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 common to focus on models with the highest efficiency ratings.
After all, the most efficient equipment provides the most comfort and lowest energy bills, right?
Not necessarily.
Energy efficiency isn't the only thing to think about 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 equally, if not more important for your home's comfort and your utility bills.
Proper sizing has a major impact on humidity control and lasting performance. The best HVAC system for your home delivers efficiency and correct sizing.
In this guide, we'll explain what an air conditioner's SEER rating or SEER2 rating actually measures, why correct HVAC size is so important and why experienced HVAC professionals consider both when recommending the best HVAC system for your home.
What Does it Mean if an AC Has a High SEER Rating?
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 test procedures that better simulate real-world operating conditions. Most new air conditioners have a SEER2 rating, simply because this rating is the current rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by AFUE, 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.
That said, high ratings don't automatically guarantee lower utility bills. Everyday heating and air conditioner efficiency depends on several key factors, including the way the system is installed, the quality of your ductwork, how much insulation your home has, thermostat settings and, most importantly, HVAC system sizing. Even the most efficient system cannot perform as intended if it is too large or smaller than needed for the home.
Why HVAC System Size Matters More Than You Probably Think
Many assume a bigger air conditioner or furnace will work the best or that they should just replace their old HVAC system with a unit of the same capacity. The truth is, new heating system installation or AC replacement should be sized based on your home's current heating and cooling needs—not just square footage or the capacity of the old system.
That's why reputable companies complete an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation considers many variables that impact your home's heating and cooling load, including:
- Home square footage
- Ceiling height
- Window size and direction
- Home insultation levels
- Drafts and air leakage
- Area climate
- Household occupants
- Heat produced from appliances and lighting
- Ductwork condition
A properly sized air conditioner runs through longer cooling cycles to cool your home consistently while pulling out excess humidity. That means more even temperatures, better indoor comfort and improved humidity control. Proper sizing also helps the equipment to operate more effciently, reducing strain that can reduce its service life or lead to more repairs and higher repair costs.
When your heating or cooling system is the right size for your home, you get greater comfort and long-lasting performance.
Problems with Oversized and Undersized Heating and Cooling Systems
You may be tempted to buy the most energy efficient, highest-capacity air conditioner or heating system on the market. In reality, that often isn't a smart choice.
heating and cooling systems that are bigger than necessary or too small can create comfort problems, 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 wear.
- Poor humidity removal: Oversized air conditioners cool your home too quickly to remove enough moisture from the air.
- Hot and cold spots: Some rooms get too cold while others aren’t ever cool enough.
- Additional equipment wear: Even though the system reaches the target temperature rapidly, those constant cycles 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 set temperature, which also causes additional wear.
- Difficulty maintaining the desired temperature: Your home may never feel as cool as you want during hot weather or never feel warm enough in cold weather.
- Increased energy consumption: Running for extended periods can increase monthly energy expenses.
- Extra stress during severe weather: HVAC systems that are too small can run extremely hard in extreme temperatures, increasing component strain and the risk of breakdowns.
Why You Should Balance HVAC System Efficiency and Size
When trying to decide between a high SEER vs right-sized system, remember that you don't automatically need the top-efficiency model on the market.
Often, a professionally sized, mid-efficiency heating and cooling system will provide better results than an oversized premium system because it runs the way it was designed to.
Thebest 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, keep these factors in mind:
- Lower energy costs: Higher-efficiency and right-sized systems can lower 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.
- Energy prices: Areas with more expensive electricity may see better long-term savings from higher-efficiency units.
- Seasonal weather conditions: It's crucial your heating or cooling system has enough capacity to handle areas with extremely 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 reduce the overall cost of higher-efficiency systems.
Real-World Example: High Seer vs. Right System Size
What does this look like in a real world scenario?
Picture two neighboring homes.
At the first home, the homeowner chooses a premium high-efficiency HVAC system has far more capacity than the home needs because the contractor only matched the previous unit. Next door, the second homeowner installs a right-sized, mid-SEER or AFUE system after completing a Manual J calculation.
Although the second system has a lower efficiency rating on paper, it may provide lower operating costs, better home comfort, more effective humidity control and have a longer lifespan because it's appropriately sized 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. An ideal system is one that meets your heating and cooling requirements.
At B & G HVAC, our knowledgeable technicians perform an HVAC load calculation. We'll evaluate your home's layout and construction, your household's comfort goals and recommend equipment that's properly matched for your home—not simply the largest, most expensive unit or the one with the highest AFUE or SEER2 rating.
Our HVAC experts will let you know about 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 B & G HVAC today. Our team will evaluate your home, answer any questions and help you choose the correctly sized energy-efficient system that keeps your family comfortable for years to come.
