New concept of solar collector integrated into a sandwich panel as an active façade; CFD based parametric assessment and case study

Abstract

The use of renewable energy sources is a clear commitment

in the process of developing alternatives to reduce the high

energy consumption in buildings. Although with intermittent

production, renewable energies are unlimited and have a

demonstrated potential to be integrated within buildings. The

facade is a key element in a strategic position for harnessing

renewable solar energy by means of the Active Solar Façade

concept.

Through a CFD model, a parametric study has been developed

to evaluate different alternatives in the design of an Active

Solar Facade, composed by a sandwich panel as unglazed solar

collector. The high influence of the conductivity together with

the absorptivity has been demonstrated. Directly linked to the

material selection for solving the absorber and the hydraulic

circuit, the advantage of metals compared with plastics, has

been verified. The minor effect of the insulation has also been

analyzed, although the necessity of a minimum quantity has

been stated looking to avoid significant heat losses.

Additionally, the performance of the system has been evaluated

in order to determine the potentially achievable energy. The

result of the extensive campaign monitored in KUBIK® and

developed in different days in a period of 12 months, has

resulted in an average daily production of 320 Wh/m2 .

This study highlights the potential benefits of this type of

solutions and the necessity to properly dimension and design

them. In such way it is aimed to contribute to a greater use of

renewable energy in buildings, and consequently for reducing

the use of fossil fuels, by means of alternatives that enable the

mitigation of the climate change.