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 look for models with the highest efficiency ratings.
After all, the most efficient system should deliver the most comfort and lowest energy bills, right?
Actually, that’s not always the case.
Energy efficiency isn't the only thing to think about when it comes to new air conditioner installation or replacing your furnace. Even though many 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 directly impacts humidity control and system longevity. The best HVAC system for your home combines efficiency and proper 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 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), indicates how efficiently a cooling system cools your home over a standard cooling season. A SEER2 rating is the newer version of SEER, using testing methods that better reflect real-world operating conditions. Today’s 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 short 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 numbers don't necessarily guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on several key factors, including the quality of the installation, the condition of your ductwork, insulation levels, thermostat settings and, most importantly, system sizing. Even the highest-rated system cannot operate at its best if it is too large or undersized 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 just replace their old HVAC system with a same-sized replacement. Actually, new heating system installation or air conditioner replacement should be chosen based on your home's current heating and cooling needs—not just square footage or the capacity of the old system.
That's why reputable technicians conduct an HVAC load calculation, also called a Manual J calculation, before selecting replacement equipment. A Manual J calculation considers many details that impact your home's heating and cooling requirements, including:
- Overall square footage
- Ceiling height
- Window size and placement
- Insulation
- Drafts and air leakage
- Local climate
- Number of occupants
- Heat produced from appliances and lighting
- Air duct condition
A properly sized air conditioner runs long enough to cool your home consistently while eliminating excess humidity. That means more consistent temperatures, better indoor comfort and improved indoor humidity management. This also allows the equipment to run more effciently, reducing strain that can cause it to wear it out sooner or lead to costly breakdowns.
When your heating or cooling system is correctly sized, 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, highest-capacity air conditioner or heating system on the market. However, that often isn't a good investment.
heating and cooling systems that are bigger than necessary or smaller than your home requires can create comfort issues, increase energy expenses and reduce efficiency regardless of their SEER rating.
Common Problems With 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 cycles repeatedly, reducing efficiency and increasing wear and tear.
- Poor humidity removal: Oversized air conditioners reach the set temperature too fast to remove indoor humidity from the air.
- Hot and cold spots: Some rooms become too cold while others aren’t ever cool enough.
- More wear and tear: Even though the system reaches the target temperature rapidly, 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:
- Long run times: The system operates almost continuously trying to reach the set 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 feel too cool during winter.
- Increased energy consumption: Running almost constantly can increase monthly energy expenses.
- Greater strain on very hot or cold days: HVAC systems that are too small can work harder in extreme temperatures, increasing component strain and the likelihood of repairs.
Why You Should Balance HVAC System Efficiency and Size
When trying to decide between a high SEER vs right-sized system, don't forget that you don't always need the most efficient model on the market.
Often, a properly sized, mid-efficiency HVAC system will deliver better performance than an oversized 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:
- Energy savings: Higher-efficiency and right-sized systems can reduce electricity use.
- Upfront investment: High-efficiency AC and heating systems often require a larger upfront investment than mid-range models but can help reduce long-term energy costs.
- Electricity rates: Areas with higher utility costs may see more significant long-term savings from higher-efficiency units.
- Climate: It's important your heating or cooling system has adequate capacity to handle areas with harsh winter weather or very hot summers.
- Length of home ownership: 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.
- Financial incentives: Manufacturer promotions, {utility|equipment rebates and tax credits can reduce the overall cost of high-efficiency HVAC equipment.
Real-World Example: High Seer vs. Right System Size
What does this look like in the real world?
Suppose there are two neighboring homes.
In one, 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 right-sized, mid-SEER or AFUE system after completing a Manual J calculation.
While the second system has a more modest efficiency rating on paper, it may deliver lower operating costs, better home comfort, more effective humidity control and have a longer lifespan because it's appropriately sized to the home's needs.
Choose the Local HVAC Professional Who Designs the Right Solution
HVAC replacent or installation should involve much more than selecting a model with the highest efficiency rating. The right system is one that meets your household heating and cooling requirements.
At Fletcher Plumbing, Heating & AC, our knowledgeable technicians perform an HVAC load calculation. Our team will evaluate your home's design, your household's heating and cooling preferences and recommend equipment that's properly matched for your home—not simply the highest-capacity, fanciest unit or the one with the highest AFUE or SEER2 rating.
Our HVAC experts 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 Fletcher Plumbing, Heating & AC today. We'll gladly evaluate your home, answer your questions and help you choose the correctly sized energy-efficient system that keeps your family comfortable for years to come.