Issue link: https://maltatoday.uberflip.com/i/1431464
9 21 NOVEMBER 2021 good solar reflectance of exterior surfaces is recommended, while insulation of the basement ceiling or floor slab should be avoided. Using simulations, another group of re- searchers monitored the air and surface temperatures of an unoccupied building with closed shutters during one hot sum- mer week in a hot Mediterranean climate area. e results indicated that thermal insulation and thermal mass exerted a positive effect as the average indoor tem- perature was only 27°C when the outdoor temperature reached 38°C. A study compared simulated data for a noninsulated conventional construction and a prototype and found that in the former, the air temperature could reach 32°C. e indoor air temperature could be reduced further by combining night ventilation with horizontal overhangs used as shading devices. e researchers recommended that the dimensions of the fixed horizontal overhangs should be op- timised, which appeared to be impracti- cal due to their large size. e adoption of an adaptive strategy en- courages building occupants to implement more sustainable methods of obtaining thermal comfort including naturally venti- lating spaces (opening/shutting windows), appropriate attire, and shading. When implemented in the context of standard housing modules, adaptive be- haviours reduced the amount of mechan- ical cooling or heating needed by greater than 50% in comparison with typical oc- cupants in similar climates. e use and application of the adap- tive thermal comfort model considerably lowered the time required by mechanical cooling and heating by in excess of 50% in comparison to the air-conditioning con- stant thermostat setting. Using wider ranges of air-conditioning thermostat setting lowers the operating energy by approximately 50% compared to operating temperatures that were fixed at a certain level. is can be ac- complished via the application of a wider scope of tolerable temperature thresholds as well as the use of methods that opti- mise energy consumption while sustain- ing the thermal comfort of occupants. A comparative study was conducted on two styles of walls: one made from bricks and the other from stone. e chosen configurations included the possibility of constructing the walls with an insulating layer. e findings revealed that the stone wall, including a sandwich comprising an insulation sheet of extended polystyrene, the thickness of which was optimised at 57 cm, offered a higher degree of indoor thermal comfort relative to its homolo- gous bricks. e impact of using light coloured paint and/or thermal insulation of a residential structure's thermal efficiency and ener- gy usage was explored. According to the findings, the Overall Solar Reflectance (TSR) of the roof and other outer surfac- es improved from 50% to 92%, which led to a decrease in the mean free-float in- door temperature of 2.0°C to 4.7°C in old buildings (without thermal insulation) and a decrease of 1.2°C to 3.0°C in new buildings (with thermal insulation). e fall in the mean inside temperature of as much as 1.5°C has a trade-off effect. e findings indicated that when cool paints were used, high savings of approxi- mately 30% in annual cooling energy con- sumption were achieved. A computation- al parametric analysis for an optimised building in the city of Amman, Jordan, was conducted, which had a thermal in- sulation of 0.5-0.7 W/m2·K for the walls and roof, a south orientation, and a win- dow to floor ratio between 12% and 20% facing south. Compared to a noninsulated base case, the optimised solution reduced heating energy demand by 86% and cooling de- mand by 26%. Another study strived to increase levels of thermal comfort, reduce the electric- ity consumed, and promote natural ven- tilation within tall residential structures by employing air conditioning that con- tained a one-sided ventilation area (only one outside wall had windows). eir objective was to assess whether an air shaft located towards the rear of the room would magnify mean air velocity by increasing the pressure differential be- tween the shaft's aperture on the roof and the window. e design and construction of green buildings can be facilitated through forms of simulation software such as computa- tional fluid dynamics (CFD), which can be utilised to construct a thermal model of a building and a virtual airflow to assess the design before construction begins. e ultimate aim is to design healthy, com- fortable, and energy-efficient buildings. Prior to any renovation, CFD is able to evaluate the probable alterations to an existing building. is will make users aware of the benefits of altering design risks and avoid overpricing while allow- ing improvements and enhancements. However, using CFD to perform a stand- ard thermal simulation of buildings (up to one year) can be problematic; for ex- ample, there are difficulties in determin- ing the correct sky temperature, peak temperature times can be inconsistent when prolonged CFD simulations are implemented, and warming issues can arise from an ongoing simulation, while problems also exist with the simulation and time step size of wind effects on the thermal efficiency of structures. Source: National Energy and Climate Plan 11 Malta projections of energy intensity compared to those from PRIMES 2007 database. primary energy and final energy consumption levels in absolute terms are projected to be 1,156 and 858 ktoe respectively (Figure 12). 12 Projected primary and final energy consumption levels in absolute terms, ktoe. Projections for primary and final energy consumption are in line with Eurostat reports of energy balances of 2016, that is, excluding energy in ambient air captured by heat pumps. Energy intensity is defined as the ratio between primary energy consumption and gross domestic product at 2005 constant prices. For translating from final electricity consumption to primary energy consumption, the of distribution losses is assumed to be constant for the period 2021-2030 as per 2017. It is also 0.09 0.08 - 0.02 0.04 0.06 0.08 0.10 0.12 0.14 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 toe/€2005 Energy intensity (excl heat pumps), PRIMES2007 Energy intensity (excl heat pumps), MT projections 1,156 858 - 2.0 4.0 6.0 8.0 10.0 12.0 14.0 - 200 400 600 800 1,000 1,200 1,400 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 Million €2005 ktoe Primary energy consumption (excl. heat pumps) Final energy consumption (excl. heat pumps) GDP 32 primary energy and final energy consumption levels in absolute terms are projected to be 1,156 and 858 ktoe respectively (Figure 12). 12 Projected primary and final energy consumption levels in absolute terms, ktoe. Projections for primary and final energy consumption are in line with Eurostat reports of energy balances of 2016, that is, excluding energy in ambient air captured by heat pumps. Energy intensity is defined as the ratio between primary energy consumption and gross domestic product at 2005 constant prices. For translating from final electricity consumption to primary energy consumption, the of distribution losses is assumed to be constant for the period 2021-2030 as per 2017. It is also assumed that renewable electricity is dispatched first, followed by a mix of conventional plants 0.09 0.08 - 0.02 0.04 0.06 0.08 0.10 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 toe/€2005 Energy intensity (excl heat pumps), PRIMES2007 Energy intensity (excl heat pumps), MT projections 1,156 858 - 2.0 4.0 6.0 8.0 10.0 12.0 14.0 - 200 400 600 800 1,000 1,200 1,400 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 Million €2005 ktoe Primary energy consumption (excl. heat pumps) Final energy consumption (excl. heat pumps) GDP Malta projections of energy intensity compared to those from PRIMES 2007 database Projected primary and final energy consumption levels in absolute terms, ktoe