Controller is possible to use one RX 3A speed controller for a few Blowair devices.
ENERGY-SAVING SPEED CONTROLLERS RX WITH THE SECURITY DEGREE IP52. Controller is used to control the speed in single-phase fans. It consists of 5 control levels 0 -70-85-105-145-230V, power supply voltage-230VAC / 50-60Hz, allowable current output:3A; protection: thermal breaker switch; dimensions: 126mm x 176mm x 56mm; weight: 1,3 kg.