Cold from (waste) heat

Waste heat that is presently released to the environment can be used to produce cold. This prevents the use of electricity or other fuels to produce that cold and therewith saves energy. A commercially available absorption chiller is a well-known example of a heat-driven cooling machine. These systems use lithium bromide/water or ammonia/water as their working medium and don?t need a compressor like a compression cooler. Essential for this application is the simultaneous release of waste heat and need of cold. The use of heat/cold storage can circumvent any time lag.

ECN is working on two concepts that produce cold out of waste heat. These are:

•  A solid sorption system based on silica gel/water that is being applied in a trigeneration system that produces heat, power, and cold.
• A thermoacoustic cooler based on a very intense acoustic wave to produce very low temperatures down to -100?C.