A system for heating a work fluid and for air circulation comprises a plurality of collectors fitted top-to-top in one or more columns, such that air ducts of the modules constitute a single duct along a column, wherein the solar collector comprises: one solar radiation planar absorber with one anterior face exposed to solar radiation and another posterior face affixed to the work fluid piping; one duct for exchanging heat with the planar absorber via the air duct which has its air inlet and outlet on opposite tops of the solar collector. The system can additionally comprise a descendent air duct to collect air from the upper part of the building and to supply air to the lower side of one or more columns of the facade.