Shopping for a new AC or furnace can be intimidating. If you're trying to find the best HVAC system for your home, it's natural to focus on models with the highest efficiency ratings.
Surely the most efficient system should deliver the most comfort and lowest energy bills, right?
It’s not quite that simple.
Energy efficiency isn'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 often even more important for your home's comfort and your power bills.
Proper sizing also influences 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 experienced HVAC professionals consider both when recommending the best HVAC system for your home.
What Does a High SEER Rating Actually Mean?
A SEER rating, (Seasonal Energy Efficiency Ratio), measures how effectively an air conditioner cools your home over a typical cooling season. A SEER2 rating is the updated version of SEER, using test procedures that better represent real-world operating conditions. Most new air conditioners have a SEER2 rating, simply because this rating 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 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 automatically guarantee lower utility bills. Real-world heating and air conditioner efficiency depends on more than just efficiency ratings, including the installation quality, the state of your ductwork, insulation levels, thermostat settings and, most importantly, system sizing. Even the most efficient 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 bigger air conditioner or furnace will heat or cool a home better or that they should simply replace their old HVAC system with a same-sized replacement. In reality, new heating system installation or a new air conditioner should be selected based on your home's true heating and cooling needs—not just square footage or the size of the previous unit.
That's why reputable technicians conduct an HVAC load calculation, also called a Manual J calculation, before suggesting replacement equipment. A Manual J calculation evaluates many factors that impact your home's comfort needs, including:
- Overall square footage
- Ceiling height
- Window size and orientation
- Home insultation levels
- Air leakage
- Regional climate
- Number of occupants
- Heat produced from appliances and lighting
- Ductwork condition
A properly sized air conditioner runs through longer cooling cycles to cool your home more uniformly while removing excess humidity. That means steadier temperatures, better indoor comfort and improved humidity control. Proper sizing also helps the equipment to operate more effciently, reducing excessive wear and tear that can shorten its lifespan or lead to more repairs and higher repair costs.
When a furnace or AC is correctly sized, you get improved comfort and long-lasting performance.
Problems with Oversized and Undersized Systems
You may be tempted to buy the most energy efficient, highest-capacity air conditioner or heating system on the market. The truth is, that's usually not a smart choice.
HVAC systems that are bigger than your home needs 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 heat or cool rapidly, but that doesn't mean it performs efficiently.
- Short cycling: An oversized HVAC system starts and stops often, reducing efficiency and increasing equipment strain.
- Humidity problems: Oversized air conditioners cool your home too quickly to remove excess moisture from the air.
- Uneven temperatures: Some rooms get too cold while others never feel comfortable.
- Additional equipment wear: Even though the system heats or cools your home fast, those constant cycles can cause avoidable breakdowns due to the strain.
Drawbacks of Undersized HVAC Systems
An undersized HVAC system also can struggle:
- Continuous operation: The system runs for long periods trying to reach the desired temperature, 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 never feel warm enough in cold weather.
- Greater energy usage: Running almost constantly can increase energy costs.
- Greater strain on very hot or cold days: HVAC systems that are too small can run extremely hard in extreme temperatures, increasing equipment wear and the chance of failure.
Why You Should Balance HVAC System Efficiency and Size
When trying to decide between a high SEER vs right-sized system, remember that you don't always need the highest-efficiency model on the market.
Often, a correctly 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 correctly 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 decrease electricity use.
- Initial cost: High-efficiency AC and heating systems often cost more initially than mid-range models but can reduce long-term energy costs.
- Electricity rates: Areas with higher utility costs may see better long-term savings from higher-efficiency units.
- Seasonal weather conditions: It's crucial your heating or cooling system has the right 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 lower the overall cost of high-efficiency HVAC equipment.
Real-World Comparison: High Seer vs. Right System Size
How does this play out in a real world scenario?
Picture two neighboring homes.
In the first, the homeowner chooses a premium high-efficiency HVAC system has far more capacity than the home needs because the contractor simply matched the previous unit. At the neighboring home, an HVAC professional installs a correctly sized, moderate-efficiency system after completing a Manual J calculation.
Although the second system has a lower efficiency rating on paper, it may deliver lower operating costs, better home comfort, improved humidity control and have a longer lifespan because it's appropriately sized to the home's needs.
Choose the Local HVAC Professional Who Designs Personalized Solutions
HVAC replacent or installation should involve much more than selecting a model with the highest efficiency rating. The best system is one that meets your heating and cooling requirements.
At Tri County Climate Control LLC, our skilled HVAC experts perform an HVAC load calculation. We'll carefully evaluate your home's design, your household's comfort needs and recommend equipment that's properly matched for your home—not simply the highest-capacity, latest and greatest unit or the one with the highest AFUE or SEER2 rating.
Our HVAC experts will let you know about 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 Tri County Climate Control LLC today. We'll evaluate your home, answer your questions and help you choose the correctly sized energy-efficient system that keeps your family comfortable for many years.