Siemens innovative zeolitic drying system

An innovative zeolitic drying system from Siemens has won the Award for Climate Protection and the Environment in the category for product and service innovations in the field of climate protection. Equipped with this system, the Siemens speedMatic dishwasher is around 20% more efficient than appliances in the highest energy-efficiency category. Its minimal water consumption, 10 instead of 14 liters per cycle, also sets a new record. Engineers at BSH Bosch und Siemens Hausgeräte are the first to take this completely new technology to the mass-production stage as well. Although it is only featured in top-of-the-range models at present, there are already plans to introduce it successively in mid-range models.
Inside the dishwasher are special minerals that generate supplementary heat. This shortens the program at 50°C to just under two hours, which is around 30 minutes less than is needed by conventional dishwashers. As a result, the speedMatic is also the fastest dishwasher in the highest efficiency category. This supplementary heat is generated by zeolites – aluminosilicate minerals with a very large surface area and microporous structure. The dishwasher exploits the ability of such minerals to absorb up to 40% of their dry weight in water and, in the process, give off heat. By the same token, they release this water when heated.

During the drying cycle, warm, moist air is fed into a container under the dishwasher chamber, which contains 1.15 kilograms of small white zeolitic granules. These absorb the moisture and release hot, dry air, thus substantially shortening the drying cycle. In the next washing cycle, the granules are heated to remove the moisture, thereby regenerating them. The zeolithes stay in the dishwasher during its whole lifetime.
Thanks to its increased efficiency, the new dishwasher helps save energy and thus reduce CO2 emissions. If all dishwashers with an energy consumption of over 1.3 kWh per cycle were replaced by ultra-efficient appliances with zeolitic drying, the savings in Germany alone would amount to over 1.2 million metric tons of CO2 a year. That corresponds to the amount of C02 produced by approximately 600,000 passenger cars, each driving 15,000 kilometers a year.