Shopping for 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 natural to focus on models with the highest efficiency ratings.
After all, the most efficient heating and cooling system will provide the most comfort and lowest energy bills, right?
Actually, that’s not always the case.
Energy efficiency isn't the only thing to think about when it comes to new air conditioner installation or replacing your furnace. Even though many focus only on energy efficiency, 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 system longevity. The best HVAC system for your home delivers efficiency and proper 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 select the best HVAC system for your home.
What Does a High SEER Rating Actually Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), measures how efficiently an AC cools your home over a standard cooling season. A SEER2 rating is the current version of SEER, using testing methods that better simulate 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 evaluated by an AFUE rating, which stands for Annual Fuel Utilization Efficiency. Similar to 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.
Even so, high ratings don't by themselves guarantee lower utility bills. Actual heating and air conditioner efficiency depends on several key factors, including the quality of the installation, the condition of your ductwork, insulation levels, thermostat settings and, most importantly, system sizing. Even the highest-rated system cannot perform as intended if it is too large or smaller than needed for the home.
Why Correct HVAC System Sizing 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 simply replace their old HVAC system with a same-sized replacement. Actually, new heating system installation or AC replacement should be chosen 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 perform an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation evaluates many details that impact your home's heating and cooling requirements, including:
- Home square footage
- Ceiling height
- Window size and direction
- Insulation
- Air leakage
- Local climate
- Household occupants
- Heat generated by appliances and lighting
- Air duct condition
A properly sized air conditioner runs through longer cooling cycles to cool your home consistently while eliminating excess humidity. That means more even temperatures, better indoor comfort and improved moisture control. Proper sizing also helps the equipment to perform more effciently, reducing excessive wear and tear that can cause it to wear it out sooner or lead to costly breakdowns.
When your heating or cooling system is properly sized, you get greater comfort and more reliable operation.
Problems Caused by Oversized and Undersized HVAC Equipment
You may be tempted to buy the most energy efficient, largest-capacity air conditioner or heating system on the market. In reality, that often isn't a great idea.
HVAC systems that are bigger than your home needs or undersized can create comfort problems, 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 heat or cool rapidly, but that doesn't mean it works well.
- Short cycling: An oversized HVAC system starts and stops often, reducing efficiency and increasing equipment strain.
- Reduced humidity control: Oversized air conditioners finish cooling cycles too soon to remove indoor humidity from the air.
- Hot and cold spots: Some rooms get too cold while others never feel comfortable.
- Increased wear and tear: 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 can have the opposite problem:
- Long run times: The system operates almost continuously trying to reach the set temperature, which also causes unnecessary wear and tear.
- Difficulty maintaining the desired temperature: Your home may feel cool enough during hot weather or feel too cool during winter.
- Higher energy use: Running for extended periods can increase monthly energy expenses.
- Greater strain on very hot or cold days: HVAC systems that are too small can struggle in extreme temperatures, increasing component strain and the risk of breakdowns.
Balancing Efficiency and Size
When trying to decide between a high SEER vs right-sized system, keep in mind that you don't always need the most efficient model on the market.
More often than not, a professionally sized, mid-efficiency heating and cooling system will deliver better performance than an oversized premium system because it functions 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 long-term goals.
When deciding how to choose a new air conditioner or furnace, keep these factors in mind:
- Lower energy costs: Higher-efficiency and right-sized systems can decrease 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.
- Local utility costs: Areas with higher utility costs may see greater long-term savings from higher-efficiency units.
- Seasonal weather conditions: It's crucial your heating or cooling system has adequate capacity to handle areas with very cold winters or intense summer heat.
- Length of home ownership: If you intend to remain 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 offset the overall cost of high-efficiency HVAC equipment.
Real-World Situation: High Seer vs. Right System Size
What does this look like in the real world?
Imagine 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. The other homeowner installs a correctly sized, mid-efficiency system after completing a Manual J calculation.
Even though 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 last longer because it's properly matched to the home's needs.
Choose the Local HVAC Professional Who Designs Solutions Tailored to Your Home
An HVAC replacement should involve much more than selecting a model with the top efficiency rating. The right system is one that meets your household heating and cooling requirements.
At Gilray Heating and Cooling, our experienced professionals perform an HVAC load calculation. Our team will evaluate your home's size and layout, your household's heating and cooling preferences and recommend equipment that's designed specifically for your home—not simply the largest, most expensive unit or the one with the highest AFUE or SEER2 rating.
Our heating and cooling specialists 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 Gilray Heating and Cooling today. Our team will evaluate your home, answer any questions and help you choose the right-sized high-efficiency system that keeps your family comfortable for the long haul.