Efficiency ratings for your HVAC equipment don’t sound particularly exciting, do they? And why are three different acronyms needed?
When it comes time to replace your HVAC system though – a project that can easily cost upwards of $10,000 – these things become a lot more important. What are you installing in your home that you might be using for the next 10-20 years?
That answer matters for your energy costs, comfort, state or local tax credits you can qualify for, and potentially even things like home resale value.
So we’re here to quickly demystify heating and cooling efficiency ratings, explain why you might care about each one, and help you make the best decision for your home.
What is AFUE Rating?
AFUE stands for Annual Fuel Utilization Efficiency. It’s a rating that’s primarily used for furnaces, but also for water heaters that are used to heat homes.
AFUE is actually probably the easiest of the efficiency ratings to understand, since it can be discussed in terms of percentages. An AFUE rating of 80%, for example, means that 80% of the energy from the system is going toward heating your home. The remaining 20% is being siphoned off and vented through an exhaust flue.
Modern furnaces range from around 80% to 98% efficiency. This might not seem like a really wide range, but when you think about how often you use your heating in the cooler months, an additional 18% can add up quickly, equalling more comfort and energy costs.
80% is a typical AFUE rating for a standard home furnace. Wear and tear on your system, or inefficiencies in airflow or installation, can drop that percentage, but this is the theoretical efficiency that many furnace systems operate at.
Older furnaces that are operating well below their theoretical levels could be as low as 40% to 50%! This is a lot of wasted energy, and a good reason why AFUE should be considered when upgrading a system.
What is HSPF Rating?
HSPF stands for Heating Seasonal Performance Factor. It’s a measure of efficiency that applies to heat pumps.
If you don’t have a heat pump – and don’t expect to have one in the future – you can skip this section. No, really, the other sections will be more useful to you.
Heat pumps actually have two efficiency metrics, though. SEER, which we’ll discuss below, is for the cooling efficiency of a heat pump. HSPF applies to the heating side of things.
So HSPF only applies in the cooler months when you’re using a heat pump to heat your home.
Also of note is that as HVAC technology improves, so does our ability to measure efficiency. HSPF calculations changed in the past decade, and this new calculation is sometimes called HSPF2. Regardless of the calculation, higher numbers are better.
As of this article being written, minimum federal standards require that heat pumps have an HSPF2 of at least 7.5, though this is an average of their efficiency in a typical heating season based on certain conditions. At the coldest temperatures, your heat pump will not operate exactly at 7.5 HSPF2.
The most efficient units can have HSPF ratings of over 10.
Because many heat pumps are in use in southern US states, they’re generally used more for cooling than heating, and as such the cooling capacity will be more important to overall comfort and energy efficiency.
However, colder areas also have heat pump systems and they’re used a lot for heating in those regions.
What is SEER Rating?
SEER stands for Seasonal Energy Efficiency Ratio. It measures cooling efficiency for air conditioners and heat pumps.
If you’ve heard of any of these previously, it’s probably SEER, since it applies to all major cooling systems.
Higher SEER ratings are better, and like HSPF, there are minimum federal standards for SEER rating. In northern regions, the minimum SEER is 13, or 14 for southern states.
Also like HSPF, the rating is an average based on certain standardized testing conditions and is meant to show the average efficiency of the equipment over a typical cooling season. Exact SEER levels for your system will vary depending on environmental factors.
SEER can climb above 20 in the most efficient whole-home air conditioning and heat pump units. And specialized cooling equipment like ductless mini-splits can reach SEER ratings of over 30! Most typical home systems range from around 14 SEER to 20 SEER, and 18-20 is considered rather efficient for a whole-home, central air system.
SEER2 and EER Ratings
Also like HSPF, there’s a SEER2 rating that is increasingly being used instead of the original SEER formula, one that measures environmental conditions in a bit more detail and provides a more thorough average for equipment efficiency. The two are extremely similar, though.
EER is another sub-classification for efficiency ratings, though this is one that only applies to standalone cooling units. You’ll usually see it applied to window air conditioners.
HVAC Efficiency and Comfort
The biggest reason to upgrade your heating and cooling efficiency is the increase in comfort that you’ll experience.
Energy is lost from your home constantly. Upgrading things like the windows, insulation, siding and curtains can help, but some energy loss is inevitable.
More of your HVAC system’s energy going directly toward heating and cooling means that your system has to work less hard to regulate your home’s temperature. It also means warm or cool air has a better chance of diffusing throughout your entire home, instead of leaving hot and cold spots or entire rooms (like master bedrooms) that struggle to stay comfortable.
We get a lot of questions about cost savings, and this is an important part of the equation as well. But ultimately it’s the ability to feel truly comfortable in your home that’s the greatest benefit.
HVAC Efficiency and the Environment
Higher efficiency equals more eco-friendly technology. The minimum requirements set by the U.S. Department of Energy are largely due to increased HVAC usage in the country and the need to reduce our energy expenditure.
HVAC technology has come a long way in recent decades. If you had a system in the 90s, you’d be lucky if it was operating at 10 SEER, and most were well below that. The energy savings between those older systems and new, state-of-the-art ones can be 60% or higher!
Combine that percentage by every household in the country and the effect is profound.
HVAC Efficiency and Cost Savings
So what does this save you? Well, we mentioned that 60% stat just above, and this is something like a best case scenario.
First, remember that HVAC isn’t your entire energy bill. Usually it accounts for around half of your total energy expenditure.
Next, you’ll want to talk to your HVAC contractor to estimate your energy savings between your old system and a potential upgraded one. Your personal savings will likely be between 20% and 60%.
Now you have to think about how long you plan on staying in your home. 20 years of 50% energy savings is a lot more than 5 years of the same energy savings.
It’s possible to figure out approximate savings, and for you to save thousands on energy costs in the coming years and decades. For most, though, you’ll want to weight the initial cost with eventual savings to figure out which is right for you.
Tax Credits & Rebates
Many states and municipalities will offer rebates and tax credits on energy-efficient systems and appliances.
This isn’t just for HVAC. Sacramento County where we’re at has rebates and incentives for solar panels, HVAC, kitchen appliances, and more!
However, many areas will have incentives for you to upgrade to a high-efficiency cooling or heating system. This can shave thousands off of the cost of an HVAC system.
So we’re not just talking about a few hundred dollars, which can still be a lot for many people.
Ask your trusted HVAC company about local incentives for eco-friendly HVAC tech, and check your county and city websites for more information as well. Chances are, you’re leaving money on the table if you don’t explore these options!
Upgrading Your Home Heating and Cooling
Do you really need to know the details of how AFUE is calculated? Or HSPF? Or SEER? No, which is why this article was about why they matter and what they tell you instead of how to do all the math behind them.
Knowing the basics matters, though, because it has implications for your comfort, your finances, and can qualify you for rebates and tax incentives depending on where you live.
These things matter, and can be the difference in thousands of dollars spent or saved if you’re careful.
CABS Heating and Air Conditioning has been helping thousands of homeowners for years navigate upgrades to their home services, including electrical, plumbing, solar and HVAC. We’re experts in what will be the best fit for you, and at the right cost.
Give us a call today and let us know you’re looking for energy-efficient upgrades to your home that will benefit your life for years to come!
