Replacing heating boilers? 

'Don't forget the boiler room and CLV system'

Heating boilers have a limited lifespan and are now giving way to a new generation of boilers, which also impose new requirements on flue gas extraction and air supply. "For example, condensing boilers are being replaced by closed systems and because better building insulation leads to less energy/heat loss, the installation of more efficient boilers is now unavoidable," knows Simon Ramaekers, director of Schiedel Benelux. Importantly, boiler replacement also involves checking the boiler room, flue gas outlet and air supply. "The adjustment of one link usually means that several links in the chain have to be adjusted or replaced. This is fueled by the safety awareness that heaters produce harmful combustion gases that must be discharged directly to the outside air."

The challenges in the boiler replacement market lie mainly with the installer, who has to work out the installation of the new boilers and the Combined Air Supply Combustion Ventilation (CLV) system as one working unit, Ramaekers knows. "If apartments undergo a total renovation including insulation, then the energy demand decreases. As a result, the existing boilers can be replaced by smaller boilers with a lower output and different dimensions when it comes to flue and air supply." Since 2017, it has been mandatory to also replace the flue gas duct when replacing the central heating boiler. "For apartments, this means that the entire installation has to be redesigned and re-calculated. The engineers at our Center of Engineering (CoE) are happy to play a role in this and take a lot of uncertainties and concerns away from the installer, who only has to focus on executing a project." The new 2023 Gas Boiler Act calls for new boilers to be installed only by companies that are CO certified.

Easy and quick assembly

The Schiedel CLV system offers installers the assurance of easy and quick installation, saving considerable time in renovation projects. "In addition, the breadth of our range ensures that we can supply a suitable system for all types of combustion appliances. Think for example of connection elements in parallel, concentric, long and short versions and in different material thicknesses, which are supplied in stainless steel as standard."

High quality and safety

Compared to materials such as aluminum and galvanized carbon steel, stainless steel offers the advantage of corrosion resistance, ensuring a long life of the CLV system. "With the Schiedel CLV system, installers are also assured of high quality and safety," said Ramaekers. "Our system has been used successfully in Europe for more than 30 years and has a service life that exceeds that of most buildings. Yet the system is invariably removed during boiler replacements because, ironically, boiler requirements and technology change much faster than the quality of our CLV system."

The current design of the Schiedel CLV system dates from 2009 and was developed in accordance with Gastec's inspection requirements. "The Gastec inspection requirements were drawn up and approved by all kinds of companies in the gas industry and have now been adopted by the Eurocode (EN-1856-1/2), whereby the Dutch regulations for gas installations are fully embedded in the inspection requirements. This guarantees consumers that their central heating appliance is connected to a safe flue/supply channel for flue gas and combustion air respectively."

Center of Engineering 

Schiedel Benelux designs, engineers and produces its CLV systems entirely in-house, Ramaekers emphasizes. "This allows us to guarantee consistently high quality and short delivery times. Moreover, far-reaching customization is possible, with an important role for our Center of Engineering. Our CoE team of engineers operates Europe-wide and specializes in consultancy, engineering, commissioning and project management of, among other things, industrial flue gas exhaust systems, industrial cascade (gas) exhaust systems and combined air supply and flue gas exhaust systems. The added value when renovating apartment buildings is reflected, among other things, in a building-specific design for the flue, ventilation or CLV systems."

Good design as a necessary starting point

Schiedel engineers are in regular contact with the installer. "For example, to engineer the right systems for each project. Here, 2D and 3D CAD drawings are produced and exchanged with the installer, so that the system can be installed on site without local adjustments and no one faces any surprises. If the structural situation requires it, the CoE also designs special deviating dimensional pieces. In addition, CoE's experience in industrial projects makes an important contribution to project planning. With our approach, we are fully in line with the recommendations made by the Ministry of the Interior and Kingdom Relations in "The Safety of Collective Flue Gas Drains in Residential Buildings," which stresses the avoidance of carbon monoxide poisoning risks and emphasizes that all parties involved must work together to develop a proper boiler replacement solution. The guide emphasizes that modifications to a collective system can have consequences for all connected homes. This makes it clear that a good design is necessary for a good project plan that guarantees the long-term safety of residents. Schiedel is taking its responsibility in this."