Using dynamic model for determination of heat losses in cold weather from a typical house in Tabriz constructed by lightweight concrete blocks

摘要

Lightweight aggregate concrete blocks are being increasingly demanded for construction purposes. These materials, whose principal purpose of their use is to retard the flow of heat, have many other important benefits over normal concrete blocks. Some of these benefits consist of less dead weight of structure, fire resistance, and more endurance against weathering conditions of the environment; therefore, due to high thermal resistance of them, there is a growing tendency in their use in many cold climate zones, especially in earthquake-prone areas. To describe thermal phenomenon through the walls, dynamic thermal circuit modeling was applied in this process. Heat-insulating properties of lightweight concrete blocks were studied by means of thermal resistance parameter. Thermal mass, as another parameter, was investigated for energy-efficient building design. The conduction, convection, and radiation of heat transfer phenomena are being taken into account in this investigation. The abundance of volcanic pumice in the East Azarbaijan Province of Iran is believed to be a remarkable source of lightweight material to produce lightweight aggregate concrete blocks sized 0.2 m × 0.2 m (variable) × 0.4 m, with two equal cavities. East Azarbaijan with its harsh winter weathering conditions was selected for practical data inputs. To obtain realistic results, a typical house of 100 m~2 in area was chosen for heat loss calculation and economic studies. Ratio of heat loss through external walls constructed with lightweight aggregate concrete blocks to that of the ones using normal concrete blocks for the same condition would be less than 0.35 that shows high potential of energy saving for heating. Furthermore, during a winter month, gas consumption, CO_2 emission, and living expenses could be decreased as much as 700 kg, 1,925 kg, 625,990 IRR, respectively. Therefore, using lightweight concrete could be economically beneficial, environmentally favorable, and suitable for earthquake-prone areas.