FAQ with Daniel Kalina
Discussion subject: making lighting more energy efficient & cost effective in commercial settings, including but not exclusively using LEDs.

1. How can we best achieve the savings large corporations are looking for when lighting new-build office complexes?
The main consideration has to be the lighting design. To use the most appropriate lighting system (direct, direct indirect combination, etc) in order to achieve not only energy savings but first the right solution for visibility, task performance and occupants' wellbeing.

It seems to be clear that Led light sources are already in some applications and will become in others, the most efficient light source but will have to be evaluated as part of a whole: lighting system and lighting design.

2. What about retrofit for older properties? Can it ever really as effective as starting over?
If we believe that the existing lighting system is adequate in respect to all the quality parameters but inefficient, one have to understand that replacing only the light source doesn't necessarily mean that quality parameters will be kept.

3. What are the best cost saving solutions for retail currently - bearing in mind the maintenance issues?
Fluorescents, if we can rely on late data claiming for around 40,000 hours life based on 12 hours cycle (quite usual in retail) are still good solution. Well-designed Led luminaires (optically, mechanically and thermally) are promising provided the $/lumen ratio is good enough, if not patience is the right solution.

4. What about colour rendering for the fashion and food sectors - is it being adversely affected by lamps of a lower quality?
The answer is simple yes, it is affected. Regarding LEDs, I am not sure the CRI system, which was developed mainly for discharge lamps, can reflect the real human appraisal when dealing with fashion and food. It seems to me that the system does not include in the calculations any subjective parameters. I heard that a new system is in the development stage.

5. What about outdoor use: what's the best option for say - street lighting in inner cities, undercover, multi-storey car parks and public parks/gardens?
Street lighting in inner cities as well as public parks and gardens looks as an ideal application, mainly due to the high maintenance costs and all around operations involved. Again, quality should not be neglected. I have hardly seen a glare free low mounting height installation. Even if calculations and measuring equipment show low and sometimes no glare, our eyes and brain are able to discriminate the milimetric size of each emitter and the result is glare (mainly when using lens optics).

6. Do you believe there's still a viable alternative to the LED for general commercial use (offices, shops, public buildings etc)?
For the next coming years yes (fluorescents and short arc ceramic metal halides). For how long? Answers 3 and 4 apply.

7. What about lighting controls? Would installing control systems in much smaller premises than is current practice, make enough cost saving to make it worthwhile to the independent retailer, small business owner or boutique hotelier?
Yes there are small, low cost control systems for presence and light harvesting and their ROI is quite promising.

8. What's most important to the specifier - and ultimately the customer - cost savings or energy reduction? If cost is top of the list, is there a way to re-educate them to look at energy savings as paramount?
Obviously, energy reduction, but always at a reasonable cost and without sacrificing the quality of the lighting system and the users' wellbeing.

9. What, in your opinion, is the single largest benefit of the LED?
If there is a need to choose only one parameter then it is life span. We need to also consider the electronics (driver). Although we might be surprised if LEDs will reach the theoretical limit of efficacy (then I might replace my chosen parameter).


The content for this article is based on Daniel Kalina participation in Total Lighting (TL) virtual round table debate, which appeared in the September 2012 issue of Total Lighting magazine.