The distance to combustible components is given in the respective declaration of performance (DoP) of the chimney or connecting piece. As a rule, a rear ventilated installation is mandatory.

If there is an existing connecting piece and there is no manufacturer's information, then the distance must be observed according to the regulation (FeuV). This is in most of the states 40 cm, but there may be country-specific deviations, which must be observed.

Effective height is the area between the smoke pipe inlet and the chimney top.

If there is an offset in the structure, this is indicated as so-called "extended length".

The distance to combustible components can be reduced if, e.g. a single wall flue is insulated with 2 cm non-combustible material e.g. mineral wool A1 according to DIN 4102, then the distance as per the rule can be reduced to up to 10 cm.

However, this possibility should not necessarily be used in lounges, as it can lead to an increased burden in breathing air through fibres of the insulating material, if they are not sufficiently covered.

For such cases the tested, double-walled flues made of stainless steel are the best option. They are tested for such applications and usually require a distance of only 10 cm to 20 cm to combustible components.

Wall brackets should always be placed close to the pipe joint, as there is the highest risk of deflection and sliding apart from the connection.

It is also recommended that a wall bracket is placed immediately after a T-connection, as wind forces occurring here can otherwise be transmitted directly to the connection piece and to the flue connection of the fireplace, which can lead to damage.

The distances between the wall brackets or any required intermediate supports must be taken from the technical documentation of the manufacturer.

The minimum height of a chimney outlet is defined by law (1. BimSchV). The performance of the fireplace, the environment (neighbouring houses) and the roof slope are considered. In addition, the location of the chimney (on the roof or ridge-proximity) and the fuel of the fireplace should be considered.

Difference in roof pitches:

<20 ° pitch: At least 100 cm above the roof (at right angles to the roof surface) Near the ridge? Then at least 40 cm above this

> 20 ° pitch: At least 40 cm above ridge

or horizontal distance from the roof at least 2.3 m

Windows, doors and vents:

The chimney top should be at least 100 cm or min. 15 m away from the upper edge of the window up to 50 KW. For every additional 50 kW total heat output, the perimeter increases by 2 m up to a maximum distance of 40 m.

Industrial plants from 1 MW to 10 MW thermal capacity:

Deviant from paragraph 1, the height of the outlet opening for gas and oil fired installations with a rated thermal input of 1 megawatt to 10 megawatts shall exceed the highest edge of the roof ridge by at least 3 m and will be at least 10 m above ground level.

With a roof slope of less than 20 degrees, the height of the outlet opening must be related to a fictitious roof ridge, the height of which must be calculated on the basis of a roof pitch of 20 degrees. Sentence 1 no. 1 does not apply to combustion plants in hot forming plants, as far as wind deflector fans are used.

Special case:

Roofs with parapet:

The assessment is made here according to the fire ordinance (FeuV) of the individual federal states. Unless otherwise specified then:

At least 1 m above the parapet or at least 1.5 m away

Attention! If balustrade is higher than 50 cm and closed on all sides, then a dangerous accumulation of exhaust fumes must be prevented!

The maximum height of a chimney depends on the type of fireplace and the external dimensions of the chimney. All common dimensions and units can be found in the corresponding tables and declaration of performance.

An exhaust system made of metal (e.g. stainless steel chimney) is considered free-standing if

- the distance to the house exceeds 1 m,
- the free height above the top lateral support is more than 3 m or
- the distance between two lateral supports is greater than 4 m.

The chimney can be free standing above roof as far as, allowed by the manufacturer for the system. The exact details are listed in the Declaration of Performance (DoP) of the respective exhaust system.