Search

Evaluating indoor daylight availability is extremely important in order to define the characteristics of an environment in terms of visual comfort and energy performances of lighting systems. The criticism of the static calculation approach based on Daylight Factor led to the development of the Climate Based Daylight Modeling (CBDM) one. Dynamic simulations are performed thanks to the use of specific software and the choice of a calculation tool or another could provide different output results. Therefore the aim of this paper is to compare results of dynamic daylight simulations carried out with two different software, Daysim and 3ds Max Design® and referred to a simple office located in 4 different cities and exposed according to the 4 main orientations. It demonstrates that differences in results are more or less significant depending on several factors: outdoor daylight conditions, window’s orientation and considered internal calculation point.

This paper reports the results of measurements performed in a test room to investigate the impact of using different wall colours and light scenes on indoor lighting quality. Eye level spectral irradiances were measured for a user located inside the room and seated at a desk. These measurements allow the use of the Irradiance Toolbox, which makes it possible to calculate equivalent illuminances for the photopigments in the human eye. Moreover, the CIECAM02 colour appearance model was used to investigate the variations in hue and chroma values of the different wall colours when changing the light scene. The results demonstrate that there are significant variations in eye level spectral irradiance distributions, photoreceptor stimulation and hue and chroma values with different combinations of wall colours and light scenes.

The research presented in this paper reports an analysis of daylight in three offices with different exposures and characteristics located in Naples (Italy). The goal was to fully investigate daylight characteristics, also considering the circadian impact of daylight entering these offices, with the hope to develop guidelines to better assess daylight quality in built environments. One of the main findings of this research is that the spectral distributions and CCTs of the light reaching the eye of a person seated at the desk in these offices are similar irrespective of the offices' different characteristics (dimensions, surfaces' spectral reflectances, external obstructions, etc.) and different sky's conditions. Moreover it was found that eye level irradiances and their circadian impact is similar to those of D50 and D55 CIE standard illuminants. The same measurements will be carried out in other seasons and a comparison between measured values and software simulated ones is also planned.

Light induces not only visual responses but also non-visual effects, indeed it affects performance, mood, attention and influences the synchronization of the biological clock. Duration, timing, intensity and the spectral power distribution of the light that reaches the eyes can have influence on human circadian rhythm and consequently on health. Given the important impact of the non-visual responses on people wellbeing, developing a model that allows lighting designers to predict them is a fundamental goal. In this paper a case study is reported: a series of measurements were carried out in a University classroom in order to study daylight and electric light characteristics and also their impact on the human circadian system by calculating melatonin suppression. The results obtained show that not only the intensity but also the SPD of the light received by the eyes plays a significant role on circadian response and the spectral characteristics of internal and external surfaces influence the SPD and therefore the CCT of the light that hits the eyes. Although the working behavior of the human circadian system is not completely understood, the results obtained give the designers new points of view to better evaluate lighting quality and its implications in indoor environments.

In the industrialized part of the world, an increasing number of people live the old age without too many restrictions due to illness or physiological impairment. This group is known asthe young elderly. On the contrary, a consistent part of seniors develops a greater number of medical conditions and become more and more dependent, these arethe old elderly. The first cause of tooth lost in industrialized word is periodontitis that generally strikes people older than 40 years and determines serious detriment of the stomatognatic organ. Smoking and stress are risk factors for periodontitis that are common and shared between young, adult, and older age. Diabetes mellitus, obesity, and osteoporosis are very frequent pathological situations in older age. They have been identified as cofactors in the progression of periodontitis. Many dental associations recognize the importance of continued research on oral fluids diagnostics and welcome the development of rapid point-of-care tests providing accurate measurements of clinically validated biomarkers. At present, well-studied molecules associated with host response factors and with derived tissue destruction mediators have been proposed as diagnostic biomarkers for periodontitis detected in the oral fluids.

Recent availability of video-cameras with CCD-type sensors (charge coupled device) has proved to be particularly stimulating for all those applications requiring photometric measurements, above all for the measurement of luminance values related to the physical and technical qualities of a built environment. This method allows the instantaneous capture of an image, thus enabling collection of luminance values relating to the points of measurement; this in turn leads to the evaluation of luminance distribution and lighting levels of the surfaces that make up the environment. Setting up this system requires the following basic configuration: a photopic filter V ( λ ), an optic interface, a computer equipped with an appropriate card for the capture and digitalisation of the acquired image (the “frame grabber”) and, finally, suitable software for the processing of collected data. In this article a detailed description of this acquisition system is reported, and subsequently a report on the procedure adopted for its calibration so as to enable the capture of relevant photometric values. Final analysis and validation of results are carried out by means of field test. A case study of CCD photometer application has been then performed using a basic software tool autonomously developed to evaluate indoor lighting level; the luminance map of a diffuse light source has been used as “input” data for the developed software, and the “output” data, i.e. illumination levels, have been then compared with measured values.

In recent years, different types of solar shading devices have been proposed, depending on building orientation, location, window characteristics, etc. They can contribute to improve or worsen building thermal and lighting performances both from an energy and comfort point of view. The present paper reports a critical analysis of some studies that investigate shading devices’ effects on building thermal and/or lighting performances. This article points out the difficulty in comparing the different results given the lack of uniformity between the studies, since they analysed buildings with different characteristics, locations and using various indices. Therefore a protocol to carry out this type of studies should be developed in order to allow the comparison of the different research investigations performed all over the world. Moreover, this paper shows that thermal comfort, economic and environmental aspects related to the use of shading devices were rarely analysed.