Shopping for a new air conditioning system or furnace can be intimidating. If you're trying to find the best HVAC system for your home, it's understandable to look for models with the highest efficiency ratings.
After all, the most efficient equipment will provide the most comfort and lowest energy bills, right?
Actually, that’s not always the case.
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, 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 lasting performance. The best HVAC system for your home balances efficiency and proper sizing.
In this article, 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 qualified HVAC contractors consider both when helping you choose the best HVAC system for your home.
What Does a High SEER Rating Actually Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), shows how efficiently a cooling system cools your home over a normal cooling season. A SEER2 rating is the updated version of SEER, using testing methods that better reflect real-world operating conditions. Nearly all new air conditioners have a SEER2 efficiency rating, simply because that is the new rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by an AFUE rating, which is for Annual Fuel Utilization Efficiency. Like cooling efficiency ratings, 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.
Even so, high ratings don't automatically guarantee lower utility bills. Everyday heating and air conditioner efficiency depends on many factors, including the installation quality, the condition of your ductwork, how much insulation your home has, thermostat settings and, most importantly, system sizing. Even the most efficient system cannot perform as intended if it is bigger than necessary or smaller than needed for the home.
Why Proper HVAC Sizing Matters More Than You Probably Think
Many assume a bigger air conditioner or furnace will heat or cool a home better or that they should just replace their old HVAC system with a unit of the same capacity. In reality, new heating system installation or a new air conditioner should be chosen 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 conduct an HVAC load calculation, also called a Manual J calculation, before selecting replacement equipment. A Manual J calculation evaluates many variables that affect your home's heating and cooling requirements, including:
- Total square footage
- Ceiling height
- Window size and direction
- Insulation
- Air leakage
- Local climate
- Number of occupants
- Heat produced from appliances and lighting
- Air duct condition
A properly sized air conditioner runs for enough time to cool your home consistently while pulling out excess humidity. That means steadier temperatures, better indoor comfort and improved indoor humidity management. It also helps the equipment to perform more effciently, reducing excessive wear and tear that can shorten its lifespan or lead to more repairs and higher repair costs.
When HVAC equipment is the right size for your home, you get better comfort and more dependable performance.
Problems Caused by Oversized and Undersized Heating and Cooling Systems
It might be tempting to buy the most energy efficient, largest-capacity air conditioner or heating system on the market. However, that’s rarely a good investment.
HVAC systems that are bigger than your home needs or too small can create indoor comfort challenges, increase energy expenses 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 delivers the best comfort.
- Short cycling: An oversized HVAC system turns on and off frequently, 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.
- Additional equipment wear: Even though the system works quickly, those frequent starts and stops can cause avoidable breakdowns due to the strain.
Issues Created by 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 set temperature, which also causes additional wear.
- Difficulty maintaining the desired temperature: Your home may feel cool enough during hot weather or never feel warm enough in cold weather.
- Higher energy use: Running for extended periods can increase monthly energy expenses.
- Extra stress during severe weather: HVAC systems that are too small can struggle in extreme temperatures, increasing equipment wear and the chance of failure.
Balancing Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, keep in mind that you don't necessarily need the highest-efficiency model on the market.
Often, a properly sized, mid-efficiency HVAC 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 future plans.
As you think about how to choose a new air conditioner or furnace, think about:
- Lower energy costs: Higher-efficiency and right-sized systems can decrease electricity use.
- Purchase price: 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 more expensive electricity may see better long-term savings from higher-efficiency units.
- Climate: It's essential your heating or cooling system has adequate capacity to handle areas with very cold winters or very hot summers.
- 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.
- Rebates and tax credits: Manufacturer promotions, {utility|equipment rebates and tax credits can reduce the overall cost of qualifying equipment.
Real-World Comparison: 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 only matched the previous unit. At the neighboring home, an HVAC professional installs a right-sized, moderate-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 correctly matched to the home's needs.
Work With an HVAC Professional Who Designs Personalized Solutions
HVAC replacent or installation should involve much more than selecting a system with the top efficiency rating. An ideal system is one that meets your home’s heating and cooling requirements.
At Kirkfield Heating & Air Conditioning, our experienced professionals perform an HVAC load calculation. Our team will evaluate your home's size and layout, your household's comfort goals and recommend equipment that's designed specifically for your home—not simply the highest-capacity, fanciest unit or the one with the highest AFUE or SEER2 rating.
Our team will help you identify any available tax rebates 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 Kirkfield Heating & Air Conditioning now. Our team will evaluate your home, answer your questions and help you choose the right-sized energy-efficient system that keeps your family comfortable for the long haul.
