The paper presents results of numerical research oriented to the influence of heat conducting inclusions on thermo-technical properties of vertical and horizontal sandwich panels. Sandwich panels consist of flat steel sheets and thermal insulation core (from foam polystyrene, foam polyurethane and rock wool). Thread forming screws, which cross the sandwich panel through its depth, and connect the sandwich panel to frame, creates the heat conducting inclusions. The numerical analysis is carried out using software ANSYS. Based on the numerical analysis results, the regression equations for calculation of minimal values of temperature on an internal surface of a vertical sandwich panel are easy to obtain. The analysis of thermal field of the “sandwich panel – metal frame” system shown that the hygiene requirements are not complied. Proposed solution allows the reduction of the influence of heat conducting inclusions on thermo-technical properties.