Glare at Outdoor Workplaces—An Underestimated Factor of Occupational Risk

Lighting is an integral aspect of electrical engineering and public safety, as buildings, public areas—both indoors and outdoors—or any type of workplace must be illuminated in a way to prevent accidents. The sensation of glare, in particular, plays an important role in visual comfort and consequently influences occupational risk. The aim of this article is to draw attention to the problem of glare at outdoor workplaces. We have carried out an assessment of glare at outdoor workplaces in 19 different industrial plants. At 20 task areas (21.5% of the 93 examined) the determined degree of glare exceeded the limits specified in the standard. In eight categories of industrial plants (66.7% of 12 examined) defined in the standard, there was at least one task area where the requirements of the standard in terms of glare limitation were not met. The presented analysis leaves no doubt about drawing the conclusion that glare at outdoor workplaces is mostly underestimated or simply neglected, although it could cause high risk in workplaces.

Design A Lighting Point Calculator System For Residential Houses Using Microsoft Visual Basic

Lighting point calculation plays an important feature in developing a new residential house. This enables people inside the house will have enough of light to perform tasks efficiently. Currently, consulting electrical engineers use rules of thumb to forecast the quantity of lighting points, however these rules are inaccurate. It does not take into account the lux required based on Malaysian Standard MS1525. Furthermore, good lighting can save money and provide visual comfort to the occupants. However, numerous parameters such as room index, utilisation factor and illuminance used for each space or room inside the house must be considered when determining the quantity of lighting point for a residential property. Three types of residential houses are considered which are: single storey house, double storey house and condominium house. This paper presents the development of lighting point calculator system for residential houses using Microsoft Visual Basic and comparison of quantity of lighting point using manual calculation using Microsoft Excel and simulation calculation using Microsoft Visual Basic.

Comparative Investigation of Daylight Glare Probability (DGP) Comfort Classes in Clear Sky Condition

Glare is considered one of the most important variables to reach visual comfort and visual quality. It represents one of the fundamental barriers for an effective use of daylighting in buildings. One of the best performing and robust glare prediction models, relative to other available metrics, is a Daylight Glare Probability (DGP). Based on a validated and precise methodology (RADIANCE) the aim of this work is to compare the DGP model (original cut-off values) with new cut-off values that differ according to the time of day (morning, noon and afternoon). Both cut-off values were compared at more than 300 simulated conditions of daylighting in an interior space. This work offers the originality of studying recently proposed cut-off values in climate luminous with predominant clear sky conditions. Currently, the application of these new cutoff values is reduced to the field of science or simulation professionals. The results showed important differences (64.86%) between the categories proposed by both cut-off values. Nevertheless, these differences do not have a significant impact in glare prediction (< 2.7%), in terms of glare absence (DGP <0.38) and presence (DGP >0.38). This analysis made it possible: (i) to regionally apply the main current corpus criteria regarding glare issues as well as emergent proposals and (ii) to present new experimental data aimed at helping the field and, together with other works, improving the tools used by professionals on a daily basis.

Working from Home in Italy during COVID-19 Lockdown: A Survey to Assess the Indoor Environmental Quality and Productivity

Italians were the first European citizens to experience the lockdown due to Sars-Cov-2 in March 2020. Most employees were forced to work from home. People suddenly had to share common living spaces with family members for longer periods of time and convert home spaces into workplaces. This inevitably had a subjective impact on the perception, satisfaction and preference of indoor environmental quality and work productivity. A web-based survey was designed and administered to Italian employees to determine how they perceived the indoor environmental quality of residential spaces when Working From Home (WFH) and to investigate the relationship between different aspects of users’ satisfaction. A total of 330 valid questionnaires were collected and analysed. The article reports the results of the analyses conducted using a descriptive approach and predictive models to quantify comfort in living spaces when WFH, focusing on respondents’ satisfaction. Most of them were satisfied with the indoor environmental conditions (89% as the sum of “very satisfied” and “satisfied” responses for thermal comfort, 74% for visual comfort, 68% for acoustic quality and 81% for indoor air quality), while the layout of the furniture negatively influenced the WFH experience: 45% of the participants expressed an unsatisfactory or neutral opinion. The results of the sentiment analysis confirmed this trend. Among the Indoor Environmental factors that affect productivity, visual comfort is the most relevant variable. As for the predictive approach using machine learning, the Support Vector Machine classifier performed best in predicting overall satisfaction.

Efficient Shading Device as an Important Part of Daylightophil Architecture; a Designerly Framework of High-Performance Architecture for an Office Building in Tehran

(1) Background: considering multiple, and somehow conflicting, design objectives can potentially make achieving a high-performance design a complex task to perform. For instance, shading devices can dramatically affect the building performance in various ways, such as energy consumption and daylight. This paper introduces a novel procedure for designing shading devices as an integral part of daylightophil architecture for office buildings by considering daylight and energy performance as objectives to be optimal. (2) Methods: to address the topic, a three-step research method was used. Firstly, three different window shades (fixed and dynamic) were modeled, one of which was inspired by traditional Iranian structures, as the main options for evaluation. Secondly, each option was evaluated for energy performance and daylight-related variables in critical days throughout the year in terms of climatic conditions and daylight situations (equinoxes and solstices including 20 March, 21 June, 22 September, and 21 December). Finally, to achieve a reliable result, apart from the results of the comparison of three options, all possible options for fixed and dynamic shades were analyzed through a multi-objective optimization to compare fixed and dynamic options and to find the optimal condition for dynamic options at different times of the day. (3) Results: through different stages of analysis, the findings suggest that, firstly, dynamic shading devices are more efficient than fixed shading devices in terms of energy efficiency, occupants’ visual comfort, and efficient use of daylight (roughly 10%). Moreover, through analyzing dynamic shading devices in different seasons and different times of the year, the optimal form of this shading device was determined. The results indicate that considering proper shading devices can have a significant improvement on achieving high-performance architecture in office buildings. This implies good potential for daylightophil architecture, but would require further studies to be confirmed as a principle for designing office buildings.

A LABORATORY STUDY ON VISUAL AND EMOTIONAL COMFORT EVALUATION OF LED WIDE BEAM ANGLE LAMPS : TAKING 3000K/ 4000K / 5000 K LINEAR LAMPS AS RESEARCH OBJECT

LED wide beam angle lamps have been widely used but might leading to glare or light pollution easily than traditional floodlighting lamps. Standards for wide beam angle products is not enough and a laboratory experiment was carried out in which visual and emotional comfort was used as evaluation items. 3 linear lamps (3000K/4000K/5000K) were used to evaluate emotional and visual comfort changes by performing different brightness or dynamic speed. Results showed that both brightness and dynamic speed could lead to negative feelings while emotional discomfort always occurs behind the eye’s discomfort. A higher brightness could leading to more negative evaluations, while some people think that medium brightness gives a more comfort feeling. A faster speed leads to more negative evaluation while some subjects prefer a medium speed (both in shading and erasure situations); In different lighting scenes, the significance of different indicators is different.

Optimising metameric spectra for integrative lighting to modulate the circadian system without affecting visual appearance

Smart integrative lighting systems aim to support human health and wellbeing by capitalising on the light-induced effects on circadian rhythms, sleep, and cognitive functions, while optimising the light’s visual aspects like colour fidelity, visual comfort, visual preference, and visibility. Metameric spectral tuning could be an instrument to solve potential conflicts between the visual preferences of users with respect to illuminance and chromaticity and the circadian consequences of the light exposure, as metamers can selectively modulate melanopsin-based photoreception without affecting visual properties such as chromaticity or illuminance. This work uses a 6-, 8- and 11-channel LED luminaire with fixed illuminance of 250 lx to systematically investigate the metameric tuning range in melanopic equivalent daylight illuminance (EDI) and melanopic daylight efficacy ratio (melanopic DER) for 561 chromaticity coordinates as optimisation targets (2700 K to 7443 K ± Duv 0 to 0.048), while applying colour fidelity index Rf criteria from the TM-30-20 Annex E recommendations (i.e. Rf$$\ge$$ ≥ 85, Rf,h1$$\ge$$ ≥ 85). Our results reveal that the melanopic tuning range increases with rising CCT to a maximum tuning range in melanopic DER of 0.24 (CCT: 6702 K, Duv: 0.003), 0.29 (CCT: 7443 K, Duv: 0) and 0.30 (CCT: 6702, Duv: 0.006), depending on the luminaire’s channel number of 6, 8 or 11, respectively. This allows to vary the melanopic EDI from 212.5–227.5 lx up to 275–300 lx without changes in the photopic illuminance (250 lx) or chromaticity ($$\Delta u'v'$$ Δ u ′ v ′ $$\le$$ ≤ 0.0014). The highest metameric melanopic Michelson contrast for the 6-, 8- and 11-channel luminaire is 0.16, 0.18 and 0.18, which is accomplished at a CCT of 3017 K (Duv: − 0.018), 3456 K (Duv: 0.009) and 3456 K (Duv: 0.009), respectively. By optimising ~ 490,000 multi-channel LED spectra, we identified chromaticity regions in the CIExy colour space that are of particular interest to control the melanopic efficacy with metameric spectral tuning.