Reference to the high resolution renders: https://yadi.sk/d/XbmPVxxJ3GSmNv  Ventilation (element 102) is made for corona render 1.5 and vray 3.2. Suitable for visualization Industrial facilities, supermarkets, gyms, the interiors in the style of "industrial" and so on. N. Easy snap on the pivot or support facilities. Auxiliary objects are on separate layer and eliminated from rendering. vray materials configured properly. In version vray, BRDF materials installed in Microfacet GTR / GGX, owners vray 2.4 must be installed in the Blinn BRDF. For Corona render, it is recommended to put the version not lower than 1.5, since the glossiness of materials customized based on PBR. Detail of the model suitable for close angles. You beautiful renderings!