This Blog explains the driving forces behind natural roof ventilation – fluid dynamics – fluid dynamics is the study of air and gases in motion including aerodynamics, pressure, density, flow velocity and temperature functions.
The basic physics for natural roof ventilation are delivered through the principles of natural air flows, convection and the venturi effect. Air currents – atmospheric flow, wind, the natural movement of air. Convection – Newton’s Law of cooling to put it in layman’s terms hot hair rising, cold air falling. The venturi effect – causing air to move through a constriction the average flow speed of air doubles increasing the air’s velocity as the air diverges to leave the constriction. It is these basic principles of fluid dynamics that need to be harnessed in the design of a roof ventilator, for effective ambient temperature to circulate a roofspace to keep you cool in summer and a dry roofspace 24/7 365 days a year.
With all the different ventilators on the market today how do you choose, when you can have too much roof ventilation or not enough, the wrong kind or two different kinds that do not work well together.
Many ventilators depend on eaves vents for inlet air, most have been installed without any consideration to inlet air at all. Some depend on ceiling vents for inlet air, this will allow cooled air to purge in summer, heated air in winter and allow all the nasties of the roofspace to enter the home – see Blog on this site “Sealing the Ceiling”.
The best way to allow the ambient temperature to circulate the roofspace 24/7 365 days a year is to have inlets and outlets in the roof covering. Very effective roof ventilation should be aerodynamically designed to incorporate all the principles of fluid dynamics for roof ventilation.
Universal Tile Ventilators have been aerodynamically designed to harness all the principles of fluid dynamics for roof ventilation and to take all that Mother Nature has to throw at them, you can’t beat that.
Universal Tile Ventilators for tiled roofs and the Smoothline Ventilator for corrugated colourbond roofs.