24 research outputs found

    Strategies for school buildings refurbishment in Portuguese climate

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    Portuguese school buildings are generally characterized by an in-service thermal discomfort, due to the poor envelope thermal properties and the lack of resources for paying energy consumption. Most Portuguese schools are free-running buildings with a natural ventilation strategy. Hundreds of high and basic schools have not been refurbished and still have problems or anomalies and inadequate in-service conditions and need to be rehabilitated in the near future. There will be, therefore, an opportunity to apply the acquired knowledge of comfort, habits, energy consumption and costs that have been studied since the last refurbishments (2008). This work studies the Portuguese Brandão schools model (from the ’70s), including about 100 non-refurbished basic schools. A prototype classroom was prepared in a Brandão school, in Porto. The in situ experimental campaign consisted of temperature, relative humidity, CO2 concentration and energy consumption measurements. The main tasks of this work are: (1) the validation of an advanced hygrothermal model with experimental measurements before and after the prototype refurbishment; (2) development of a sensitivity study in order to choose the best refurbishment and heating strategies for these buildings, regarding their typology, the local climate features and the actual capacity to support the operating costs; (3) assessment of the roof insulation thickness in Brandão schools; (4) quantification of discomfort indicators.This work was financially supported by: Base Funding - UIDB/04708/2020 of the CONSTRUCT -Instituto de I&D em Estruturas e Construcoes - funded by national funds through the FCT/MCTES (PIDDAC). Francisca Cavaleiro Barbosa would like to thank FCT for financial support through the grant PD/BD/52658/2014

    Thermal renders for traditional and historic masonry walls: Comparative study and recommendations for hygric compatibility

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    To reach European climate neutrality by 2050, the strategic importance of retrofitting the existing building stock is clear. For this scope, thermal rendering systems have emerged as a very feasible solution for historic and traditionally constructed walls. Nonetheless, a definitive guideline for the selection of suitable solutions for the application in this context is not yet available. This research aims at providing recommendations for the choice of hygric-compatible solutions in an early-stage design, for the context of temperate climates with mild winters. In this study, the massive masonry walls of three historic buildings located in Portugal and Italy are considered. Mono-dimensional hygrothermal simulations are validated against the data measured on-site. Simulations are then used to evaluate the impact of thermal renders on the walls, in comparison to more common insulation materials. Two moisture-related risks are considered: moisture accumulation and reduction of drying. This investigation shows that, for traditional porous walls, retrofitted configurations should be simulated not only under typical operational conditions but also considering a very high initial water content in the wall substrate, when the insulation is applied. Otherwise, moisture-related risks may be overlooked. Recommendations on the choice of thermal rendering systems are provided.ISSN:0360-1323ISSN:0360-132