Air Cooled V.S. Liquid Cooled Generators

What are the key differences between air cooled and liquid cooled home generators, what are the pros and cons?

Air Cooled Example: Cummins Quiet Connect

As an example we’ll take a look at two different 20kW generators from Cummins. The first is an Air Cooled model (RS20A) that runs on Natural Gas, the other is a Liquid Cooled model that runs on Diesel fuel (C20D6). Although these units have similar output power, almost everything about them is different. 

In this case, the Air Cooled unit is significantly lighter, smaller and more fuel efficient. The Cummins unit here is a square form factor, coming in at 3x3x3 feet. This unit overall has a very low profile, and blends pretty well with your average yard scape, being similar in size and shape to your average HVAC unit. For these units, temperatures are easily managed by ambient air being pulled through the engine. 

Liquid Cooled Example: Cummins Diesel

The most obvious difference here is the large diesel tank inside the generator, which makes the overall footprint of the unit significantly larger. In this case the overall heat generation and design of the unit necessitates a liquid cooled system. These units must be attached to a large metal base, which then needs to be placed on a concrete slab.

Although liquid coolant is highly effective and even necessary (in many cases) it also comes with the drawback of consuming more energy, since whatever liquid is being used has to be pumped through the unit. It is probably the case that units with liquid coolant would be more reliable in high temperature environments where the air temperature is already extremely high.

The Key Difference: Necessity

Liquid coolant has tons of benefits and is highly effective technology, but is only used on these standby generator units when it’s absolutely necessary. Just the difference in cost alone can be a substantial differentiator. In a climate like ours (North East U.S.) temperatures rarely exceed 100 degrees, so the need for liquid cooling on a home standby unit is very unlikely.

The residential units we frequently recommend from Cummins and Champion are all air-cooled, and during your research you will probably discover that most standby units around or under 20kW from various manufacturers are also air-cooled. Larger units, like the commercial 30kW units that Cummins makes, are liquid cooled because of their larger size.

Hurricane Home Solutions is a regional service provider of Standby Generators all across New York and Pennsylvania. We offer free, all inclusive, quotes for installations in our service areas. As generator experts, we can provide you with the solutions you need to keep the lights on when the power goes out.