Generac vs. Cummins Air-Cooled Home Standby Generators. Is There a Winner?

The consumer has plenty of choices when it comes to home standby power. Generac is a familiar brand name to many homeowners thanks to extensive and successful marketing and advertising campaigns. Many readers will also recognize Cummins as an engine manufacturer from trucks and train engines to marine and generator engines.

Interestingly, Fridley, Minnesota based Cummins Power Generation is also a world leader in power generation equipment. Cummins and Generac offer homeowners an affordable and popular choice with their respective air-cooled generators.

So, which generator should you sink your hard-earned? Should you buy one like your neighbor Joe, or should you do your own research? If you’re reading this article, congratulations! You have successfully entered the “research phase”. This article will focus on product specification differences between models offered by Generac and Cummins.

The Air-Cooled Generator Line-Up from Generac and Cummins

Generac offers a wide array of air-cooled generators ranging from 7.5 – 26kW. Cummins offers 3 air-cooled models rated at 13, 17 & 20kW. Most homeowners purchasing an air-cooled generator focus on the 18-22kW range because these generators can start and run a 5-ton air conditioner while also providing power to house circuits found on a typical 200-Amp Main Breaker Panel. Air-cooled generators are considerably less expensive than liquid-cooled generators, thus the popularity among consumers.

As we compare manufacturer specifications for models offered by Generac and Cummins, we’ll point out what to look for and why. At the end of the day, you simply want the best value for money while securing your family’s safety and well-being during a power outage.

We decided to cherry pick important specs for the Generac 14-20kW air-cooled generators and compare the numbers to Cummins 13-20kW air-cooled generators.

The Engine, Unit Weight, and Physical Dimensions

As you view the table below, note that Cummins uses the same 999cc V-Twin engine for each of the models. Generac uses a smaller 2-cylinder 816cc engine for its 14kW generator and the 999cc V-Twin engine is used for the 18 and 20kW generators. Not a major issue either way. While we favor Cummins engines, we’ll label the engine category a toss-up between the two brands.

Under unit weight, the Cummins RS13A 13kW weighs 479 pounds while the Generac 14kW weighs 385 pounds. That’s a big difference! The Cummins RS20A weighs 596 pounds while the Generac 20kW weighs 448 pounds. The RS20A weighs nearly 150 pounds heavier than the 20kW Generac. Makes one wonder what Cummins is packing under the hood.

Physical Dimensions of the generators are found on the far-right side of the table below. Cummins air-cooled generators measure roughly 3-foot square and just over 27” high. Generac air-cooled generators in this range are roughly 4-feet length and a bit over 20-feet deep with a 28.6” height.

Next, Cummins reports Motor Starting kVA, but we found no specs from Generac. With that said, we’re confident each Generac model has ample motor starting capability for heavy air conditioning loads.

Sound Levels Are Important

Noise pollution is an irritant to neighbors and generator owners. Cummins takes sound very seriously as evidenced by the Quiet Connect series name. Cummins has engineered a unique housing that makes its air-cooled generators the quietest on the planet. At normal load, all three Cummins models came in at 65 dB(A), the quietest in the industry. The Cummins engine is surrounded by two housings. The exterior aluminum housing has a powder coat finish while the interior housing is made of galvanized steel.

Generac air-cooled generators are only slightly noisier at 67 dB(A). So, the Low Noise Award goes to Cummins Power Generation.

Let’s look at Fuel Consumption

Fuel consumption is an important consideration, particularly when prepping for extended power outages lasting days. Fuel consumption numbers come from each manufacturer and Cummins saves 10-15% on fuel consumption.

Here’s another fuel saving option to consider. As you may know, standby generators are programmed to go through a periodic exercise routine. The engine may run 5-10 minutes during each exercise routine. Generac owners typically choose a weekly exercise because that’s the only option available. Cummins Quiet Connect air-cooled generators can be programmed to exercise weekly, bi-monthly, or monthly. Monthly exercises result in 12 exercise routines annually. A weekly exercise results in 52 routines each year. Think of the potential fuel savings by selecting bi-monthly or monthly exercise routines!

What About the Wind Rating?

If you live in areas prone to hurricanes and high winds, a generator’s wind rating is an important consideration. Buckeye Power Systems is based in Tennessee, and Memphis area residents remember all too well a 2003 straight-line windstorm with 80-100 mph winds. Memphians nicknamed the storm Hurricane Elvis. So, yes, wind resistant generator housings are important, even if you are not in hurricane country.

Each of the Cummins air-cooled generators can sustain winds up to 180 mph while the Generac models are rated at 150 mph. Both provide good coverage for most circumstances, but Cummins wins the battle with its higher wind rating.

Code Compliance

Certifications are an important consideration and Cummins Power Generation easily wins in this category having met requirements for UL2200, CSA, EPA Emissions, and NFPA 37. The Generac equipment meets requirements for UL2200 and NFPA 37 only. As an engine manufacturer of all types and sizes, Cummins Power Generation seeks to meet the rigid EPA Emission standards with all engine products.

And the Winner is …

Air-cooled generators from Cummins Power Generation rate higher against Generac in all five categories:

• Sound – 65 dB(A) for Cummins vs. 67 dB(A) for Generac.
• Unit Weight & Size – Heft in a small package is a plus!
• Fuel Consumption – Cummins achieves better fuel efficiency than Generac.
• Wind Rating – Cummins is rated at 180 mph winds vs. 150 mph winds for Generac.
• Code Compliance – Cummins air-cooled generators are certified UL 2200, CSA, EPA, and NFPA 37 while Generac is not CSA or EPA certified.

Homeowners looking for reliable standby power can trust the world leader in power generation equipment, Cummins Power Generation and its Quiet Connect air-cooled generators.

Click here to view pricing on Cummins Air-Cooled Generators. Or check out this post on The Top 5 Reasons to Buy a Cummins RS20A – Best Generator on the Market! Better still, call Buckeye Power Systems today with any questions you may have regarding standby power for your home. Call 901-379-8097 Monday – Friday, 9:00 am – 5:00 pm.