Mixed Flow Roof Fans (RMH)

At a Glance:
• Motors protected to IP44
• Motor insulation Class ‘B’
• Maximum operating temperature 40˚C
• Standard Thermal Overload Protection IP65
• P65 service isolator
• Guard included as standard
• All models speed controllable
• Performance tested to BS 848 parts 1 & 2
• Manufacture controlled to BS EN ISO 9001
• 2 Year Guarantee

Specially designed for use when medium pressure characteristics are required, the Vent-Axia Mixed Flow roof range is delivered on-site fully assembled and ready for installation. To meet COSHH requirements, a service isolator is fitted and pre-wired as standard. Equally suitable for flat or inclined roofs, the range is suitable for kerb or purlin box mounting and boasts a wide range of accessories to suit many different industrial applications. There are five sizes available with duties ranging from 0.606m³/s to 3.63m³/s (2182m³/h to 13068m³/h) with pressure development available up to 600 Pa.

The mounting plate is moulded with a fixed integral bellmouth to ensure optimum efficiency and precise alignment. The weather-cowl is also moulded to produce a smooth, internal surface and a tough, stable UV resistant finish. Colour: BS 10A07. Alternative colours available on request.

Vent-Axia Mixed Flow Roof fans are designed for either kerb or inclined fixing (maximum angle 30°).

Electrical
Single phase 220-240V 50 Hz. Capacitor start and run. Three phase 380-415V 50Hz. A service isolator switch is provided for local isolation and the enclosure is protected to IP65 according to BS EN 60529. All motors are fitted with Standard Thermal Overload Protection (S.T.O.P.), which for three phase fans should be wired into all controller circuits and into starter contactors. Most models are available with 4 and 6 pole motors.

Motors
The Mixed Flow roof range features a proven external rotor motor and backward curved mixed flow aluminium impeller assembly (355 Ø in polyamide) selected for performance and non-overloading characteristics. The assembly is dynamically balanced to VDI 2060. The motors in this range are rated IP44 according to BS EN 60529. Ball bearings are greased for life and are designed to run at any angle. Insulation is Class 'B' (from -30°C to +40°C). Manufacture is controlled to BS EN ISO 9001 standards.

Sound Levels
Published dB(A) figures are free field sound pressure levels at 3m with spherical propagation at a reference level of 2 x 10-5Pa (20 micro-Pascal). The sound power level spectra figures are dB with a reference level of 10-12 Watts (1 pico-watt).

Performance
Tested to BS 848 Parts 1 & 2.

Accessories
Soaker Flanges
The Vent-Axia range of soaker flanges are a simple and neat solution to weathering when a roof extract unit is required on a pitched corrugated roof. Colour: BS 00A 05.

Purlin boxes
Available in sizes to suit all models and should be used to support the fan in conjunction with a soaker flange sheet.

Roof attenuators
Available in all sizes to cover the range of Mixed Flow Roof fans in three lengths: 600, 900 or 1200mm according to the attenuation required.

Shutters
Robust construction, designed to fit beneath the fan using the fittings provided. Airflow operated, manual or motorised shutter. A minimum distance of half the attenuator width is required between an airflow shutter and a roof attenuator for satisfactory operation.

DIMENSIONS:

Fan Size a b c d Weight Kg
335/400 800 780 480 83 24/27
450 950 930 575 103 45
500/560 1230 1055 630 103 48/64

Overview

Specially designed for use when medium pressure characteristics are required, the Vent-Axia Mixed Flow roof range is delivered on-site fully assembled and ready for installation. To meet COSHH requirements, a service isolator is fitted and pre-wired as standard. Equally suitable for flat or inclined roofs, the range is suitable for kerb or purlin box mounting and boasts a wide range of accessories to suit many different industrial applications. There are five sizes available with duties ranging from 0.606m³/s to 3.63m³/s (2182m³/h to 13068m³/h) with pressure development available up to 600 Pa.

The mounting plate is moulded with a fixed integral bellmouth to ensure optimum efficiency and precise alignment. The weather-cowl is also moulded to produce a smooth, internal surface and a tough, stable UV resistant finish. Colour: BS 10A07. Alternative colours available on request.

Vent-Axia Mixed Flow Roof fans are designed for either kerb or inclined fixing (maximum angle 30°).

Electrical
Single phase 220-240V 50 Hz. Capacitor start and run. Three phase 380-415V 50Hz. A service isolator switch is provided for local isolation and the enclosure is protected to IP65 according to BS EN 60529. All motors are fitted with Standard Thermal Overload Protection (S.T.O.P.), which for three phase fans should be wired into all controller circuits and into starter contactors. Most models are available with 4 and 6 pole motors.

Motors
The Mixed Flow roof range features a proven external rotor motor and backward curved mixed flow aluminium impeller assembly (355 Ø in polyamide) selected for performance and non-overloading characteristics. The assembly is dynamically balanced to VDI 2060. The motors in this range are rated IP44 according to BS EN 60529. Ball bearings are greased for life and are designed to run at any angle. Insulation is Class 'B' (from -30°C to +40°C). Manufacture is controlled to BS EN ISO 9001 standards.

Sound Levels
Published dB(A) figures are free field sound pressure levels at 3m with spherical propagation at a reference level of 2 x 10-5Pa (20 micro-Pascal). The sound power level spectra figures are dB with a reference level of 10-12 Watts (1 pico-watt).

Performance
Tested to BS 848 Parts 1 & 2.

Accessories
Soaker Flanges
The Vent-Axia range of soaker flanges are a simple and neat solution to weathering when a roof extract unit is required on a pitched corrugated roof. Colour: BS 00A 05.

Purlin boxes
Available in sizes to suit all models and should be used to support the fan in conjunction with a soaker flange sheet.

Roof attenuators
Available in all sizes to cover the range of Mixed Flow Roof fans in three lengths: 600, 900 or 1200mm according to the attenuation required.

Shutters
Robust construction, designed to fit beneath the fan using the fittings provided. Airflow operated, manual or motorised shutter. A minimum distance of half the attenuator width is required between an airflow shutter and a roof attenuator for satisfactory operation.

Technical

DIMENSIONS:

Fan Size a b c d Weight Kg
335/400 800 780 480 83 24/27
450 950 930 575 103 45
500/560 1230 1055 630 103 48/64

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