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The design of a regular packing with a three-dimensional PN-3D structure, which is fabricated from individual polymeric components assembled into a unit, is proposed. Results are presented for aerothermal tests of a segment of a packing intended for a water-air system. The effectiveness of the PN-3D packing employed in heat and mass exchangers, including cooling towers, is established.Regular and filled industrial packings have certain deficiencies. As a rule, regular structured packings are built in the form of bundles of vertical corrugated sheets [1], which within the volume of the apparatus, form structurally closed parallel channels that render transverse mixing of contacting liquids impossible. In addition, these packings provide minimal hydraulic resistance over a highly developed specific surface. For a free chaotic charge within the apparatus, irregular filled packings promote appreciably better transverse mixing as compared with regular packings. Due to the inevitable near-wall effect associated with the increased porosity of a layer of an irregular packing of any shape, however, undesirable bypass of gaseous flows develops in the filled layers near the wall of the apparatus [2].A new design proposed for a regular packing with a three-dimensional structure, which incorporates certain advantages of both the regular and filled packings, is devoid, to a certain degree, of the above-noted deficiencies (Fig. 1). Ideas spawned by Karnaukhov [3], including his model of non-intersecting rods, were used for its development.The design of the regular film-drop-type of packing is fabricated from individual polymeric elements assembled into a unit. The three-dimensional design of the PN-3D packing imparts quasi-isotropic properties to the latter; this ensures more effective transverse mixing of contacting flows as compared with the familiar structured sheet packings described, for example, in [1]. Moreover, the structure of the proposed packing is constant throughout the entire volume of the apparatus. Individual elements of the packing are n-turn helicoids (conditionally shown in the form of cylinders), and are fabricated by the method of extrusion.An additional advantage of the PN-3D packing is its ability to redistribute the liquid phase uniformly throughout the volume of the apparatus, irrespective of the uniformity of the initial spray.Aerothermal tests of a segment of the packing were performed for a water-air system. The density q l of the spray was varied within the limits from 7 to 11 m 3 /(m 2 ⋅h), and the linear velocity w 0 of the air flow within the range of 1-2 m/sec.