Subfloor Ventilation Systems

An example of mould in subfloor without proper ventilation.

Effective ventilation of the underfloor area is essential to the health and logevity of any building with a subfloor area.

Queensland Timber offers  good advice on the basic principles of subfloor ventilation in technical data sheet: Subfloor Ventilation

Unfortunately many homes and other buildings can not achieve the necessary ventilation under the floors through passive natural ventilation – but require additional mechanical ventilation to control humidity.

High humidity levels under the house results in a damp subfloor which may cause mould, rotting floor boards and stumps,  mustiness,  odours and musty smells which can make their way into the house. Moist sub floor areas serve as  ideal breeding grounds for termites, white ants,  fungi,  wood borers etc. It is therefore paramount to protect any property by ensuring good under floor ventilation. A well ventilated sub floor should also prevent rising damp.

Underfloor Ventilation to Reduce Asthma Symptoms

Asthma sufferers should be aware that asthma attacks generally are triggered by poor air quality, which might be caused by issues in the subfloor area.

The most common approach to sub floor ventilation is constant or timer operated mains powered fans. These fans are designed to remove moisture from the sub-floor area – with the aim of allowing replacement air to enter the area under the house via vents located around the building. The problem with constant or timer operated fans is that they also operate when there is high humidity e.g. when it is raining – which means that they actually bring damp air into the sub floor area. Due to the normally lower temperature under the house this causes condensation – and a deterioration of conditions – not an improvement.

Solar Powered Subfloor Ventilation Systems

Solar powered fans offers a couple of obvious advantages over the traditional mains powered and timer operated systems:

• The systems only operate during sunny conditions – ensuring that the replacement air generally is quite dry and therefore contributes to keeping the subfloor dry                      
• Solar powered fans cost nothing to operate
  

  12 volt Solar Fans

Global Eco & Environmental Solutions offers a variety of Solar Powered subfloor and underfloor ventilation options:

• Solar collector Ventilation Systems
• 150 mm Solar Fans – medium volume
• Solar Whiz – High volume – Subfloor/gable fan for moisture extraction from subfloor requiring about 500 mm diameter for installation

Subfloor Ventilation – Solar Air Collector Systems

Traditionally subfloor ventilation has focused on removing moisture for underfloor areas. However, GES has over the past few years successfully solved many customers severe damp problems with a unique approach that involves using solar air collectors to heat up and deliver fresh dry air into the problem areas.

A 3 square meter collector can on clear sunny days deliver fresh heated air with a humidity content of less than 10% during a significant part of the day. In most cases we will combine the collector with an extraction fan placed on the opposite side of the house – which will help remove the moist and stale air from the underfloor area. The dry air effectively lowers the amount of moisture accumulated in the sub floor area – and the cross flow from the system ensures a much dryer environment.

Graph showing temperature and relative humidity of air supplied from 3 square meter collector:

Subfloor Ventilation – Solar Fan Systems

The “wall integrated” Solar Whiz fan is a very cost effective approach for creating cross flow ventilation in sub floor areas. The Solar Gable Fan offers very high airflow volumes (1400/2100 cbm/h), with whisper quiet operation and no power consumption.

Solar Whiz Sub Floor Ventilation Fan (Seen from sub floor area)

Solar Panel for Solar Whiz SubFloor Ventilation Fan

The Solar powered operation ensures the unit only operates when the humidity content of the replacement air is relatively low and prevents operation during rainy periods, which would increase humidity in the sub floor area.

GES specialises in solar ventilation for improving the indoor air quality, comfort and health of occupants in homes, commercial buildings, schools, holiday accommodation etc. by introducing fresh pre-heated or pre-cooled air or extracting stale or warm air.

Brochure for subfloor & underfloor ventilation