Shopping for a new air conditioner or furnace can be stressful. If you're trying to find the best HVAC system for your home, it's common to look for models with the highest efficiency ratings.
Surely the most efficient heating and cooling system provides the most comfort and lowest energy bills, right?
Not necessarily.
Energy efficiency isn't the only thing you should consider when it comes to new air conditioner installation or replacing your furnace. Although many people focus only on efficiency ratings, proper HVAC system sizing is just as, if not more important for your home's comfort and your utility bills.
Proper sizing directly impacts humidity control and long-term reliability. The best HVAC system for your home delivers energy efficiency and correct sizing.
In this article, 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 helping you choose the best HVAC system for your home.
High Seer Ratings: What Do They Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), shows how effectively an AC cools your home over a normal cooling season. A SEER2 rating is the newer version of SEER, using evaluation methods that better represent real-world operating conditions. Most new air conditioners have a SEER2 rating, simply because that is the updated rating system for cooling equipment.
Fuel-burning heating system efficiency is rated by something called AFUE, which is for Annual Fuel Utilization Efficiency. Like SEER and SEER2, 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. 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 highest-rated system cannot perform as intended if it is bigger than necessary or undersized for the home.
Why Correct HVAC System Sizing Matters More Than You 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 new one the same size. The truth is, new heating system installation or a new air conditioner should be selected based on your home's true heating and cooling needs—not just square footage or the capacity of the old system.
That's why reputable technicians complete an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation considers many factors that affect your home's comfort needs, including:
- Overall square footage
- Ceiling height
- Window size and orientation
- Insulation
- Air leakage
- Local climate
- Household occupants
- Heat produced from appliances and lighting
- Ductwork condition
A properly sized air conditioner runs for enough time to cool your home evenly while removing excess humidity. That means more even temperatures, better indoor comfort and improved moisture control. It also helps the equipment to operate more effciently, reducing excessive wear and tear that can cause it to wear it out sooner or lead to more repairs and higher repair costs.
When your heating or cooling system is correctly sized, you get better comfort and more reliable operation.
Problems Caused by Oversized and Undersized Heating and Cooling Systems
You may be tempted to buy the most energy efficient, largest-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 necessary or undersized can create indoor comfort challenges, increase utility costs and reduce efficiency regardless of their SEER rating.
Drawbacks of 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 starts and stops often, reducing efficiency and increasing equipment strain.
- Humidity problems: Oversized air conditioners cool your home too quickly to remove indoor humidity from the air.
- Uneven temperatures: Some rooms feel too cool while others stay too warm.
- More wear and tear: Even though the system heats or cools your home fast, those constant cycles can cause avoidable breakdowns due to the strain.
Drawbacks of Undersized HVAC Systems
An undersized HVAC system has a different set of problems:
- Continuous operation: The system operates almost continuously trying to reach the set temperature, which also causes additional wear.
- Difficulty reaching thermostat settings: Your home may feel cool enough during hot weather or always feel chilly in the winter.
- Greater energy usage: 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.
Why You Should Balance HVAC System Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, keep in mind that you don't automatically need the highest-efficiency model on the market.
Often, a professionally sized, mid-efficiency heating and cooling system will deliver better performance than an oversized premium system because it operates the way it was designed to.
Theideal choice is an energy-efficient HVAC system that's matched for your home, your budget, your climate and your long-term needs.
As you think about how to choose a new air conditioner or furnace, consider:
- Energy savings: Higher-efficiency and right-sized systems can decrease electricity use.
- Purchase price: High-efficiency AC and heating systems often cost more initially than mid-range models but can reduce long-term energy costs.
- Local utility costs: 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 the right capacity to handle areas with extremely cold winters or extremely hot summers.
- 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 be worth the investment.
- Financial incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can reduce the overall cost of high-efficiency HVAC equipment.
Real-World Comparison: High Seer vs. Right System Size
How does this play out in a real world example?
Suppose there are two neighboring homes.
In one, the homeowner chooses a premium high-efficiency HVAC system that's too big 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 last longer because it's correctly matched to the home's needs.
Choose the Local HVAC Professional Who Designs Solutions Tailored to Your Home
HVAC replacent or installation should involve more than selecting a model with the top efficiency rating. An ideal system is one that meets your home’s heating and cooling requirements.
At Integrity AC & Heating LLC, our skilled HVAC experts perform an HVAC load calculation. Our team will evaluate your home's design, your household's heating and cooling preferences and recommend equipment that's properly matched for your home—not simply the largest, latest and greatest unit or the one with the highest AFUE or SEER2 rating.
Our heating and cooling specialists will let you know about 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 Integrity AC & Heating LLC now. We'll gladly evaluate your home, answer your questions and help you choose the properly sized energy-efficient system that keeps your family comfortable for many years.
