As part of the lecture Renewable Energies (REN1) in the fourth semester of the Energy Technology and Renewable Energies degree programme as well as the energy technology specialisation for industrial engineers in the Master's programme, semester projects are prepared on current topics in the field of renewable energies and sustainable energy use.

In the winter semester 2024/25, alternative heating systems of a historic building were designed as part of the course using the example of the Church of St. George in Bensheim.

The current heating system of St. George's Church is getting old and therefore the people in charge are looking for an economic and ecological solution for the future. This set the goal for the student work to develop a sustainable, energy-efficient and economical heating solution that at the same time meets the requirements of monument protection.

As an industrial partner, Company Kübler as a specialist for intelligent solutions for hall heating cooperated. This made it possible to consider the innovative infrared heaters as a heating system for the church.

Basic conditions in the development of a heating system included:

- Monument protection, noise protection, fire protection,

- min./max. temperatures, with the aspects of "feel-good temperature" and prevention of mold formation,

- Maximum temperature gradients to avoid organ detuning.

These restrictions, together with the size, building materials and heating volume of the church, formed the framework for the heating systems to be developed.

The project topics were generally based on typical project procedure. Starting with the legal basis for monument protection, the basis for considerations was laid with a heating load calculation according to DIN EN 12831. Particularly challenging was the determination of exact geometries and a sensible estimation of the materials used, as only rudimentary documents of the church were available. Other tasks dealt with various heating systems such as heat pumps with or without PV systems, gas heating systems, combination solutions or infrared heaters. Finally, in addition to technical aspects, economic aspects were also considered.

In the course of the project, it became apparent that infrared heating is a very good option for the heating system of a historic church building in many respects. Other systems such as pellet heating systems, fuel cells, wood chips, etc. were excluded from the considerations.

An important result was gained: no project can be implemented without the early involvement of monument protection authorities, no matter how ecological, economical and innovative.