You have likely noticed that, even if you have climate control systems in your home, certain elements can feel very cold or very warm depending on the situation; this is due to their ability to transfer heat at different rates, known as thermal conductivity of materials.
At Inditer, we are a leading company in the heat exchanger industry, with over a decade of experience in the sector, providing solutions tailored to our clients’ needs. In this article, we present all the necessary information regarding thermal conductivity.
What is thermal conductivity?
Thermal conductivity is a physical property of materials that measures their ability to conduct heat. It refers to the capacity of a substance to transmit the kinetic energy of its molecules to other adjacent substances.
- It is an intensive quantity inversely related to thermal resistivity.
- Thermal conductivity varies according to the type of material.
- In pure metals, it usually remains approximately constant with temperature.
- It is measured in watts per meter-kelvin (W/m·K) in the International System of Units.
What is the thermal conductivity of materials?
The thermal conductivity of materials measures their ability to transfer heat to other substances in contact with them.
- In metallic solids, heat is transmitted via free electrons.
- Non-metallic solids are usually thermal insulators.
- Metals exhibit high thermal conductivity.
- Metals feel colder or hotter due to their rapid heat transfer.
- They transfer heat quickly.
- They absorb or release heat to the body or the environment.
- Wood is a poor thermal conductor.
- Thermal sensation depends on the heat transfer capacity.
Characteristics of thermal conductivity
- It depends on the composition and structure of the material.
- Metals have high thermal conductivity.
- Polymers usually act as insulators.
- It can vary with temperature.
- The presence of structural defects has an influence.
Thermal conductivity is specific to each material and is key in industrial applications.
How to determine the thermal conductivity of materials?
It can be determined using measurement methods based on heat transfer through a sheet of the material.
It is normally measured at a standard temperature of 300 K to allow for material comparison.
Factors such as pressure, geometry, surface area, and phase changes can influence thermal conductivity.
Benefits of thermal conductivity
Efficient heat transfer
Materials with high thermal conductivity allow heat to be dissipated quickly and efficiently.
Improved energy efficiency
They contribute to reducing thermal losses and improving the energy efficiency of buildings and systems.
Heat exchanger design
They are fundamental in the manufacturing of industrial heat exchangers.
Optimization of industrial processes
They allow for temperature control in industrial processes and improve production efficiency.
Thermal conductivity of copper
Copper exhibits a thermal conductivity of approximately 372–385 W/m·K, making it one of the best thermal conductors.
- High heat transfer.
- Used in heat exchangers.
- Excellent electrical conductor.
- High durability and resistance.
Thermal conductivity of aluminum
Aluminum has a thermal conductivity between 80 and 230 W/m·K.
- Heat exchangers.
- Kitchen utensils.
- Radiators and climate control.
- Electrical conductors.
Thermal conductivity of silver
Silver is the best known thermal conductor, surpassing even copper.
- Specialized electrical applications.
- Limited use due to its high cost.
Thermal conductivity of gold
Gold exhibits a thermal conductivity of approximately 318 W/m·K.
- High thermal transmission capacity.
- Surpassed only by copper and silver.
At Inditer, we use materials with high thermal conductivity in our heat exchangers, optimizing thermal transfer between fluids.