Towards displacing domestic air conditioning in KSA, an assessment of hybrid cooling strategies integrated with 'Fabric First' passive design measures

Reducing energy use and CO2 emissions to curb global warming and climate change are the greatest challenges now facing mankind. The vast majority of energy generated from fossil fuels is burned to run vehicles, fuel power stations and cool or heat homes. Saudi Arabia, the world's largest producer and exporter of petroleum, currently consumes almost three times higher than the world average energy use and hence; ranked ninth among nations for CO2 emissions. Among all fossil energy consumers, residential buildings use almost half of the Saudi's prime energy sources and are responsible for almost 50% of the emitted CO2. In such a hot climate region, air conditioning (AC) of dwellings is by far the major consumer representing 69% of domestic energy use and drives peak loading. Future projections predict a continuous increase in energy use as the majority of existing buildings are poorly designed for the prevailing climate, leading to excessive use of mechanical AC. Therefore, it is crucial for Saudi Arabia to consider a horizon where hydrocarbons are not the dominant energy resource. The adoption of energy efficiency measures and low carbon cooling strategies may have the potential to displace a substantial percentage of oil currently used to run conventional AC plants. Therefore, the current study investigates the viability of 'fabric first' intelligent architectural design measures, in combination with hybrid ground cooling pipes integrated with black-body radiant night cooling systems, with a specific purpose to displace AC systems and decrease the carbon footprint while sustaining year-round thermal comfort. The interrogation of this hypothesis was addressed in three stages. The first stage was to generate a baseline analysis of the thermo-physical and energy performance of a typical residential block in Jeddah. The second stage involved developing an alternative low energy cooling approach that could handle high ambient temperatures. The task involved designing ground pipe ventilation integrated with high emissivity blackbody radiator to displace AC systems. The design of such 'hybrid' system required a parametric analysis combined with testing prototypes in field trials to establish actual ground temperatures at various depths and black body emissivity ranges under different sky conditions. This hybrid system became the subject of numerical modelling and simulation using DesignBuilder software in conjunction with EnergyPlus simulation engine. The third stage was to assess the simulation results and validate the cooling efficiency and cost-effectiveness of the hybrid system compared to the baseline. The preliminary results of prototype thermal simulation and field trials suggest that 'fabric first' passive designs and measures (PDMs), combined with night hydronic radiant cooling (HRCS) and supply ventilation via ground pipes (GPCS), can negate the necessity for a standard AC system by displacing over 80% of cooling demand and lower the carbon footprint of a typical housing block by over 75%. Such passive and hybrid system applications also have a remarkably short payback period with energy savings offsetting the capital costs associated with building thermo-physical enhancement.Reducing energy use and CO2 emissions to curb global warming and climate change are the greatest challenges now facing mankind. The vast majority of energy generated from fossil fuels is burned to run vehicles, fuel power stations and cool or heat homes. Saudi Arabia, the world's largest producer and exporter of petroleum, currently consumes almost three times higher than the world average energy use and hence; ranked ninth among nations for CO2 emissions. Among all fossil energy consumers, residential buildings use almost half of the Saudi's prime energy sources and are responsible for almost 50% of the emitted CO2. In such a hot climate region, air conditioning (AC) of dwellings is by far the major consumer representing 69% of domestic energy use and drives peak loading. Future projections predict a continuous increase in energy use as the majority of existing buildings are poorly designed for the prevailing climate, leading to excessive use of mechanical AC. Therefore, it is crucial for Saudi Arabia to consider a horizon where hydrocarbons are not the dominant energy resource. The adoption of energy efficiency measures and low carbon cooling strategies may have the potential to displace a substantial percentage of oil currently used to run conventional AC plants. Therefore, the current study investigates the viability of 'fabric first' intelligent architectural design measures, in combination with hybrid ground cooling pipes integrated with black-body radiant night cooling systems, with a specific purpose to displace AC systems and decrease the carbon footprint while sustaining year-round thermal comfort. The interrogation of this hypothesis was addressed in three stages. The first stage was to generate a baseline analysis of the thermo-physical and energy performance of a typical residential block in Jeddah. The second stage involved developing an alternative low energy cooling approach that could handle high ambient temperatures. The task involved designing ground pipe ventilation integrated with high emissivity blackbody radiator to displace AC systems. The design of such 'hybrid' system required a parametric analysis combined with testing prototypes in field trials to establish actual ground temperatures at various depths and black body emissivity ranges under different sky conditions. This hybrid system became the subject of numerical modelling and simulation using DesignBuilder software in conjunction with EnergyPlus simulation engine. The third stage was to assess the simulation results and validate the cooling efficiency and cost-effectiveness of the hybrid system compared to the baseline. The preliminary results of prototype thermal simulation and field trials suggest that 'fabric first' passive designs and measures (PDMs), combined with night hydronic radiant cooling (HRCS) and supply ventilation via ground pipes (GPCS), can negate the necessity for a standard AC system by displacing over 80% of cooling demand and lower the carbon footprint of a typical housing block by over 75%. Such passive and hybrid system applications also have a remarkably short payback period with energy savings offsetting the capital costs associated with building thermo-physical enhancement

Sustainable energy for a resilient future: proceedings of the 14th International Conference on Sustainable Energy Technologies

Volume I, 898 pages, ISBN 9780853583134 Energy Technologies & Renewables Session 1: Biofuels & Biomass Session 5: Building Energy Systems Session 9: Low-carbon/ Low-energy Technologies Session 13: Biomass Systems Session 16: Solar Energy Session 17: Biomass & Biofuels Session 20: Solar Energy Session 21: Solar Energy Session 22: Solar Energy Session 25: Building Energy Technologies Session 26: Solar Energy Session 29: Low-carbon/ Low-energy Technologies Session 32: Heat Pumps Session 33: Low-carbon/ Low-energy Technologies Session 36: Low-carbon/ Low-energy Technologies Poster Session A Poster Session B Poster Session C Poster Session E Volume II, 644 pages, ISBN 9780853583141 Energy Storage & Conversion Session 2: Heating and Cooling Systems Session 6: Heating and Cooling Systems Session 10: Ventilation and Air Conditioning Session 14: Smart and Responsive Buildings Session 18: Phase Change Materials Session 23: Smart and Responsive Buildings Session 30: Heating and Cooling System Session 34: Carbon Sequestration Poster Session A Poster Session C Poster Session D Policies & Management Session 4: Environmental Issues and the Public Session 8: Energy and Environment Security Session 12: Energy and Environment Policies Poster Session A Poster Session D Volume III, 642 pages, ISBN 9780853583158 Sustainable Cities & Environment Session 3: Sustainable and Resilient Cities Session 7: Energy Demand and Use Optimization Session 11: Energy Efficiency in Buildings Session 15: Green and Sustainable Buildings Session 19: Green Buildings and Materials Session 24: Energy Efficiency in Buildings Session 27: Energy Efficiency in Buildings Session 28: Energy Efficiency in Buildings Session 31: Energy Efficiency in Buildings Session 35: Energy Efficiency in Buildings Poster Session A Poster Session D Poster Session

Full Proceedings, 2018

Full conference proceedings for the 2018 International Building Physics Association Conference hosted at Syracuse University

Phase Change Materials for Thermal Regulation of Building Integrated Photovoltaics

In outdoor deployed photovoltaics (PV), standard test conditions (STC) of 25 °C PV temperature, 1000 Wm-2 solar radiation intensity and 1.5 air-mass rarely prevail. PV temperature can rise 40-100 °C above STC inducing a power drop in crystalline silicon PV with a coefficient of -0.4 to -0.65 %/K above STC. Increased operating temperature also results in accelerated PV degradation due to cell delamination allowing moisture ingress. vConventional building integrated photovoltaics (BIPV) cooling techniques using passiveor active heat removal by air or water flow are limited by (i) very low heat transfer or (ii) large capital as well as maintenance costs respectively. A PV cooling technique employing phase change materials (PCM) exploits latent heat absorption during solidliquid phase change in a very narrow range of PCM transition temperature was investigated. The current research aims to investigate suitable PCM materials through experimental characterization in terms of melting point, heat of fusion, thermal conductivity, densityand specific heat capacity to determine the suitability of different PCMs for PV cooling in different climatic conditions indoors and outdoors employed at small scale cell size PV systems as well as larger PV panel size system through extensive experimental work supported by the reasonable numerical modeling to determine the associated power improvement of PV through cooling produced by PCM.Indoor experiments were conducted at small scale cell size PV at 500 Wm-2, 750 Wm-2 and 1000 Wm-2 insolation representative PV operating condition that would require PV cooling in most cases. The effect of (i) thermal mass of PCM (ii) melting point of PCM and (iii) thermal conductivities of PCM and PV-PCM system on temperature regulationperformance of PCM was observed. Two out of five PCM, a salt hydrate (CaCl2.6H2O) and a eutectic mixture of capric -palmitic acid (CP), , an aluminium alloy based PVPCM systems were found optimum for PV temperature regulation at most of the solar radiation intensities. To extend experiments on PV panel size systems, A larger scale PVPCM system with dimensions 700 cm x 600 cm with metallic fins was fabricated. PCMCaCl2.6H2O and CP found optimum through cell size experiments were characterized at 500 Wm-2, 750 Wm-2 and 1000 Wm-2 insolation contained in the large scale PV-PCM system. The experiments on large scale PV-PCM systems showed promise for PV cooling provided by PCM and associated power gain. PV-PCM systems were then characterized outdoors in Dublin, Ireland (53.33 N, 6.25 W) and Vehari, Pakistan (30.03 N, 72.25 E) to observe their performance in real time outdoor condition in different climates. Higher PV cooling and associated power savings were observed in climate of Vehari than that of Dublin. Out of the two PCMs, CaCl2.6H2O achieved higher PVcooling and power saving than CP. In the best case, peak PV cooling of 21.5 °C with associated measured peak power saving of 13 % and predicted peak power saving of 14 % were recorded in Vehari on 30-10-2009. The results show that PCM are an effective way to cool PV and maintain higher power outputs in higher insolation climates

ECOS 2012

The 8-volume set contains the Proceedings of the 25th ECOS 2012 International Conference, Perugia, Italy, June 26th to June 29th, 2012. ECOS is an acronym for Efficiency, Cost, Optimization and Simulation (of energy conversion systems and processes), summarizing the topics covered in ECOS: Thermodynamics, Heat and Mass Transfer, Exergy and Second Law Analysis, Process Integration and Heat Exchanger Networks, Fluid Dynamics and Power Plant Components, Fuel Cells, Simulation of Energy Conversion Systems, Renewable Energies, Thermo-Economic Analysis and Optimisation, Combustion, Chemical Reactors, Carbon Capture and Sequestration, Building/Urban/Complex Energy Systems, Water Desalination and Use of Water Resources, Energy Systems- Environmental and Sustainability Issues, System Operation/ Control/Diagnosis and Prognosis, Industrial Ecology

Recent Development of Hybrid Renewable Energy Systems

Abstract: The use of renewable energies continues to increase. However, the energy obtained from renewable resources is variable over time. The amount of energy produced from the renewable energy sources (RES) over time depends on the meteorological conditions of the region chosen, the season, the relief, etc. So, variable power and nonguaranteed energy produced by renewable sources implies intermittence of the grid. The key lies in supply sources integrated to a hybrid system (HS)

Energy: A continuing bibliography with indexes, issue 34

This bibliography lists 1015 reports, articles, and other documents introduced into the NASA scientific and technical information system from April 1, 1981 through June 30, 1981