Summertime Overheating Risk Assessment of a Flexible Plug-In Modular Unit in Luxembourg

Abstract

Modular buildings offer faster construction process, provide better construction quality, allow reducing construction waste and are potentially flexible. Frames of modular units can be made of metal, timber, concrete or mixed materials but lightweight structures do not always allow erecting high-rise buildings and generally present a higher risk of overheating and/or overcooling. To reconcile these pros and cons, a typology of modular building called Slab was designed by a group of architects. The building is composed on the one hand of a permanent concrete structure named shelf-structure and on the other hand of several flexible removable timber modular units, also known as modules. The shelf-structure will host the common utility rooms and will serve as docking infrastructure for the housing modules. To provide high flexibility, the Slab building was designed to adapt to any orientation and location in Luxembourg. An energy concept and a HVAC systems design has been developed for the Slab building. Furthermore, a two-fold sustainability analysis was carried out. The first part of the analysis regards the determination of the minimum required wall thicknesses of the modules in accordance with Luxembourgish regulatory requirements, although the current regulation does not yet consider the Slab building typology. The second part, which is the subject of this paper, is thermal comfort assessment, more precisely, summertime overheating risk assessment of these modules, in compliance with Luxembourgish standard. In this regard, dynamic thermal simulations have been realized on two module variants; the first fulfills the passive house requirements, and the second—the current requirements for building permit application, which in principle corresponds to low energy house requirements. Simulations showed that with adequate solar shading and reinforced natural ventilation by window opening, overheating risk could be avoided for the normal residential use scenario for both module variants.

Exploring the Knowledge Domain of Risk Management in Prefabricated Construction

“…To solve this issue, through experimental testing, Rodrigues, Sougkakis, and Gillott [118] found that the application of high-density fiberboard and phase change materials could regulate the internal temperature. Simulations also showed that with adequate solar shading, reinforced natural ventilation [121], and climate-adaptive design [122], overheating risk of PC could be mitigated greatly. In short, the result reveals that PC itself does not have an excellent mitigation effect on overheating risk, but the construction logic of PC provides a platform to apply more mitigation measures from the design stage.…”

Simulation and Analysis of Thermal Insulators Applied to Post-Disaster Temporary Shelters in Tropical Countries

“…This concept is congruent with Lacey et al [20] and Musa et al [18] which complement it, indicating that this is a technique applicable to volumetric units which generally constitute the building's structural element. Ye et al [21], Rakotonjanahary et al [22], and Hong [3] go forward describing the components that compose the modular unit and that must be integrated in order to allow the transport of a complete module to the building installation site, that is, wall solutions, ceiling, frames, electrical and hydraulic installations, HVAC, and fixed furniture. Finally, Musa et al [18] highlight the need to consider the logistical aspects as part of the modular construction process, as the use of the method only brings the expected results if executed in accordance with rigorous planning.…”

“…As a result, most of the construction process can be carried out using the production line model, similar to that of the automobile industry, with well-defined workstations and less need for workers to move around the factory floor. This peculiarity, in addition to significantly reducing occupational risks [26], allows for optimizing internal finishing work and even facades, decreasing the construction schedule [20,21] as they are carried out in an industrial environment and not on the construction site which is subject to various adversities [22]. In addition, the use of specialized labor in a controlled environment favors a higher quality product delivery [18,21] and less waste generation [13,20].…”

The Effect of European Climate Change on Indoor Thermal Comfort and Overheating in a Public Building Designed with a Passive Approach

“…When evaluating summer overheating within homes, the exceedance of fixed absolute values is generally used [37,38]. The overheating criterion is usually defined at 26 • C most cases [39,40]; CIBSE (Chartered Institution of Building Services Engineers) indicates that bedroom temperature should be maximized at 26 • C since sleep quality and thermal comfort decrease when the temperature rises above 24 • C [36]. In our analysis, we used this threshold and the ODH 26 indicator to evaluate the overheating of the analyzed building.…”