Investigations on Thermal Performance of Building Elements

Abstract

A large amount of heat loss through building envelopes takes place via inhomogeneous components such as windows, doors, and thermal bridges. This loss can be approximated by measuring in laboratory the actual thermal transmittance of these components with the use of a Guarded Hot Box (GHB). It is necessary for design guidance and research to look into the performance of materials and constructions and for verification of simulation models.

A detailed literature review pertaining to the design and technical specifications of a Guarded Hot Box was carried out. Based on the same, the dimensions and details of the proposed Guarded Hot Box was worked out. The CFD analysis to study the air flow pattern inside the Guarded Hot Box was done using FLUENT software. The CFD results indicate that for a fairly uniform velocity and pressure profile the suitable position of the air circulation fan is on the front wall (side) in the Guard box as well as in the Cold box. For the Metering box, the suitable position of the air circulation fan is observed to be at the centre of the side wall.