Shopping for a new AC or furnace can feel overwhelming. When you're looking to find the best HVAC system for your home, it's understandable to focus on models with extremely high efficiency ratings.
Surely the most efficient system should deliver the most comfort and lowest energy bills, right?
Not necessarily.
Energy efficiency isn't the only thing that matters when it comes to new air conditioner installation or installing a new furnace. While many homeowners focus only on efficiency ratings, proper HVAC system sizing is just as, if not more important for your home's comfort and your power bills.
Proper sizing directly impacts humidity control and long-term reliability. The best HVAC system for your home combines efficiency and correct sizing.
In this article, 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 choose the best HVAC system for your home.
High Seer Ratings: What Do They Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), indicates 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. Nearly all new air conditioners have a SEER2 designation, simply because this rating is the new rating system for cooling equipment.
Fuel-burning heating system efficiency is measured by AFUE, which is for Annual Fuel Utilization Efficiency. Similar to 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.
However, high numbers don't by themselves guarantee lower utility bills. Everyday heating and air conditioner efficiency depends on many factors, including the installation quality, the state of your ductwork, insulation levels, 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 too small for the home.
Why Proper HVAC 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. The truth is, new heating system installation or air conditioner replacement should be chosen based on your home's actual heating and cooling needs—not just square footage or the size of the previous unit.
That's why reputable technicians complete an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation analyzes many variables that affect your home's heating and cooling requirements, including:
- Total square footage
- Room height
- Window size and direction
- Home insultation levels
- Drafts and air leakage
- Local climate
- Household occupants
- Heat produced from appliances and lighting
- Air duct condition
A properly sized air conditioner runs through longer cooling cycles to cool your home consistently while removing excess humidity. That means more even temperatures, better indoor comfort and improved humidity control. It also helps the equipment to perform more effciently, reducing unnecessary wear that can reduce its service life or lead to frequent or expensive repairs.
When a furnace or AC is the right size for your home, you get better comfort and more dependable performance.
Problems with Oversized and Undersized HVAC Equipment
It might be tempting to buy the most energy efficient, highest-capacity air conditioner or heating system on the market. The truth is, that's usually not a good investment.
heating and cooling systems that are too large or smaller than your home requires can create indoor comfort challenges, 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 delivers the best comfort.
- Short cycling: An oversized HVAC system cycles repeatedly, reducing efficiency and increasing wear.
- High indoor humidity: Oversized air conditioners cool your home too quickly to remove excess moisture from the air.
- Hot and cold spots: Some rooms become too cold while others never feel comfortable.
- More wear and tear: Even though the system works quickly, those frequent starts and stops 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 runs for long periods trying to reach the desired temperature, which also causes additional wear.
- Difficulty maintaining the desired temperature: Your home may feel cool enough during hot weather or always feel chilly in the winter.
- Higher energy use: Running nonstop 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 equipment wear and the likelihood of repairs.
Finding the Right Balance Between Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, don't forget that you don't always need the top-efficiency model on the market.
More often than not, a properly sized, mid-efficiency heating and cooling system will deliver better performance than an overly large premium system because it operates the way it was designed to.
Thesmartest choice is an energy-efficient HVAC system that's correctly sized for your home, your budget, your climate and your future plans.
As you think about how to choose a new air conditioner or furnace, consider:
- Efficiency savings: Higher-efficiency and right-sized systems can lower electricity use.
- Upfront investment: High-efficiency AC and heating systems often require a larger upfront investment than mid-range models but can lower long-term energy costs.
- Local utility costs: Areas with higher electricity rates may see better long-term savings from higher-efficiency units.
- Climate: It's crucial your heating or cooling system has the right capacity to handle areas with very cold winters or very hot summers.
- Time you plan to own the home: 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.
- Available rebates or tax incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can offset the overall cost of qualifying equipment.
Real-World Comparison: High Seer vs. Right System Size
What does this look like in a real world scenario?
Imagine two neighboring homes.
In one, the homeowner chooses a premium high-efficiency HVAC system that's too big for the house because the contractor only matched the previous unit. At the neighboring home, an HVAC professional installs a properly sized, mid-SEER or AFUE system after completing a Manual J calculation.
Even though the second system has a lower efficiency rating on paper, it may deliver 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 HVAC Professional Who Designs the Right Solution
HVAC replacent or installation should involve much more than selecting the unit with the highest efficiency rating. The best system is one that meets your heating and cooling requirements.
At LTS Plumbing & Heating Inc., our experienced professionals perform an HVAC load calculation. We'll carefully evaluate your home's design, your household's comfort needs and recommend equipment that's properly matched for your home—not simply the highest-capacity, most expensive unit or the one with the highest AFUE or SEER2 rating.
Our team will connect you with 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 LTS Plumbing & Heating Inc. 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 many years.