Why do you need subfloor ventilation fans?
Tackle mould, mildew, condensation and poor air quality in your home with inline fans
Noticing a musty smell around your home or signs of damp beneath your floors? Poor subfloor ventilation might be the cause. Moisture and stagnant air in these areas can lead to mould, timber rot, and even attract pests. Subfloor ventilation fans offer a practical solution, helping circulate fresh air, reduce humidity, and keep the space under your home dry and healthy.
If there isn’t enough space to install a Solar Whiz subfloor ventilation fan, inline fans offer a great alternative for underfloor ventilation.
There are three different-sized inline fans for subfloor ventilation available: 8, 16, and 25 Watts:
| Model | Wattage | Diameter | Use Case | Solar Compatible | 12V Option |
|---|---|---|---|---|---|
| 8W | 8W | Small | Tight crawlspaces | ✅ | ✅ |
| 16W | 16W | Medium | Moderate airflow needs | ✅ | ✅ |
| 25W | 25W | 320mm | High airflow, limited height | ✅ | ✅ |
The 25 Watt high capacity inline fan is predominantly used for applications requiring large amounts of air to ventilate the sub floor area effectively, if you do not have adequate room (500mm+) to fit the Solar Whiz gable (in this case, wall mounted) mounted fan. The 25-watt inline fan has a diameter of 320mm and may be more appropriate for applications with limited space.
Solar Whiz recommends that sub floor ventilation fans be powered by solar panels for the most effective underfloor ventilation; however, all fans are available with a 12-volt power pack.
Besides sub floor ventilation fans, Solar Whiz inline fans can also be used for general ventilation, as well as heat extraction from rooms or greenhouses, etc. In most of these cases, the sub floor vents have to be installed in the wall and are powered by an external solar panel placed on the roof for optimum solar access.
If a Solar Whiz unit is too large—and you wish to extract air through the ceiling and out through the roof—our 150 mm fans may be combined with roof penetrations and roof cowls for this application to be successful.
Solar Whiz Sub Floor Ventilation fans that we offer are:
| Model | SW-AU-W-40 | SW-AU-W-28 | SW-RAF-G-2100 | SUB2100G |
| Capacity | 2,500 m³/h | 2,000 m³/h | 2,100 m³/h | 1,400 m³/h |
| Fan Motor | 10-26 Volt DC Brushless motor with double-shielded ball bearings | |||
| Fan Decibels | <55 dBA | <45 dBA | <60 dBA | <45 dBA |
| Dimensions |
Height: 147mm Diameter: 360mm |
Height: 147mm Diameter: 360mm |
Height: 185mm Diameter: 500mm |
Height: 230mm Diameter: 650mm |
These sub-floor fans are set up to draw air through subfloor vents set up around your subfloor. Depending on the home, we can offer a variety of installation methods to achieve the results you need. If you have a brick subfloor with little to no air intakes, we can map airflow through your subfloor space. We can duct, or we can even extract air through the roof via a roof-mounted Solar Whiz!
