Lighting Implications of Urban Mitigation Strategies through Cool Pavements: Energy Savings and Visual Comfort

Indoor lighting is facing a massive retrofit to LED lighting. Research is needed to assess whether LED-based lighting can promote energy efficiency, boost visual comfort and support biological functions. This field study considered the lighting of four identical classrooms in an upper secondary school in Helsingborg, Sweden. Two classrooms were fitted with state-of-the-art ceiling pendants containing T5 fluorescent tubes and that had a direct/indirect light distribution (the control rooms). The other two classrooms were fitted with an experimental LED indirect lighting system (the experimental rooms). In the classrooms, 72 students aged 17–18 years performed their usual educational activities over a whole academic year. The light environment, electricity consumption, and students’ mood, light perception and saliva cortisol concentration were monitored. The two lighting systems produced only marginal differences. Overall, the experimental rooms were slightly preferred but achieved only small energy savings due to high parasitic losses.

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Transformation of an Office Building into a Nearly Zero Energy Building (nZEB): Implications for Thermal and Visual Comfort and Energy Performance

Energies ◽

10.3390/en12050895 ◽

2019 ◽

Vol 12 (5) ◽

pp. 895 ◽

Cited By ~ 14

Author(s):

Ilaria Ballarini ◽

Giovanna De Luca ◽

Argun Paragamyan ◽

Anna Pellegrino ◽

Vincenzo Corrado

Keyword(s):

Thermal Comfort ◽

Energy Savings ◽

Energy Performance ◽

Primary Energy ◽

Building Envelope ◽

Office Building ◽

Indoor Environmental Quality ◽

Visual Comfort ◽

Zero Energy ◽

Efficiency Measures

Directive 2010/31/EU promotes the refurbishment of existing buildings to change them into nearly zero-energy buildings (nZEBs). Within this framework, it is of crucial importance to guarantee the best trade-off between energy performance and indoor environmental quality (IEQ). The implications of a global refurbishment scenario on thermal and visual comfort are assessed in this paper pertaining to an existing office building. The retrofit actions applied to achieve the nZEB target consist of a combination of envelope and technical building systems refurbishment measures, involving both HVAC and lighting. Energy and comfort calculations were carried out through dynamic simulation using Energy Plus and DIVA, for the thermal and visual performance assessments, respectively. The results point out that energy retrofit actions on the building envelope would lead to significant improvements in the thermal performance, regarding both energy savings (−37% of the annual primary energy for heating) and thermal comfort. However, a daylighting reduction would occur with a consequent higher electricity demand for lighting (36%). The research presents a detailed approach applicable to further analyses aimed at optimizing the energy efficiency measures in order to reduce the imbalance between visual and thermal comfort and to ensure the best performance in both domains.

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Analysis of Energy Savings and Visual Comfort Produced by the Proper Use of Windows

International Journal of Engineering and Technology ◽

10.7763/ijet.2016.v8.913 ◽

2016 ◽

Vol 8 (5) ◽

pp. 358-365 ◽

Cited By ~ 3

Author(s):

I. Acosta ◽

M. A. Campano ◽

J. F. Molina

Keyword(s):

Energy Savings ◽

Visual Comfort

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Innovative electrochromic devices: Energy savings and visual comfort effects

Energy Procedia ◽

10.1016/j.egypro.2018.08.096 ◽

2018 ◽

Vol 148 ◽

pp. 900-907 ◽

Cited By ~ 4

Author(s):

Alessandro Cannavale ◽

Ubaldo Ayr ◽

Francesco Martellotta

Keyword(s):

Energy Savings ◽

Visual Comfort ◽

Electrochromic Devices

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The Optimum Performance of Building Integrated Photovoltaic (BIPV) Windows Under a Semi-Arid Climate in Algerian Office Buildings

Sustainability ◽

10.3390/su12041654 ◽

2020 ◽

Vol 12 (4) ◽

pp. 1654 ◽

Cited By ~ 1

Author(s):

Abdelhakim Mesloub ◽

Ghazy Abdullah Albaqawy ◽

Mohd Zin Kandar

Keyword(s):

Energy Consumption ◽

Energy Savings ◽

High Energy ◽

Office Buildings ◽

Arid Climate ◽

Energy Output ◽

Visual Comfort ◽

Building Integrated Photovoltaic ◽

Pv Modules ◽

Semi Arid

Recently, Building Integrated Photovoltaic (BIPV) windows have become an alternative energy solution to achieve a zero-energy building (ZEB) and provide visual comfort. In Algeria, some problems arise due to the high energy consumption levels of the building sector. Large amounts of this energy are lost through the external envelope façade, because of the poorness of the window’s design. Therefore, this research aimed to investigate the optimum BIPV window performance for overall energy consumption (OEC) in terms of energy output, heating and cooling load, and artificial lighting to ensure visual comfort and energy savings in typical office buildings under a semi-arid climate. Field measurements of the tested office were carried out during a critical period. The data have been validated and used to develop a model for an OEC simulation. Extensive simulations using graphical optimization methods are applied to the base-model, as well as nine commercially-available BIPV modules with different Window Wall Ratios (WWRs), cardinal orientations, and tilt angles. The results of the investigation from the site measurements show a significant amount of energy output compared to the energy demand. This study revealed that the optimum BIPV window design includes double-glazing PV modules (A) with medium WWR and 20% VLT in the southern façade and 30% VLT toward the east–west axis. The maximum energy savings that can be achieved are 60% toward the south orientation by double-glazing PV module (D). On the other hand, the PV modules significantly minimize the glare index compared to the base-model. The data extracted from the simulation established that the energy output percentages in a 3D model can be used by architects and designers in early stages. In the end, the adoption of optimum BIPV windows shows a significant enough improvement in their overall energy savings and visual comfort to consider them essential under a semi-arid climate.

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Evaluation of impact of passive design measures with energy saving potential through estimation of shading control for visual comfort

Journal of Building Physics ◽

10.1177/1744259117742989 ◽

2017 ◽

Vol 42 (3) ◽

pp. 220-238 ◽

Cited By ~ 6

Author(s):

Lakshya Sharma ◽

K Kishan Lal ◽

Dibakar Rakshit

Keyword(s):

Energy Consumption ◽

Energy Savings ◽

Climatic Conditions ◽

Design Parameters ◽

Visual Comfort ◽

Passive Design ◽

Lighting Energy ◽

Insulation Thickness ◽

Heating Loads ◽

Cooling Loads

Residential and commercial buildings together account for one-third of world’s final energy consumption, thus making energy management in buildings of considerable significance. Passive design concept that depends on climate and location can be used as an effective and economical method to reduce the energy consumption in buildings. Seven cities in India, each representative of different geographic and climatic conditions, were selected for analysis. This article studies how the peak cooling and heating load are affected by varying some of the passive design parameters for each of the seven cities. The parameters varied are wall insulation thickness, roof insulation thickness, overhang depth, window orientation, and window-to-wall ratio. Results show that optimized passive design could reduce the peak cooling and heating loads by about 50%. Shading reduces cooling loads but is found to increase heating loads. In some of the locations, both heating in winter and cooling in summer are needed and designers should adopt appropriate passive measures depending on the location. Also for the same building, evaluation of shading is done in the context of lighting energy savings. An algorithm has been developed to iteratively alter and analyze set of roller blind positions to maintain visual comfort; as a result, the corresponding potential annual energy savings due to lighting were estimated. It was also observed that even after providing visual comfort to the occupants, energy savings only reduced by approximately 1% as compared to the case when visual comfort was overlooked.

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