Duct Fan Diagonal 400mm 6890 m³/h 300 Pa IE3 Motor IP55, Harmann

Quick Facts — Harmann Duct Fan MAXEE 400/4/6800T

• Diagonal duct fan, 400 mm connection
• Maximum capacity 6890 m³/h, max pressure 300 Pa
• Three-phase IE3 motor, 3~400 V, 50 Hz
• Speed control via frequency inverter 20–70 Hz
• Motor protection IP55, insulation class F
• Steel housing powder-coated RAL 7012, corrosion class C3
• Weight 23.2 kg, horizontal or vertical mounting

The Harmann MAXEE 400/4/6800T is a medium-pressure diagonal duct fan designed for transporting clean, dust-free air in supply and extract ventilation installations. The fan is built for mechanical ventilation systems that require high capacity, stable pressure and the ability to mount directly in the duct run.

The diagonal impeller design combines favourable flow parameters with a compact steel housing. The fan achieves a maximum capacity of 6890 m³/h and a maximum pressure of 300 Pa, making it suitable for medium and larger duct installations where air must be effectively transported through ducts, grilles, dampers, silencers, filters or other system components.

How does the fan perform in duct installations?

The Harmann MAXEE 400/4/6800T is built for systems requiring stable capacity and medium available pressure. The capacity of up to 6890 m³/h makes it usable in extended general ventilation installations, and the maximum pressure of 300 Pa lets it overcome typical resistance from ducts and installation fittings. The diagonal flow characteristic combines the advantages of axial and centrifugal fans and performs well in ducts with larger cross-sections.

How is the impeller constructed?

The key component is the diagonal impeller with six three-dimensional blades and a conical hub. This design efficiently guides the airflow and achieves higher pressure than many traditional axial fans. The impeller is made of powder-coated steel for durability and mechanical resistance. Dynamic balancing to class G6.3 supports stable operation and limits vibration transfer to the installation.

What motor and control does the fan have?

The fan is fitted with a three-phase asynchronous motor in efficiency class IE3, with a voltage of 3~400 V and a rated frequency of 50 Hz. Speed can be controlled with a frequency inverter within the range of 20–70 Hz, allowing capacity to be matched to the building's actual needs. The recommended acceleration/braking time with the inverter is 20–30 seconds for smooth start-up and stable operation.

How is the fan installed?

The fan is intended for installation in ducts with a connection diameter of 400 mm and can be mounted horizontally or vertically. The mounting flange has holes according to the EUROVENT 1/2 standard for easy connection to the installation and accessories. The fan can be installed in a plant room, technical space, below a ceiling, in a dedicated installation zone or directly in the duct run.

What accessories are available for the fan?

A wide range of system accessories can be selected: vibration isolators (FSD), mounting feet (FAL), anti-vibration couplings (EXP), inlet nozzles (ESD), round connections (RVS), inlet flanges (RAF), backdraft dampers (RVK/RVK H/SGE), protective grilles (SGW), crossbars (TRA), service switches (AS) and mounting rings (MR).

Suitable for: mechanical supply and extract ventilation in industrial, technical, commercial and public buildings, as well as warehouse and office environments, where clean, dust-free air must be transported through ducts with typical installation resistance. Suits both new installations and the modernisation of existing ventilation systems.

Industries: industry, technical facility management, warehousing and logistics, offices and public sector.

Frequently asked questions (FAQ)

Can the Harmann duct fan MAXEE 400/4/6800T be used for humid or aggressive air?

No, the fan is intended for transporting clean, dust-free air at a maximum operating temperature of 60°C. The housing's C3 corrosion class makes it suitable for normal indoor environments, but it is not designed for aggressive chemical vapours or extremely humid process air streams.

How much noise does the Harmann MAXEE 400/4/6800T generate?

The Harmann MAXEE 400/4/6800T has a sound power level of 69 dB(A) and a sound pressure level of 62 dB(A) measured at a distance of 3 metres. The noise level can be reduced by running the fan at a lower frequency via the inverter, down towards 20 Hz.

What sets a diagonal duct fan like the Harmann MAXEE 400/4/6800T apart from a traditional axial fan?

A diagonal duct fan like the Harmann MAXEE 400/4/6800T combines the compact form of an axial fan with a higher achievable pressure, up to 300 Pa compared with what many traditional axial fans can deliver. This makes it better suited to duct systems with greater resistance, such as filters, silencers and long duct runs.