“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 Dual Fan motors which is integrated into the adaptor for various reasons:
- That the solution is placed at the source of the problem.
- For smaller spaces at approximately 5m2
- Quiet operation (30dBa) which does not translate to any undue noise in the dwelling or building unlike 240v systems. (30dBa is approximately one half of the noise of a modern domestic refrigerator).
- Being 12v this caters for significant power consumption reductions than 240v systems.
- Utilising two (3,500 litres/min @ 7.5v) individual fans 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.
- Australian made ventilation system.
- 2 years manufacturers warranty.
- IP68 rated.
- Digital timer is recommended.
Whilst this product does half the volume of airflow than the EF10-4SQR-150 at 3.5m3 (3,500 litres per minute @ 7.5v) it can be used in smaller spaces approx. the average bedroom size which is 5 x 5 mtrs where the client would like a little more than what passive vents can deliver.
Also on construction sites that are cut and fill where the dwelling has been built into the side of a hill and a retaining erected. Ventilation is quite restrictive and the EF5-SQR-150K will bolster the air-flow in this particular area by placing the system approximately in the centre of the room or a little more in the sub floor area.
These are placed 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.
In cases where the external ground level is higher than the sub floor area especially in double brick construction this system should be positioned approximately 750mm from both walls opposite to the door opening (as there usually is an opening in the sub wall under the door)
NB- The Single brick cul-de-sac system kit does have a variable voltage selector on the transformer. By increasing the voltage will increase the rpm’s which will increase the ventilation properties.
NB– The spigot attaches to the back of the passive vent as seen below. It is compatible with a flexible 150mm duct. Duct not included.