Energy Performances of Tensile Material in Building Renovation in the Nordic Region

Abstract

Tensile materials are increasingly used in the building envelope as second-skin systems, despite a lack of investigation on their effects. In this work, a second-skin system integrating a tensile material as an outer layer has been adopted in the retrofit analysis of two of the most common building typologies in the Norwegian context. The simulations were carried out by implementing a custom control logic for the system, considering the outdoor air temperature and the global vertical irradiation on the façades. The proposed retrofit solution allowed for a primary energy saving of about 35%.

Flexible and Lightweight Solutions for Energy Improvement in Construction: A Literature Review

“…A broader range of aspects has been covered on the topic of flexible and lightweight materials and systems implemented in or used as building façades. On this topic, the most investigated system was the ventilated façade, as seven works [19][20][21][22][23][24][25] studied the use and performance of lightweight and flexible materials added to the exterior of the building envelope in a ventilated façade system. In [19], the authors analyzed the behavior of ventilated façades realized with fiberglass-reinforced cement boards upon varying the air cavity depth between the building wall and the external cladding (Figure 15a).…”

“…However, [20]'s focus was on the thermal performances of the system, monitoring the temperature distribution and its thermal inertia and calibrating a numerical thermal model to replicate the behavior of the whole system, which allowed them to calculate a potential in energy-saving rates of up to 50% in summer and 30% in winter when compared to a traditional wall. Instead, in [21], the authors focused on monitoring the behavior and calibrating a thermal model of a ventilated façade integrating different materials, a PVC-coated polyester fabric, which allowed them to carry out further numerical research in different climates [22][23][24]. In particular, in the experimental phase, the PVC-coated polyester fabric proved to be as effective as cladding in a ventilated façade system, resulting in a good chimney effect in the air cavity with natural ventilation despite being a highly porous material [21], whereas the numerical analysis carried out in various climates using the thermal model developed in TRNSYS allowed them to exploit the main characteristics of the material (rollable and semi-transparent) and test the logic behind the control of the rollable section in front of the windows in a variety of boundary conditions [21][22][23][24].…”

“…Instead, in [21], the authors focused on monitoring the behavior and calibrating a thermal model of a ventilated façade integrating different materials, a PVC-coated polyester fabric, which allowed them to carry out further numerical research in different climates [22][23][24]. In particular, in the experimental phase, the PVC-coated polyester fabric proved to be as effective as cladding in a ventilated façade system, resulting in a good chimney effect in the air cavity with natural ventilation despite being a highly porous material [21], whereas the numerical analysis carried out in various climates using the thermal model developed in TRNSYS allowed them to exploit the main characteristics of the material (rollable and semi-transparent) and test the logic behind the control of the rollable section in front of the windows in a variety of boundary conditions [21][22][23][24]. The results of the numerical studies showed a potential in primary energy saving up to 9.12% in temperate climates [21,23], up to 13.6% in hot climates [24], and up to 35% in cold climates [22] while also suggesting the need for more incentive policies to promote the endorsement of such energy efficiency measures on existing buildings [23,24].…”

“…In particular, in the experimental phase, the PVC-coated polyester fabric proved to be as effective as cladding in a ventilated façade system, resulting in a good chimney effect in the air cavity with natural ventilation despite being a highly porous material [21], whereas the numerical analysis carried out in various climates using the thermal model developed in TRNSYS allowed them to exploit the main characteristics of the material (rollable and semi-transparent) and test the logic behind the control of the rollable section in front of the windows in a variety of boundary conditions [21][22][23][24]. The results of the numerical studies showed a potential in primary energy saving up to 9.12% in temperate climates [21,23], up to 13.6% in hot climates [24], and up to 35% in cold climates [22] while also suggesting the need for more incentive policies to promote the endorsement of such energy efficiency measures on existing buildings [23,24]. Lastly, in [25], the authors reported the design, construction process, and thermal performance evaluation of a bio-based ventilated façade on a 1-story building in Dubai (UAE), highlighting the high sustainability of the whole construction process, from the sourcing of the bio-based composite material (made from renewable and recyclable sources) and the improved thermal performances of the envelope, which dissipated more heat during the day and preserved a comfortable indoor air temperature at night (Figure 15b).…”