A currently unresolved problem in building design in the paradox between increasing demand for good thermal insulation, and the requirement for ample levels of ventilation, to maintain a healthy indoor environment. A possible solution to this problem is a supply air 'ventilated' window. An experimental set-up has been designed to test the performance of the window under various conditions. The behaviour of the window is shown, and the factors affecting it's performance discussed.
The influence of natural convection on the thermal properties of insulating porous medium with air cavity is studied. Here, the combined effect of air movement in the air cavity and the air movement inside the insulation is evaluated with the help of numerical analysis. The influence of total natural convection on the thermal properties of mineral wool, loose-fill insulation, insulation made of small and large polystyrene ball with air cavity are studied. The results are presented in terms of dimensionless numbers and the temperature distribution across the insulation.
The Paper deals with numerical computations, carried out, in order to predict the effects of natural convection on the thermal performance of porous material. In this paper the effect of natural convection in a horizontal porous layer will be discussed. The study of the above configuration is essential to understand the functioning of insulation of the type used in attics. The influence of natural convection on the thermal properties of mineral wool, loose-fill insulation, insulation made of small and large polystyrene balls are studied.
This paper examines historical data on Government expenditure on grants for home energy efficiency improvements, and the effect that this had on the uptake of insulation measures. The analysis focuses on loft insulation, this being the main measure that has been targeted by grant schemes. The paper shows that variations in loft insulation uptake between 197 4 and 1996 were closely tied to changes to grant schemes. Furthermore, there is a clear correlation between the uptake rate achieved and the level of funding provided by the Government.
Low energy buildings should satisfied two main tasks: to assure a low energy use and provide an excellent residence comfort. The building envelopment elements, especially the transparent one, have major influence on both tasks. The paper presents research results of heat transfer and fluid flows through double pane window with tight, opaque insulation screen. The insulation screen was installed in such a way, that a semi open air gap was formed. An air gap is connected with the building interior through an opening on the bottom and with exterior through siphon at the top.
A systematic analysis of recently constructed dwellings in the Flemish Region has been undertaken within the SENVIVV-project (1995-1998). In total 200 dwellings have been examined in detail. The study involved various aspects: energy related building data (thermal insulation level, net heating demand, installed heating power, .. ), indoor climate (temperature levels in winter and summer), building airtightness, ventilation, appreciation of the occupants, . . . This paper especially focuses on the results for thermal insulation, airtightness and ventilation.
There is a need to improve building envelopes in many parts of the developing world. In cold climates, scarce fuel is consumed in an attempt to maintain reasonable indoor temperatures. In Northern Pakistan, traditional houses are made with stone walls while newer buildings, houses and schools, use uninsulated concrete block that has even lower thermal resistance. Evaluation and improvement of these buildings were undertaken with a regional non-governmental organization. Measurements were made of the thermal resistance of typical exterior walls.
The paper presents a bioclimatic house in the Negev Desert, lsrael, as a case study through which it attempts to present a comprehensive and critical view of bioclimatic architecture, design support tools, and appropriate details vis-a-vis common construction technologies and practices, assessing their relative impact and limitations. A number of topics are examined from different aspects, such as insulation and thermal mass, window systems incorporating double glazing, insulated shutters and window screens, vis-a-vis solar gains.lr ventilation and infiltration.
ln the past, passive solar buildings were specifically designed with respect to energy and thermal comfort requirements. Within this framework a fa9ade able to collect solar energy and bring indoor suitable conditions for occupants was thought of as an optimal building device. On the contrary, little attention was paid to their acoustic behaviour.