How it works – correct chimney length
A too-short chimney has the following risks:
- The chimney does not draw sufficiently and there is a pressure in the chimney. Flue gas may flow undefinedly into the environment from the chimney transfers because of this.
- Heat in the boiler rises up and the burner installed there can be damaged if cooling is insufficient due to lack of flue draught.
A too-long chimney has the following risks:
- In standstill, the chimney will draw unnecessary amounts of fresh air through the steam boiler and cool it off.
- Long chimneys are accordingly more expensive and may need elaborate catching constructions.
Therefore, it is important to choose the proper chimney length. No overpressure may build up in the chimney during burner operation. Therefore, a flue draught is necessary. The burner blower pushes the flue gases to the chimney. Standstill is more critical than operation; there must be enough draught to protect the burner from rising heat.