Hydronic Heating of Parking Areas Instead of Mechanical Clearing of Snow and Ice

Winter weather can severely impact traffic safety for motorised transport, cyclists, and pedestrians. To combat this, mechanised clearing services and road salt are used. However, winter maintenance reduces road durability and service vehicles are increasingly costly due to diesel consumption. As a substitute, this paper proposes a porous interlayer (PIL) heat exchanger system coupled with an active heating system in lieu of a heat reservoir. It is based on a ZIM AiF cooperative research and development project “HEIZ” between TU Darmstadt and an industry partner. It was partially funded by the German Ministry for Economy and Climate Action. A 10-m by 4-m prototype for a hydronic pavement was constructed and operated during two cold periods. A heat source was used to heat the water flowing through the PIL of the hydronic pavement. The following temperatures were passively and continuously monitored: the surface of adjacent conventional asphalt pavement, the surface and inside of the hydronic pavement, and water at the inlet, the outlet, and in the buffer tanks and the ambient. As predicted, the hydronic pavement achieved consistently higher temperatures than the surrounding conventional pavement and thereby prevented the formation of ice and snow at all times. Using an energy balance approach, the thermal efficiency of the hydronic asphalt was calculated as 84%. This suggests that the proposed system could be a feasible and economically viable substitute for conventional winter services if the application area is adjacent to a building with a heat source. Other potential benefits include increased road safety in cold weather and a cooling effect in hot weather.