SMSCom 4.5A Twin Fan Speed Controller Mk2

Keep intake and outtake fans working as a pair

The SMSCom Twin Fan Speed Controller Mk2 is the ideal climate control for any room running both an intake and an outtake fan. It is software regulated and holds your grow room within +/- 1 degree of your set temperature, adjusting both fans smoothly and fluidly rather than snapping between speeds. Crucially it is designed to always run your out fan slightly faster than your in fan, keeping the room under negative pressure so odours stay contained.

Key Benefits

• Twin fan control for coordinated intake and outtake
• Holds temperature within +/- 1 degree of your set point
• Maintains negative pressure by keeping the out fan ahead of the in fan
• Smooth, fluid speed changes instead of abrupt stepping
• Runs a single fan too, if you do not need both
• Plug and play, both fans connect directly with no extra wiring

Negative pressure drifting as fans speed up and down?

When intake and outtake fans are not coordinated, negative pressure slips and odours escape through gaps and tent seals. The twin controller deliberately biases the out fan faster to hold that inward pull. This applies with free-flowing fans not fitted with a filter, and we recommend your out fan is around 25% more powerful than your in fan for the best result.

How to Use

• Plug both fans directly into the twin controller, no extra wiring
• Position the probe at canopy height for an accurate reading
• Set your target temperature and let the software balance both fans
• For best negative pressure with unfiltered free-flowing fans, size the out fan roughly 25% stronger than the in fan