVAC System Sizing Matters More Than You Probably Think
Many assume a higher-capacity air conditioner or furnace will make their home the most comfortable or that they should simply replace their old HVAC system with a unit of the same capacity. In reality, new heating system installation or a new air conditioner 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 suggesting replacement equipment. A Manual J calculation evaluates many factors that impact your home's comfort needs, including:
- Total square footage
- Room height
- Window size and placement
- Insulation
- Air leakage
- Regional climate
- Number of occupants
- Heat produced from appliances and lighting
- Air duct condition
A properly sized air conditioner runs long enough to cool your home evenly while eliminating excess humidity. That means more even temperatures, better indoor comfort and improved humidity control. It also helps the equipment to perform more effciently, reducing unnecessary wear that can shorten its lifespan or lead to costly breakdowns.
When your heating or cooling system is correctly sized, you get better comfort and long-lasting performance.
Problems Caused by Oversized and Undersized Heating and Cooling Systems
Many homeowners are tempted to buy the most energy efficient, biggest air conditioner or heating system on the market. However, that's usually not a good investment.
heating and cooling systems that are bigger than necessary or undersized can create indoor comfort challenges, increase operating costs and reduce efficiency regardless of their SEER rating.
Common Problems With Oversized HVAC Systems
An oversized air conditioner or heating system may heat or cool rapidly, but that doesn't mean it performs efficiently.
- Short cycling: An oversized HVAC system turns on and off frequently, reducing efficiency and increasing wear and tear.
- Humidity problems: Oversized air conditioners reach the set temperature too fast to remove indoor humidity from the air.
- Hot and cold spots: Some rooms become too cold while others stay too warm.
- Increased 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.
Drawbacks of Undersized HVAC Systems
An undersized HVAC system also can struggle:
- Continuous operation: 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 feel too cool during winter.
- Increased energy consumption: 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 equipment wear and the likelihood of repairs.
Balancing Efficiency and Size
When trying to decide between a high SEER vs right-sized system, remember that you don't necessarily need the most efficient 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 operates the way it was designed to.
Thesmartest choice is an energy-efficient HVAC system that's matched for your home, your budget, your climate and your future plans.
When deciding how to choose a new air conditioner or furnace, consider:
- Efficiency savings: Higher-efficiency and right-sized systems can decrease 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.
- Local utility costs: Areas with higher utility costs may see more significant long-term savings from higher-efficiency units.
- Climate: It's essential your heating or cooling system has the right capacity to handle areas with very cold winters or intense summer heat.
- Length of home ownership: 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 Comparison: High Seer vs. Right System Size
What does this look like in a real world example?
Imagine two neighboring homes.
In one, 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 right-sized, moderate-efficiency system after completing a Manual J calculation.
Even though the second system has a more modest efficiency rating on paper, it may deliver lower operating costs, better home comfort, improved humidity control and have a longer lifespan because it's appropriately sized to the home's needs.
Choose the HVAC Professional Who Designs Solutions Tailored to Your Home
HVAC replacent or installation should involve much more than selecting a model with the top efficiency rating. The right system is one that meets your home’s heating and cooling requirements.
At Jet Electrical, Air Conditioning, Heating & Plumbing, our skilled HVAC experts perform an HVAC load calculation. We'll carefully evaluate your home's size and layout, your household's comfort needs 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 or 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 Jet Electrical, Air Conditioning, Heating & Plumbing now. Our team will 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.