Browsing by Author "Ustaoglu A."

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Characteristics, energy saving and carbon emission reduction potential of gypsum wallboard containing phase change material
(2022-11-25) Yaras A.; Ustaoglu A.; Gencel O.; Sarı A.; Hekimoğlu G.; Sutcu M.; Erdogmus E.; Kaplan G.; Bayraktar O.Y.
Phase change materials (PCM) used in the development of building materials with thermal energy storage (TES) capacity can minimize temperature fluctuations by reducing the heating and cooling load in building envelopes due to their energy storage/release properties. The present study aims to produce, characterize and measure energy performance under real weather conditions of novel gypsum wallboard containing shape-stable attapulgite (ATP) based composite PCM as TES material. Shape-stable composite PCM was prepared by impregnating 1-Dodecanol (DD) into attapulgite (ATG) and then incorporated with gypsum in volume fraction of 25 and 50 %. The impacts of the shape stable ATG/DD composite PCM additive on the thermo-physical and mechanical properties were systematically assessed. The DCS measurements revealed that the shape-stable ATG/DD composite melts at 20.06 °C with a melting enthalpy of 115.9 J/g while the gypsum/shape-sable ATG/DD (50 v/v%) melts at 20.03 °C with melting enthalpy of 20.06 J/g. Thermoregulation tests demonstrated that the indoor temperatures of the test room made by gypsum/shape-stable composite PCM were about 1.2 °C–2.66 °C warmer than that of the reference gypsum room for about 6–12 h in a cold weather. Theoretical calculations showed that the thermal enhanced gypsum wallboard, because of its TES capability, has a favorable future in terms of energy savings and low CO2 emission.
Investigation of physico-mechanical, thermal properties and solar thermoregulation performance of shape-stable attapulgite based composite phase change material in foam concrete
(2022-04-01) Gencel O.; Ustaoglu A.; Benli A.; Hekimoğlu G.; Sarı A.; Erdogmus E.; Sutcu M.; Kaplan G.; Yavuz Bayraktar O.
Thermal energy storage (TES) by means of phase change materials (PCM) is of great concern to decrease heating and cooling loads. In building envelopes, one of the most efficient TES methods is integration of PCMs with construction materials for preventing temperature fluctuations by taking advantage of energy storage/release feature of PCMs. Aim of this research was to develop novel foam concretes containing shape-stable attapulgite (ATP) based composite PCM as TES material. Shape-stable ATP/Capric-Myristic acid eutectic mix composite (ATP/C-M) was incorporated into foam concrete at three different ratios (15, 30 and 45 wt%) and characterized. Impacts of ATP/C-M inclusion on physico-mechanic and TES characteristics of foam concretes including composite PCM (FCPCM) were worked systematically. DSC results showed that ATP/C-M composite melts at 22.12 °C with latent heat storage capacity of 74.97 J/g, whereas FCPCM-45 melts at 21.05 °C with latent heat storage ability of 10.98 J/g. Inclusion of ATP/C-M instead of silica sand decreased flow diameter of foam concretes. Compared to reference mixture FCPCM-0, compressive strengths of FCPCM-15, FCPCM-30 and FCPCM-45 samples were reduced in the range of 11–46% while reduction in flexural strength was found to be about 35–57% at 28th day. All FCPCM samples showed lower thermal conductivity values than the specified value and could be defined as better insulation materials. Solar thermoregulation performances of foam concretes containing ATP/C-M were comparatively tested in laboratory and also actual ambient conditions. Results showed that foam concretes with acceptable mechanical properties can be used for internal temperature controlling and energy saving in buildings.
Properties of eco-friendly foam concrete containing PCM impregnated rice husk ash for thermal management of buildings
(2022-10-15) Gencel O.; Sarı A.; Kaplan G.; Ustaoglu A.; Hekimoğlu G.; Bayraktar O.Y.; Ozbakkaloglu T.
Thermal energy storage (TES) through the use of construction materials incorporating phase change materials (PCMs) can prevent temperature fluctuations and allow energy saving in buildings. With this background, aim of this work is to develop new kind eco-friendly foam concrete (FC) containing lauryl alcohol (LA)-impregnated rice husk ash (RHA) composite PCM. RHA, an agricultural waste product, was used as a carrier material to eliminate the leakage problem of LA. Thus, leakage-free composite PCM (LFCPCM) was first prepared, and then such an RHA-based LFCPCM was integrated with cementitious FC for the first time in this study. The fabricated novel FCs were subjected to detailed examinations in terms of morphological, mechanical, physical, and TES properties. The DSC outcomes indicated that LFCPCM showed melting phase change at 19.97 °C and had a latent heat TES capacity of 99.60 J/g, while the PCM into FC-LFCPCM50 melted at 20.01 °C and had a latent heat TES capacity of 16.55 J/g. Solar thermoregulation performance test results revealed that compared to the reference FC (RFC), the FC-LFCPCM50 wallboard provided about 1.29 °C warmer indoor temperature during the cold weather hours, whereas the room center temperature was about 2.8 °C lower during the daytime in hot weather conditions. An energy-saving of 14.28 kW h per day is obtained by FC-LFCPCM50 wallboard. The carbon emission equivalences of this energy-saving amount account for 38 kg-CO2, 37.7 kg-CO2, and 6.19 kg-CO2 for coal, natural gas, and electricity, respectively. These results suggest that the fabricated novel FC-LFCPCM50 can be effectively evaluated as green building materials for thermo-regulation and energy saving of buildings.