Utilizing waste heat of moisture containing exhaust gases is often complicated by dust particels, pollutants and smell. A usefull recycling of waste heat into the technological process is difficult due to the low dew-point temperature of the exhaust gas. A solution to this problem is the utilisation of open absorption circuits with concentrated solutions. These circuits work as scrubbers and - at the same time - allow the utilisation of the sensible amount of the recoverable waste heat at a temperature level higher then by washing with water. In contrast to absorption cycles those absorption circuits can operate without additional driving energy. Under the condition of long operation time, economic estimations showed pay-out times down to one year.