The article considers the possibility to use different types of polymer thermal store materials for regenerative heat exchangers in local ventilation systems. The research provides evidence for the benefits of the replacement of the most commonly used metal and non-metallic materials in the manufacture of the regenerator honeycomb matrix. It does so by presenting the results of calculations and comparative analysis of the influence of thermo-physical properties of a wide range of polymers on the thermal efficiency of a fixed counter-flow regenerator operating with humid air. In order to evaluate the efficiency, we have used a numerical solution of the system of mathematical physics equations describing the process in the regenerator. The system also includes an appropriate CFD model of the evaporation-condensation phase change process.

The article presents verification and validation of a numerical model of conjugated heat and mass transfer processes and aerodynamics in a fixed "honeycomb" type regenerator with square channels for heat recovery from the exhaust air of a local ventilation system. The processes in the regenerator are simulated by the CFD method. The influence of the processes of condensation and evaporation of moisture in the humid air on the efficiency of the regenerator has been investigated through these simulations and is shown in the article. The calculations of the fixed regenerator's thermal efficiency and pressure losses are made by known analytical models and the results are compared with those of the numerical model. The article compares the model simulation results with experimental data and data from reference sources.

Various solutions are currently being offered to modernize the ventilation in old residential buildings. In small apartments, it is very appropriate to use decentralized ventilation units - for example with regenerative heat exchangers. Theoretical and experimental studies of such devices show a significant impact of the operational mode of regenerators (determined by the environment) on their efficiency. The aim of this article is to demonstrate the impact of the buoyancy forces in multi-storey buildings on the efficiency of a regenerative air handling unit for decentralized residential ventilation with heat recovery. Numerical solutions are presented for close to the real operating modes, airflow rates and air temperatures of the supply and the exit air, and the temperature ratio.

The article presents an experimental field study of the influence of environmental factors on the functionality of a commercial decentralized ventilation device for regenerative utilization of heat from the exhaust air, intended for installation in an external wall of buildings. The experiments included measurements during the winter and summer seasons. Real operating situations with two regenerative heat exchange matrices are presented and tested. The results of the experiments show that the functionality of the ventilation and heat recovery device does not meet the characteristics that the device shows under standard laboratory conditions.