Most windows, especially older ones, let in a little air anyway and if the radiators are beneath them they will circulate that air.

Then someone suggested an alternative-a small fan to circulate the air around me.

The fans that circulate the air use less electricity than a light bulb.

Ventilation was natural, relying primarily on the piston effect of trains pushing through the tunnels to circulate the air.

Or a fan-assisted oven that use a small fan to circulate the air in the cooking chamber, can be used.