Choosing a new air conditioning system or furnace can be stressful. If you're trying to find the best HVAC system for your home, it's natural to look for models with extremely high efficiency ratings.
Surely the most efficient heating and cooling system provides the most comfort and lowest energy bills, right?
It’s not quite that simple.
Efficiency ratings aren’t the only thing to think about when it comes to new air conditioner installation or furnace replacement. 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 directly impacts humidity control and system longevity. The best HVAC system for your home combines 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 trusted HVAC experts consider both when recommending the best HVAC system for your home.
High Seer Ratings: What Do They Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), measures how efficiently a cooling system cools your home over a standard cooling season. A SEER2 rating is the updated version of SEER, using test procedures that better represent real-world operating conditions. Nearly all new air conditioners have a SEER2 designation, simply because this rating is the current rating system for cooling equipment.
Fuel-burning heating system efficiency is rated by something called AFUE, which is for Annual Fuel Utilization Efficiency. Similar to SEER and SEER2 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. Real-world heating and air conditioner efficiency depends on several key factors, including the quality of the installation, the quality of your ductwork, how much insulation your home has, thermostat settings and, most importantly, HVAC system sizing. Even the highest-efficiency system cannot perform as intended if it is oversized or too small for the home.
Why Proper HVAC Sizing Matters More Than You Think
Many assume a larger air conditioner or furnace will make their home the most comfortable or that they should simply replace their old HVAC system with a unit of the same capacity. In reality, new heating system installation or AC replacement should be chosen based on your home's current heating and cooling needs—not just square footage or the size of the previous unit.
That's why reputable companies 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:
- Home square footage
- Room height
- Window size and placement
- Home insultation levels
- Air infiltration
- 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 evenly while pulling out excess humidity. That means more consistent temperatures, better indoor comfort and improved moisture control. It also helps the equipment to run more effciently, reducing strain that can reduce its service life or lead to more repairs and higher repair costs.
When a furnace or AC is correctly sized, you get better comfort and long-lasting performance.
Problems Caused by Oversized and Undersized Systems
It might be tempting to buy the most energy efficient, largest-capacity air conditioner or heating system on the market. The truth is, that's usually not a smart choice.
heating and cooling systems that are too large or smaller than your home requires can create comfort problems, increase utility costs and reduce efficiency regardless of their SEER rating.
Issues Created by 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 equipment strain.
- Poor humidity removal: Oversized air conditioners finish cooling cycles too soon to remove enough moisture from the air.
- Uneven temperatures: Some rooms get too cold while others aren’t ever cool enough.
- Additional equipment wear: Even though the system works quickly, those constant cycles can cause avoidable breakdowns due to the strain.
Drawbacks of Undersized HVAC Systems
An undersized HVAC system can have the opposite problem:
- Long run times: The system stays on for extended periods trying to reach the thermostat setting, which also causes unnecessary wear and tear.
- Trouble reaching the thermostat setting: Your home may never feel as cool as you want during hot weather or always feel chilly in the winter.
- Greater energy usage: Running for extended periods can increase monthly energy expenses.
- Added strain during extreme weather: HVAC systems that are too small can struggle in extreme temperatures, increasing equipment wear and the risk of breakdowns.
Balancing Efficiency and Size
When trying to decide between a high SEER vs right-sized system, don't forget that you don't automatically need the most efficient model on the market.
More often than not, a properly sized, mid-efficiency heating and cooling system will outperform an oversized premium system because it runs 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 future plans.
When deciding how to choose a new air conditioner or furnace, consider:
- Lower energy costs: Higher-efficiency and right-sized systems can decrease electricity use.
- Upfront investment: 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 electricity rates may see more significant long-term savings from higher-efficiency units.
- Your local climate: It's essential 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 plan to stay 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 lower the overall cost of qualifying equipment.
Real-World Situation: High Seer vs. Right System Size
How does this play out in a real world scenario?
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 properly sized, mid-efficiency system after completing a Manual J calculation.
Even though the second system has a lesser efficiency rating on paper, it may deliver lower operating costs, better home comfort, improved humidity control and last longer because it's appropriately sized to the home's needs.
Choose the HVAC Professional Who Designs Solutions Tailored to Your Home
HVAC replacent or installation should involve more than selecting the unit with the highest efficiency rating. The right system is one that meets your home’s heating and cooling requirements.
At Central Heating & Plumbing, our experienced professionals perform an HVAC load calculation. Our team will evaluate your home's layout and construction, your household's heating and cooling preferences and recommend equipment that's properly matched for your home—not simply the largest, fanciest unit or the one with the highest AFUE or SEER2 rating.
Our team will help you identify any available rebates or 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 Central Heating & Plumbing now. We'll 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.