In order to realise this and minimise support structures, the aircooled lamp holder would need to be assembled from four individual parts; an air-cooled base and the air-cooled lamp housing, which would be assembled from two main parts completed by a capping ring to shroud reflected light (See figure ). The dimensions for the lamp holder components were based on the 32 Kessil H150W, we also designed an insert that would hold the smaller 18 W Hepatochem lamp. Having the capacity to use either type interchangeably would subsequently allow us to have access to a wide range of wavelengths subject to the demands of any given photochemistry methods. The air-cooled base (figure ) was designed to support the photo-CDR above the air entry port and at the opposite end have a conduit to direct the air up and back over the photo-CDR to cool both sides. The base was also designed to hold the mirror (70 mm diameter) which can be readily sourced for low cost. The dimensions were kept to a minimum to reduce waste and print time. We designed the lamp holder in 2 parts so that they could be joined. This allowed the lower lamp holder to encase the air-cooled base and direct air up and around the lamp to assist with cooling the lamp itself. Radial vents in the upper lamp holder were intended for this air to vent readily (figure ). The CAD diagrams for all individual parts are included in the supplementary information.