The creation of ventilated air mattress between two surfaces, which one is exposed to some type of thermal energy, consist in an architectural trick very efficient to promote heat insulation of facades, scantlings and roofing of any kind.
When the first surface allows the transfer of the received thermal energy to the air mattress, before reaching the second surface, this energy is dissipated in the air in renewal that in its process of natural convection by pressure difference minimizes the effects of radiation on the second surface.
Guaranteed ventilation between these surfaces is obtained by proper sizing and placement of the air outlet and intake openings, with sized based on the volume of this air mass, height difference between the openings, the flow velocity, everything with the purpose of allow the perennial flow of the air that, regardless of any other variable, looks for regions of lower pressure.
In regions of temperature oscillation during the year regulatory devices (mobile shutters, for example) could be adopted close to the air intake openings. Same procedures are applied to cold climate regions, but inducing the circulation of the warm (internally) air mass of the environments.
The air and any gas when heated, keeps its mass but increases its volume. It becomes less dense. Then in enclosed spaces, warm air seeks the higher regions, and cold air seeks the lowest.
This is the basic principle of natural convection of air pressure difference. It doesn´t require the use of any mechanical or electro- mechanical equipment if properly sized.
And more, for the same volumes and needs, the greater the height difference between the outdoor air outlet and its output, smaller effective ventilation openings are required.
In the event of combination of natural ventilation of a room with its sound insulation, noise attenuators must be installed in the required openings.
Thermal comfort project and execution in buildings:
Thermal insulation of heat caused by direct heat radiation on the roof;
Thermal insulation for masonry and concrete walls;
Thermal insulation for the exposed slabs;
Natural ventilation induced by natural convection of air (pressure difference);