In the present study, the performance of a heat pump unit is measured by varying the secondary fluid flow rate and compressor speed. Test results are applied to design the GCHP system, and then the effects of the flow rate and the thermal conductivity on the performance of the system and the...

Rooms with concrete slab roofs directly exposed to the sun become unbearably hot during summer and very cold during winter. Huge amounts of energy are required to keep them comfortable. Application of thermal insulation on roofs significantly reduces energy required for heating and cooling. The...

The synergy between highly energy-efficient buildings and low-energy district heating (DH) systems is a promising concept for the optimal integration of energy-saving policies and energy supply systems based on renewable energy (RE). Network transmission and distribution heat loss is one of the...

Taking into account the random scatterings due to random eigenfrequencies and random hopping matrices, we obtain the correlation functions for phonon and sound density fluctuations, which yield three and one entropy fluctuation modes at high frequencies, and three and one thermal conductivity at...

A new improved way for the inclusion of the vibrational degrees of freedom into the calculation of the thermal conductivity of dilute gases of diatomic molecules is proposed and has been tested for nitrogen and carbon monoxide. The effective cross-sections needed have been obtained using...

We demonstrate the ability to calculate thermal conductance and elastic properties on three-dimensional images of industrial polymer foamed materials. Results for thermal conductivity and elasticity show little scatter and provide the basis for accurate empirical correlations between phase...

Aerogel is a kind of synthetic porous material, in which the liquid component of the gel is replaced with a gas. Aerogel has specific acoustic properties and remarkably lower thermal conductivity (≈0.013W/mK) than the other commercial insulating materials. It also has superior physical and...

The effect of thermal conductivity of the absorber plate of a solar collector on the performance of a thermo-siphon solar water heater is found by using the alternative simulation system. The system is assumed to be supplied of hot water at 50°C and 80°C whereas both are used in domestic and...

PA/GO (palmitic acid/graphene oxide) as PCMs (phase change materials) prepared by vacuum impregnation method, have high thermal conductivity. The GO (graphene oxide) composite was used as supporting material to improve thermal conductivity and shape stabilization of composite PCM (phase change...

LED (light emitting diode) technology has been developed rapidly in recent years in the area of illumination applications. However, the rate of heat generation increases with the LED illumination intensity. The LED chip temperature is critical to determine the LED lifetime and efficiency. In...