Generator Cooling Methods-Reduce Overheating in Generators

Generator Cooling Methods-Reduce Overheating in Generators

As generators are known for their efficiency and long life but with all these things it has some issues like overheating, lubrication loss, wear & tear and decrease efficiency as time goes. Overheating is one of the main issues in Diesel Generators. It is caused by both internal and external factors.

There are different Generator Cooling Methods to prevent your vehicle from overheat. It is necessary to keep it in constant contact with a cooler liquid to reduce overheat. And the only way to do that is to keep the coolant in constant circulation. If the coolant circulation stops, temperatures begin to rise and the engine starts to overheat.

In this article, we will talk about different generator cooling methods to solve the overheating issue. Before that let’s have a brief about generators. Also, the basic comparison between Air-cooled V/S liquid-cooled generators.

What is a Generator?

It is basically an electric machine that converts mechanical energy into electrical energy. The electric energy produced from the generator is used as a power source in electric circuits for running different machines and devices.

Generators are used as a backup power source for our homes to large industrial units. And also used as a primary power source at remote drilling sites.  They all are different in size and functions but one thing same about all generators they produce heat.

They have different sizes that may range from small and portable kind to big and massive size. The size of the generator basically matters upon the amount of energy and power needed by the resources.

As we first talk about what is generator now we will talk about the different cooling methods:

Different types of cooling methods used in generators

There are two different generator cooling methods which are as follows:

  • Air-Cooled Systems
  • Liquid-Cooled Systems

So, these are the two methods used for cooling the generators. Let’s discuss them in details

Air-Cooled Systems

In air-cooled systems, the air is basically used as the main source for cooling the entire machine. The air circulation is used basically to bring down the temperature of the system.  This type of cooling method is basically used for portable generators and standby generators up to 22 kilowatts.

In this method, the engine receives the cooler air from the atmosphere, and then this cooler air is transferred across the different parts of the generators that help to cool the circuits of the machine and prevent it from overheating.

Air-cooled systems easily get overheated when they are used for a long period of time. Once the temperature of the generator increased it will not work properly and finally, it stops providing electricity.

In an air-cooled system, there are two different methods are available for cooling :

Open-Ventilated Systems

In the open-ventilated systems, an exhaust system is used which helps to receive the cool air from the atmosphere and released the hot air back into the atmosphere. The cool air helps to cool the entire system. During this process, the air becomes very hot so it is released back into the atmosphere.

Enclosed Ventilated Systems

As the name suggests, the air enclosed in the system and just keeps re-circulating in the internal parts of the generator. Which helps to maintain the temperature of the machine. In this method, the same air is used again and again. for cooling the circuit.

Advantages of Air Cooling Method

Air Cooling Method system is used to brings down the temperature of the generator. This system is either open-ventilated or completely enclosed. In the open-vent system, atmospheric air is used and the exhaust is released back into the atmosphere. In an enclosed system, the air is re-circulated inside to cool the internal parts of the generator.

The air-cooled system has no radiator or pump so the system is light. In Water Cooling Method there is a leakage issue but in this case, there is no leakage issue.  Coolant and antifreeze solutions are not required in the Air Cooling Method.

Disadvantages of Air Cooling Methods

In comparison to Liquid Cooling Method, it is less effective and reliable. And it is used in Airplanes and motorcycle engines where the engines are exposed to air directly.

Liquid-Cooled systems

In the liquid-cooled system, different types of oil/coolants are used to cool the internal generator parts. This method is also referred to as a water-cooled system. There are numerous types of liquid cooling agents that use in generator cooling, Hydrogen is also one of them.

A Liquid-cooled system consists of a radiator and a water pump. The water pumps help to move the coolant around the engine by using a number of hoses/pipes. The coolant helps to absorb the heat radiated out from the generator, this leads to a lower down temperature of the system.

This type of method is best suitable for larger generators as they require more heavy-duty components to keep the generator cool. This type of system is most suitable for commercial and industrial use. Most of the generators that are used for providing more than 22 kilowatts of power uses this type of cooling method.

In large generators, hydrogen-cooled systems are basically used as hydrogen has a very high thermal conductivity. It helps to pull out the heat from the system at a very faster rate that can’t be possible by using any other coolant.

Advantages of Liquid Cooling Method

These are more reliable and less break-down complex nature of the mechanism in comparison to the Air-cooled method. Mostly they prefer large-scale operations, like hospitals, schools, and government buildings, and are strong enough to handle the extreme loads that come with keeping these buildings running optimally.

Liquid-cooled methods come with the benefit of lowering your homeowner’s insurance.

Disadvantages of Liquid Cooling Methods

The liquid cooling method is more expensive than Air cooling method due to its complex design and adequately securing hoses and tubes which prevent leakage in tubes. As these are less breakdown in comparison to Air cooling generator but if unfortunately need repairing it is more expensive to repair.  As there are many security features in Liquid cooling generators just because of it you need to pay an extra amount.

The last Air-cooled method is suitable for portable and residential generators up to around 22kW whereas, the Liquid-cooled method is best for industrial and large-scale operations up to 22kW and above.

Which cooling method to prefer?

Now the main question that arises in our mind is which is the best cooling method to be used in generators. Well, there are different factors that can help you to determine the best cooling methods for generators. Some of them are as follows:


Before choosing the suitable cooling method it is very important to understand that the size and usage of a generator play a very important role in decision making.

Air-cooled systems are perfect for small and portable for minimum power-consuming generators.

But they are not effective for the larger generators that consume over 22kilowatts of power as they can’t pull enough amount of heat from the system that can easily lead to system overheating.

So for the larger generators, liquid-cooled generators are effective.

Cost comparison

Depending upon the size and power usage the price of the generator also varied. Liquid-cooled generators are costly because of their sophisticated and complex designs. They are more powerful, durable, and very effective in nature. They are more reliable and effective for cooling larger generators.

As hydrogen-cooled units are the most effective and reliable but at the same time, they are also one of the most expensive systems.

Whereas the air-cooled systems are not suitable for larger generators as they can’t provide that much cooling to the system. They are affordable and perfect solutions for small-size generators.

Noise level

It is also a very important factor as most of the time people usually don’t like the noise produced by the generators. Almost every cooling system has a noise issue.

The unusual sound comes from the air while cooling a generator. Somewhere, most liquid-cooling systems produce very low sound. But it is only with some generators as they are enclosed by some level of sound reduction. Almost every generator produces a good amount of head.


Maintenance is the most important factor that can help in determining the best cooling method for generators. The generators whose designs are simple are very easy to maintain while it is very difficult for the systems whose designs are complex.

Usually, Air-cooled systems have a simple and easy design to use. You can easily maintain them from time to time without any hectic.

Whereas the liquid-cooled systems have more complex and sophisticated designs that is why they create a lot of mess while maintaining them as they require a specialized kit to clean the system.

Well, it is a known fact that each system has its own advantages and disadvantages. Usually, people prefer to choose Air-Cooled systems as they are less expensive and easy to maintain. Meanwhile, the Liquid-Cooled systems are more powerful and effective, but at the same time, they are also very costly in nature.

Air-cooled systems are very useful for a variety of range products whereas liquid-cooled systems are best suitable for huge and massive projects.

You can opt for any cooling method which is best suitable for your choice and can fit in your budget.

Advantages of cooling the Generator machine

There are many advantages of using the generator cooling methods which are as follows:

  • Cooling is very important as you can generate the most effective result from it.
  • Make the generator machine stable.
  • It helps to increase the efficiency and rating of the machine.
  • Coolings help to add life to the longevity of the machines and also help to maintain safe operation.
  • It helps to protects the inner components of the generator from the thermal damages.

Cause of heating of the generators?

As we talk about the different generator cooling methods now we will discuss the reason behind the overheating. A portable generator uses coils of wires which rotate through a magnetic field to create voltage. So, whenever the current is flowing through the wires which makes the system very hot.

There are many other factors that can lead to generators overheat which are as follows:

  • Poor circulation of coolant due to internal or external leakage. The result could be loose clamps or damaged gaskets.
  • The dust accumulated on the exterior part of the generator can also lead to system overheating as it prevents normal heat dissipation.
  • The cooling fan may be broken.
  •  Need to check Diesel injectors. If the injectors are clogged, the system will be overloaded in order to compensate for the clogged injector.
  • Damaged exhaust which restricts the exhausting process.
  • Generator overload is also may be a factor of overheating. Because imbalance irregular load can cause the generator to overheat.
  • Low level of oil.
  • High humidity can also be the reason for generator overheating because the coolant and outside environment are lump-sum the same. So it is very difficult to dissipate the heat.
  • High external temperature decreases the temperature which results in the inadequate air supply which means less oxygen for combustion. But the engine tries to push itself to produce the same power and it might get overheated.

Why overheating is dangerous?

Due to the generator overheat, the alternator will also overheat and it burns all the insulating properties. They are very sensitive in nature and can either melt or catch fire easily. You may also face other problems like:

  • Warping of the rotor
  • Bearing start to melt
  • It also damages radiator core
  • Exhaust valves may damages valve guide
  • Overheating may also crush head gasket resulting in restricted coolant flow to the cylinder

Overheating of the generator may cause lead to damage many parts of it and they need to repair or replace. It also reduces the life limit of the generator.

Why do generators need cooling?

Generators are a combination of numerous conductors. And they produce a huge amount of heat when the current is flown through them. The heat generated by the conductors can damage the other important components of the circuits which can leads to power failure as it can’t be able to work properly.

So, in order to minimize the risk of damage, it is very important to remove the heat from the generator. This can also be possible by using different generator cooling methods. By using these methods you can easily eliminate the maximum amount of heat produced from the generators.

In summary

So far, here in this article, we have studied that generators can be used for various purposes. You can use them in your home, office, and industrial areas very easily. Depending upon the needs and usage of the power the size of the generators also varied.

But importantly all the generators need cooling as they produce heat while generating electricity.

In this article, we learn about the different Generator Cooling Methods. The air-cooled systems are best suitable for powering those small regions that need a very less amount of heat and electricity. You can easily give power to those resources that don’t consume more than 22kw energy. Whereas the liquid-cooled system is suitable for any kind of generator whether it is small or big. It is perfect for use in industrial areas.

So, now you are able to understand which type of cooling method you should choose for your generators. The choice is all yours. If you have any queries and suggestions then you can mention them in the comment box.

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