Thermal conductivity is an important thermal transport property, the magnitude of which is basis to determine the thermal application of any material. A relatively simple and ease at use measuring equipment using the principle of calorimeter is developed to get the value of thermal conductivity of insulation materials at low and medium temperature range. The details of components used, assembly, its working is entailed herein with necessary information. The thermal conductivity of materials and composites developed using hand-layup technique is calculated and the result is also validated by comparing with value calculated theoretically for composites. In composites, the filler material used is bamboo fiber, which shows the effect of decrement in thermal conductivity compared to the glass fiber in common epoxy matrix. The time to reach the steady state is evaluated for different cases and was found to be dependent on flow rate. The effective flow rate range is identified to get near to accurate value. The time taken to reach the steady state was found to reduce on increasing the flow rate within the effective range. On analysis, it is found that besides thermal conductivity of specimen, increase in temperature of cold plate and coolant outlet at steady state act also as a function of flow rate. The repeated results with negligible difference have arrived for particular specimen on varying the related parameters. Error is found in the measured value when compared to the standard value that can be owed to measurement of primary parameters in the process.