Shopping for a new AC 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.
After all, the most efficient equipment should deliver the most comfort and lowest energy bills, right?
It’s not quite that simple.
Efficiency ratings aren’t the only thing you should consider when it comes to new air conditioner installation or furnace replacement. Although many people focus only on energy efficiency, proper HVAC system sizing is equally, if not more important for your home's comfort and your utility bills.
Proper sizing also influences humidity control and system longevity. The best HVAC system for your home balances efficiency and proper sizing.
In thisguide, 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 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), indicates how efficiently a cooling system cools your home over a typical cooling season. A SEER2 rating is the current version of SEER, using testing methods that better represent real-world operating conditions. Nearly all new air conditioners have a SEER2 efficiency rating, simply because this rating is the current rating system for cooling equipment.
Fuel-burning heating system efficiency is evaluated by an AFUE rating, which is short for Annual Fuel Utilization Efficiency. Like 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.
However, high ratings don't necessarily guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on several key factors, including the way the system is installed, the condition of your ductwork, your home's insulation, thermostat settings and, most importantly, system sizing. Even the highest-efficiency system cannot operate at its best if it is too large or smaller than needed for the home.
Why Correct HVAC System Sizing Matters More Than You Think
Many assume a higher-capacity air conditioner or furnace will make their home the most comfortable or that they should just replace their old HVAC system with a same-sized replacement. The truth is, new heating system installation or air conditioner replacement should be sized 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 technicians perform an HVAC load calculation, also called a Manual J calculation, before selecting replacement equipment. A Manual J calculation analyzes many variables that affect your home's comfort needs, including:
- Overall square footage
- Room height
- Window size and placement
- Home insultation levels
- Air leakage
- Local climate
- Household occupants
- Heat generated by appliances and lighting
- Air duct condition
A properly sized air conditioner runs long enough to cool your home more uniformly 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 costly breakdowns.
When HVAC equipment is correctly sized, you get improved comfort and more reliable operation.
Problems Caused by Oversized and Undersized Heating and Cooling Systems
You may be tempted to buy the most energy efficient, biggest air conditioner or heating system on the market. The truth is, that often isn't a good investment.
heating and cooling systems that are bigger than necessary or smaller than your home requires can create indoor comfort challenges, 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 heat or cool rapidly, but that doesn't mean it works well.
- Short cycling: An oversized HVAC system turns on and off frequently, reducing efficiency and increasing equipment strain.
- Reduced humidity control: Oversized air conditioners cool your home too quickly to remove indoor humidity from the air.
- Uneven temperatures: Some rooms get too cold while others aren’t ever cool enough.
- Increased wear and tear: 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 has a different set of problems:
- Continuous operation: The system runs for long periods trying to reach the desired temperature, which also causes unnecessary wear and tear.
- Difficulty reaching thermostat settings: Your home may never feel as cool as you want during hot weather or never feel warm enough in cold weather.
- Greater energy usage: Running almost constantly can increase energy costs.
- Added strain during extreme weather: HVAC systems that are too small can struggle in extreme temperatures, increasing equipment wear and the chance of failure.
Why You Should Balance HVAC System Efficiency and Size
When weighing the pros and cons of a high SEER vs right-sized system, remember that you don't necessarily need the highest-efficiency model on the market.
Often, a properly sized, mid-efficiency heating and cooling system will provide better results than an overly large premium system because it runs 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 needs.
When deciding how to choose a new air conditioner or furnace, think about:
- Lower energy costs: Higher-efficiency and right-sized systems can lower electricity use.
- Initial cost: High-efficiency AC and heating systems often have a higher purchase price than mid-range models but can reduce long-term energy costs.
- Local utility costs: Areas with higher utility costs may see better long-term savings from higher-efficiency units.
- Seasonal weather conditions: It's essential your heating or cooling system has adequate capacity to handle areas with very cold winters or intense summer heat.
- 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 justify the investment.
- Rebates and tax credits: Manufacturer promotions, {utility|equipment rebates and tax credits can lower 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 scenario?
Picture 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 replaced it with the same size system as the previous unit. Next door, the second homeowner installs a correctly sized, moderate-efficiency system after completing a Manual J calculation.
Even though the second system has a more modest efficiency rating on paper, it may provide lower operating costs, better home comfort, improved humidity control and have a longer lifespan because it's properly matched to the home's needs.
Choose the HVAC Professional Who Designs the Right Solution
Replacing your HVAC system should involve much more than selecting a model with the highest efficiency rating. The best system is one that meets your household heating and cooling requirements.
At Forster Heating, our knowledgeable technicians perform an HVAC load calculation. We'll evaluate your home's design, your household's comfort goals and recommend equipment that's right 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 help you identify 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 Forster Heating today. We'll evaluate your home, answer any questions and help you choose the properly sized efficient system that keeps your family comfortable for the long haul.
