A proposal for ''correction values'' for winter outdoor design temperatures

This study aims to find a correlation between winter outdoor design temperature (WDT) and mass of the building envelope. The daily variations of the inside surface temperatures and heat fluxes of the walls under various climatic conditions and different wall constructions have been calculated by a computer program based on the response factor technique, which uses variable outside air temperature and solar radiation and constant inside air temperature values as input climatic data. The analysis of the relation between mass of the walls and inside surface heat fluxes resulted with the correction values for winter design temperature (WDTCV) depending on the mass of the wall and on the direction of facades for different climatic zones. Copyright (C) 1996 Elsevier Science Ltd

Effects of building wall arrangements on wind-induced ventilation through the refuge floor of a tall building

Wind-induced natural ventilation plays an important role in the fire and smoke safety of a refuge floor. This paper reports a computational fluid dynamics study to investigate the effect of building wall arrangements on the amount of wind-induced ventilation through a refuge floor which is located at the building mid-height. The refuge floor analysed has a large service core at its centre and is surrounded by exterior building walls, which are arranged in nine configurations that represent varying degrees of opening to wind flow. Results of computed flow patterns show that the wind-induced natural ventilation rate of a refuge floor varies significantly depending on the number of enclosing external walls and the incidence wind angle. A refuge floor, having only one side open, results in the worst natural ventilation and is not recommended. © 2008 Elsevier Ltd. All rights reserved.link_to_subscribed_fulltex

A CFD study of Hong Kong refuge floor design: floor height effect

Since 1996, the provision of a refuge floor has been a mandatory feature for all new tall buildings in Hong Kong. These floors are designed to provide for the building occupants a fire safe environment that is also free from smoke. However, the desired cross ventilation on these floors to achieve the removal of smoke, assumed by the Building Codes of Hong Kong, is still being questioned so that a further scientific study of the wind-induced ventilation of a refuge floor is needed. This paper presents an investigation into this issue. The developed computational technique used in this paper was adopted to study the wind-induced natural ventilation on a refuge floor. The aim of the investigation was to establish whether a refuge floor with a central core and having cross ventilation produced by only two open opposite external side walls on the refuge floor would provide the required protection in all situations taking into account behaviour of wind due to different floor heights, wall boundary conditions and turbulence intensity profiles. The results revealed that natural ventilation can be increased by increasing the floor height provided the wind angle to the building is less than 90°. The effectiveness of the solution was greatly reduced when the wind was blowing at 90° to the refuge floor opening.link_to_subscribed_fulltex

Combined Effect of Global Warming and Buildings Envelope on the Performance of Ground Source Heat Pump Systems

Heating and cooling systems as well as domestic hot water account for over 50 % of the world’s energy consumption. Due to their high thermal performance, ground source heat pump systems (GSHP) have been increasingly used to reduce energy consumption. The thermal performance of GSHP systems strongly depends on the temperature difference between indoor and ground operation temperature. This temperature difference is a function of mean annual air temperature and energy demand for heating and cooling over the year. The thermal load of a building, on the other hand is influenced by the thermal quality of the building envelope (TQBE) and outdoor temperature. Over the time, there is a change in heating and cooling load of buildings due to two reasons; improving the comfort requirements and outdoor temperature change. The overall aim of the current work is to study the impact of climatic changes in combination with TQBE on driving energy of GSHP. This was achieved by comparing the driving energy of the GSHP for different global warming (GW) scenarios and different TQBE. Under climate conditions of selected cities (Stockholm, Roma, and Riyadh), the current study shows that GW reduces the driving energy of GSHPs in cold climates. In contrast, GW increases the driving energy of GSHPs in hot climates. Also it was shown that buildings with poor TQBE are more sensitive to GW. Furthermore, the improvement of TQBE reduces the driving energy more in cold climates than in hot or mild climates