Is Water a Good Thermal Conductor?

Any material that allows thermal charge to pass through is known as a good thermal conductor. We see hundreds of such examples in daily life as well, such as metals. Though it is clear about the properties of metals and what makes them a good thermal conductor, not many of us are aware is water a good thermal conductor or not.

Water is a basic requirement for all, and it is used by every human being. Other than human consumption, water is needed in an array of applications, industries, and trades. Knowing whether it is a good thermal conductor or not is therefore crucial for all.

Before you get to know the answer to the question, let’s have a quick recap of what thermal conductivity actually is and why it is important to learn about it.

What is thermal conductivity?

It refers to the process of transfer of heat through a specified material that flows per unit time. In simpler words, it is the measurement of the potentiality of heat conduction. A material that has the capability to disseminate heat has thermal conductivity.

If heat can travel or pass through an object, it is said to be a good thermal conductor, and if the object does not allow the heat to move, it will be known as the insulator. An insulator will automatically be a poor conductor.

Objects that do not have free electrons to allow heat to pass through, such as glass, mineral wool, are good insulators. They will have poor thermal conductivity.

On the other side, if an object has free electrons to allow heat to pass through, such as aluminum, zinc, and copper, these materials are good conductors of heat, and the heat will move quickly.

Is water a bad thermal conductor?

Now, as you understand what thermal conductivity means, we will see what the case with water is.

Liquids are typically rated as poor conductors of heat, and the same goes for water. Water is not a good thermal conductor. It is, in fact, classified as a good insulator.

Having said that, if a liquid is exposed to enough heat for a longer period of time, it will eventually conduct heat and will become hot. Water is a thermal conductor, and we have felt its effects on a hot day.

Another take is that water is not a good thermal conductor against most of the metals. However, when compared to air, water is a good thermal conductor.

So, it all depends on which you are comparing the water with. Talking about it in general, water is a good insulator and is a bad thermal conductor. Water’s ability to absorb and retain heat is what makes it stand and useful for industries and trades.

What are the top good thermally conductive materials?

If not water, then what are other materials that are rated as a good thermal conductor? Keep in mind that it is the excess number of free electrons in materials that allows the thermal energy to pass through that makes the material a good conductor. There are several elements that are known as good conductors. Among all, a few of them are listed below.

  • Diamond
  • Gold
  • Silver
  • Tungsten
  • Graphite

Along with these top 5 materials, copper, zinc, aluminum, and silicon carbide also lie in the category of good thermal conductors.

Some materials and elements are better conductors of heat than others; it all depends on their individual characteristics and properties. In the case of water, it can absorb and retain heat but cannot be classified as a good thermal conductor. Not to forget, the water thermal conductivity also depends on various other factors such as temperature, pressure, and the presence of any other material near to it.


Water is used in a variety of applications, including for the purpose of heating and cooling in industries. This makes it important that you know the concept of thermal conductivity and whether the water is a good thermal conductor or not. After reading this, can you tell how you can use the water to keep us warm when we are cold?