Vapour Cooling: Working Principle, Benefits and Applications

1. What Is Vapour Cooling?

Vapour cooling is a collective term for cooling technologies based on evaporation and condensation.

Instead of relying on solid-metal conduction alone, phase-change cooling utilizes latent heat transfer from a working fluid.

As a result, small amounts of fluid can absorb or release large quantities of thermal energy.

When operating within its limits, the liquid flows through the evaporator to absorb heat in a sealed two-phase device.

Then, it evaporates into vapour before moving toward a cooler area.

The vapour condenses and relinquishes thermal energy afterward.

Finally, liquid returns toward the evaporator to repeat the process.

Heat pipes, vapor chambers, and some two-phase thermosyphons use vapour cooling technologies.

However, they employ different internal designs and methods to achieve liquid return.

Heat pipes often include capillary wick structures to circulate fluid from the condenser to the evaporator.

Conversely, thermosyphons typically use gravity as the primary force for liquid return.

As a result, engineers should choose the appropriate technology based on their operating environments.

Please refer to 【What Is a Heat Pipe】 and 【What Is Vapor Chamber】 for more details.

2. How Does Vapour Cooling Work?

The vapour cooling process begins with a phase change from liquid to vapour.

It occurs in an evaporator after absorbing heat from a thermal source.

Afterward, vapour flows toward a condenser by following a pressure gradient.

The vapour then releases energy and condenses into liquid form.

Finally, liquid returns toward the evaporator to repeat the cooling cycle.

Step 1: Heat Absorption

Heat conducts into the evaporator from a hot surface or component.

The liquid inside absorbs heat energy from the evaporator.

Step 2: Evaporation

When the liquid absorbs enough heat, it changes into vapour through evaporation.

Latent heat allows phase-change technologies to transfer large quantities of thermal energy.

Step 3: Vapour Movement

The vapour flows toward an area with lower vapour pressure.

For example, vapour usually flows from the hot end to the cold end of a device.

Step 4: Condensation

The vapour releases heat when it arrives at the condenser section.

It condenses back into liquid after giving up heat.

Step 5: Liquid Return

The condensed liquid returns to the evaporator section to begin the process again.

A wick structure can generate capillary force to facilitate liquid return.

In other cases, gravity or a different mechanism forces liquid circulation.

Step 6: Repeat the Cooling Process

Finally, the vapour cooling process repeats while the device remains in its operating range.

3. Main Components of a Vapour Cooling System

Each vapour cooling technology employs unique internal components and structures.

However, most sealed two-phase devices have several common components.

3.1 Evaporator

The evaporator is the region that receives heat from the intended thermal source.

3.2 Condenser

Condenser regions transfer heat energy toward a cooler area or heat sink.

Furthermore, the condenser often integrates with fin stacks or other heat exchangers.

3.3 Working Fluid

A working fluid undergoes phase changes to transfer heat energy from hot to cold regions.

Heat pipes and vapor chambers typically use water as a working fluid.

However, other fluids can allow a system to operate at higher or lower temperature ranges.

3.4 Sealed Casing

The casing of the device contains the working fluid and internal vapour space.

As a result, engineers must correctly seal the device to prevent fluid leakage.

3.5 Wick Structure

Heat pipes and vapor chambers often use wick structures to circulate liquid through capillary force.

The wick is a porous structure that can transport liquid from the bottom to the top of a device.

Many types of wick structures exist, including sintered powder, grooves, and mesh.

3.6 Heat Dissipation Structure

Heat dissipation structures commonly connect to the condenser section of a device.

As a result, heat can dissipate into air or another liquid coolant.

For example, the fins on a heat sink allow heat to dissipate into the air.

4. Types of Vapour Cooling Technology

Many heat transfer technologies use vapour as part of their cooling process.

4.1 Heat Pipe Cooling

Heat pipes consist of a working fluid sealed inside of a hollow tube.

The fluid then evaporates when absorbing heat, then condenses when releasing heat.

Moreover, heat pipes use wick structures to assist in returning liquid to the evaporator.

As a result, heat pipes efficiently transport heat between hot and cold regions.

Computers, LED lightbars, and other electronics often use heat pipes.

See 【Heat Pipe Production Line】 to learn about heat pipe manufacturing equipment.

4.2 Vapor Chamber Cooling

A vapor chamber spreads heat through phase changes in a sealed flat structure.

Vapor chambers allow for two-dimensional spreading of heat, as opposed to heat pipes.

They excel at spreading large fluxes of heat from heat sources.

For this reason, vapor chambers often cool GPU and CPU chips. See 【Vapor Chamber Manufacturing Process】.

4.3 Thermosyphon Cooling

Similar to heat pipes, thermosyphons transfer heat via evaporation and condensation.

The major difference is liquid typically returns to the bottom of the device by gravity.

Orientation becomes important in these applications as a result.

Therefore, thermosyphons are applicable to industrial and selected electronics cooling.

4.4 Two-Phase Liquid Cooling

Two-phase liquid subcoolants can also transport heat through evaporation and condensation.

In this case, a pump or natural circulation moves the working fluid through a circuit.

The liquid absorbs heat, causing it to partially or fully vaporize.

After vaporization, the vapour travels towards a cooling area to release energy.

Finally, a pump or natural convection returns liquid toward the heat source.

4.5 Immersion Phase-Change Cooling

Immersion cooling puts electronic components into compatible contact with a dielectric liquid.

When certain components heat up, localised boiling will occur in the fluid.

The resulting vapour makes its way to cooler regions to condense.

Phase change occurs repeatedly to transfer heat energy away from components.

Fluid selection, containment, and maintenance are critical considerations for this technology.

5. Vapour Cooling vs Air Cooling

Air cooling transports heat energy away from electronics through airflow.

On the other hand, vapour cooling uses phase change to move heat within a device.

Air cooling and vapour cooling work together in many applications.

Take heat pipes, for instance, which often transport heat to an air cooled heatsink.

Phase change mechanisms can enhance heat transport away from high heat fluxes. Vapor cooling may help here.

This does not get rid of the heat. The system overall still needs a heat rejection path.

Engineers will want to analyze the full thermal loop.

6. Difference between Vapour Cooling and Liquid Cooling

Liquid cooling and vapour cooling both utilize fluids to manage heat.

The details of how they operate can differ though. Liquid cooling with a single-phase will transfer heat primarily through temperature gradients in the moving liquid.

Vapour cooling works off of evaporation and condensation. Two phase systems can leverage latent heat.

None of these technologies is superior for all applications.

Instead, engineers should assess heat load, available space, reliability requirements, and maintenance expectations.

Learn more: 【 Vapor Chamber vs Liquid Cooling 】

7. Vapour Cooling vs Heat Pipe Cooling

Heat pipe cooling is one type of vapour cooling system.

As a result, these terms are not interchangeable as descriptions of two different technologies.

Essentially, a traditional heat pipe features a sealed enclosure with internal working fluid.

Some models also contain a capillary wick structure.

The liquid evaporates and condenses while the device operates.

As a result, heat pipes conduct thermal energy using a vapour phase cycle.

On the other hand, vapour cooling includes a few other relevant technologies.

For instance, vapor chambers enable heat spreading across flat surfaces.

Thermosyphons, in some configurations, utilize gravity-assisted liquid return.

As such, heat pipe cooling is a subset of vapour cooling technology.

8. Benefits of Vapour Cooling

Efficient Heat Transfer

Heat pipes and vapor chambers achieve heat transfer through phase-change methods.

As a result, appropriate devices allow for efficient heat transport.

Compact Thermal Design

Small heat pipes and vapor chambers exist to fit inside small electronic products.

As a result, manufacturers can design thermally efficient products without using too much space.

Improved Heat Spreading

Vapor chambers spread point heat sources across a larger area.

As a result, they help decrease the temperature gradient.

Passive

Many heat pipes do not require a pump to move the working fluid from place to place.

This can minimize the number of moving parts in your thermal device.

Flexible Integration

Since heat pipes and vapor chambers can be placed alongside other technologies.

People can use them in conjugation with fins, heatsinks, and even liquid cooling.

High Heat Flux

Correctly configured two-phase systems can handle high heat fluxes.

Bear in mind that performance will vary by conditions and system limits.

Versatile Application

Vapor cooling is used in consumer electronics, commercial products, and computer systems.

9. Vapour Cooling Applications

Vapour cooling is used in many industries and applications.

CPU Cooling

CPUs can produce a lot of heat in a small area.

Heat pipes and vapor chambers can move heat to adjacent cooling fins.

GPU Cooling

Just like CPUs, GPUs can benefit from vapor chambers as a method of heat spreading.

Server Cooling

Servers need to remain on 24/7/365.

As a result, reliable heat transfer is key to consistent operation.

Telecommunication

Small form factor is usually required in telecom.

Heat pipes are great at moving heat to remote heatsink areas.

Industrial Electronics

Power supplies, converters, industrial controllers – these all generate heat.

Vapour based components can be used within these products.

LED Lighting

High power LEDs need to be cooled.

One way to cool them is by using heat pipes to draw heat away.

Aerospace

Heat pipes are used in some aerospace applications.

Take note that thermal design will change with gravity, orientation, and more.

Energy

Industrial energy systems use evaporation and condensation to move heat.

There are many applications for phase change cooling outside of electronics.

10. Vapour Cooling in Electronics

One of the biggest uses of vapour cooling is in electronics.

Electronic devices need to dissipate heat to prevent damage to components.

Today’s electronics pack more powerful components into tighter spaces.

As a result, thermal management is growing more difficult.

Laptop Cooling

Laptops will often use flat heat pipes.

These devices transport heat to a stack of cooling fins.

A fan then moves heat away from the fins and into the air.

Gaming Computer Cooling

Gaming computers can use several heat pipes or vapor chambers.

This allows heat to be spread across a larger cooling solution.

Server Cooling

Data center servers can produce a large amount of heat.

Heat pipes and vapor chambers can be used within certain thermal modules.

Direct liquid cooling may be more effective for some high power systems.

Power Modules

Power modules used in industrial applications can produce significant amounts of heat.

A specialized heat spreading solution can improve heat dissipation.

11. Vapour Cooling Manufacturing Process

The manufacturing process will vary slightly depending on the technology.

Heat pipes and vapor chambers go through several similar steps.

Step 1: Material Preparation

The manufacturer starts by selecting copper or a compatible material for the casing.

Fluid compatibility and intended use will determine material selection.

Step 2: Cutting and Forming

Next, the machine cuts the material to create the proper casing size.

An can help manufacturers prepare copper tubes.

Step 3: Cleaning

The manufacturer ensures that the internal surfaces are free of contaminants.

Doing so will help promote optimal thermal performance.

Step 4: Wick Manufacturing

A majority of heat pipes use some form of porous wick.

An can fill copper powder into the desired casing.

Step 5: Sintering

A will create a porous copper wick from the copper powder.

The machine will bond the copper particles while keeping the pores open.

Step 6: Vacuum Processing

The manufacturer places the cylinder into a machine that removes gases.

A can remove unwanted internal gases.

Step 7: Working Fluid Filling

Next, the machine fills the heat pipe or vapor chamber with working fluid.

A fills and seals heat pipes.

Step 8: Sealing

Finally, the manufacturer seals the cylinder to maintain the environment inside.

The better the seal, the less likely the device is to leak or become contaminated.

Step 9: Mechanical Forming

Heat pipes may need to be flattened or bent to meet design requirements.

Vapor chambers require specific shaping to match product specifications.

Step 10: Thermal Testing

The manufacturer tests thermal performance to ensure quality production.

A will ensure your heat pipes meet design requirements.

12. Vapour Cooling Equipment and Production Lines

Producing advanced vapour cooling components is no easy task.

You’ll need multiple machines to create a cohesive production system.

Equipment Main Function

Automatic Casing Cutter Cuts copper to the correct tube length

Heat Pipe Powder Filling Machine Fills copper powder to create a sintered wick

Vacuum Sintering Furnace Sintering machine to create porous copper wick

Heat Pipe Necking Machine Cuts heat pipe ends

Vacuum Degassing Machine Removes unwanted gases from inside the tube

Heat Pipe Filling & Welding Machine Automatically fills heat pipes and seals them

Heat Pipe Automatic Tail Cutting Cuts excess heat pipe tail material

Multi-station Thermal Performance Tester Tests thermal performance of heat pipes

Heat Pipe Multi-Station Dry-out Tester Tests heat pipes near maximum heat load

Vapor Chamber Production Line Produces vapor chambers

When selecting equipment, you should always consider your product design and desired output.

Also, a production line can minimize unnecessary handling.

Learn more: 【 Heat Pipe Manufacturing Line 】 & 【 Vapor Chamber Production Line 】

13. Key Factors Affecting Vapour Cooling Performance

A few factors will affect the performance of your vapour cooling system.

Working Fluid Selection

Not every working fluid works for every heat pipe.

Make sure the fluid you select works with your intended temperature range and material.

Wick Structure

The wick structure allows liquid to return to the heat source.

The pore size will affect the capillary pressure and permeability.

Internal Pressure

A heat pipe’s internal pressure will affect saturation temperature.

Manufacturers must ensure the internal environment is up to standards.

Heat Load

Just like any cooling device, there is a limit to what your vapour cooling device can handle.

Apply too much heat to the device and you’ll hit a dry-out limit or something similar.

Orientation

Heat pipes use liquid return to move heat from your heat source to your heat sink.

Because gravity can affect liquid return, some heat pipes are_orientation_dependent.

Condenser Cooling

Your condenser needs to be able to reject heat as well.

Without proper cooling of the condenser, your heat pipe is limited.

Manufacturing Quality

How well the device was made affects performance as well.

Poor filling techniques and leaky seals will degrade performance.

14. Challenges of Vapour Cooling Technology

Vapour cooling isn’t perfect and comes with several challenges.

Manufacturing Complexity

Two phase heat transfer devices require a controlled internal environment.

As such, manufactures need precision machinery to maintain tight tolerances.

Fluid Compatibility

Working fluids must be compatible with the materials used inside the heat pipe.

If the fluid corrodes the internal material, it could cause issues down the road.

Dry-out Limits

If too much heat is applied to the device, it will exceed the liquid return capabilities.

This results in a rapid increase in evaporator temperature.

Orientation Sensitivity

As mentioned before, some heat pipes are orientation_dependent.

Make sure the heat pipe you select will operate under the same orientations that your product will.

Sealing

Leakage will affect the internal environment of your device.

Strong welds and leak testing are important!

Cost

Heat pipes/vapor chambers and the equipment to make them aren’t cheap.

You as the manufacturer need to weigh the performance benefits against your cost.

15. How to Choose a Vapour Cooling Solution

No one wants to pick a cooling solution blindly.

Here are some things to take into consideration when selecting a vapour cooling device.

Consider the entire thermal system.

Heat Load

What heat load are you trying to cool? The cooling solution you pick needs to able to handle the thermal load.

Heat Source Size

Small heat sources can benefit from vapor chambers.

However, heat pipes are great at moving heat to other locations.

Space Constraints

You’re building something small? You’ll have to be smart about what heat pipe/vapor chamber you pick.

Operating Temperature

Just like fluid selection, make sure the structure will work with the desired temperature range.

Orientation

Will your device remain horizontal during operation? Will it change orientations?

Cooling Method

Will the heat from the condenser be cooled using air? Liquid? Something else?

Reliability

Look at sealing methods, material compatibility, max heat load, and more. Will the device work in your environment?

Production Needs

This goes back to my previous statement about equipment. You need to take into consideration your product design and how many you intend to make.

When you know what you want, picking a vapour cooling device isn’t that difficult.

16. Why Choose Bangwin Machine?

Bangwin Machine specializes in thermal management manufacturing equipment and customized production lines.

While they offer a variety of products, their focus is on heat pipes, vapor chambers, and heatsinks.

Click the link above to check out Bangwin Machine’s thermal manufacturing equipment.

Heat Pipe Manufacturing Equipment

Bangwin Machine has equipment solutions for nearly every stage of heat pipe production.

From cutting, powder filling, sintering, necking, vacuum processing, filling and welding, to testing.

Vapor Chamber Production Equipment

Need equipment to manufacture vapor chambers? Look no further! Bangwin Machine has you covered.

They offer everything you need to build your own vapor chamber production line.

Customized Production Lines

Every thermal management product is different. As such, you have the ability to customize your production lines.

Discuss fixture customization, automation, and machine configuration with the manufacturer.

Automated Testing Equipment

Ensure that your production quality is up to par with automated testing equipment.

Bangwin Machine has several machines that can test your heat pipes/vapor chambers.

Complete Production Lines

Remember how at the beginning I said you need multiple machines to create a production line?

Well, Bangwin Machine offers connected heat pipe production lines that will satisfy your needs.

Not only that, many of the production lines utilize some level of automation.

If you’re a manufacturer looking to develop vapour cooling components, Bangwin Machine is the company to talk to.

17. FAQ

What is vapour cooling?

Vapour cooling is a method of heat transfer that utilizes evaporation and condensation.

Vapour cooling is used in many thermal systems to efficiently transport heat.

How does vapour cooling work?

A working fluid absorbs heat and evaporates.

The vapour then travels to a cool area and releases its heat while condensing.

The liquid then travels back to the heat source.

Is vapour cooling the same as vapor chamber cooling?

No, vapor chamber cooling is not the same as vapour cooling.

Vapor chamber cooling is a type of vapour cooling.

Is vapour cooling better than air cooling?

No, they both have their uses. Vapor cooling is great at transporting heat.

Whereas air cooling is great at rejecting heat.

Many systems use both vapor cooling and air cooling.

Does vapour cooling require electricity?

No, not necessarily. Vapor pipes/vapor chambers do not require electricity to circulate the working fluid.

However, the overall cooling system may use electricity to power a fan or pump.

What fluids are used for vapour cooling?

Typically, the fluid used depends on the operating temperature and material the heat pipe is made from.

Copper heat pipes/vapor chambers typically use water as the working fluid.

Other fluids are used for more specific applications.

Can vapour cooling be used for GPU cooling?

Yes! Vapor chambers and heat pipes are common methods of cooling GPUs.

Is vapour cooling used for servers?

Yes, some server cooling solutions use heat pipes/vapor chambers.

Just remember to consider the heat load and cooling requirements.

What is the difference between vapour cooling and liquid cooling?

Vapour cooling deals with phase change, liquid cooling does not.

Single phase liquid cooling moves heat through a liquid without boiling the liquid.

What is dry-out in vapour cooling?

Dry-out occurs when there is not enough liquid in the evaporator.

As a result, the heat pipe/vapor chamber will not operate at maximum efficiency.

What machines are used to manufacture vapour cooling components?

Machines used can include: casing cutter, powder filling machine, sintering furnace, necking machine, vacuum degassing machine, filling & welding machine, tail cutting machine, thermal performance tester, dry-out tester, and vapor chamber production line.

Can I purchase vapour cooling manufacturing equipment from Bangwin Machine?

Yes, Bangwin Machine sells customizable thermal management manufacturing equipment.

Check them out to see the variety of heat pipes and vapor chamber machining they have to offer.

18. Conclusion

Vapour cooling is a method of heat transfer that takes advantage of evaporation and condensation.

Heat pipes, vapor chambers, and other two phase systems allow for heat to be transported from one area to another.

Not only does vapour cooling support CPUs, GPUs, and servers. It supports telephone systems and industrial electronics as well.

Just like liquid cooling, there are many factors that can affect the performance of your vapour cooling system.

Material selection, manufacturing process, heat load, orientation, and more can change the output of your device.

Manufacturing heat pipes/vapor chambers require several machines to ensure quality production.

Whether you’re looking for a heat pipe production line or a vapor chamber production line, Bangwin Machine can help.

Visit Bangwin Machine to see what thermal manufacturing equipment they can offer your business.<|end_of_document|>