Outdoor test cells for building envelope experimental characterisation - A literature review

In the past decades the construction sector experienced the diffusion of a wide variety of complex building envelope components and passive elements and strategies, characterized by a dynamic response to the climatic parameters. Many of these components have been claimed to contribute to reducing building energy use and improving occupants’ comfort. These kind of envelope elements need nevertheless to be tested under laboratory and real dynamic weather conditions in order to characterise, and possibly to model, their behaviour and their effectiveness both in terms of energy saving and indoor environmental quality. Both indoor laboratories and outdoor test cells have been developed in order to tackle the challenging issue of experimentally characterising innovative envelope elements. However, not always the experimental methodologies are fully and explicitly described in the available literature, and they are rarely compared to other types of experimental procedures. The aim of the present paper is to describe and review recent state of the art technologies for outdoor test cells. The paper starts with a short introduction on potentialities and limitations of outdoor facilities with respect to indoor laboratories and real buildings field tests, and it continues with a detailed classification and description of the most relevant outdoor test cells developed in recent years.