Condensation damage (called “Versottung” in German) shows up as yellowish-brown stains on the chimney wall and an acrid smell, and in the worst case as moisture seeping through the masonry into living spaces. The cause is almost always the same: flue gases cool below the dew point inside the chimney, condensate forms and soaks into the brick.
DruckZugPro calculates the temperature profile along the entire chimney and shows whether and where the flue gas temperature drops below the dew point.
Highlights
- Temperature curve visible across the full chimney height.
- Dew point violation highlighted in red.
- Compare different insulation options in one click.
How it works
- Enter your appliance data (exhaust temperature and mass flow are the key values).
- Fully describe your chimney: height, material, insulation thickness, ambient conditions.
- The temperature profile instantly shows whether and at what height condensation is expected.
FAQ
Which appliances are most prone to condensation?
Anything with low exhaust temperatures: condensing gas boilers, modulating pellet stoves at part load, and low-temperature oil boilers. Wood stoves at nominal load are rarely affected because the exhaust is hot enough.
Can adding insulation prevent condensation?
Sometimes. If the exhaust temperature falls just below the dew point, better insulation can tip the balance. DruckZugPro shows the effect of different insulation options side by side. With heavily oversized cross-sections, however, only a liner (reducing the effective diameter) will solve it.
I already see stains on my chimney. What now?
Stains indicate existing condensation damage. A chimney sweep should inspect the condition. DruckZugPro can show whether your current setup is causing the problem and which changes would fix it.