An Innovative Façade Element with Controlled Solar-Thermal Collector and Storage

Thomas Wüest,Lars O Grobe,Andreas Luible

doi:10.3390/su12135281

Thomas Wüest, Lars O Grobe + Show 1 more

Open Access

https://doi.org/10.3390/su12135281

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Journal: Sustainability	Publication Date: Jun 30, 2020
Citations: 11	License type: CC BY 4.0

Affiliation: Lucerne University of Applied Sciences and Arts

Abstract

A novel façade element is presented that forms a symbiosis between an enhanced box-type window, a closed cavity façade, and a Trombe wall. This hybrid, transparent-opaque façade element features an absorbing water tank, that is installed behind a controlled shading device toward the cavity of a non-ventilated Double Skin Façade in the parapet section. To evaluate the potential impact on building performance, a transient simulation model is developed in Modelica and calibrated by comparison with measurements on a prototype. The effect of the absorbing thermal storage on heat transfers under solar radiation is analyzed in comparison to (i) conditions excluding solar radiation and (ii) an empty tank. An evaluation for four European cities demonstrates that the annual heating demand can be reduced by more than 4.2% and cooling demand by at least 6.6% compared to a façade without thermal storage. The effect is explained not only by the increased thermal mass, but also by the effective modulation of solar gains by the controlled absorbing storage. The dampening of heat flow fluctuations and the control of solar gains is a promising means to reduce the installed power of HVAC (heating/ventilating/air conditioning) installations.

Highlights

Since Double-Skin Façades (DSFs) are usually applied to buildings with highly glazed building envelopes, they potentially lead to overheating in summertime, when peak outside-air temperatures coincide with high solar gains, which is usually considered the main drawback of these façade types [2,3]
The Solar Energy Balanced Façade (SEBF) shading control is applied as described in Section 2.4.2 and the HVAC control according to Section 2.4.3
E.g., the climate in Stockholm is characterized by lower air temperatures and reduced solar irradiance compared to other locations, which reduce the effect of the additional thermal mass of SEBFw

Summary

Introduction

Since the 1980s, Double-Skin Façades (DSFs) have been used in tall office and administration buildings. DSFs offer various advantages: high aesthetic value, good thermal/acoustic performance and the ability to protect shading devices from dirt and wind gusts. The ongoing development and improvements of the technology led to the emergence of new systems, e.g., the Closed-Cavity Façade (CCF). The CCF differs from the naturally ventilated DSF in that its cavity is fully sealed with a modest dry air flow [1]. Since DSFs are usually applied to buildings with highly glazed building envelopes, they potentially lead to overheating in summertime, when peak outside-air temperatures coincide with high solar gains, which is usually considered the main drawback of these façade types [2,3]

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