Our Most Efficient AC Systems

April 25, 2024

It’s “Air Conditioning Season 2024” in the Denver-Boulder metro area, and once again our most efficient cooling systems are proving to be very popular with our customers. In this post, our team at Save Home Heat Company would like to feature the two most efficient air conditioners that we currently install.

Something we find interesting and noteworthy is that our second most efficient air conditioner is a fairly conventional central AC unit – albeit with an advanced design – from Lennox, while the most efficient AC system we install is actually a mini-split heat pump made by Mitsubishi. Unlike the Lennox unit, the Mitsubishi system provides both cooling and heating, and in a package that allows for zoning different rooms within your home.

family having dinner outside on a nice summer night

Both systems are highly rated, have found great applications with the homeowners we serve, and are built by reputable, established manufacturers that we’ve represented for many years.

In addition to briefly discussing those two featured products and their designs, efficiency ratings, and available sizes, we’ll start out by revisiting the meaning of the AC efficiency rating known as “SEER.”

What Is a SEER Rating for an Air Conditioner or Heat Pump?

2024 energy start logoSEER ratings are issued by the U.S. Department of Energy and represent an objective measurement of the electrical efficiency of an air conditioner. The acronym stands for Seasonal Energy Efficiency Ratio (SEER) and is translated into a number, or SEER rating for each product. The higher the SEER rating, the more energy efficient the unit is, which means lower energy usage and cost to cool your home. You can use this number to compare air conditioners and heat pumps units to find efficient and cost-effective units to cool your home.

To muddy the waters just a little, a revised efficiency rating known as the SEER2 is in the process of coming into effect, with the result that some units may carry both a SEER rating as well as a SEER2 rating. They often differ just a little, with the SEER2 number normally being just a bit lower. We won’t bore you with more details, here.

Mitsubishi intelli-HEAT coil-2

Air Conditioners vs. Heat Pumps

While the names can be a little misleading, both heat pumps and air conditioners provide cooling, essentially in the same way. Heat pumps do double duty as heaters, and as a result have a bit more involved controls and valving. For the sake of this discussion, we’ll focus on just the air conditioning side of things and group both these products together for the job they do as air conditioners.

Do Heat Pumps or Air Conditioners Have the Higher SEER Ratings?

Unfortunately, the answer to the above question is not as straightforward as some people might hope. It varies, depending on the specific product. Regardless, there are many aspects of their designs and internal components that both air conditioners and heat pumps have in common – especially when you look closer at top-of-the-line products. More on that below.

What our team concludes is that, whether a conventional air conditioner or a heat pump, the most efficient units available reflect a variety of similar factors, including a commitment to state-of-the-art high efficiency design, exceptional engineering, the highest quality components, and very high standards in the manufacturing process. It so happens that at this time the most efficient AC unit we currently install is a heat pump – but that’s not to belittle AC-only systems in the least. Careful not to be overly seduced by the numbers game!

Our Most Efficient Air Conditioners for Denver-Boulder Homeowners

As mentioned above, most high-end air conditioners and heat pumps have certainly similarities that allow them to attain the highest SEER ratings in the industry. Foremost among these similarities is the heart of the system, the compressor that’s installed in the outdoor condensing unit.

Mitsubishi Electric Diamond Elite Contractor Logo
Lennox Premier Dealer

Variable-Speed Compressors: The Key to Variable-Capacity AC Systems

Virtually all top-end air conditioning systems have a highly electrically efficient, variable-speed compressor, which is the key component in all variable-capacity systems. A variable-speed compressor has the ability to respond very precisely to the cooling needs of the home – providing just the right amount of cooling that’s needed, in real time, instead of wasting electricity creating cool air that isn’t needed to satisfy the thermostat setting. This type of compressor is essential to achieving the very high SEER ratings that variable-capacity AC and heat pump systems are known for.

Let’s take a closer look at our two most efficient AC systems, one of which is a central air conditioner, and the other is a mini-split heat pump. As alluded to above, both have variable-speed compressors.

Lennox Signature Series Model SL28XCV Central AC

According to Lennox, the SL28XCV is the most precise and efficient central air conditioner currently available, and it’s our leading central cooling-only product.

Highlights of the SL28XCV include:
  • Cooling efficiency ratings up to 28 SEER
  • ENERGY STAR® Most Efficient certified
  • Among the lowest outdoor sound ratings for central AC equipment in the industry
  • Available in cooling capacities up to 5 tons (60,000 BTUs per hour) in a single system, able to accommodate many of the homes we work in
Lennox condenser install

While the SL28XCV is the most efficient AC-only system that Lennox makes, close behind is their highly rated, top-of-the-line central heat pump, the SL25XPV. This heating and cooling system offers cooling efficiencies up to 24 SEER, which is also considered to be among the highest SEER ratings in the industry. Save Home Heat is a nationally recognized Dave Lennox Premier Dealer.

The Mitsubishi MSZ-FS Deluxe Mini-Split Heat Pump

Mitsubishi has been recognized as the world leader in mini-split ductless technology for many years, and the MSZ-FS is a prime example that this isn’t just marketing hype.

Key features of Mitsubishi’s Deluxe Mini-split Heat Pump include:
Mitsubish modern living, bright living room-compact image
  • Our most efficient air conditioner, featuring the Deluxe wall-mounted indoor blower unit, and capable of achieving cooling efficiencies up to 33.1 SEER
  • Contains Mitsubishi’s exclusive Hyper-Heating Inverter (H2i) compressor technology, the most efficient and highest quality variable-speed compressor made
  • Currently available in cooling capacities up to 4 tons (48,000 BTUs per hour)
  • Can be incorporated with an existing furnace in a Mitsubishi intelli-HEAT dual fuel system – achieving optimal dual-system performance and unsurpassed system flexibility

Mitsubishi is unsurpassed in the efficiency and flexibility of their mini-split systems, and they continue to refine and expand their product line. Save Home Heat is a nationally recognized Mitsubishi ELITE Diamond Contractor.

A Broad Range of Cooling Efficiencies & BTU Ratings

As with many HVAC manufacturers, both Mitsubishi and Lennox offer a broad range of cooling capacities and efficiency ratings in their central and mini-split cooling and heating product lines, designed to match the varying needs of many different homeowners.

Central AC Sizes & Efficiencies

SEER ratings for central AC systems currently range from approximately 14 SEER on the lower end of the efficiency scale, up to nearly 30 SEER. Demand for the lowest rated systems continues to decline, and our team finds that many homeowners in the metro Denver-Boulder market opt for units in the 18 to 22 SEER range. Interest in our most efficient systems continues to steadily grow, especially among those who plan to stay put in their homes for the foreseeable future. Whole-home systems from Lennox are available in sizes from 1 ½ tons (18,000 BTUs) to 5 tons (60,000 BTUs), covering a wide range of size homes.

Lennox condenser corner of house install

Mini-Split Cooling Capacities & SEER Ratings

Mini split dual image

Keep in mind that mini-split systems are essentially independent room comfort systems, capable of providing multi-zone comfort all around a home. As a result, the cooling capacities for Mitsubishi mini-splits start at low as 6,000 BTUs per hour and go up steadily to accommodate virtually any size room or area in a home. In some cases, they can even be employed in a ducted system or be used in tandem with an existing gas furnace (the intelli-HEAT dual fuel system). Mitsubishi outdoor units are available in sizes up to 4 tons (48,000 BTUs), and cooling efficiencies range from approximately 18 SEER to over 33 SEER.

In the Mitsubishi accolades department: According to a recent article published by Consumer Reports, of nearly 20,000 members surveyed in 2020 and 2022, out of 25 brands mentioned, Mitsubishi alone received an ‘excellent’ rating for both reliability and owner satisfaction. High praise, considering that many popular brands were mentioned. Lennox ranked high, but Mitsubishi stood alone in this particular survey.

Your Denver-Boulder AC Comfort Experts

Licensed Master Electrician - Save Home HeatOur team at Save Home Heat Company has been installing both Lennox and Mitsubishi home comfort systems for nearly 30 years. Both manufacturers are industry leaders with strong reputations for high quality products and reliable customer support. Together, they are in a select group of companies that manufacture the most efficient and reliable air conditioners and heat pumps currently available.

Whether your home comfort needs require a top-of-the-line, long term solution, or a more basic, durable alternative, homeowners in the Boulder-Denver metro area can count on receiving friendly, highly informative, low-pressure, professional service when they consult Save Home Heat for home comfort recommendations. Please reach out to us today to learn more and to schedule a visit for a free installation quote.

Please contact me to schedule a quote for a new cooling system installation!