Choosing a new air conditioner or furnace can feel overwhelming. If you want to find the best HVAC system for your home, it's understandable to look for models with the highest efficiency ratings.
Surely the most efficient system will provide the most comfort and lowest energy bills, right?
Not necessarily.
High efficiency isn't the only thing to think about when it comes to new air conditioner installation or furnace replacement. While many homeowners focus only on {energy efficiency|efficiency ratings, proper {HVAC system sizing is equally, if not more important for your home's comfort and your energy bills.
Proper sizing directly impacts humidity control and long-term reliability. The best HVAC system for your home delivers efficiency and proper sizing.
In thisblog, 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 recommending the best HVAC system for your home.
What Does a High SEER Rating Actually Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), shows how effectively an air conditioner cools your home over a normal cooling season. A SEER2 rating is the newer version of SEER, using evaluation methods that better reflect real-world operating conditions. Most new air conditioners have a SEER2 rating, simply because this rating is the updated rating system for cooling equipment.
Fuel-burning heating system efficiency is rated by AFUE, which is short for Annual Fuel Utilization Efficiency. As with cooling efficiency ratings, higher AFUE ratings indicate a high-efficiency HVAC system that uses less electricity to keep you comfortable than lower-rated systems under standardized laboratory testing.
Even so, high numbers don't by themselves guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on more than just efficiency ratings, including the way the system is installed, the state of your ductwork, insulation levels, thermostat settings and, most importantly, system sizing. Even the highest-rated system cannot operate at its best if it is too large or undersized for the home.
Why HVAC System Size Matters More Than You Think
Many assume a larger air conditioner or furnace will work the best or that they should simply replace their old HVAC system with a new one the same size. In reality, new heating system installation or air conditioner replacement should be selected based on your home's actual 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 recommending replacement equipment. A Manual J calculation analyzes many details that impact your home's heating and cooling load, including:
- Home square footage
- Ceiling height
- Window size and orientation
- Home insultation levels
- Air infiltration
- Area 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 more uniformly while pulling out excess humidity. That means more even temperatures, better indoor comfort and improved humidity control. This also allows the equipment to operate more effciently, reducing excessive wear and tear that can cause it to wear it out sooner or lead to frequent or expensive repairs.
When a furnace or AC is correctly sized, you get improved comfort and more dependable performance.
Problems Caused by Oversized and Undersized Systems
It might be tempting to buy the most energy efficient, biggest air conditioner or heating system on the market. In reality, that’s rarely a good investment.
heating and cooling systems that are bigger than necessary or too small can create comfort issues, 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 work quickly, but that doesn't mean it works well.
- Short cycling: An oversized HVAC system starts and stops often, reducing efficiency and increasing wear and tear.
- Poor humidity removal: Oversized air conditioners cool your home too quickly to remove enough moisture from the air.
- Uneven temperatures: Some rooms become too cold while others aren’t ever cool enough.
- More wear and tear: Even though the system works quickly, those frequent starts and stops can cause avoidable breakdowns due to the strain.
Drawbacks of 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 set temperature, which also causes unnecessary wear and tear.
- Difficulty reaching thermostat settings: Your home may feel cool enough during hot weather or never feel warm enough in cold weather.
- Greater energy usage: Running almost constantly can increase utility bills.
- Greater strain on very hot or cold days: HVAC systems that are too small can run extremely hard in extreme temperatures, increasing component strain and the risk of breakdowns.
Balancing Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, remember that you don't automatically need the most efficient model on the market.
Often, a professionally sized, mid-efficiency HVAC system will provide better results than an overly large premium system because it functions the way it was designed to.
Thebest choice is an energy-efficient HVAC system that's properly sized 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:
- Energy 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 lower 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 crucial your heating or cooling system has the right capacity to handle areas with extremely cold winters or very hot summers.
- How long you'll own the home: If you intend to remain in your home for many years, the long-term energy savings of a higher-efficiency unit may offset 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 Situation: High Seer vs. Right System Size
How does this play out in a real world example?
Suppose there are two neighboring homes.
At the first home, the homeowner chooses a premium high-efficiency HVAC system that's too big because the contractor only matched the previous unit. Next door, the second homeowner installs a properly sized, mid-efficiency system after completing a Manual J calculation.
Although the second system has a lesser efficiency rating on paper, it may provide lower operating costs, better home comfort, improved humidity control and have a longer lifespan because it's appropriately sized to the home's needs.
Choose the HVAC Professional Who Designs Personalized Solutions
HVAC replacent or installation should involve more than selecting the unit with the top efficiency rating. The best system is one that meets your home’s heating and cooling requirements.
At Thurston Heating & Air Conditioning, our experienced professionals perform an HVAC load calculation. We'll evaluate your home's layout and construction, your household's heating and cooling preferences and recommend equipment that's designed specifically for your home—not simply the biggest, 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 or tax incentives and provide information about HVAC financing options that make high-efficiency systems more accessible for all budgets.
Schedule an HVAC consultation online with Thurston Heating & Air Conditioning to get started. We'll gladly evaluate your home, answer any questions and help you choose the correctly sized efficient system that keeps your family comfortable for many years.