Although notebooks have developed much in recent history they continue to generate great amounts of heat. The amount of heat generated has gone up due to the immense power of notebooks today. The heat is dealt with by cooling systems, which are often designed specifically for a specific notebook.

Let’s start off with something basic, metals. There are generally two metals used for notebook heatsinks, copper and aluminum. A major reason is due to their high heat conductivity, 400 W/mK and 255W/mK at 125C.

Though the cooling system will vary from model to model, the concept will not. Let’s start at the components. There are several heatsink forms you may find in a notebook and a couple you will definitely find.

1) Extrusion
Though not common in the average notebook, extruding heat sinks are seldom found in high-end gaming machines. Though not used in the main cooling system they are often used on the ACPI (Advanced Configuration and Power Interface).

2) Die-cast
Die cast heatsinks are in almost every notebook on the market. Generally fitted to the CPU and GPU the heat sink is attached to a heatpipe building the bulk of the cooling system.
Though rare, in order to save costs, the contact surface may be milled. If the color is uniform then the heatsink was not milled, if there is a swirl pattern the heatsink was milled. By milling the contact surface of the heatsink is smoother allowing better contact.

3) Heat Pipes
Heatpipes are designed to channel heat away from components such as GPU and CPU. On desktop heatsinks heatpipes are generally round, though in notebooks they are flat. This is to increase surface area and increases the coppers density and rigidity. Heatsinks may have a cover or a casing around them.

4) Bonded/Folded Fin
Fins are used in nearly all if not all notebooks on the market today. They are connected to the end of a heatsink that channels heat from the CPU and GPU to the fins. The fins are usually at the exhaust of a fan.

It is a simple yet effective form of heatsink as aluminum or copper plates are bonded to a base plate. A bonded fin heatsink is when each fin is made out of a separate plate. Folded fin heatsinks are made of a large single plate that is folded to form fins. Notebooks do not contain the latter.

Bonded	Folded

They are used due to their high surface area and low weight, though if the bonding is not properly done performance of the heatsink takes a toll.

5) Forged
Forged heatsinks like extrusion are not common in notebooks. If found, they are usually attached to the ACPI and are not part of the main cooling system.

Now that we have the different types of heatsinks that you may find in a notebook it is time to continue on to other components of a cooling system.

Fans
The fan is very important. It pushes the heat out of the notebook. Most notebooks have at least a single fan, while high end gaming systems often have two or more. The RPM of a notebook fan will vary depending on the notebook and the fan manufacturer. Unfortunately there is no way to calculate an average speed let alone a range due to confidentiality by the companies.

There are several locations that a notebook will exhaust the heat, read our Notebook Coolers Buyers’ Guide for the specific locations.

Thermal Paste/Pads

Thermal paste and pads are the bridge between a notebook’s hardware and the cooling system. Both are applied to CPUs, GPUs, and if a heatpipe is rather close to the heat sink it may be used.

Thermal paste is a liquid substance that is greasy which increases the thermal conductivity of a thermal interface by compensating for irregular surfaces. There are several types which include, ceramic, metal, carbon, and liquid metal.

Thermal pads are often used by notebook manufacturers rather than thermal paste. Thermal paste can cause a mess during installation, though thermal pads are simple to install making it more reliable for mass production. Unfortunately it does not perform as well as thermal paste.

For more on thermal paste, pads and adhesive please read our Thermal Paste Guide. (Coming Soon)

Let’s put it all together
The first diagram (below) displays the basic components of a notebook cooling system. Though it may not be always laid out this way it will often have a similar concept.

(click for larger view)

Here are some examples of other layouts of cooling systems.

This diagram is to show how heat is channeled away from the parts. As you can see, other than the ACPI the majority of the heat is transferred along the heat pipes to the fin exhaust heatsink and cools down the heatsink. The ACPI heat would likely dissipate through a vent.

In conclusion we hope that you have a better understanding of what a notebook cooling system consists of, what role each part plays, and how it works.