The ADDA fans offered by SEPA EUROPE are also available as temperature-controlled versions in numerous sizes. A sensor at the hub of the motor (see photo) controls the speed which changes linearly with the rise in temperature. This type of fan control is not only simple but ingenious. When the air flow on the outlet side is below 25°C, the fan rotates moderately at around half the subsequent nominal speed. This is achieved at a warm air flow of approx. 50°C. The speed increases linearly and infinitely variably between room temperature and 50°C. The resulting effects are immense, as notably both the noise and the current consumption decrease considerably when the speed is reduced and the full performance is only required when absolutely necessary. A current consumption of 54 mA and a noise of 24 dB(A) was measured on the conventional and popular fan AD 1212HB-A78 (120x120x25 mm) at 25 °C and a speed of 1150 rpm. Furthermore, a current consumption of 155 mA and a noise of 39 dB(A) was measured at a temperature of 50°C and a speed of 2080 rpm.

It is not difficult to recognize that the reduction of the noise in particular, holds considerable potential. The major advantage i s that electronic devices for controlling the speed are not required. One therefore, achieves a demand-controlled cooling solution with a fixed DC voltage.