Description
Quiet, Efficient EC Extraction in an Airtight Steel Duct Fan
The Systemair K EC is the EC-motor version of Systemair's K circular duct fan, sold in the UK by G.A.S. (Global Air Supplies) as the K Fan EC. A backward-curved radial impeller on a high-efficiency external-rotor EC motor moves from 321 m³/h on the 4" (100mm) model up to 1,734 m³/h on the 12" (315mm) L, all inside an airtight galvanised steel casing that keeps stale, odour-laden air in the duct until it has passed through your carbon filter. Its speed is set by a 0–10 V signal from a G.A.S. digital EC controller, and seven sizes cover everything from a single grow tent to a full grow room.
Key Benefits
- EC motor with 0–10 V speed control — runs smoothly at low speed with no motor hum, so it can tick over quietly when the room is settled
- Over 50% lower running cost than the equivalent K AC fan, according to G.A.S.
- 321 to 1,734 m³/h across seven models for 4" (100mm) to 12" (315mm) ducting
- Airtight galvanised steel casing — air-tightness class C to EN 1751 and corrosion class C3, for leak-free extraction through a carbon filter
- Built-in electronic protection — thermal and locked-rotor protection with a soft start
- Fits in any position, indoors or out, using the supplied mounting bracket and 25mm spigots made for fast clamps
- Maintenance-free running, backed by a 2-year warranty
Heat, Humidity and Noise in the Grow Room
Grow lights pour heat into a tent or room and plants release moisture all day through transpiration. If stale air is not cleared fast enough the temperature climbs, humidity builds and the risk of mould and mildew rises; run an extractor flat out instead and you pay for the electricity and live with the noise. An AC fan slowed by a basic voltage controller can hum and lose torque at low settings. The K EC changes speed electronically, so it can run gently through lights-off and ramp up the moment heat or humidity rises, keeping airflow steady and the space at the slight negative pressure that draws every bit of exhaust air through the carbon filter for reliable odour control.
How to Use
- Size it to your space: multiply length × width × height in metres, then × 60 for one complete air change a minute, and add 25–50% for the carbon filter and ducting. A 1.2 × 1.2 × 2 m tent comes out at about 215–260 m³/h, which the 4" (100mm) model covers.
- Mount it: fix the bracket inside or outside the tent; the fan runs in any orientation, with the airflow arrow on the label pointing away from the carbon filter.
- Connect the ducting: push the ducting or carbon filter onto the 25mm spigots and secure each joint with a fast clamp so it stays airtight.
- Power it: the fan is pre-wired with an IEC connector — power it with a UK kettle lead (IEC C13), sold separately.
- Control it: link the fan to a G.A.S. digital EC controller with a G.A.S. Pack 8 active EC cable to set the speed by hand or let the controller follow the room temperature.
Technical Specifications
- Duct size: 100mm, 125mm, 150mm, 200mm, 250mm or 315mm
- Airflow: 321–1,734 m³/h
- Brand: Systemair (sold in the UK by G.A.S. as the K Fan EC)
- Type: EC circular inline duct fan with backward-curved radial impeller
- Airflow, 4" (100mm): 321 m³/h maximum
- Airflow, 5" (125mm): 482 m³/h maximum
- Airflow, 6" (150mm): 598 m³/h maximum
- Airflow, 8" (200mm): 774 m³/h maximum
- Airflow, 10" (250mm): 1,033 m³/h maximum
- Airflow, 12" (315mm) M: 1,415 m³/h maximum
- Airflow, 12" (315mm) L: 1,734 m³/h maximum
- Motor: EC external-rotor motor with integrated control electronics
- Speed control: 0–10 V signal from a G.A.S. digital EC controller (Pack 8 active EC cable)
- Supply: 220–240 V single phase, 50/60 Hz
- Motor protection: integrated electronic thermal protection, locked-rotor protection and soft start
- Enclosure: IP44 motor, IP55 terminal box
- Casing: galvanised sheet steel, corrosion class C3, air-tightness class C (EN 1751)
- Impeller: backward-curved, glass-fibre-reinforced polyamide, dynamically balanced
- Power connection: IEC connector; UK mains lead not included
- Installation: any position, indoors or outdoors; mounting bracket included; 25mm spigots for fast clamps
- Warranty: 2 years
Frequently Asked Questions
Can I use an ordinary AC fan speed controller with the K EC?
No. The K EC takes its speed from a 0–10 V control signal, so it needs an EC controller such as the G.A.S. digital EC range, linked with a G.A.S. Pack 8 active EC cable. A triac or voltage controller made for AC fans cannot control it and should not be wired into its supply.
Does it come with a plug?
It is pre-wired with an IEC connector rather than a UK plug, so you need a UK kettle lead (IEC C13) to power it, sold separately.
Which size do I need for my tent?
Work out the volume in cubic metres, multiply by 60 for one air change a minute and add 25–50% for the carbon filter and ducting. A 1.2 × 1.2 × 2 m tent needs roughly 215–260 m³/h, within the 4" (100mm) model's 321 m³/h; a 2.4 × 1.2 × 2 m tent needs roughly 430–520 m³/h, which suits the 6" (150mm) at 598 m³/h.
What is the difference between the 12" M and L?
Both fit 315mm (12") ducting. The L is the higher-output model at 1,734 m³/h against the M's 1,415 m³/h, for large rooms, long duct runs or big carbon filters.
Will I get the full rated airflow?
The figures are maximum free-air ratings. A carbon filter, long duct runs and bends all add resistance, so real airflow is lower — which is why the sizing rule above adds headroom.
Works Well With
