What power of electric heater to choose?

To properly heat your home without breaking the bank, it is important to make sure you choose the right power for your electric heaters. However, this choice is not so simple since several criteria must be taken into account, such as the location of the accommodation, its insulation, the volume to be heated or the desired temperature comfort. Let’s do a check in.

What are the criteria to take into account to determine the power of an electric heater?

To properly assess the power of an electric heater, it is important to take into account several criteria.

The volume of the room to be heated

Considering the volume is important, because a radiator that lacks power will run continuously and wear out prematurely to heat an area too large for it. Conversely, a too powerful radiator will never really work properly and can be exhausted by its disproportionate power.

To estimate the correct power of an electric heater, it is necessary to base oneself on the volume of the room or its surface.

  • In terms of surface, there are 85 W/m².
  • In terms of volume (which is obtained by multiplying the surface of the room by the height under the ceiling), we count 30 W/m3.

Here is the recommended power according to the surfaces and volumes:

  • For a room of less than 10 m² (about 25 m3) : 750 W
  • For a room of 10 to 15 m² (about 35 m3) : 1 000 W
  • For a room of 15 to 25 m² (about 50 m3) : 1 500 W
  • For a room of more than 25 m² (more than 55 m3): at least 2000 W

Also, for large rooms, be aware that it makes more sense to install two or more radiators than a single unit that will run at high power all the time. It is indeed more economical to distribute heat sources and this makes it possible to obtain a more harmonious effect.

The location of the accommodation

In an area where the outside temperature is very cold, the impact on the inside temperature will be greater, so you will need more powerful radiators. Count about 10% more as you cross altitude stages of 500 meters.

Likewise, the exposure of the rooms in the dwelling is important. Rooms facing south will naturally be heated more by the sun’s rays than those facing north. You can therefore reduce the heating power by around 10 to 15%.

The quality of the insulation

The more your home is insulated, the less heat loss you will experience. As a result, your radiators will work less to heat better. It is useless to invest in efficient appliances if the insulation of your home is poor. It is recommended to review the latter before or at the same time so that your investment is profitable for you and allows you to make real energy savings.

The comfort temperature

Of course, the comfort temperature is important. If you are chilly, you will appreciate a more powerful radiator than if you tolerate low temperatures. Likewise, if you have young children, a higher temperature may be necessary, especially in the event of a cold or minor ailments. As for the bathroom, it is a separate room which requires a rapid rise in temperature, but only when it is used. It is therefore important to choose the right model.

What is the recommended ideal temperature per room?

Depending on the rooms, the recommendations for the ideal temperature may vary. Here they are with the recommended number of Watts per cubic meter.

  • In a living room, kitchen or office, the recommended temperature is 20°C, or 77 W/m3.
  • In a bedroom, the recommended temperature is 18°C, or 70 W/m3.
  • In a bathroom, the recommended temperature is 22 to 24°C, or 85 to 93 W/m3, but only when in use.

What are the specific parameters to take into account?

To perfect your choice of electric heater, be aware that some very specific parameters must also be taken into account.

  • Wet rooms: for these, you need about 20 to 25% more power.
  • Rooms at altitudes and rooms exposed to the north: for these spaces, count 10 to 20% more power.
  • South-facing rooms: for these sunny rooms all day, allow 5 to 10% less power.
  • Adjoining rooms: in this case, a power reduction of 20% is possible.

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