Choosing a new AC 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.
After all, the most efficient heating and cooling system should deliver the most comfort and lowest energy bills, right?
Not necessarily.
Efficiency ratings aren’t the only thing that matters when it comes to new air conditioner installation or furnace replacement. Even though many focus only on {energy efficiency|efficiency ratings, proper {HVAC system sizing is often even more important for your home's comfort and your power bills.
Proper sizing directly impacts humidity control and system longevity. The best HVAC system for your home delivers energy efficiency and proper sizing.
In thisarticle, we'll explain what an air conditioner's SEER rating or SEER2 rating actually measures, why correct HVAC size is so important and why qualified HVAC contractors consider both when helping you select 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), measures how efficiently an AC cools your home over a standard cooling season. A SEER2 rating is the current version of SEER, using test procedures that better reflect real-world operating conditions. Today’s 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 measured by an AFUE rating, which stands for Annual Fuel Utilization Efficiency. Similar to cooling efficiency ratings, 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 automatically guarantee lower utility bills. Actual heating and air conditioner efficiency depends on more than just efficiency ratings, including the quality of the installation, the quality of your ductwork, insulation levels, thermostat settings and, most importantly, proper HVAC system sizing. Even the most efficient system cannot deliver peak performance if it is too large or smaller than needed for the home.
Why Proper HVAC Sizing Matters More Than Most Homeowners Realize
Many assume a larger air conditioner or furnace will make their home the most comfortable 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 air conditioner replacement should be selected 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 technicians complete an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation evaluates many variables that impact your home's heating and cooling load, including:
- Overall square footage
- Ceiling height
- Window size and direction
- Insulation
- Drafts and air leakage
- Area climate
- Household occupants
- Heat generated by appliances and lighting
- Ductwork condition
A properly sized air conditioner runs for enough time to cool your home consistently while eliminating excess humidity. That means steadier temperatures, better indoor comfort and improved indoor humidity management. This also allows the equipment to run more effciently, reducing strain that can shorten its lifespan or lead to costly breakdowns.
When your heating or cooling system is properly sized, you get better comfort and long-lasting performance.
Problems Caused by Oversized and Undersized HVAC Equipment
You may be 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 great idea.
HVAC systems that are too large or smaller than your home requires can create comfort problems, increase operating 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 cycles repeatedly, reducing efficiency and increasing wear.
- Poor humidity removal: Oversized air conditioners cool your home too quickly to remove indoor humidity from the air.
- Hot and cold spots: Some rooms become too cold while others never feel comfortable.
- Increased wear and tear: Even though the system heats or cools your home fast, those constant 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 stays on for extended periods trying to reach the desired temperature, which also causes additional wear.
- Difficulty maintaining the desired temperature: Your home may not feel comfortable during hot weather or feel too cool during winter.
- Increased energy consumption: Running almost constantly can increase utility bills.
- Extra stress during severe weather: HVAC systems that are too small can run extremely hard in extreme temperatures, increasing wear and the likelihood of repairs.
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 always need the most efficient model on the market.
Often, a properly sized, mid-efficiency HVAC system will outperform an overly large premium system because it functions 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 goals.
As you consider how to choose a new air conditioner or furnace, think about:
- Efficiency savings: Higher-efficiency and right-sized systems can decrease electricity use.
- Initial cost: High-efficiency AC and heating systems often have a higher purchase price than mid-range models but can help reduce long-term energy costs.
- Energy prices: Areas with higher electricity rates may see better long-term savings from higher-efficiency units.
- Seasonal weather conditions: It's important your heating or cooling system has adequate capacity to handle areas with extremely cold winters or extremely hot summers.
- How long you'll own the home: If you expect to live in your home for many years, the long-term energy savings of a higher-efficiency unit may be worth the investment.
- Rebates and tax credits: Manufacturer promotions, {utility|equipment rebates and tax credits can reduce the overall cost of high-efficiency HVAC equipment.
Real-World Example: High Seer vs. Right System Size
How does this work in a real world example?
Imagine 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 replaced it with the same size system as the previous unit. At the neighboring home, an HVAC professional installs a right-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 deliver lower operating costs, better home comfort, improved humidity control and have a longer lifespan because it's correctly 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 the unit with the highest efficiency rating. The right system is one that meets your household heating and cooling requirements.
At America's Green Heating & Air Conditioning, our knowledgeable technicians perform an HVAC load calculation. Our team will evaluate your home's layout and construction, 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 HVAC experts will connect you with any available rebates or tax incentives and provide information about HVAC financing options that make energy-efficient HVAC systems more accessible for all budgets.
Schedule an HVAC consultation online with America's Green Heating & Air Conditioning to get started. 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 many years.
