The Dachs is generally equipped with an exhaust heat exchanger. Given the exhaust gas leaves the Dachs with approx. 150 °C, it still contains a high amount of thermal energy.
With the additional condensing heat exchanger, the latent heat can be utilised to provide up to an additional 2.5 kW of heat (depending on return flow temperature of the heating circuit).
This increases the overall efficiency of the Dachs unit from approx. 90% to 98%.

Due to increased exhaust heat recovery, the use of the condenser reduces the final temperature of the exhaust gas to levels where plastic exhaust materials can be used as opposed to either single wall or twin-wall stainless steel. Depending on the length of the flue system this could considerably reduce the cost of installing the Dachs due to the use of lower costing materials.