Microfluidic devices have become more and more popular over the last ten years. One of their applications is the implementation of micro heat exchangers or micro reactors for thermal process engineering tasks [1-3]. Typical micro heat exchangers consist of micro channels of several 100 mu m in height and width. Due to their large surface-to-volume ratios, they offer very effective heat transfer capabilities. Micro heat exchangers/reactors can replace large and dangerous systems in the chemical industry as they offer precise process control due to the effective heat and mass transfer, enhanced safety due to the small reaction volumes, and effective catalytic coatings due to the small diffusion lengths. For the consumer market, however, micro heat exchangers/reactors have not yet become popular. This might change as the demand for effective cooling of consumer electronic devices is still increasing. Moreover "new fields" in households, such as direct heating or cooling of water using micro technology, might be advantageous compared to conventional technology. To move a step forward towards the integration of microfluidic technology into the consumer world, a system consisting of a cheap, conventional R134a (Tetrafluoroethane) cooling technique in combination with a newly developed metallic micro heat exchanger/evaporator was set up. This system enables the direct cooling of a non-continuous water flow to temperatures <= 8 degrees C at a maximum transferred cooling power of approximate to 650 W. (C) 2010 Elsevier B.V. All rights reserved.