Choosing a new air conditioning system or furnace can feel overwhelming. When you're looking to find the best HVAC system for your home, it's common to look for models with extremely high efficiency ratings.
Surely 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 you should consider when it comes to new air conditioner installation or installing a new furnace. Although many people focus only on energy efficiency, proper HVAC system sizing is equally, if not more important for your home's comfort and your power bills.
Proper sizing has a major impact on humidity control and lasting performance. The best HVAC system for your home delivers 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 size is so important and why trusted HVAC experts 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 an AC cools your home over a typical cooling season. A SEER2 rating is the newer version of SEER, using testing methods that better represent real-world operating conditions. Most new air conditioners have a SEER2 rating, simply because this is the updated rating system for cooling equipment.
Fuel-burning heating system efficiency is rated by something called AFUE, which stands for Annual Fuel Utilization Efficiency. Like SEER and SEER2, higher AFUE ratings indicate a high-efficiency HVAC system that uses less electricity to heat your home than lower-rated systems under standardized laboratory testing.
However, high ratings don't automatically guarantee lower utility bills. Everyday heating and air conditioner efficiency depends on more than just efficiency ratings, 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 bigger than necessary or too small for the home.
Why Proper HVAC Sizing Matters More Than You Probably Think
Many assume a bigger air conditioner or furnace will heat or cool a home better or that they should simply replace their old HVAC system with a new one the same size. Actually, new heating system installation or AC replacement should be chosen based on your home's actual heating and cooling needs—not just square footage or the size of your existing equipment.
That's why reputable technicians perform an HVAC load calculation, also called a Manual J calculation, before selecting replacement equipment. A Manual J calculation evaluates many variables that impact your home's comfort needs, including:
- Total square footage
- Ceiling height
- Window size and direction
- Insulation
- Air leakage
- Local climate
- Number of occupants
- Heat produced from appliances and lighting
- Air duct condition
A properly sized air conditioner runs for enough time to cool your home more uniformly while eliminating excess humidity. That means steadier temperatures, better indoor comfort and improved indoor humidity management. Proper sizing also helps the equipment to run more effciently, reducing unnecessary wear that can reduce its service life or lead to costly breakdowns.
When a furnace or AC is properly sized, you get greater comfort and more reliable operation.
Problems with Oversized and Undersized HVAC Equipment
Many homeowners are tempted to buy the most energy efficient, highest-capacity air conditioner or heating system on the market. The truth is, that often isn't a smart choice.
HVAC systems that are bigger than your home needs or too small can create comfort issues, increase energy expenses and reduce efficiency regardless of their SEER rating.
Issues Created by Oversized HVAC Systems
An oversized air conditioner or heating system may heat or cool rapidly, but that doesn't mean it delivers the best comfort.
- Short cycling: An oversized HVAC system starts and stops often, reducing efficiency and increasing equipment strain.
- Humidity problems: Oversized air conditioners cool your home too quickly to remove excess moisture from the air.
- Uneven temperatures: Some rooms become too cold while others stay too warm.
- Additional equipment wear: 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:
- Long run times: The system operates almost continuously trying to reach the set temperature, which also causes extra strain.
- Difficulty maintaining the desired temperature: Your home may never feel as cool as you want during hot weather or feel too cool during winter.
- Increased energy consumption: Running almost constantly can increase monthly energy expenses.
- Added strain during extreme weather: HVAC systems that are too small can work harder in extreme temperatures, increasing equipment wear and the likelihood of repairs.
Balancing Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, keep in mind that you don't necessarily need the most efficient model on the market.
In many cases, a properly sized, mid-efficiency heating and cooling system will outperform an overly large premium system because it functions 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 needs.
As you consider how to choose a new air conditioner or furnace, consider:
- Lower energy costs: 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 lower long-term energy costs.
- Local utility costs: Areas with more expensive electricity may see more significant long-term savings from higher-efficiency units.
- Climate: It's important your heating or cooling system has enough capacity to handle areas with very cold winters or extremely hot summers.
- Length of home ownership: If you expect to live in your home for many years, the long-term energy savings of a higher-efficiency unit may justify the investment.
- Financial incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can lower the overall cost of higher-efficiency systems.
Real-World Situation: High Seer vs. Right System Size
What does this look like in the real world?
Suppose there are two neighboring homes.
In the first, the homeowner chooses a premium high-efficiency HVAC system that's too big for the house because the contractor simply matched the previous unit. At the neighboring home, an HVAC professional installs a properly sized, mid-efficiency system after completing a Manual J calculation.
Although the second system has a lower efficiency rating on paper, it may deliver 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.
Work With an HVAC Professional Who Designs Solutions Tailored to Your Home
An HVAC replacement should involve more than selecting a model with the highest efficiency rating. The right system is one that meets your household heating and cooling requirements.
At Pure Comfort Heating and Air Conditioning, our knowledgeable technicians perform an HVAC load calculation. We'll 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 largest, fanciest unit or the one with the highest AFUE or SEER2 rating.
Our HVAC experts will connect you with 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 Pure Comfort Heating and Air Conditioning to get started. We'll evaluate your home, answer any questions and help you choose the properly sized efficient system that keeps your family comfortable for many years.