Safe and Ecological Refluxing with a Closed‐Loop Air Cooling System

Off‐the‐shelf computer cooling hardware was used to construct a closed‐loop air cooling system (CLACS) that is distinguished by scalability, low energy, and no tap water consumption. Constructed to be generally used with laboratory condensers, the system was tested with several common low and high boiling solvents and showed a condensation performance equivalent to conventional tap water cooling. Reaction yields were therefore unaffected. Also, long‐lasting Soxhlet extractions showed no performance loss relative to conventional cooling. Optionally, the device can be assembled from low‐voltage components and be powered from a battery, rendering it independent of the main power. Both investment and running costs are minimal, allowing a lab‐wide adoption and elimination of the two major drawbacks of commonly employed tap water cooling: waste of drinking water and the risk of flooding. Closing the water‐tap: Tap water to cool reflux condensers is replaced with a closed‐loop air cooling system. The simple and robust device retains refluxing solvents equally well as tap water, while it consumes little energy and no water at all. This way, the hazards of flooding and loss of water flow are eliminated. The system has been extensively field‐tested and is suitable for refluxing both small and large amounts of both volatile and high boiling solvents, especially during long‐term experiments.