Investigation of a combined ventilation and heating system for residential buildings.

Combined ventilation and heating systems in floors demand extensive investigations about the heat transfer before they could be installed in residential buildings. For basic investigation about the heat transfer two experimental plants with different duct geometries are build in a laboratory of the University of Essen. Especially the measurements of temperature on different places of the plants are taken to determine the heat transfer at the two floors. The evaluation of the test data show that a floor with a cavity which is built with cones is unqualified for a combined ventilation and heating system. The difference of the temperature between the air inlet and the room is too low, because the heat loss at the floor surface is too high. A good combination is the air duct system which is ending in an area of 1000 mm lenght containing a cavity which is built with cones. This system guarantees sufficient high temperature at the air inlet to obtain a comfortable room temperature.