Evaluation of different wall heating systems in historic monuments – aspects of energy and conservation

There are many different ways of heating in historic houses – radiative, air, or convective heating, high- and low-temperature systems, local and area heating. Four different heating systems with high suitability for historic buildings were chosen and compared in long-term measurement campaigns. Two low-temperature area wall heating systems – prefabricated clay elements with serial pipes as well as a wall heating system with parallel pipes – were installed and two radiative high-temperature systems – a radiative plate heater and a Temperierung system that heats the base of the wall. While these systems were installed in four nearly identic rooms, indoor climate and energy monitoring has shown the difficulties with a direct comparison. This also shows the special problems when dealing with comparative measurements in historic buildings with their often unknown wall constructions. In the end, all four systems were compared to a reference system (a convective electric heater) room by room. For the specific examined case at Benediktbeuern, both low-temperature area wall heating systems and the radiant heater showed similar energy demand like the convective system. The high-temperature Temperierung heating system had an about 1.5 times higher energy demand. All wall heating systems were favourable in terms of comfort and preventing damp damages.