QM for Biomass DH Plants is a quality management system for automatic hot water and hot water heating systems based on wood-based fuels and biomass with a combustion heat output of 70 kW or more for supplying heat to individual properties and thermal networks. The focus is on the professional design, planning, execution, operation and optimisation of the energy generation plant and the thermal network. Important quality criteria include high operational safety, precise control, good air hygiene properties and economical fuel logistics. The aim is to ensure efficient, low-emission and economical operation of the entire plant.

The quality management system was developed in Switzerland in 1998 and has been gradually expanded since then. In 2004, the international working group QM for Biomass DH (ARGE QMH) was founded to jointly offer quality standards for wood-fired heating plants under the name QM Holzheizwerke.

Wood heating systems, especially those with district heating networks, are long-term projects with high investment requirements and long depreciation periods. The demands on the projects are correspondingly high. Among other things, heat demand determination is challenging because it is subject to strong fluctuations due to construction activity - both in the new construction and renovation sectors.

Professional project management is therefore an indispensable prerequisite for the successful implementation and operation of larger wood heating systems. Integral components of project management are quality management, presented in the form of a Q-plan, and the examination of economic viability, e.g. with a business plan. They guarantee that plants are built which achieve a high utilization rate at low investment costs and can be operated successfully with low emissions.

QM efforts focus on the professional design, planning and construction of the heat production plant and the district heating grid. The most important quality objectives are:

• reliable, low-maintenance operation
• high utilisation ratios and low distribution losses
• low emissions in all operating conditions
• precise and stable control systems
• ecological and economic sustainability

Throughout the entire planning and implementation phase, right up to acceptance and during the first years of operation, QM for Biomass DH Plants ensures that a technically and operationally flawless plant is realised with high efficiency and minimal investment and operating costs.

Continuous and comprehensive quality assurance, operational optimisation and the assessment of the quality targets set at the outset complete the quality monitoring process.

The following quality requirements are particularly noteworthy:

• The energy demand values must be determined in a comprehensible and plausible manner in accordance with the applicable regulations and must be presented in the form of a load characteristic curve and an annual duration curve.
• The thermal network should achieve the highest possible connection density.
• The wood boiler should be designed to be as small as possible so that it achieves the high utilisation required by QM for Biomass DH Plants.
• Where possible, defined standard circuits should be used for the hydraulic integration and the associated measurement and control technology.
• The net volume of the fuel storage facility should not exceed the demand for a few days of nominal output operation.
• Where possible, the detailed classification of QM for Biomass DH Plants should be used for the selection of wood fuels.

Most important actors of QM for biomass district heating plants

• The plant owner or his authorized representative ensures clear responsibilities and competencies. He decides on quality requirements after consultation with the Q-manager, and he is responsible for the economic efficiency of the project.
   
• A main planner must be mandatorily designated for project planning according to the QM system. He is responsible for the planning of the entire heating plant within the scope of his engineering contract and thus also for compliance with the state of the art and for the quality of the heating plant.
   
• The Q-manager ensures that the quality management system QM for biomass district heating plants is defined, realized and maintained. With this objective he advises the plant owner and the main planner. His activities are quality planning, quality control and quality inspection.