– Presented to you by the Lighting India Content team
One of the advantages of working as a lighting designer and qualified Illuminating Engineer is that every day at work, I figure out a way to explore the many potential technologies that enter the market.
Today, we see the LED market exceeding boundaries, in terms of an increase in efficacy and a reduction in cost. LED-pioneer Roland Haitz, also known for the Hait’z Law which states that the cost per lumen (unit of useful light emitted) falls by a factor of 10, the amount of light generated per LED package increases by a factor of 20, for a given wavelength (colour) of light. The law predicts an exponential improvement in semiconductors used in LED-technology. The increase in performance decreases in cost over time. In short, we can infer that the energy era in lighting, commenced with the oil crisis in the year 1973 which is officially over with the advent of LEDs, hence achieving efficacy of 200 lm/W + calling an end to the return on investment (ROI) from luminous efficacy and lifetime advances. SSL has truly matured and is replacing traditional lamps practically in all applications, indoor or outdoor – right from residence to retail and road to sports.
I see growing possibilities in LED lighting design changing its route from performance-metric tunnel vision to space utilisation and lighting experience through the form and function of integrated lighting by occupants. LED technology has given us the ability to be artists like never before, and hence LED business will have energy efficacy for which resolving light quality challenges of the products and systems by the lighting industry in association with integrating profession will play a key role.
A watt saved is easy to communicate and build a return on investment from. However, the value of quality lighting can exceed energy savings. Looking at the 3/30/300 (utilities/real estate/employee), the rule of thumb cost to operate a square foot of commercial building space, a 50+% reduction in energy costs can be substantial, but even a modest reduction in real estate or improvement in employee output is far higher. The key elements of quality electric lighting in practice focus on colour quality, limiting glare, light distribution, visual comfort, flicker, and health and well-being.
Colour Quality: Putting ANSI TM30 2018 standard into practice through education, while designing & specifying the community and of course its implementation in design particularly in Retail, Offices, Hospitality, Health Care, Education and Human Centric Lighting (HCL). To limit glare in various applications, the need of the hour is the compulsion of Photometric Testing of Luminaires by OEMs and the use of BIS standard accepted UGR Method in design calculations and thereby implementing the use of glare fee products in all applications.
Flicker is another quality feature of lighting design and is associated with the quality of drivers. To date, IES standards exist for its measurement but much of the work to be done.Best design practices – such as individual or group tunability of lighting, automatic tuning for circadian, time of day, daylight integration, or another requirement; and user overrides – require a control system with flexibility and intelligence. This is the front end of what controls can do to support lighting quality. At the backend, things get even more interesting with different types control systems & protocol like, DMX, KNX, IoT, PoE, Wi-Fi, Li-Fi, Bluetooth (BLE ) Mesh, and so on.
Tunable White is Human Centric Lighting (HCL) – A half-truth is widely promoted by most in India. There is a need to educate on a priority basis and not only is the design & specifying community as well as users but also the lighting manufacturers, distributors, dealers and marketing or sales personnel. To date, two popular metrics are used -Melanopic Lux at eye level by WELL standard and CS method promoted by LRC – for true implementation of Human Centric Lighting (HCL). For good quality of Tunable White lighting from all luminaires in any installation, there is a need for DALI D8 Drivers and associated software. There is a strong need to promote quality lighting in India for which ISLE, IALD India chapter, ELCOMA, BIS, Contractor’s Association and similar bodies in India can take a leading role to define LED Product quality parameters. Guideline can be taken from the Design Lights Consortium’s (DLC) Qualified Products List, USA.
The DLC’s Qualified Products Lists of LED products and networked lighting control systems offer a resource to the industry for sourcing products and to numerous utilities and energy-efficiency organizations for qualifying products for rebate programs in the USA. The DLC’s Technical Requirements Version 5.0 incorporates a new and substantial emphasis on lighting quality for LED products attributes such as colour quality, glare, flicker and light distribution, which will increase the value of the resource and provide specifiers more information to evaluate products beyond basic performance metrics.