Thermal barrier for ventilated roofs

Abstract

A system and a method are described for the passive conditioning of internal environments having ventilated roofs as coverings; the method involves absorbing at least part of the heat coming from the external environment during the hottest hours of the day, so as to reduce the heat entering the environment to be conditioned and transferring the absorbed heat back to the external environment during the night, the absorption being implemented through Phase Change Materials, PCM, in which the heat exchange between PCMs and the external environment is favored by an air current that is generated spontaneously due to the effect of natural thermal gradients.

What is claimed is: 
     
         1 . A system for a passive conditioning of internal environments having ventilated roofs for covering, of a type comprising one or more ventilation chambers placed under a waterproof roofing mantle, the one or more ventilation chambers having the function of dissipating part of heat entering the environment to be conditioned,
 the system further comprises a plurality of containers containing Phase Change Materials, PCM, positioned inside the one or more ventilation chambers, the containers of PCMs being in a heat exchange relationship with air present inside the one or more ventilation chambers;   wherein:   the containers are installed in a center of a ventilation channel suspended between tiles and an underlying support layer, so that a ventilation air flow completely envelops the containers;   the system further comprises perforated metal profiles to which supports are fixed on which the PCM containers lean; and   the supports comprise a bar fixed, one third of its length, to an element on which there are anchors which, made to pass through holes in the metal profile and inserted in an opposing element, prevent its movement.   
     
     
         2 . The system of  claim 1 , wherein the containers are plates made of plastic material. 
     
     
         3 . The system of  claim 2 , wherein the plates comprise a plurality of PCM macro-containers, independent of each other, so that they can be trimmed for any dimensional issues during installation. 
     
     
         4 . The system of  claim 3 , wherein the PCM macro-containers are provided with a stiffening frame. 
     
     
         5 . The system of  claim 3 , wherein each of the macro-containers has longitudinal welds, designed to divide each of the macro-containers into at least two parts, so as to reduce the risk of segregation of the PCM. 
     
     
         6 . The system of  claim 1 , wherein the containers have overall dimensions of 0.9×0.3×0.01 m 3 . 
     
     
         7 . Method for a passive conditioning of internal environments with ventilated roofs, of a type which uses a system according to  claim 1  and involves absorbing at least part of heat coming from an external environment during hottest hours of a day, so as to reduce heat entering the environment to be conditioned and to transfer the absorbed heat back to the external environment during nights, the absorption being implemented through Phase Change Materials, PCMs, wherein the heat exchange between PCMs and external environment is favored by an air current that is generated spontaneously due to an effect of natural thermal gradients.