Lighting

Behaviour of Light

In the first article I touched on the behaviour of light which is what we will consider now and how it directly relates to your application (what is the intended use of the space) so here we go….

Down lighting is probably the most common source of light in a house coming into popularity over the last 20-25 years, it started as Incandescent which was a large diameter and deep fitting (approximately 200mm deep and around 1800mm diameter), then progressed to compact fluorescent (CFL), onto halogen than finally to LED (Light Emitting Diode) which is our current best option for energy efficiency and longevity of operation. So if you have any of these prior platforms I would strongly recommend you consider moving to the latest LED option for the following reasons.

Incandescent is the least energy efficient (thank you Mr Edison) for example a 60 watt globe which BTW now generally comes as a globe with a little Halogen bulb inside as incandescent was prohibited from being shipped into Australia last year so existing stock can be sold but no more can be brought in (so there for 60w = 52w a small saving energetically) and is comparable in light output, then CFL which is again lack lustre as it takes time to heat up the gas inside the tube to get to full brightness not to mention all the nasty chemicals within the gas I.E. Mercury, etc (bad for our planet). Finally onto Halogen which isn’t to bad and has prior to LED been the main form of down lighting but aside from the fact that each globe operates at 200 degrees so there is a cost associated with cooling the space and is a big factor with this technology, and on a technical aspect of Halogen the fitting is high current draw so this style of fitting promotes failure of the terminals connecting the parts (does anyone out there have a halogen light at home which goes on and off by itself)? This means your Halogen is now in need of new parts not just the globe. So the conclusion with regard to the maximum benefit of said energy efficiency please understand changing the globe the “Light Source” to LED will save you buying new globe more often but it “WILL NOT” save you money as the Electrical Losses occur at the Transformer or the Ballast, these things are parts within the fitting prior to the electricity reaching the globe so I would recommend you buy a complete new fitting for maximum savings as the new electronic Driver (the name given to a Transformer for LED) is very frugal with your electricity.

Now as for the financial savings from your new lighting in my opinion in a Domestic application the pay back (I.E. the time it takes for your initial outlay to buy the new lighting and for financial savings to begin) should be around 14-18 months depending on your hours of use. Obviously in a Commercial application this time frame is greatly reduced as their hours of operation are far greater than in Domestic and typically the Commercial pay back is 8-10 months but this does vary somewhat from job to job.

So here we are you are about to purchase all new LED downlights well done! There are a few variables to consider Dimmable or non dimmable fortunately most down lights come dimmable weather you do dim them or not. Secondly the term of choice is Fixed or Single color (which I hope is self explanatory) now there’s nothing wrong with fixed color as long as you know what you want because even with the tri color fittings (which I will enplane momentarily) once they are installed you will never pull them out to change them verses Tri-color which simply means your fitting has a small selector switch located on the back side of the fitting generally which allows you to select the “Color Temperature” (often referred to in Kelvin so 3k = warm white, 4k = cool or neutral white and 5k = daylight anything above that is so brutally blue it’s like living inside a Seven 11) my preference is 3k Warm white as it matches the original color of an Incandescent globe which I love and weather its inside or outside I like to stick to Warm White. Please note sticking to color numbers instead of color name is the best way to refer to your fittings color temperature as some company’s did away with the color name “Day Light” and moved the name “Cool White over to 5k and it confuses the hell out of everybody weather you’re in the industry or not! So color numbers listed in “k = Kelvin” is the best way moving forward….

At this point for those of you with children may I inform you color plays a big part in their behaviour, some 10 years ago a study was done on the effect of color temperature of lighting in a school room environment verses children’s behaviour and 5k lighting produced problematic behaviour in 70%  of the class compared to 30% under 3 or 4k so let me say that anything above 4k promotes behavioural problems this is most certainly a consideration I’ve refitted many School campuses and I always specify and supply 4k as it’s not too warm and not to blue, it’s a bit like the 3 bears “Just Right!”

So let me just say as a general rule the downlight’s available today whether they are Architectural “Low Glare” fittings that generally come in fixed color while the “Wide Angle” predominantly come as Tri Color, this may change in time but for now it’s the way it is….

So I just introduced the terms “Low Glare” and “Wide Angle” and these concepts are equally as important as Color Temperature because these two factors being the Color and spread of light directly affect how the house will look and feel moody or not! So wide angle downlights are are in general the cheaper of the two options but the behaviour of the light fanning out in a 120 degree radius with all that light bouncing about isn’t what or how I would prefer to live as I find it very glary. Its how I light an office or a retail; outlet where the lights are up high in an oversized space at3-4m plus ceiling height where its at such an oblique angle to where you are standing. Don’t get me wrong they are good strong lights they are just indiscriminate! On a technical level the fittings themselves are quite shallow being around 35mm thick (Deep) so they can be used where there is limited depth! That said there are still deep set options that are as shallow and also “Gimbal” (the face pivots so they can be angled), but the price is higher due to the better technologie that’s gone into their development. If you couple these wide angle fittings with a dimmer then you can wind them down reducing their potency I would highly recommend you do because when my clients come into store and I show them the behavior of these two styles side by side its so obvious how unsettling the one is compared to the Low Glair!

So Architectural “Low Glare” in my opinion is the only way to go in a domestic application as it just so easy on the eye and in most cases the wattage is higher with this style of fitting so in reality you are getting more light with better manners which will totally enhance your space and create mood and ambiance complementing the style and energy you have put into your build……. “Job Well Done!”

 

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