Jorge S. Carlos

DAYLIGHT IN A CISTERCIAN HERITAGE CHURCH IN LISBON, FROM RURAL TO URBAN CONTEXT

ABSTRACT Light levels in the churches of the Cistercian Order are mostly related to the fulfilment of liturgical needs. The compound building of Bernardas’ Convent includes a church at the utmost southern corner that dates back to the 17th century. It only has one facade facing due southeast. This paper analyses the relationship between daylight conditions within the building before and after the urbanisation of the surrounding area; taking into account the relationship between the church, its main activities, and solar trajectory. A comparative analysis of the relationship between the actual surrounding context and the initial period after it was built (open field) is given. The highest reflectance of the street canyon has augmented the levels of available daylight.

Ventilated Double Window for the Preheating of the Ventilation Air Comparison of Its Performance in a Northern and a Southern European Climate

Keeping the indoor air quality within the reference levels requires that the polluted indoor air be replaced by fresh air coming from the outside. This paper presents a sensitivity analysis and a series of simulations where the performance of this passive system is studied. The influence of each relevant factor, like the wind, the solar radiation, and the outdoor air temperature, is assessed. Two different local sets of climatic data were chosen, a mild and a cold winter.

The impact of thermal mass on cold and hot climate zones of Portugal

The aim of this paper is focused on the energy performance of buildings containing massive wall alternatives. The analysis comprised the comparison of the heating and cooling loads of seven characteristic wall configurations of one sample building with different dynamic internal heat capacity (ISO 13790:2008) in spite of the equal thermal resistance. The equal thermal resistance, as derived from simple steady-state condition, was imposed in order to allow research of effects solely attributed to the wall heat capacity on the building performance. A detached one floor dwelling exposed to different climate conditions in Portugal was analysed to illustrate the effect of the same wall in terms of energy demand during cold and hot weather conditions. A whole building dynamic modelling using EnergyPlus was employed for the energy analysis. The best thermal performance was obtained with massive walls that were located at the inner side, for a very heavy weight building and high building time constant.

Simulation of the influence of an attic on the building energy efficiency in the Portuguese climate

The thermal performance of the building envelope is of critical importance to the overall building performance. This paper presents an investigation of the influence of most common attic typologies used in Portuguese housing stock on heating/cooling loads of conditioned spaces under different weather conditions. Unused attics are part of the building envelope, which provide protection from the external environment acting as a buffer space. To improve this protective ability, some scenarios such as insulation, low emissivity, ventilation and the slant of the roof are considered. The aim of this study is to assess the influence of such scenarios by investigating through simulating the heat transfer between the attics and spaces underneath. The extent to which an improved attic steers towards low energy buildings is established where a dynamic U d -values can be as low as 0.15 W/(m2K) and the yearly thermal reduction may surpass 20%.

Sustainability assessment of government school buildings in Portugal

ABSTRACT An accepted design feature of passive buildings in the northern hemisphere has been to have small windows facing north and large windows facing the equator, in order to minimize losses on the north side while gaining solar heat on the south. Solar gains and daylight are key passive strategies to improve energy performance without incurring additional construction and operational costs. The purpose of this research was to investigate how sustainable traditional government school buildings that can be found all over Portugal are in terms of more efficient use of energy and materials through design solutions. The selected case study is a typical vernacular located in Covilhã with cold winter and hot summer climate. The findings demonstrated that solar gains reduced the heating load in winter; however, the internal daylight level in the building was insufficient.

OPTIMAL WINDOW GEOMETRY FACTORS FOR ELEMENTARY SCHOOL BUILDINGS IN PORTUGAL

INTRODUCTION With respect to thermal performance, windows are the weakest component of the building envelope, essentially because the U-value is usually higher than the opaque envelope. This would ...