Replacement of tubular fluorescent lamps with tubular LEDs lamps and daylight integration in classrooms and laboratories

Abstract

The quality of lighting significantly influences our ability to perform tasks in enclosed spaces, and certain characteristics of lighting sources play a crucial role. Light-emitting diode (tubular LED) lamps offer advantages for both home and office use. Choosing tubular LED lamps over fluorescent ones is beneficial for several reasons. Tubular LEDs are mercury-free, ensuring environmental safety compared to the small amount of mercury present in fluorescent tubes. Furthermore, tubular LEDs provide directional lighting, minimizing light loss in fixtures and unnecessary areas, and offering better efficiency (around 40% more than tubular fluorescent lamps). Also, they produce high-quality light with various color temperatures, eliminating flickering issues that can cause discomfort such as eye strain, headaches, and migraines. Additionally, tubular LEDs have a longer lifespan making them a preferable lighting option. The superior quality of natural light makes it the optimal source of illumination, which matching well with the visual response of the human eyes. Daylight has a positive influence on people, instilling a feeling of vibrancy and brightness within their living environment. The acknowledged benefits of daylight extend to enhancing visual comfort, promoting health, and improving overall performance among building occupants. This paper focuses on the integration of natural daylight with artificial light, particularly through tubular LED lamps, and investigates the daylight factor. Two groups of six tubular LED lamps (60cm with 9 Watt and 120cm with 18 Watt) and another group of six tubular fluorescent lamps (60cm with 18 Watt and 120cm with 36 Watt) were studied. The study involved two sets of six tubular LED lamps (60cm with 9W and 120cm with 18W) and another set with six tubular fluorescent lamps (60cm with 18W and 120cm with 36W). Measurements were conducted using Spectroradiometer Ocean Optics HR 2000 with 4.7% uncertainty and a photometric bench to assess the spectral output. Additionally, UVA/B silicon detector and Luxmeter detector setups with uncertainties of 5.2% and 6%, respectively, were employed for irradiance and illuminance measurements of tubular LEDs and fluorescent lamps. Various parameters, including daylight factor ratio, UVA power to luminous flux (K) for tubular fluorescent lamps, spectral power distribution, and illumination levels were obtained. Integration between daylight and tubular LED lamps was also determined. The maximum detected value lmW /013.0  is less than the safe limit for human health but still there are effects on human health if they use these types of lamps. Therefore, it is advisable to switch from tubular fluorescent lamps to tubular LEDs to mitigate the impact of UVA on human health and the environment.