The take-up of the many voluntary energy efficiency standards which exist in the UK and internationally has been limited. As a result, governments have recognised the need to introduce mandatory schemes through legislation, e.g. from 2016 all new build homes in the UK will be required to achieve...

The thermal performance of building envelopes is the determinant factor of building energy consumption, and especially envelope retrofitting is an effective way of reducing energy consumptions in existing building. For different climates, there may exist different optimal retrofitting schemes....

Buildings play an important role in greenhouse gas emissions since they constitute a large proportion of the global energy demand. This dramatic scenario is usually a consequence of poor thermal insulation characteristics of building fabric. Among the elements of a typical building envelope,...

The Rainwater–Friend theory is used for the evaluation of the initial density dependence of the thermal conductivity of the noble gases using accurate realistic potentials. This theory, which was originally developed for spherically symmetric potentials, is adapted for the calculation of the...

For the purposes of enhancing the heat-transfer utility of the heat pipe in a solar collector, the present work attempted to improve nanoparticle dispersion stability by means of a chemical reformation process wherein nanofluid is formulated with hydroxyl radicals combined with oxidized...

The effective thermal conductivity of six vertical closed-loop ground heat exchangers (GHEXs), which were installed in a test bed located in Wonju, South Korea, has been experimentally evaluated by performing in-situ thermal response tests (TRTs). To compare the thermal efficiency of the GHEXs...

The Kelvin line-source equation, used to analyze thermal response tests, describes conductive heat transfer in a homogeneous medium with a constant temperature at infinite boundaries. The equation is based on assumptions that are valid for most ground-coupled heat pump environments with the...

Convection is shown in earlier studies to improve the thermal contact between heat exchanger and borehole wall in water-filled boreholes. This study investigates the effect of convection on the required borehole length for a ground-coupled heat pump installation. Artificial convection was...

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...