Helenice Maria Sacht

Glazing daylighting performance and Trombe wall thermal performance of a modular façade system in four different Portuguese cities

The need to reduce energy consumption in buildings leads to the development of new façade systems that can be energy efficient; thus, contributing significantly to heat transfer between outdoor and indoor spaces. Here, the versatility and flexibility of the modules are key attributes. For this purpose, this study focused on the thermal performance of Trombe walls and glazings and the glazing daylighting performance of a modular façade system in four different Portuguese cities. Computational simulations for the thermal performance of different arrangements of the modules were accomplished with the DesignBuilder software, while the glazing daylighting performance was studied by means of Ecotect and Desktop Radiance software, and compared with the transmittance curves of glazings. Occupancy profile and internal gains were fixed according to the Portuguese reality for both studies. The main characteristics considered in this research were the use of two double glazings, four different Portuguese climates and one or two Trombe walls in the façade. According to results, the use of Trombe walls and double self-cleaning glazing in the façade showed an important reduction in the energy consumption as well as better daylighting performance.

Different module placements in a modular façade system for natural ventilation

Nowadays natural ventilation has gained prominence because its correct use can reduce energy consumption for cooling systems and improve thermal comfort among users. In this paper, we report on the modelling initiative, based on the wind tunnel tests that were carried out for the determination of the influence of natural ventilation in buildings. Indeed, the renewal of air in a closed environment without using an air conditioning system with mechanical elements can lead to energy savings and, in addition, provide air quality. The wind tunnel tests were carried out by varying the positioning of six ventilation modules in the facade system configuration. The modules were positioned below the window-sill (ventilated window-sill) as well as separately above and below the facade. The wind speed measurements were taken inside and outside the model for the different facades configurations to evaluate the best performance in relation to natural ventilation. The results supported the positioning of the six ventilation modules below the window-sill, forming a “ventilated window-sill” as the most effective natural ventilation solution.

Cast-in-place concrete walls: thermal comfort evaluation of one-storey housing in São Paulo State

This paper presents a proposal of thermal performance evaluation of a one-storey housing typology (TI24A) executed by CDHU - Companhia de Desenvolvimento Habitacional e Urbano do Estado de Sao Paulo, considering the use of cast-in-place monolithic panels of concrete, with different thicknesses panels (8, 10 and 12 cm) and density between 1600 and 2400 kg/m³. In this study, the specific purpose was discussing the influ ence of the characteristic of concrete walls on the housing thermal performance without slab. Was defined of first parameters of study (definition of the one-storey housing typology, survey about housing users behavior and cities choose) and executed computational simulation (winter and summer), for four Sao Paulo State cities (Sao Paulo, Sao Carlos, Santos e Presidente Prudente), with the software Arquitrop 3.0 in a one-storey housing. Was observed that in winter and summer the typologies analyzed, the panels thickness variation had more influence about results than different concrete densities. The minimum level of thermal performance (M) in winter has been granted for some cities, with exception of Santos. In summer one of Sao Paulo city’s typology was attended the minimum level of thermal performance in agreement with standard “NBR 15575 Residential buildings up to five storied – Performance, Part 1: General requirements”.