Search

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]

The light-emitting diode (LED) market is expected to account for half of lamps worldwide in 2020. Despite the numerous benefits of LED lighting, the heat from LED lights affects indoor thermal conditions in buildings and increases the indoor cooling load in summer. A new method for integrating LED lighting with heating, ventilation, and air conditioning (HVAC) systems are proposed to prevent this heating effect in buildings by exchanging the lighting heat to outdoor and indoor spaces according to a seasonal operating strategy. Field measurements of a mock-up model were used to determine the lighting heat removal and reuse rates of the seasonal strategy. The ratio of lighting heat removal and reuse to LED input power was 70.3% in the summer test and 49.5% in the winter test. An indoor thermal effect analysis was performed using a simulation program with lighting heat input fractions obtained from the measured data. The sensible thermal loads in the mock-up chamber were reduced by 7.5% for cooling and 1.4% for heating using the proposed method, and the annual site energy reductions of reference office buildings were 8.5% for Houston, 8.1% for Atlanta, and 5.9% for Boulder, compared to the base case. [ABSTRACT FROM AUTHOR]

Highlights: [•] We measured the thermal performance of different window systems. [•] We also analyzed their effects on building energy savings in S. Korea. [•] The maximum ratings of the southern region and Jeju Island are Ratings 1. [•] The maximum ratings of the central region is just Ratings 2. [•] We suggest more specific and local criteria of the certification system. [ABSTRACT FROM AUTHOR]

Abstract: Solid adsorbents comprising 50, 70, and 90wt.% heteropolyacid Fe2.0SiW12O40 (Fe–HPA) and mesoporous cellular foams (MCFs) have been synthesized by wetting impregnation. The adsorbents were characterized by various physicochemical, thermal and spectral techniques and the CO2 adsorption capacity of the adsorbents were investigated. The structure of Fe–HPA on the surface of the support was confirmed by TEM, SAXS, XRD, SEM, FTIR, 29Si MAS NMR, and XPS. XPS of the Fe 2p3/2, 2p1/2, 3p and W 4f7/2, 4f5/2, 4d5/2, 4d3/2 confirmed the presence of typical Fe(2+) and W(6+) in the adsorbent, respectively. The adsorbents showed a very high adsorption capacity due to the chemisorption of CO2. The CO2 adsorption capacity of a 70wt.% Fe–HPA–MCF sample was 111.8mg/g-adsorbent at 25°C. This result indicated that the reported iron (Fe2+) complex could be used as an efficient adsorbent for the separation of CO2. The adsorbents displayed excellent CO2 adsorption capacity and were thermally stable and recyclable. [Copyright &y& Elsevier]