Land use is maximised in the cities of Melbourne and Sydney by reducing building block sizes and integrating medium to high density housing. Given that neighbours live in close proximity to each other in these cities, sub floor ventilation can be a challenge with the noise generated by the fans likely to disturb the peace.

Envirofan was recently contacted by a potential client who had installed a 150mm sub floor ventilation system from another brand in Neutral Bay, Sydney. The local council had received a complaint regarding the noise generated by the sub floor ventilation fan. This client sought to resolve the issue by switching to a quieter system.

Sub floor ventilation systems can have a noise rating ranging between 47 and 60 dba at one metre, which can be quite substantial but are sold by ventilation companies in Sydney and Melbourne. These systems are available at competitive prices and therefore, favoured by builders. However, this lower price point comes at the cost of a neighbour’s peace of mind.

The primary benefit of these 150mm systems is that 150mm ducting can be attached to the rear spigot to ventilate from a sub floor space, which is enclosed on two or three sides as ground levels outside the building may be nearly as high as the internal floor level and a brick size ventilation system cannot be fitted in the constrained space.

However, if there is adequate crawl space in the sub-floor area, Envirofan offers a similar system, the EF10-4 quad fan system, which has a noise rating of 27 dba, and presents a better alternative than the noisy 150mm systems.

An installation of Envirofan’s EF10-4 quad fan system can be viewed at this link ‘Cul-de-sac Ventilation’.

Envirofan’s EF10-4 quad fan system also offers another performance benefit when compared to the 150mm system. In the event a 150mm fan ceases to operate for any reason, 100% of the ventilation properties would be lost. With Envirofan’s quad fan system, if one fan motor stops operating, only 25% of the ventilation properties would be lost with the system delivering continued airflow using the remaining three fans.

So is there an alternative if there is insufficient crawl space to mount a cul-de-sac ventilation system or where a brick size ventilation system cannot be installed on the outside wall? Only the 150mm sub floor ventilation system can be used in such an application with the noise level reduced by turning down the pitch of the motor using a variable voltage controller. However, this solution will reduce the 150mm system’s ventilation properties, resulting in compromised performance.

The Envirofan sub floor ventilation system is recommended for ventilating cul-de-sac areas in Sydney and Melbourne, provided there is sufficient sub-floor access.