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Air Cooled vs Liquid Cooled Generator: How They Differ

Air Cooled vs Liquid Cooled Generator
Written by Jamie Masterson

The primary difference between an air-cooled generator and a liquid-cooled generator is the use of coolant. Air-cooled generators use surrounding air to cool the engine while liquid-cooled units use water, oils, or other coolants.

Let’s dig deeper and see what differentiates them.

Air Cooled vs Liquid Cooled Generator: How They Differ

1. Use

Air-cooled generator

The air-cooling system is used by small to medium powered generators and they are the most widely available generators. The basic principle comes down to the heat dissipation technique. Air-cooled generators use the flow of air to cool the engine down.

Air cooling is the perfect system for any backup generator. They are mainly used in household, non-industrial, or smaller works (up to 22 kW). Most home appliances use air-cooled generators.


Liquid-cooled generator

Unlike air-cooled generators, liquid-based cooling systems use a wide range of cooling liquids (just like your car) and can disperse heat much more efficiently. These generators feature enclosed radiator systems and are usually seen in higher-kilowatt units (above 22 kW).

Liquid-cooled generators are a bit more expensive, mainly because of the better heat dissipation technology. You’ll find them in industrial and commercial settings.

2. Complexity

Air-cooled generator

The air-cooling system is simpler in design. The basic idea is to let the colder air pass through the hot parts of the engine. Engines produce a lot of heat, and the cooling system protects the engine from overheating. Modern engines achieve this feat by increasing the surface area.

Air-cooled generators are designed in such a way that cold air will enter the machine from one side and the hotter air will exhaust the system from another.

Air-cooled generator

Liquid-cooled generator

This might be true that the air cooling system is efficient, but it has its limitations. Air isn’t a good heat conductor. As a result, the heating will be more difficult to handle as the engine runs for a long time.

Coolants like water, oil, or chemicals are much more efficient at heat dissipating. However, they are also more complex. The coolants require a closed system, a radiator, a thermostat, and many other additional components just to keep your generator going uninterrupted.

3. Maintenance

Air-cooled generator

Air-cooled generators are compact and lightweight by design. That’s why they’re much easier to maintain as well. Without all the complexities of a liquid-cooled engine, the maintenance of an air-cooled engine is pretty straightforward.

The general maintenance process includes checking oil levels, understanding safety precautions, and keeping an eye on the battery level.


Liquid-cooled generator

The more complex a system gets, the more sophisticated its maintenance becomes. You’ll need more frequent and intricate maintenance tasks when it comes to taking care of the liquid-cooled generators.

Some of those tasks include inspecting the antifreeze level, lines, and connections for potential leaks; and making sure the liquid is working properly. Luckily, these complex machines have dedicated maintenance kits that need to be used regularly.

4. Requirements

Air-cooled generator

As mentioned above, air-cooled generators are mostly used in small power levels. The more steady output you need from your generator, the longer it has to run and the more sophisticated it needs to be.

A smaller and lighter air-cooled generator can provide you with around 8 – 22 kilowatts of power. That’s why they’re a good choice as an occasional backup power source. Air-cooled generators are mostly used in household tasks.

Air-cooled generator Requirements

Liquid-cooled generator

Designed for a more heavy and steady workload, liquid-cooled generators are the perfect solution for industrial or heavy-duty power supply tasks.

The greatest advantage of liquid-cooled generators is their longevity. They can provide a steady stream of power over an extended period of time. They are used in hospitals, databases, apartments, stadiums, malls, and other big infrastructures.

5. Noise

Air-cooled generator

Air-cooled generators produce a loud noise while working, mainly due to the combustion process happening inside. The intake or exhaust fan (if you have any) can also create noise that can be identified as loud.

In most cases, air-cooled generators produce a loud noise that can be irritating to many people.

Noise of generator

Liquid-cooled generator

Liquid-cooled generators are loud as well, but they are quieter than their air-cooled counterparts. The sound they produce can be easily contained using attenuated enclosures. Technically, liquid-cooled generators are more noisy than loud.

Pros & Cons of Air-Cooled and Liquid-Cooled Generators



  • Portable and lightweight
  • Emergency backup solution
  • Perfect for smaller tasks
  • Less complex design
  • More affordable
  • Easy to use and maintain


  • Not good for heavy-duty jobs
  • Can’t provide power over an extended period of time
  • They’re loud
  • More prone to overheating



  • They’re more effective and powerful
  • Produces less noise
  • Perfect for long-term power supply
  • More durable and heavy-duty machine
  • Good in industrial/commercial environments
  • Perfect as a primary power source


  • More expensive
  • Less portable
  • Required more maintenance

Which one’s best for you?

That greatly depends on how much power you need, for how long, and how much you are willing to invest. If you are looking for a backup power source for your home and household appliances, you won’t need a large amount of power over a long time.

An Air-cooled generator will be your perfect choice in that case.

Air-cooled vs liquid-cooled generator - Which one’s best for you

However, if you want more power over a long period of time, air-cooled generators won’t cut it. You’ll need more powerful liquid-cooled generators. They’ll be perfect for powering your industrial or commercial appliances.

The heavier the load, the more powerful the generator should be. Liquid-cooled generators offer a viable solution to mid-high level power demands.


Q. Do generators have to be maintained?

Yes, of course. Like most other machines, your generator will also require regular maintenance. The frequency and intensity of the maintenance will depend on the quality of your generator. Lightweight and smaller units will need less frequent maintenance.

Q. Can an air-cooled generator be installed indoors?

No. We don’t recommend any kind of generators to be used indoors. It can cost you more and toxic fumes may build up indoors, leaving your lives at risk.

Q. Is a liquid-cooled generator worth it?

Yes. Not only do liquid-cooled generators provide a larger amount of power, but they also provide additional comfort by reducing fire hazards, and noise levels while increasing fuel efficiency.

About the author

Jamie Masterson

With decade-long experience as a generator technician, Jamie has worked with USA’s top generator manufacturers and suppliers as an independent contractor.

The long years of service to the industry has taught Jamie the ins and outs of troubleshooting, repairing, and maintaining all kinds of generators in home, industrial and outdoor settings.

Jamie thinks this platform is a great opportunity to share his tips and tricks with you so you can make the most of such power equipment for better living.

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