Wind-Solar Driven Natural Electric Hybrid Ventilators

Abstract

Current building ventilators individually rely upon a single source of energy for operation. The turbine ventilator relies entirely of the prevailing wind conditions with no facility to extract energy from the sun. The solar ventilator is at the complete mercy of ambient solar radiation conditions and cannot extract energy from the wind. The initial Wind-Solar hybrid ventilator was considered a solution to the problem of turbine ventilator operation at zero wind speeds. Air extraction capability at zero wind speed was provided by using an electric motor and solar cell to power the turbine ventilator. The significant findings upon testing of this hybrid design were the vastly improved flow rate performance compared with a purely solar powered ventilator; comparable performance with the standard turbine ventilator, and the vastly improved operational flexibility of the device. The standard turbine ventilator acting as a centrifugal pump provided much better air flow compared to an axial propeller subjected to the same power input. The hybrid design had slightly less performance than the turbine ventilator alone. This was mainly due to the back-driving of the electric motor under zero solar radiation conditions, and the crudity of the device. The performance level of the hybrid device was vastly improved by removing the solar cell from atop the rotating ventilator and decoupling the electric motor on overrun with a one way bearing. The combination of the turbine ventilator and solar powered ventilator provided a hybrid design that had vastly improved flexibility of operation compared to the individual constituent components. The horizontal axis ventilator was a solution to the marginal performance of a turbine ventilator at low wind speeds. Testing of the horizontal axis ventilator found significantly improved performance at low wind speed conditions. The device extracted more than double the volume flow rate of air and spun at more than twice the RPM for any given wind speed condition. The overall conclusion is that a continuous pre-determined volume air-extraction ventilator that relies predominantly on renewable energy is entirely possible