The heart of the Whole House Fan Cooling and Ventilation System is the large, in-roof fan. Windows in the rooms you wish to cool are opened. You switch on the fan which immediately creates a powerful updraught and opens the air actuated ceiling shutter.

Fresh air is drawn in to replace hot, stale air which is pulled through the house towards the fan, up through the ceiling shutter and into the roof space.  Air in the roof space is pressurised and flushed outside via eave or gable vents and through whirly birds if they are in situ.

You can direct the breezes simply by opening some windows and doors and closing others. So, you achieve optimum ventilation and more concentrated air flow where you need it most, such as through living areas by day and bedrooms at night.

Multiply the length x width x ceiling height of your home, excluding the garage, to calculate the cubic metre volume (M³).  Multiply the sum by 35.  This will tell you how much air ventilation you need every hour through your whole home (M³/H).

Look at the M³/H rating for each fan listed in the table below to select the correct sized fan for you.