Wolter · 2 series
Duct fans for rectangular ducts
A duct fan fits straight into the ductwork and needs no plant room. Wolter builds two series for rectangular ducts — with forward-curved and with backward-curved impellers — in standard and insulated casings.
Wolter rectangular duct fans can be installed in any position. The impeller sits on an external-rotor motor, and the speed can be controlled over the full range by a transformer or electronic controller.
- EKN / DKN — forward-curved (drum) impeller, sizes 200–450; EKNS/DKNS in a sound-insulated casing.
- EK / DK — backward-curved impeller, sizes 175–400; EKS/DKS in an insulated casing, ZW and TR twin and triple models.
E in the code means a single-phase 230 V motor, D a three-phase 400 V motor. Both series are available in explosion-proof versions.
Series
Wolter duct fan series
EKN / DKN — forward-curved duct fans
Rectangular duct fan with a drum impeller on an external-rotor motor; EKNS/DKNS in a sound-insulated casing, sizes 200–450.
EK / DK — backward-curved duct fans
Rectangular duct fan with a backward-curved impeller: insulated EKS/DKS, twin ZW and triple TR models, sizes 175–400.
Series comparison
Accessories
The manufacturer offers JK volume-control dampers, SDK/SDKN silencers, TFK bag-filter sections, EVK/EVKN flexible connections and NE, RTD and RPE speed controllers for its duct fans, so a system can be assembled from ventilation equipment of one programme.
Typical uses
Duct fans serve ventilation and air-conditioning systems, including extract from toilets and plant rooms. For round ducts, see inline tube fans; for quiet operation at higher airflow, cabinet fans; for car-park extract by two independent fans, the GAES / GADS units.
What we need for a selection
Airflow, system resistance, duct size, permissible noise level and power supply. We select the series, size, casing version and accessories.
Applications
Where they are used
FAQ
Frequently asked questions
Can the speed of a duct fan be controlled?
Yes. External-rotor motors can be controlled over the full range by a transformer or electronic controller; Wolter offers NE, RTD and RPE controllers for them.
Are explosion-proof duct fans available?
Yes, EKN/DKN and EK/DK come in explosion-proof versions with PTC thermistor-protected motors. The manufacturer does not publish ATEX zone data, so we confirm suitability for a specific zone at selection.
In what position can the fan be installed?
Any — EKN/DKN and EK/DK rectangular duct fans can be mounted in the duct in any position.
Need equipment selection or a system design?
Send us the layouts or the brief — we will prepare a selection, a calculation and a quotation.