Energy estimation and photometric measurements of LED lighting in laboratory
Electricity demand is prevailing all over the world now and energy management becomes very complex. This paper aims at providing solution for power demand and energy management by using HB white LED lights for domestic applications. LED lights consume very less power and gives out high energy in the form of brightness. A laboratory model is created in DIALUX 4.11 using CAD window and is illuminated with LED lights. Photometric measurements and energy evaluation are done for the laboratory model with room components of different construction materials in the presence of LED lighting. Reflectivity of different materials under illumination is determined. Simulation is done for varying brightness and calculated results are carried over to Pov-Ray 3.6 for determining the real lighting appearance of the laboratory model. Energy evaluation is done for a year and photometric values of lighting system are measured. The calculated results proves that LED lighting system can be used as an efficient lighting system for domestic purposes when compared to other lighting systems. Simulated results and photometric values of LED lighting are presented here.
AHP-based approach for lighting system selection in an underground parking
This research aims to identify the most suitable lighting system for an underground parking in an academic building according to international standards. Nine lighting systems scenarios were evaluated and the most suitable was selected considering experts criteria through an Analytical Hierarchical Process (AHP). The decision criteria considered were: total power, average lifespan, life-cycle cost, illuminance, uniformity, glare, energy efficiency, color rendering and energy saving, some of which were simulated through DIALux software. Among these criteria, the uniformity of the illuminance was the most influential criterion in the final decision according to experts’ judgement. Contrariwise, glare and color rendering were the least important criteria. As a result, a LED technology lighting system with an expected annual energy saving of 35% turned out the most suitable for the indoor facility under study. Keywords— AHP, DIALux, lighting system, underground parking.
Laminar heat or mass transfer in rectangular channels and in cylindrical tubes for fully developed flow: comparison of solutions obtained for various boundary conditions
Abstract A comparison is made of results obtained with various boundary conditions at the wall of the channels. By comparing blood Sherwood numbers for finite wall resistance with those for constant concentration boundary condition only a small variation is found for various points along the blood channel.