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In relation to recent attention focused on the use of energy by lighting, there is a large potential for commercial buildings to save energy in this respect. The use of energy-saving bulbs or dimming controls triggered by daylight, not only enables lighting energy saving, but delivers cooling energy through a reduction in indoor heat production. In this study, we examine the energy use in commercial buildings by evaluating lighting energy saving methods and the effect of using dimmer controls with a heat control method, which can both maximize the cooling load reduction during summer and save energy. Results show that the total energy from the reference commercial building was reduced by 20.9% by replacing LFL T12 bulbs with LEDs, together with an additional saving of 19.9% in cooling energy by using the lighting heat & dimming control method. [ABSTRACT FROM AUTHOR]

Highlights: [•] Improved performance in a vertical PV module via a PCM was assessed. [•] The optimal PCM melting temperature was determined according to weather conditions. [•] The PCM thickness was also determined to maximize the performance of the PV module. [•] The electrical power out of the PV/PCM module was increased by 1.5%. [Copyright &y& Elsevier]

Highlights: [•] Application of heat control strategy reduces total energy consumption of LED lighting. [•] Convective heat from LED lighting should be emitted outdoors during cooling period. [•] Seasonal optimization of convective heat lowers total energy consumption. [ABSTRACT FROM AUTHOR]

Abstract: Geothermal energy has been provided to improve the energy performance of buildings with great support from the government in Korea. However, despite the many advantages of using a ground-coupled heat pump (GCHP) with geothermal energy, the high construction cost of the ground-coupled heat exchanger (GCHE) is the primary obstacle to prevent the supply and spread of GCHPs. In this study, in order to overcome the problems of the conventional GCHP, a GCHP integrated with a PHC (prestressed high-strength concrete) pile, which is used in the foundation of buildings, was introduced and its thermal performance was analyzed through experiments conducted in summer. To increase the thermal performance, a coil-type pipe was used. The PHC-pile-integrated GCHP was installed at a depth of 15m. However, because it was installed in the beneath of the building, it was not largely affected by the outdoor temperature. The measured effective thermal conductivity was 3.69W/m°C, which is similar to that of a conventional vertical GCHP. Also, the COP was determined to be 3.9–4.3, which is slightly lower than the conventional vertical GCHP. However, considering the fact that the expensive drilling cost could be mitigated by 83.7%, the thermal performances were satisfactory. [Copyright &y& Elsevier]