Comprehensive assessment of agricultural waste effect on the thermal bridge phenomenon using ZUB ARGOS software, a case study in Iran

Abstract

High energy use in buildings plays a key role in climate change and air pollution in cities of Iran. In this regard, the use of thermal insulation to reduce energy demand has been proposed as an important solution. Production of thermal insulation made from chemicals consumes high energy and their disposal has high environmental effects. Therefore, the use of agricultural waste due to their abundance in Iran, low energy consumption for production and high renewability rate, seems to be justified as an alternative to chemical-based insulation. Due to the importance of the above issues, in the present work for the first time with the aim of investigating the phenomenon of thermal bridges in traditional buildings of Iran, the ZUB ARGOS software is used to evaluate the effect of 10 different agricultural wastes (cork, cellulose fiber, meadow grass, flax, sheep wool, straw, hemp, cotton, grain granules, and cattail) as thermal insulation on the inside face of the wall, find the optimal thickness of common waste (straw) to remove the phenomenon of thermal bridges and evaluate the effect of the horizontal or vertical direction of straw fibers to the heat transfer path in the city of Yazd located in the hot and dry climate of Iran. The results of the current situation simulations showed that the thermal bridge phenomenon occurs in the building under study and the most critical connection with f = 0.48 is related to the wall-to-wall connection. Among the agricultural wastes, cork is the most suitable insulation with fmin = 0.76. The results of the 10 wastes investigation also showed that the wall-to-wall connection and the window lintel connection are according to the order the most critical and safest connections for creating a thermal bridge in the building under study. Due to the abundance of straw waste in the studied climate, this insulation was selected to optimize the current situation. The results showed that the placement of straw fibers perpendicular to the heat flow compared to its horizontal direction has a maximum advantage of 4.35%. The results showed that the optimal thickness for straw insulation is 3 cm, which means that no thermal bridge in connections occurs and cork is the most suitable insulation among the agricultural wastes studied.