SMSCOM MK2 Lite 4.5A Twin Fan Controller — Automatic Temperature Control for Intake & Exhaust Fans
Best for: Growers who want plug-and-play climate control without faffing about with manual adjustments or complex setup
Our thoughts
This is the controller we recommend most to growers stepping up from manual fans. Simple three-dial setup, no wiring needed, and it actually does what it promises — holds your temperature steady without running your fans flat out all day. One we sell a lot of for new growers building their first proper setup.
The SMSCOM MK2 Lite is a dual-socket fan speed controller that automatically regulates both your intake and extraction fans based on temperature. Plug your fans in, set your target temperature with three simple dials, and it calculates the exact speed needed to keep your room stable — no overshooting, no hunting around, just steady airflow. It's the kind of controller that's been trusted in UK grow rooms for years because it does the job without drama.
How it compares
This sits in the sweet spot between basic manual dimmers and premium smart systems.
- Proper automatic temperature control — fans speed up and down smoothly as your room changes temperature
- Simpler and cheaper than WiFi-enabled controllers, with no app faffing required
- More affordable than silent Hybrid models, though you may hear a slight buzz at low speeds
- Five-year warranty backing it up
You're paying for reliability and ease of use, not for bells and whistles you won't use.
Usage guidance
Setup takes minutes. No electrician, no hard-wiring, no complications.
Basic installation
Plug your intake fan into the left socket, extraction fan into the right. Plug the unit into the wall. Done. The temperature probe (5 metre cable) goes near the centre of your room, away from direct light or heat sources.
Setting your controls
Three dials control everything. Left dial sets your minimum fan speed (the slowest they'll run — useful if you're using oversized fans). Right dial sets your maximum speed (caps how hard they work). Middle dial sets your target temperature. The unit then automatically calculates the exact speed needed to hit that temperature, moment by moment.
Temperature management in practice
In summer, fans speed up to cool. In winter, they slow right down to avoid overcooling. The MOTION FLOW software adjusts speeds gradually, so you don't get temperature spikes — it's one of the reasons this controller keeps rooms so stable.
Negative pressure control
By controlling both intake and extraction simultaneously, you can dial in a balanced system with proper negative pressure. This keeps odours contained and fresh air flowing steadily — exactly what you need.
Noise consideration
At very low speeds, you might hear a slight buzzing from the fan motors themselves. This is normal with software-controlled fan speed adjustment. If silent operation is a priority, the SMSCOM Hybrid models run completely silent — but they cost more.
Technical specifications
- Type: Software-controlled dual fan speed controller
- Maximum capacity: 4.5 Amps (per socket)
- Sockets: Two independent outlets for intake and/or extraction fans
- Temperature probe: 5 metre cable, ±1°C accuracy
- Control method: Three mechanical dials (target temp, min speed, max speed)
- Temperature range: Adjustable via dial
- Software: MOTION FLOW — gradual speed adjustment to minimise temperature fluctuations
- Installation: Plug-and-play, no wiring required
- Power socket: IEC socket (standard kettle-type connector) for extended cable options
- Safety: Replaceable fuse protection
- Warranty: 5 years
- Available in: UK, EU, Swiss, and AUS plug configurations
Who this is for
- First-time growers setting up their first proper climate control
- Budget growers who want proven reliability without premium pricing
- Anyone running 2-4 tents or a single larger space needing temperature stability
- Growers with oversized extraction fans who need to dial them down in winter
- Operators who prefer simple mechanical controls over app-based systems
- Anyone tired of manual fan adjustments or temperature swings
Particularly well suited to setups where consistent, hands-off climate control matters more than advanced features.
Our take
This is a proper bit of kit. The SMSCOM MK2 Lite does exactly what a fan controller should do — holds your temperature steady, balances your airflow, and lets you get on with growing without thinking about it. It's been proven in UK grow rooms for years, it's got a solid warranty, and it doesn't ask you to learn an app or call an electrician.
If you're building a new room or upgrading from manual control, worth picking up while stock lasts. Does exactly what it should, day in, day out.
