Shopping for a new air conditioner or furnace can be stressful. If you want 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 system provides the most comfort and lowest energy bills, right?
Not necessarily.
Efficiency ratings aren’t the only thing you should consider when it comes to new air conditioner installation or replacing your furnace. Although many people focus only on energy efficiency, proper HVAC system sizing is just as, if not more important for your home's comfort and your utility bills.
Proper sizing has a major impact on humidity control and long-term reliability. The best HVAC system for your home delivers energy efficiency and proper sizing.
In this blog, 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 experienced HVAC professionals 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), measures how efficiently a cooling system cools your home over a typical cooling season. A SEER2 rating is the current version of SEER, using test procedures that better simulate real-world operating conditions. Most new air conditioners have a SEER2 rating, simply because that is the new rating system for cooling equipment.
Fuel-burning heating system efficiency is measured by something called AFUE, which is for Annual Fuel Utilization Efficiency. Like SEER and SEER2, 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 quality of your ductwork, your home's insulation, thermostat settings and, most importantly, HVAC system sizing. Even the most efficient system cannot deliver peak performance if it is oversized or too small 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 simply replace their old HVAC system with a same-sized replacement. Actually, 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 size of the previous unit.
That's why reputable companies complete an HVAC load calculation, also called a Manual J calculation, before selecting replacement equipment. A Manual J calculation evaluates many factors that impact your home's heating and cooling requirements, including:
- Overall square footage
- Room height
- Window size and placement
- Insulation
- Air infiltration
- Regional climate
- Household occupants
- Heat generated by appliances and lighting
- Ductwork condition
A properly sized air conditioner runs for enough time to cool your home more uniformly while pulling out excess humidity. That means steadier temperatures, better indoor comfort and improved humidity control. Proper sizing also helps the equipment to run more effciently, reducing unnecessary wear that can cause it to wear it out sooner or lead to costly breakdowns.
When a furnace or AC is properly sized, you get better comfort and more reliable operation.
Problems Caused by Oversized and Undersized HVAC Equipment
Many homeowners are tempted to buy the most energy efficient, biggest air conditioner or heating system on the market. However, that's usually not a great idea.
heating and cooling systems that are bigger than your home needs or smaller than your home requires can create comfort issues, 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 delivers the best comfort.
- Short cycling: An oversized HVAC system cycles repeatedly, reducing efficiency and increasing wear and tear.
- Poor humidity removal: Oversized air conditioners finish cooling cycles too soon to remove indoor humidity from the air.
- Hot and cold spots: Some rooms feel too cool while others aren’t ever cool enough.
- More wear and tear: Even though the system heats or cools your home fast, those repeated on-and-off cycles can cause avoidable breakdowns due to the strain.
Cons Associated with Undersized HVAC Systems
An undersized HVAC system has a different set of problems:
- Continuous operation: The system operates almost continuously trying to reach the set temperature, which also causes additional wear.
- Difficulty reaching thermostat settings: Your home may not feel comfortable during hot weather or feel too cool during winter.
- Higher energy use: Running for extended periods can increase monthly energy expenses.
- Extra stress during severe weather: HVAC systems that are too small can run extremely hard in extreme temperatures, increasing wear and the likelihood of repairs.
Balancing 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 most efficient model on the market.
More often than not, a professionally sized, mid-efficiency heating and cooling system will deliver better performance than an oversized 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, keep these factors in mind:
- 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 utility costs may see greater long-term savings from higher-efficiency units.
- Climate: It's important your heating or cooling system has the right capacity to handle areas with harsh winter weather or intense summer heat.
- Time you plan to own the home: If you expect to live in your home for many years, the long-term energy savings of a higher-efficiency unit may justify the investment.
- Available rebates or tax incentives: 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 play out in a real world example?
Imagine two neighboring homes.
At the first home, the homeowner chooses a premium high-efficiency HVAC system that's too big because the contractor replaced it with the same size system as the previous unit. Next door, the second homeowner 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 appropriately sized to the home's needs.
Choose the HVAC Professional Who Designs Personalized Solutions
Replacing your HVAC system should involve more than selecting a model with the top efficiency rating. An ideal system is one that meets your household heating and cooling requirements.
At Heartland Heating & Cooling, our skilled HVAC experts perform an HVAC load calculation. We'll evaluate your home's design, your household's comfort needs and recommend equipment that's designed specifically for your home—not simply the largest, 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 and tax incentives and provide information about HVAC financing options that make energy-efficient HVAC systems more accessible for all budgets.
Schedule an HVAC consultation online with Heartland Heating & Cooling today. Our team will evaluate your home, answer your questions and help you choose the right-sized efficient system that keeps your family comfortable for the long haul.