scholarly journals Impact of insulation thicknesses of several types of thermal insulator on energy cost with respect to different climate zones in Morocco

2020 ◽  
Vol 307 ◽  
pp. 01023
Author(s):  
Ayoub Gounni ◽  
Mohamed Tahar Mabrouk ◽  
Abdelhamid Kheiri ◽  
Mustapha El Alami

In Morocco the thermal insulation of buildings envelop was not a common practice until it becomes obligatory since 2015 to meet the requirements of the Moroccan construction thermal regulation (RTCM) depending on six climate zones. The aim of this paper is to determine the optimum thickness of expanded polystyrene (EPS) and rock wool (RW) of walls constructed of brick for different Moroccan climate zones: Agadir (first zone), Tanger (second zone), Fes (third zone), Ifrane (fourth zone), Marrakech (fifth zone), Errachidia (sixth zone). A numerical model of a multilayered wall is developed to compute the annual heating and cooling loads. These loads are used as input to life cycle cost analysis using the energy and insulation costs. The liquefied petroleum gas (LPG) and electricity are used as energy source, respectively, for heating and cooling. For each case, the calculation is carried out for annual heating and cooling loads and total cost including insulation and energy costs. Results show that the optimum thermal insulation depends on climate zones and insulation types. The lowest value of energy savings is obtained for climate zone 1 which are 289.55 and 300.55 dh/m² respectively for EPS and RW.

2020 ◽  
Vol 12 (6) ◽  
pp. 2287 ◽  
Author(s):  
Luis M. López-Ochoa ◽  
Jesús Las-Heras-Casas ◽  
Luis M. López-González ◽  
César García-Lozano

The residential sector of the European Union consumes 27% of the final energy of the European Union, and approximately two-thirds of the existing dwellings in the European Union were built before 1980. For this reason, the European Union aims to transform the existing residential building stock into nearly zero-energy buildings by 2050 through energy renovation. The most effective method to achieve this goal is to increase the thermal insulation of opaque elements of the thermal envelope. This study aims to assess the energy, environmental and economic impacts of the energy renovation of the thermal envelopes that are typical of the existing multi-family buildings of the 26 provincial capitals in the cold climate zones of Spain. To achieve this goal, the insulation thickness to be added to the walls, roof and first floor framework is optimized by a life cycle cost analysis, and the existing building openings are replaced, thus minimizing both the total heating costs and the total heating and cooling costs. The study uses four thermal insulation materials for four different heating and cooling systems in 10 different models. The results obtained will be used to propose energy renovation solutions to achieve nearly zero-energy buildings both in Spain and in similar Mediterranean climate zones.


2020 ◽  
pp. 174425912098002
Author(s):  
Malik Elmzughi ◽  
Samah Alghoul ◽  
Mohamed Mashena

An efficient way to reduce the energy required for conditioning buildings and therefore to reduce CO2 emission is the use of proper thermal insulation in buildings’ external walls. This measure requires data from metrological stations that can be used in the optimization of the thermal insulation. The main objectives of this study are to construct thermal climatic zones for Libya and to specify the optimum insulation thickness for external walls for the different zones. This work is comprehensive as the metrological data from all existing 33 weather stations has been collected and used for identifying thermal zones. For the optimization of the construction of external walls, the most commonly used local wall structures are investigated: hollow concrete block, limestone block and hollow brick. In addition, four thermal insulation materials: extruded polystyrene, expanded polystyrene, rock wool and foamed polyurethane are used with every wall type. Optimum insulation thickness, energy savings, energy cost and payback periods were estimated for the 33 locations using life cycle cost analysis. A map is constructed for the thermal zones based on degree-day values for the entire country. The results show that limestone blocks with expanded polystyrene insulation form the optimum wall construction as it provides the minimum total cost for all locations. Depending on the Degree-day values, the optimum insulation thickness varies between 5.4 and 15.3 cm across the country with energy saving varies between 28 and 178 $/m2. Using the optimum thickness, the average CO2 emissions can potentially be reduced by about 85%. Finally, a contour map represents the optimum thickness of expanded polystyrene is presented in this work.


2017 ◽  
Vol 12 (1) ◽  
pp. 78-106 ◽  
Author(s):  
Issam Sobhy ◽  
Abderrahim Brakez ◽  
Brahim Benhamou

The purpose of this research is to assess thermal performance and energy saving of a residential building in the hot semi-arid climate of Marrakech (Morocco). The studied house is built as usual in Marrakech without any thermal insulation except for its external walls, facing East and West, which are double walls with a 5 cm air gap in between (“cavity wall” technique). The cavity wall effective thermal conductivity was carefully calculated taking into account both radiation and convection heat transfers. Experimental results, obtained from winter and summer monitoring of the house, show well dampening of air temperature, thanks to its thermal inertia. However, this temperature remained outside the standard thermal comfort zone leading to large cooling/heating load. Simulation results indicate that the cavity wall contributes to an overall reduction of 13% and 5% of the house heating and cooling loads respectively. Moreover, the addition of XPS roof thermal insulation significantly enhances the heating and cooling energy savings to 26% and 40% respectively.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3876
Author(s):  
Sameh Monna ◽  
Adel Juaidi ◽  
Ramez Abdallah ◽  
Aiman Albatayneh ◽  
Patrick Dutournie ◽  
...  

Since buildings are one of the major contributors to global warming, efforts should be intensified to make them more energy-efficient, particularly existing buildings. This research intends to analyze the energy savings from a suggested retrofitting program using energy simulation for typical existing residential buildings. For the assessment of the energy retrofitting program using computer simulation, the most commonly utilized residential building types were selected. The energy consumption of those selected residential buildings was assessed, and a baseline for evaluating energy retrofitting was established. Three levels of retrofitting programs were implemented. These levels were ordered by cost, with the first level being the least costly and the third level is the most expensive. The simulation models were created for two different types of buildings in three different climatic zones in Palestine. The findings suggest that water heating, space heating, space cooling, and electric lighting are the highest energy consumers in ordinary houses. Level one measures resulted in a 19–24 percent decrease in energy consumption due to reduced heating and cooling loads. The use of a combination of levels one and two resulted in a decrease of energy consumption for heating, cooling, and lighting by 50–57%. The use of the three levels resulted in a decrease of 71–80% in total energy usage for heating, cooling, lighting, water heating, and air conditioning.


2018 ◽  
Vol 760 ◽  
pp. 231-236
Author(s):  
Jiri Zach ◽  
Martin Sedlmajer ◽  
Jan Bubenik ◽  
Vitezslav Novak

Along with energy savings for heating and cooling, the demand for thermal insulation materials is increasing and is an attempt to achieve good thermal insulation properties for some of the construction materials. In the field of porous and lightweight concrete, this is e.g. concrete for foundations, concrete for floor constructions or flat roofs. The problem with these concrete is a relatively rapid drop in mechanical properties in reducing bulk density, with using conventional silicate binders, especially in the area below 1000 kg/m3. The paper describes the possibility of using recycled organic fibers in combination with lightweight aggregates based on foam glass for the production of porous and lightweight concrete with a good ratio of mechanical and thermal insulation properties.


2019 ◽  
Vol 9 (7) ◽  
pp. 1285 ◽  
Author(s):  
José D. Silvestre ◽  
André M. P. Castelo ◽  
José J. B. C. Silva ◽  
Jorge M. C. L. de Brito ◽  
Manuel D. Pinheiro

This paper analyses the environmental, energy, and economic performances of the External Thermal Insulation Composite System (ETICS) using agglomerated insulation cork board (ICB) or expanded polystyrene (EPS) as insulation material applied in the energetic renovation of the building envelope during a 50-year study period. A comparison between ETICS using ICB and EPS, for the same time horizon, is also presented. The environmental balance is based on “Cradle to Cradle” (C2C) Life Cycle Assessment (LCA), focusing on the carbon footprint and consumption of nonrenewable primary energy (PE-NRe). The characteristics of these products in terms of thermal insulation, the increased energy performance provided by their installation for retrofit of the buildings’ envelope, and the resulting energy savings are considered in the energy balance. The estimation of the C2C carbon and PE-NRe saved is considered in the final balance between the energy and environmental performances. ETICS with ICB is environmentally advantageous both in terms of carbon footprint and of PE-NRe. In fact, the production stage of ICB is less polluting, while EPS requires lower energy consumption to fulfil the heating and cooling needs of a flat, due to its lower U-Value, and its lower acquisition cost results in a lower C2C cost. Comparing both ETICS’ alternatives with reference solutions, it was found that the latter only perform better in the economic dimension, and only for an energy consumption to fulfil less than 25% of the heating and cooling needs. This paper represents an advance to the current state-of-the-art by including all the life-cycle stages and dimensions of the LCA in the analysis of solutions for energy renovation of building envelopes.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2195
Author(s):  
Belen Moreno Santamaria ◽  
Fernando del Ama Gonzalo ◽  
Matthew Griffin ◽  
Benito Lauret Aguirregabiria ◽  
Juan A. Hernandez Ramos

High initial costs hinder innovative technologies for building envelopes. Life Cycle Assessment (LCA) should consider energy savings to show relevant economic benefits and potential to reduce energy consumption and CO2 emissions. Life Cycle Cost (LCC) and Life Cycle Energy (LCE) should focus on investment, operation, maintenance, dismantling, disposal, and/or recycling for the building. This study compares the LCC and LCE analysis of Water Flow Glazing (WFG) envelopes with traditional double and triple glazing facades. The assessment considers initial, operational, and disposal costs and energy consumption as well as different energy systems for heating and cooling. Real prototypes have been built in two different locations to record real-world data of yearly operational energy. WFG systems consistently showed a higher initial investment than traditional glazing. The final Life Cycle Cost analysis demonstrates that WFG systems are better over the operation phase only when it is compared with a traditional double-glazing. However, a Life Cycle Energy assessment over 50 years concluded that energy savings between 36% and 66% and CO2 emissions reduction between 30% and 70% could be achieved.


1990 ◽  
Vol 112 (4) ◽  
pp. 273-279 ◽  
Author(s):  
M. Judson Brown

Based on results from a one-year intensive monitoring project of a Northern New York commercial building with energy-conserving design features, a thermal storage project was undertaken to optimize the design of a thermal mass storage system for a moderately sized commercial building and transfer the technology to the commercial building sector. A generic commercial building design of 27,000 square feet (2508 m2) was selected for the optimization project. Several different types of thermal mass designs were considered as potentially practical for a commercial building. These included a “sandmass” design such as the mass incorporated in the previously monitored commercial building mentioned above, a foundation slab of sufficient thickness to serve as a significant building thermal mass, and the use of poured cement in interior wall and floor construction. Five different office building thermal designs were selected which represented various thermal storage features and two different building insulation levels (R10 and R20). Energy performance of the five thermal designs was modeled in building energy simulations using DOE 2.1C (Department of Energy 2.1C) energy simulation code. Results of the simulations showed a reduction in peak heating and cooling loads would be experienced by the HVAC equipment. The reduction in peak heating and cooling loads was anticipated because thermal mass within a building serves to average peak heating and cooling loads due to the capacity of the thermal mass to store and release heat from all building heat sources over a period of time. Peak heating loads varied from 1972 kBtuh (578 kW) for the R-10 light construction base case to a minimum of 980 kBtuh (287 kW) for the R-20 heavy construction sandmass storage case. Peak cooling loads dropped from 772 kBtuh (226 kW) for the R-20 light construction case to 588 kBtuh (172 kW) for the R-20 heavy construction sandmass storage case. Results of the simulations also showed annual energy savings for the high thermal mass designs. Energy savings varied from 20 percent [16.0 kBtu/ft2 (50 kWh/m2)] for the R-10 high thermal mass design in comparison to its base case to 18 percent [12.2 kBtu/ft2 (39 kWh/m2)] for the R-20 high thermal mass design in comparison to its base case. The annual energy savings are due to the ability of the thermal mass to absorb heat from all sources of heat generation (lights, occupancy, solar, and auxiliary) during occupied periods and release the heat during unoccupied periods. An optimized thermal design was developed based on results from the DOE 2.1C simulations. The initial cost for the optimized thermal storage design is lower than the initial costs for light construction office buildings, since the lower initial cost of the down-sized HVAC system for the optimized thermal storage design more than offsets the increased cost of wall and floor systems incorporated in the optimized design. Annual energy savings are realized from the high thermal mass system in both cooling and heating modes due to the interaction of building HVAC systems operation in the simulated 27000 ft2 (2508 m2) office building. Annual operating savings of $3781 to $4465 per year are estimated based on simulation results.


Author(s):  
J Arias ◽  
P Lundqvist

The effective use of energy and the replacement of CFC and HCFC refrigerants are two factors that have influenced the design and operation of refrigeration systems in supermarkets during recent years. The potential for increasing energy efficiency in refrigeration systems, indoor climate and refrigerated cabinets is large. Since the energy systems of a supermarket are relatively complex, improvements in one subsystem affect other systems, thus making analysis of potential improvements non-additive. A computer model, CyberMart, that predicts building heating and cooling loads, HVAC (heating, ventilation, and air conditioning), and refrigeration system performances of a supermarket, has been developed. The focus of the model is on energy use, environmental impact (TEWI), and life cycle cost (LCC) of the refngeration system. The refrigeration system solutions included in the model are: direct system, completely indirect system, partially indirect system, cascade system, parallel system with mechanical sub-cooling (where the refrigerant in the low-temperature system is sub-cooled with the brine of the intermediate temperature level), and district cooling (that cools the condenser of the refrigeration machines). Measurements of different parameters such as outdoor and indoor temperatures, relative humidity, and compressor power have been carried out in several stores to validate the model. A theoretical description of the model and results from the model and measurements are presented in this paper.


Sign in / Sign up

Export Citation Format

Share Document