The paper presents an analysis of the cooling performance of a microchannel beam heat exchanger powered by the combustible refrigerant R290 (propane) as a function of design parameters. R290 is an environmentally friendly refrigerant, in the context of growing concerns about climate change and the need for sustainable cooling solutions. Propane characterized by low global warming potential (GWP=3) and zero ozone depletion potential (ODP=0). The studied heat exchanger is dedicated to refrigeration devices where waste heat from mechanical ventilation installations serves as the lower heat source. Performance analyses of the exchanger operating as a condenser in the refrigeration system were conducted based on its design parameters. Several design variations of the exchanger were examined, including different microchannel shapes. Simulation studies were also performed under various operating conditions. The mass flow rate of the refrigerant in the exchanger and the volumetric flow rate of ventilation air were varied. The aim of the conducted research was to reduce the dimensions of the heat exchanger, enabling a reduction in the mass of the combustible refrigerant in the exchanger. Simulation studies were conducted using SolidWorks software with the Flow Simulation library. Over 500 simulations were performed. Based on the obtained results, it was found that using hexagon-shaped or triangle-shaped microchannels with corrugated walls could double the heat transfer rate of the condenser compared to the commonly used square or circular channels.