• EF10-4 SQR150
  • cul-de-sac
  • cul-de-sac + brown vent
  • cul-de-sac + white vent
  • cul-de-sac + shale grey vent
  • cul-de-sac + heritage vent

Envirofan Quad Fan Cul-de-sac System-(EF10-4SQR-150-NK)


As per our Envirofan In-Line fan-forced sub-floor ventilation solution, this “cul-de-sac” system is typically used to treat enclosed areas  harboring damp air. This vent can be installed where the distance between floor and the ground beneath is the smallest, and where a “musty” smell within the home is likely to be most pronounced.

  • Approximately 2 bricks high x 1 brick wide.
  • 6.5m3 (6,500 litres/min) @ 7.5volts from your sub floor area
  • 7.5m3 (7,500 litres/min) from your sub floor @ 12volts
  • Can be purchased as a stand-alone product or with a passive vent that has a 150mm spigot. Vents are available in White, Shale Grey & Brown.

Boxed as a Envirofan motor assembly integrated into the  “square-to-round” with hanging straps only & unless  a passive vent with spigot is ordered.

NB- The  transformer has a variable voltage selector on it. 6.5m3/min is based upon a 7.5v setting. This can be adjusted to a higher setting by the client on installation with a small screw driver which will increase the ventilation properties.

NB- The spigot is attached to the back of the passive vent as seen below. It is compatible with 150mm flexi duct.


SKU: EF10-4SQR-150-NK Category: Tag:


“Cul-de-sac ventilation,” although the term is not commonly used in the industry, refers to a “dead” pocket of sub-floor space without any vents on the external wall, and where air flow is non-existent. For example:

  • Where concrete slabs surround the suspended floor area on 2 or 3 sides.
  • Where the ground level outside the building is at the same height as the internal floor level.

To remedy this, you can lower the external ground level via retaining walls and install adequate ventilation. However, there is an exception to the rule, whereas flexible ducting can be utilised to extract the damp air from these problem areas. The Envirofan Quad Fan motors which is integrated into the adaptor which In the video is utilised for various reasons:

  • That the solution is placed at the source of the problem.
  • Quiet operation (30dBa) which does not translate to any undue noise in the dwelling or building unlike 240v systems. (30dBa is approximately halp the noise of a modern domestic refrigerator).
  • Being 12v low votage power would mean less of a carbon footprint than 240v systems.
  • Utilising  four fans collectively (6,500 litres/min) means that the sub-floor ventilation properties will continue only with a slight loss if one impeller ceases to operate. Whereas with a single fan ventilation system, sub-floor ventilation properties would be totally lost when the impeller ceases.
  • Cul-de-sac systems are integrated into a square to round which caters to 150mm flexiduct or 150mm plumbers pvc pipe.
  • Australian made ventilation system.
  • IP68 rated
  • 2 years manufacturers warranty.
  • Digital timer is recommended.


At the problem area where the musty smell is most pronounced inside the dwelling. This can be verified by accessing the sub-floor area to determine that the musty smell is more concentrated in this area. Where discolouration (darkened appearance or fungi) on the soil is apparent as compared to other soil appearance in the sub-floor area. Where a brick size dual fan system cannot be installed on an exterior wall. To ventilate at the centre of the dwelling (incidental to brick veneer construction) Located in the middle sub-floor area of the dwelling whereby fresh air can be drawn in through the existing exterior passive vents then extracted through the sub-floor ventilation system through ducting to the double brick size Envirofan passive vent mounted on the exterior wall. Designed to ventilate ‘cul-de-sac’ areas provided that there is sufficient sub-floor access.

Additional information


System Only – No Vent $229.99, w/ Brown Vent w/ 150mm Spigot +$89.99, w/ White Vent w/ 150mm Spigot +$89.99, w/ Shale Grey Vent w/ 150mm Spigot +$99.99, w/ Heritage Vent w/ 150mm Spigot +$129.99

© 2016 Envirofan Sub-Floor Ventilation Solutions, Sydney – Reduce Mould & Prevent Termites.
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Envirofan sub-floor ventilation systems are available in Melbourne, Gippsland, Adelaide, Perth, Brisbane, Gold Coast, Lismore, Mullumbimby, Northern Rivers, Coffs Harbour, Mid-North Coast, Port Macquarie, Taree, Hunter, Newcastle, Central Coast, Sydney, Illawarra, Wollongong, Shoalhaven, Eurobodalla, Southern Highlands, Canberra, Central West, Bathurst, Orange & the United Kingdom (UK).