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Description
The K Fan EC is the EC-motor version of the German-built K Series circular duct fan — the same industrial ventilation platform behind the Systemair RVK, but with the motor control and protection electronics built into the fan itself.
Because an EC (electronically commutated) motor varies its speed by changing the motor's actual drive frequency rather than by throttling the voltage, it runs smoothly right down to low speeds with no hum, no buzz and no transformer whine — and it draws only the power it actually needs. Global Air Supplies quote a saving of over 50% on running cost against the equivalent K Fan AC.
- EC motor with integrated control and protection electronics
- 0–10V speed control — runs quietly at low speed, no humming
- Over 50% lower running cost than the equivalent AC fan
- Built-in thermal overload protection
- Maintenance-free galvanised steel casing
- Made in Germany
- 2 year manufacturer warranty
Please read before you order — this fan does not come ready to plug in
To power it, you need a 13A stripped-end lead. The K Fan EC has no plug and no kettle-lead socket. It terminates in a sealed IP55 terminal box, so the mains supply is wired directly into the fan. The part you need is the 13A Fitted Plug with Stripped End (3m) — moulded UK plug at one end, bare conductors at the other, ready to land straight into the terminal block. Five minutes for anyone comfortable wiring a plug; if that is not you, have an electrician do it.
To run it from a controller, you also need a Pack 8 cable. The K Fan EC talks to G.A.S. digital controllers over their own connector, so add a GAS Digital EC Cable (Pack 8) — 5m Active Male to Male. That is the one for a single fan into a single controller. Running two fans off one controller? Add a Pack 9 Active Y-Splitter as well.
Which controller? For straightforward speed control, the GAS AC-EC Fan Speed Controller handles both EC and AC fans and is the natural pairing. If you want temperature and humidity control, or you have more kit to run than just a fan, step up to the GAS Enviro Controller V4 (26A) — it manages your environment rather than just your fan speed. Both are in the fan speed controller range. Running a TrolMaster? See the section below.
Before you buy — two more things worth knowing
1. An EC fan needs an EC controller. This is the single most common mistake we see. You cannot run an EC fan from a standard AC / triac voltage controller such as the SMS Twin — it will not work and you risk damaging the electronics. The K Fan EC takes a 0–10V signal, which is why the controllers listed above are the ones to pair it with.
2. The airflow figures are free-air maximums. Every quoted m³/h figure on every fan on the market is measured with nothing attached. Put a carbon filter on the intake and a few metres of ducting on the outlet and you will realistically see 60–75% of that number. Size up accordingly rather than buying exactly to your calculated requirement.
Running it on a TrolMaster Tent-X or Hydro-X
You need two parts — the EFC-1 and a Pack 8 cable
TrolMaster controllers do not take the G.A.S. connector directly, so there is one adaptor in the middle. Add both of these to your order:
- TrolMaster EC Fan Controller (EFC-1) — the adaptor that plugs into your Tent-X (TCS-1) or Hydro-X base station
- GAS Digital EC Cable (Pack 8) — the lead between the fan and the EFC-1
How they join up: the Pack 8 plugs into the fan at one end. The other end you cut off, strip the conductors back, and land them into the terminal block on the EFC-1. The EFC-1 then plugs into your Tent-X or Hydro-X on its RJ12 lead.
Do not go by the wire colours. The colour coding on these cables has changed more than once, so older guides and diagrams no longer match what is in the box — which is why we do not publish a colour code. Work it out by trial and error instead. This is the low-voltage 0–10V control pair, not mains, so nothing is at risk if you get it the wrong way round: the fan simply will not respond to the controller. Try each combination, change the setpoint on the controller, and watch for the fan speed responding. Stop when it does. Only ever cut and rewire the Pack 8 control cable — never the 13A mains lead. If you get stuck, give us a ring and we will talk you through it.
Sizes and airflow
| Model | Duct size | Max airflow (m³/h) | Typical tent |
|---|---|---|---|
| K 100 EC | 4" / 100mm | 321 | Up to 80 x 80cm |
| K 125 EC | 5" / 125mm | 482 | 80 x 80 to 100 x 100cm |
| K 150 EC | 6" / 150mm | 598 | 100 x 100 to 120 x 120cm |
| K 200 EC | 8" / 200mm | 774 | 120 x 120 to 150 x 150cm |
| K 250 EC | 10" / 250mm | 1033 | Small grow room |
| K 315M EC | 12" / 315mm | 1415 | Grow room |
| K 315L EC | 12" / 315mm (long body) | 1734 | Large grow room |
Specification
| Detail | Value |
|---|---|
| Motor type | EC, integrated control electronics |
| Supply | 230V, 50/60Hz, single phase |
| Speed control | 0–10V via G.A.S. digital controller (Pack 8 cable required) |
| Mains connection | IP55 terminal box (hard wired, no plug or lead supplied) |
| Motor protection | IP44 (terminal box IP55, cable gland IP68) |
| Insulation class | B |
| Max air temperature | 40°C |
| Casing | Galvanised sheet steel |
| Warranty | 2 years |
| Origin | Made in Germany |
As a worked example, the K 315M EC draws 166W at 2117rpm for 1415 m³/h, weighs 6kg, and measures 314mm bore x 408mm casing diameter. Figures published by Systemair.
What else you will need
- 13A Fitted Plug with Stripped End (3m) — required, this is how the fan gets its mains supply
- GAS Digital EC Cable (Pack 8) 5m Active Male to Male — required if you are running the fan from a controller
- GAS AC-EC Fan Speed Controller — speed control for EC and AC fans
- GAS Enviro Controller V4 (26A) — full temperature and humidity control when you have more than a fan to manage
- TrolMaster EC Fan Controller (EFC-1) — only if you are running the fan from a TrolMaster Tent-X or Hydro-X
- Rhino Pro Carbon Filter — match the filter's m³/h rating to the fan, not the other way round
- Phonic Trap Ultra Silent Acoustic Ducting or standard acoustic ducting — the fan is quiet, so duct noise becomes the loudest part of the system
- Quick Connection Kit and jubilee duct clips for a secure, leak-free join
Alternatives worth comparing
We would rather you bought the right fan than the most expensive one. Here is how the K Fan EC sits against the rest of our range.
| Fan | Type | Why you might pick it instead |
|---|---|---|
| Rhino Ultra Silenced EC Fan | EC, acoustically insulated | Similar money, similar airflow, but wrapped in acoustic insulation. If noise is your priority this is usually the better buy. |
| Air EC Fan | EC, entry level | The budget route into EC. Less refined and a shorter warranty, but a big step up from any AC fan on running cost. |
| Systemair RVK | AC | Same German factory, same reliability, a fraction of the price. You lose the quiet low-speed running and the efficiency. |
| Can-Fan Isomax | AC, silenced | The classic quiet AC option, with a stator-rotor design that keeps noise down without EC electronics. |
| Revolution Super Silent Vector EC | EC, high power | When 1734 m³/h is not enough. 315mm and 355mm, up to 5929 m³/h. |
| Air AC Fan | AC, entry level | The cheapest way to move air in a single tent, if budget is the deciding factor. |
Browse the full EC fan range or the AC duct fan range.
Frequently asked questions
What is the difference between an EC fan and an AC fan?
An AC fan runs at a fixed speed set by the mains frequency, and you slow it down by reducing the voltage — which is what causes the hum and buzz you get from a cheap controller at low speed. An EC fan has a DC motor with a built-in inverter that generates its own drive frequency, so it can be told to run at any speed and does so smoothly and quietly. EC motors are also substantially more efficient, particularly at part load, which is where most extraction fans spend their lives.
Can I use my existing SMS or triac fan controller with the K Fan EC?
No. Voltage-regulating AC controllers such as the SMS Twin will not control an EC fan and may damage it. You need a 0–10V controller. The GAS AC-EC Fan Speed Controller handles both AC and EC fans, so it will cover you if you are running a mixed setup, and the GAS Enviro Controller V4 adds temperature and humidity control on top. Either way you will also need a Pack 8 EC cable to connect the fan to the controller.
Can I run the K Fan EC from a TrolMaster Tent-X?
Yes, with two extra parts. You need the TrolMaster EC Fan Controller (EFC-1), which is the adaptor that plugs into your Tent-X (TCS-1), and a GAS Digital EC Cable (Pack 8) to bridge the fan to it. The Pack 8 plugs into the fan at one end; you cut the other end off and wire the bare conductors into the EFC-1's terminal block. Ignore the wire colours — they have changed between batches, so it is a matter of trying each combination until the fan responds when you move the setpoint. It is a low-voltage control signal, so a wrong combination does no damage. The same applies to a Hydro-X base station.
Does the K Fan EC come with a plug or a lead?
No — and it does not take a kettle lead either. The K Series uses a sealed IP55 terminal box, so the mains supply is wired directly into the fan. Add a 13A Fitted Plug with Stripped End (3m) to your order: moulded UK plug at one end, stripped conductors at the other, which land straight into the terminal block. It is the same lead our RVK customers use. If you would rather have something you can simply plug in and go, the Rhino Ultra Silenced EC is the one to look at.
How do I wire it up?
Unscrew the lid of the terminal box on the side of the fan casing, feed the stripped end of the 13A lead through the cable gland, and land live, neutral and earth on the marked terminals. Tighten the gland so the seal is made and refit the lid. The control side is simpler — the Pack 8 cable plugs straight into the fan at one end and your controller at the other, no wiring involved. If you are not confident with the mains side, have an electrician do it; it is a ten minute job for them.
Which EC cable do I need — Pack 8 or something else?
For one fan into one controller, the Pack 8 (5m Active Male to Male) is the one. If you want to run two fans from a single controller channel, add a Pack 9 Active Y-Splitter. Need more reach? The Pack 11 Active Female to Female Extension adds length to an existing run. If you are unsure, tell us your fan, your controller and the distance between them and we will tell you exactly what to order.
What size K Fan EC do I need for my tent?
As a rule of thumb, work out the volume of your space in cubic metres and aim to exchange the air once every one to three minutes, then add roughly 30–40% headroom for the resistance of a carbon filter and ducting. A 120 x 120 x 200cm tent is 2.88m³, so you want somewhere around 350–500 m³/h of real-world airflow — which is the 6" or 8" in this range once the filter is accounted for.
Which way round does it go?
Airflow direction is marked on the casing. For odour control you want the carbon filter on the intake side, inside the tent, pulling air through the filter and then out through the fan — not blowing into it.
Is it quiet?
For an uninsulated inline fan, yes — particularly at reduced speed, where an EC motor has a real advantage over AC. But it is a bare metal fan, not a boxed acoustic unit. If silence matters more than anything else, either pair it with Phonic Trap acoustic ducting or look at the Rhino Ultra Silenced EC, which is insulated as standard.
What is the warranty?
Two years from the manufacturer. The motor is maintenance-free and has thermal overload protection built in.
K Series fan specifications published by Systemair. K Fan EC supplied in the UK by Global Air Supplies.
