SEER vs. SEER: Comparing A/C Efficiency Ratings For Your Denver Home

As you may already know, air conditioners are often marketed according to their SEER (Seasonal Energy Efficiency Rating). You'll usually hear that a higher SEER means a more energy efficient air conditioner, and these usually come with a higher price tag.

So, you may be wondering, "Well, what SEER should I get?"

We get this question a lot. And the answer is: it depends. That's because SEER alone won't accurately tell you how much you'll actually save on energy costs.

Only a professional can recommend what SEER you should get because energy savings also depend on these 3 main factors:

• The correct size of your A/C and number of stages
• If your system is matched or not
• The quality of your home's ductwork

Let’s go into more detail about each of these reasons and why you need a professional’s help...

The correct size of your A/C and number of stages

The size of your air conditioner and how many stages it has affects your system’s overall energy efficiency, so you must take these factors into account when comparing SEERs. Let’s take a closer look at these 2 factors:

1. The correct size of your A/C:
   Air conditioner size is measured in tons. The higher the tonnage, the more energy your A/C will consume to cool your home. Generally, bigger homes require bigger A/C units. However, if you get an air conditioner that’s too big for your home, it’s just as bad (if not worse) than getting an undersized A/C unit. So, the key is to find an air conditioner that’s the correct size for your home.
   
   You should know the correct size of your A/C before looking at SEERs. If you don’t know the correct size, you won’t be getting an accurate estimate of potential energy savings when you compare different SEERs.
   
   To help you determine the correct A/C size you need, you should hire a professional perform a Manual J Load calculation. This calculation will let you know the exact size A/C you need for your home, and then an HVAC professional can help you compare different SEERs.
   
   Related article: How to Estimate A/C Size For Your Denver Home
2. Number of stages:
   Another A/C factor that affects SEER and energy efficiency is staging. Air conditioners can come in single-stage (meaning they only run on 1 set speed), 2-stage or variable speed models. Variable speed models are highly efficient because they run on multiple speeds. So, before you compare SEERs, you should factor in how many stages your system has because that will also determine overall energy efficiency. Your HVAC Design Consultant can help you compare SEERs based on your A/C’s stages.
   
   Related article: Single vs. Two-Stage vs. Variable-Speed ACs for Denver Homes

If your A/C system is matched or not

When comparing different SEER ratings, it’s important to make sure you have a matched system.

What do we mean by a matched system?

Your air conditioning system consists of 3 parts: the indoor coil, air handler/furnace and an outdoor (condensing) unit. A matched system means your indoor components are matched in size and rated with your outdoor air conditioning unit.

A perfectly matched system = peak performance from your A/C.

A/C marketing materials focus on SEER numbers, but don’t take them at face value: If you replace one half of your system and it doesn’t match with the other half, your actual SEER could be very different.

The quality of your home’s ductwork

Most homes lose up to 20–30% of conditioned air to leaks or poorly connected ducts, according to EnergyStar. If your home has poor ductwork, you can’t properly estimate what A/C you need just by looking at the SEER alone because you’re already losing efficiency to leaks.

So, before you start comparing SEERs, you should have a professional inspect your ducts for leaks. A certified air conditioning contractor can perform the necessary tests to determine the health of your ductwork and then seal your ducts should they find any leaks. After your ducts are sealed, your technician can give a more accurate recommendation about what SEER you should get.

Whew! That’s a lot to consider when comparing SEERs. Luckily, there are professionals who make the job a whole lot easier.