Posts Tagged ‘planning lighting’

How to stop LEDs from flickering

If only life were simple! If only we could buy an LED fitting, or retro-fit LED lamp, wire it in, connect it to a dimmer and hey presto – a perfectly dimming light.  Unfortunately, as so many of you will have experienced, this is not always the case and lamentably, the answer is not always crystal clear.  So how to stop LEDs from flickering? The following explanation in layman’s terms may help you resolve any problems you may have or, even better, avoid them in the first place.

Speak the Same Lanuguage

All LEDs have electrical control gear known as Drivers – even retro-fit LED lamps have tiny drivers in the base of them. These need to speak the same language as the dimming module.  When using a simple Mains dimming switch there are two methods of dimming – one is Trailing Edge and the other is Leading Edge.  Trailing Edge tends to be better; the dimmers are slightly more expensive but they are less prone to buzz and are generally more compatible with a wider range of fittings.  The manufacturers of the LED driver or lamp should stipulate the dimming method recommended (some will say either) so then you can ensure that the correct dimmer is installed. Do check that the LED retro fit lamps are dimmable – not all of them are!

For large projects always check that the dimmers are compatible with the LED fixtures or lamps that will be used; I usually combine Philips MasterLED lamps with Varilight V-pro intelligent dimmers which currently work well together – please note the word ‘currently’ as specifications can change and  manufacturers will always state that testing should be carried out to ensure compatibility.  Forbes and Lomax combine beautifully styled fittings incorporating Varilight dimming modules but it always advisable to state that the dimmer will be used for LEDs when ordering.

Don’t Overload the Circuit

A common mistake is to look at the maximum wattage on the dimmer, say 250 watts (in old money) and decide that, as the LED lamps are only 5 watts for example, you would be able to dim a multitude of fittings on that circuit. Wrong.  Ideally you should downrate by 6-10 times so in this case you would be best running  5 – 8 max fittings of 5 watts each.  It is possible to get larger load dimmers so it is best to check the number of fittings on each circuit before installation.

Don’t Underload the Circuit

Some dimmers, especially Leading Edge dimmers, need a minimum load in order to work, some as much as 40 watts before they will kick in. The more modern Trailing Edge dimmers will generally work from a lower load set point but be wary of trying to dim one or two LED fittings on one dimmer or you may need to incorporate a ‘dummy load’ to enable the dimmer to work.

Keep it Simple

Try to avoid using MR16 equivalent LEDs where possible when dimming as you then have three factors to bear in mind – the dimming module, the driver and the transformer which involves more ‘communication’ and more chances of incompatibility.  GU10 retro fit LED lamps or GLS replacement lamps are much simpler altogether.  However, on a positive note I have had success with using Philips MasterLED MR16 lamps with low voltage fittings on a Hamilton Mercury system but this was several years ago so may not be true today.  Always best to check.

Phase Adaptive Dimmers

If you don’t know whether you are going to use Leading Edge or Trailing Edge drivers then go for a Phase Adaptive dimmer; more high spec but flexible. Try Lutron for the latest in cutting edge dimming technology.  And if you’re wiring a new-build or self-build property it is worth considering a digital method of dimming such as DALI.

Favour Constant Current

Constant current LED drivers general work much better than constant voltage ones. The LED fittings for constant current drivers should be wired in series and your electrician should always check what products are specified before any wiring is done.

Dig Deeper

If you are still having problems with flickering lights and you have assessed all of the above then it may be time to check out the wiring in the property. Loose or faulty wiring or spikes and troughs in the electrical supply reaching the circuits in question could be having a knock-on effect so it is always advisable to check this out as well.

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Disclaimer: The above article is the individual opinion of the author and no commercial transactions should take place on the basis of any advice given above.

 


How to Plan Garden Lighting for New-Build Projects

Planning exterior lighting often comes low on the agenda of self-builders new-build projects. Here lighting designer Claire Pendarves gives some tips and advice on planning your garden lighting.

Landscape-lighting-design

Plan the Layout

The more you plan the better the effect. If you’re not a keen gardener and don’t have a basic plan in your head then I would strongly advise bringing in a professional landscape architect or garden designer. So often I see the landscape design being left as an afterthought and although it’s workable, especially if the coffers are running low, it can mean that the project can seem half finished for a number of months or even years.

Less is More

Francis Bacon said “In order for the light to shine so brightly the darkness must be present” and this is so true when it comes to lighting our gardens. An over-lit garden can seem flat and dazzling whereas careful placement of exterior fixtures can make it seem quite magical. Also, I find that the lighting budget for a new-build can balloon by over-specifying on the exterior landscape lighting quite unnecessarily.

Light the Outside for Inside

When you consider the British climate we spend most of our time in our houses and sadly the evenings where we are relaxing in warm summer gardens are all too few. With so many new-build designs featuring large expanses of windows and the trend being to connect the design of the interior and exterior spaces it makes sense to consider how the garden lighting will look from the inside. Accent garden lighting placed near the house can visually extend the living space and relieve the cold appearance of black glass panes at night making occupants feel less vulnerable.

Accentuate the Positive

Take a critical look at your building and planting to see what existing features you can highlight. Rough stone walls take on a magical warmth when uplit with low glare inground LEDs as can well-structured trees and shrubs. If you’re struggling to find any existing features this could help you decide on your planting; palms, silver birch and olive trees for example light well and oversized lit planters can look stylish and dramatic.

Paths and Steps

I always think of lighting as a journey and nowhere more than when lighting routes within a garden where functional lighting should dovetail with the aesthetic. Consider the approach from the parking area, unloading shopping on a winter’s evening and the trail up the garden path to the enveloping warmth of home. It is particularly important to select low glare fittings for all paths and steps ensuring that the route is smoothly lit with no dark patches on the way.

Using spike spotes to light garden foliage

Using spike spots to light garden foliage

Trees and Shrubs

Up-lighting and back-lighting trees and shrubs can be dramatic and effective although positioning of the light source should be carefully considered to create impact with minimal glare. Fixed in-ground lights with adjustable lamps within the fitting can work well for larger trees but for shrubbery that will grow and alter throughout the seasons, the ubiquitous spike spot is a wonderful tool offering flexibility and effect at a relatively low cost

Durability

There is no doubt that exterior lighting can bump up the cost of a project but it is a lamentable mistake to buy cheaper fittings with the aim of stretching the budget further. If the bottom line is looking too inflated it is better to choose fewer fittings and still stick with quality. Beware of stainless steel as there is a vast range on the market and I’ve seen cheap fittings corrode within six months near the coast. Go for 316L stainless steel or galvanised when selecting steel; alternatively copper is incredibly resilient and tones down well and bronze is practically indestructible. Alternatively hard anodised aluminium can work well or a good quality powder coated finish can be more economical.

Energy Efficiency

It is true to say that with modern technology it is now possible to illuminate an entire garden with the equivalent of a 60 watt incandescent bulb. Whether the decision is made to light the exterior entirely by dedicated LEDs or a mixture of light sources will rather depend on budget and logistical factors such as the placement of drivers and transformers. Mains fittings offer more flexibility and combine well with retro fit LED lamps although for smaller punchier lights LEDs are general the best choice. Fibre optics can also look magical when combined with water features and, once in situ will last for years although your electrician will not love you for specifying them.

Controls

Ideally there should never be less than two control circuits, three being the optimum and a fourth giving prime flexibility. The first will be atmospheric lighting close to the house, the second will be security and facility lighting (this will often be on a PIR with a timer and over-ride facility), and the third will generally be for landscaping beyond the immediate vicinity of the house, such as driveways and additional features. The luxury of the fourth can allow for an entertaining circuit such as illuminating a barbeque and dining area, swimming pool or hot tub if such indulgences exist.

Lighting a garden can be a functional exercise or an exciting adventure which will add a totally new dimension to a property. There’s no quick fix solution to creating it but with careful consideration and measured planning the effect can be a work of art. It’s a matter of choice.

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