Dry or Fluid Inertia Radiator: We Help You Choose

Posted on 11 April 2022 

After spending 14 hours comparing 29 models by writing our comparisons, here are our tips to help you choose between dry or fluid inertia radiators.


The dry inertia radiator, ideal for living rooms

Radiateur à inertie sèche

  • Good resistance to time
  • Little temperature variation
  • Good heat release over time
  • Usually fixed solution
  • More expensive to buy
  • Slower temperature rise

The heating core of a dry inertia radiator is made of refractory material: this can be metal (cast iron or aluminium) but it is preferable to choose stone (ceramic brick, marble, granite or volcanic stone), as it accumulates heat even better.

This type of material has a very low temperature variation. Therefore, it takes a little longer to heat up, but it also gives off heat for a long time.

These radiators have the advantage of durability, but they are generally more expensive to buy and weigh more. This is the type of device that is usually left in a room, without trying to move it.


The fluid inertia radiator, interesting as a back-up solution

Radiateur à inertie fluide

  • Faster heating
  • Easier to move
  • Cheaper
  • Less sustainable
  • Less heat storage capacity
  • Consumes a little more electricity
  • May make some noises

Fluid inertia radiators work with a heat transfer liquid (glycol water, or vegetable or mineral oil), in which a resistor is placed. The resistor then heats up, while the liquid rotates in a closed circuit. It is a heating method similar to that of a central heating system, but without the difficulty of connections.

With this type of radiator, heating is faster. This makes it interesting for rooms that are not heated all day, such as bathrooms (provided the radiator is protected against humidity) or bedrooms. It is also generally easier to move because it has wheels and a handle.

However, although it is cheaper to buy, it is also less resistant in the long term since fluid leaks can occur.


In conclusion

Inertia radiators, whether dry or fluid, have the advantage that they store heat and continue to release it even after the device is switched off. They are therefore both preferable to other electric heating systems. However, they differ in the nature of their heating core.

More durable but also heavier, dry inertia radiators are more suited to main living areas. In a large room, it is preferable to install two radiators at medium power rather than one at maximum power. Fluid inertia radiators are less expensive and ideal for heating bedrooms or bathrooms quickly.

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