Electric fans: how they work

In short: An electric fan moves air with rotating blades driven by an electric motor. It does not cool the air in the room, but the draught feels cooler on the skin.

In more detail: Moving air carries away the warm layer of air right next to the skin and makes sweat evaporate faster, which draws heat from the body. The motor itself actually gives off a little extra heat into the room.

In detail

• Drive: An electric motor turns the blades; several speeds can be selected with a switch or electronics.
• Cooling effect: Evaporating sweat and the constant exchange of air at the skin make the same room temperature feel more pleasant.
• Desk and pedestal fans: Angled blades push the air forwards along the axis; often the head swings back and forth to reach a wider area.
• Tower fans: A long, cylindrical impeller draws air in from the side and blows it out through a narrow slot as a wide, flat stream.
• Ceiling fans: Large, slowly turning blades move a lot of air quietly; on many models the direction can be reversed so that in winter warm air from the ceiling is gently spread downwards.
• Fans without visible blades: Here a blower in the base draws in air and forces it through a narrow gap in the ring, pulling surrounding air along with it.
• Energy use: A fan usually needs much less electricity than an air conditioner; because it cools people rather than the room, it should be switched off when leaving the room.
• Care and safety: Only dust the grille and blades from the outside while unplugged, do not open the motor housing, and make sure children cannot reach through the safety grille (klimaanlage-funktionsweise, luftreiniger-funktionsweise).