The Dual Air Vented Thermal Box: A Laboratory Apparatus to Test Air Permeable Building Envelope Technologies

Dynamic insulation technology has been investigated in detail in the context of a research program conducted by the Building Physic group of the Department of Energy in the Politecnico di Milano. In order to assess the energy performance of this kind of building envelope, either in steady-state or in dynamic conditions, a specific test apparatus has been designed and built. It consists of two thermally controlled chambers, separated by a metal frame hosting the air-permeable wall sample, one fed by a temperature controlled air flow, and the other discharged of the air flowing through the sample. The air flow is realized through a close air loop between the two chambers. The temperature control is achieved with three parallel water circuits (two for the boxes, one for the air loop) mixing cold (~11°C) and hot (~60°C) water. This work deals with the description of the whole apparatus and its measurement and control system, along with the procedure of characterization and calibration of the temperature control system in steady-state conditions.