The Albedo of the surfaces. In-the-field test Procedure for building skin characterization

The optical and energetic characterization of an external surface directly in contact with the outdoor environment is fundamental to understand the behaviour of the building in response to external thermal inputs (i.e. solar radiation) that can strongly influence energy balance of the entire building. Equally, it is useful to distinguish and understand all the surfaces that can be found in different urban macro-zones. This may help us to foresee how they can influence the town micro-climate under particular conditions (thermal mass and heat island). Hence, this paper shows an in-the-field procedure to measure optical-energetic performances of surfaces used for building envelopes. And presents a critical analysis of the results obtained by this field approach compared with laboratory measurements. The leading procedure starts from an ASTM standard for in-the-field measurement of surfaces albedo, that actually require two pyranometers and a specimen of 16 m2 .The aim is to propose a procedure that could be easy applied on testing materials for building envelope, using only a 1 m2 specimen and a simplified testing appliance.