Although photochemical processes are currently experiencing a renaissance and attracting significant interest from researchers worldwide, challenges with the reproducibility of reaction conditions due to various factors hinder the widespread adoption and implementation of these technologies. One such challenge is the thermal radiation emitted by LEDs, which, depending on the equipment used and its efficiency, can lead to increased or decreased heating of reaction systems and distortion of the results obtained. In this paper, we propose the use of an accessible 3D printing technique to create a hollow PLA-based photochemical reactor with the ability to incorporate flow-through cooling using water from a central water supply system. Water can be replaced with any coolant, and a chiller can be used to maintain a predetermined temperature. This reactor can be customized for any application in minutes or hours and can be scaled up or down as needed. The type of plastic used in the reactor can be easily replaced, making it a versatile and adaptable solution for any laboratory worldwide.