Wood, pellet,
air, wooden roofs, chimney systems: learn more

Here are some of the main characteristics compiled from recommendations provided by installers with whom we have collaborated for more than 25 years:

Material with excellent heat resistance: the smoke ducts should be constructed using materials capable of withstanding the high temperatures generated by wood combustion, ranging from 400°C to 600°C.

Diameter: the diameter of the smoke duct should be proportionate to the stove's power and is typically specified by the manufacturer of the generator. Only the chimney connection can be adjusted in size.

Length: the length of the smoke duct significantly influences the proper functioning of the stove. Correct sizing of the system is crucial for the optimal operation of the generator.

Thermal insulation: smoke ducts reach high temperatures and can pose a risk of burns upon contact. In cases where the duct passes through a room other than the one in which the generator is installed, where there is a potential risk of human contact, the duct must be protected against accidental contact in compliance with industry standards to ensure safety.

Cleaning and maintenance: smoke ducts must be regularly cleaned and checked to prevent the accumulation of soot and debris that can obstruct the stove's airflow and increase the risk of fire.

Smoke ducts for wood-burning stoves should be carefully engineered and constructed to guarantee optimal performance and safe operation of the stove. To ensure the utmost safety and reliability of the system, it is important to engage the expertise of a qualified professional who meets the requirements outlined in Letter C of Ministerial Decree No. 37/2008 for the proper design and installation of smoke ducts.

Here are some of the main characteristics that smoke ducts for pellet stoves must have according to the flue and chimney standards.

Diameter: the diameter of the smoke duct should be proportionate to the stove's power and is typically specified by the manufacturer of the generator. Only the chimney connection can be adjusted in size.

Materials used: the materials should be resistant to corrosion, condensation and combustion products.

Thermal insulation: these ducts can reach substantial temperatures, which makes them dangerous to human contact. In cases where the smoke duct passes through a room other than the one in which the generator is installed, where there is a potential risk of human contact, the duct must be protected against accidental contact in compliance with industry standards to ensure safety.

Resistance to high temperatures: smoke ducts must be made of materials capable of withstanding elevated temperatures, which is why they undergo thermal and mechanical sealing tests.

Adequate slope: the smoke duct must have an adequate incline to ensure effective smoke evacuation and prevent condensation build-up. Typically, a minimum slope of 3% towards the exterior is recommended.

Easy cleaning: the design of the smoke duct should facilitate cleaning through a T-union with an inspection cap. This helps prevent the accumulation of combustion residues that may obstruct the duct or pose fire hazards; therefore, it is advisable to conduct additional inspections at the most critical points.

Compliance with standards: smoke ducts for pellet stoves must comply with the relevant standards and regulations.

The pipes used for air ducting in heating systems should have certain key characteristics to ensure efficient operation.

Adequate size: the pipes must be adequately sized according to the volume of air they will transport. Proper dimensions are necessary to facilitate optimal airflow without significant restrictions or pressure losses along the path.

Sealing: pipes must be effectively sealed to prevent air leakage within the system. This ensures maximum energy efficiency of the heating system by minimising heat loss through cracks or unsealed joints.

Thermal resistance: pipes must be capable of withstanding high temperatures without deformation or damage. This becomes particularly crucial in heating systems that use high-temperature heat sources, such as boilers or furnaces.

Thermal insulation: ideally, air ducting pipes should be equipped with thermal insulation to minimise heat loss during the transportation of heated air. Thermal insulation helps maintain a constant temperature along the route and enhances the overall efficiency of the system.

Corrosion resistance: pipes can be exposed to humid or corrosive environmental conditions. Therefore, they must be constructed from corrosion-resistant materials such as stainless steel or chemical-resistant PVC. This ensures a prolonged service life and prevents damage.

Ease of cleaning and maintenance: it is recommended to use pipes that are easy to clean and maintain. This can include features such as accessible cleaning points, smooth internal surfaces to reduce the accumulation of dust and debris, and easily removable connections for easy inspection and maintenance.

Low airflow resistance: pipes should have minimal airflow resistance to prevent pressure loss and slowdown of airflow. Using pipes with smooth internal surfaces and an optimised flow design can minimise resistance and enhance the system's efficiency.

It is important to consider the specifications of the heating system, such as the type of fuel used, required thermal output and building layout, when selecting the most suitable pipes for the project. Engaging a professional with expertise in thermal engineering or heating systems is recommended in order to obtain an accurate assessment and design of the air ducting system.

Below is a list of some of the main characteristics gathered from installers throughout Italy with whom we collaborate:

Heat-resistant materials: given their particular function and proximity to wood and other flammable materials, fittings must be made of high-quality, highly heat-resistant materials, such as stainless steel.

Double chamber: fittings featuring a “pipe within a pipe” design, insulated with rock wool and/or air space, play a crucial role in ensuring the safety of the system.

Heat-resistant gaskets: gaskets used to seal the fittings must be heat-resistant to prevent exhaust gases from escaping and infiltrating the roof or the surrounding environment.

Corrosion resistance: fittings must be resistant to corrosion as exhaust gases may contain corrosive substances that could harm the material of the fitting.
Considering their exposure to weather conditions, fittings must also demonstrate resistance to corrosion and other environmental stresses

Chimney systems must be installed in compliance with legal regulations and the specific technical requirements outlined by the manufacturer of the combustion appliance. They must also be positioned to avoid any contact with inflammable materials like wood, insulation, paper or textiles. It is important to thermally insulate the chimney correctly in order to protect the building's structures from the high temperatures of the flue gases.

The installation of chimney systems is a difficult and delicate operation that requires specialised technical expertise and the use of high-quality materials. It must be carried out by professionals certified according to Ministerial Decree No. 37/2008. The installation must be accompanied by the proper legal documentation. Regular maintenance checks must also be carried out to assess the wear and tear of the chimney system. If any issues are identified, the system must be replaced to ensure the utmost safety and correct functioning.

Wall passages for smoke evacuation must be designed and made with particular care to ensure effective and safe evacuation of combustion gases. Here are the features they must have:

Safety: It is important to choose a wall passage that has been tested and certified by the manufacturer to ensure safe installation. It is appropriate to choose a complete system to be installed and not a set of products to be assembled on site.

Heat Resistant Materials: Wall passages must be made of heat resistant materials such as AISI 316L steel, in addition to very high performance insulating materials that can withstand high temperatures without deformation or compromising their structural integrity.

Suitable diameter: the wall passage must have an adequate diameter in accordance with the generator and the planned chimney system.

Resistance to atmospheric agents: The wall passages must be constructed in such a way as to prevent the infiltration of rainwater. In addition to having a waterproof structure must also be sealed efficiently with water-repellent silicone.