Saturday, 9 April 2011

About LED Garden Lighting

LED Outdoor Lights vs Conventional Outdoor Lighting

Outdoor LED lighting first started appearing as part of the range of low voltage garden lighting systems only just a few years ago, but has since become extremely popular. LED garden lights deliver beautiful after dark effects while being very easy to install, safe for plants, animals and children, fairly inexpensive to buy and very cheap to run.

Traditionally, garden lighting has relied on normal incandescent bulbs and halogen spotlights and as a result can overwhelm many normal sized family gardens. Also, unlike low voltage LED outdoor lighting, the range of effects possible is more limited, and even traditional 12v low voltage garden lighting can be quite hazardous on account of the very high temperatures of the bulbs. Finally, traditional out door lighting costs significantly more to run because incandescent and halogen lamps use easily ten times more electricity than LED garden lights and also need the bulbs to be replaced on a regular bases (some LED garden lights are capable of lasting a decade or more).



Outdoor LED Lighting Options

So, what choices do you have with LED landscape lighting? Well, there’s outdoor LED spot lights of course, LED flood lights (which are basically more powerful spot lights), colored clear rock lights, LED patio and deck lights in a variety of sizes and colors, bollards, lanterns, spikes, and LED pond lights, for starters.

Let’s just take LED deck lighting for example. These can be fitted very easily into decking boards or indeed any outdoor wooden garden structure. It’s simply a matter of drilling a hole the same diameter as the deck light unit, dropping the connecting cable thru and pushing the LED light itself into the hole. And there it will sit, quite likely for several decades, performing reliably night after night with absolutely negligible cost.

Because they are so robust, durable and lightweight, you can fit LED deck lights not only into the regular deck boards that you walk over, but into the side panels of your decking and even into upright posts and the cross beams of pergolas where you can install LED deck lights at different angles to direct light back down. Put LED deck lights into fence panel posts or even highlight a garden shed if you feel so inclined. You are limited only by imagination (and taste).

Many people assume they can’t use LED deck lights if they don’t have a deck – well, don’t let that stop you! LED deck lights are one of the most versatile components recently introduced into the outdoors and general garden lighting arena. I have seen them installed as patio lighting, fitted into steps and stepping stones, even mounted into wood blocks and deployed as standalone ground level lighting in among flower borders.

Interesting variants on regular LED deck lighting are solar deck rail lights and solar post cap lights which you can fit to pick out the line of deck rails and fencing. These are low power ambient LED lights that aren’t intended for illumination as such, more as a decorative finishing touch. They are easy to install and effortless to maintain.

LED garden spot lights have been around for a while of course, not least because the highly directional nature of LED light is exactly what is required in a spot light but without the need to fit reflectors to focus the light beam. Used outside in the garden, LED spots are a perfect substitute for equivalent halogen bulbs but require a fraction of the power consumption and generate negligible heat (which can otherwise easily damage nearby plants or curious fingers and paws).

The key points to look out for when installing LED spotlights in a garden are beam angle (do you want a tightly focussed beam of light or one a little more spread out?) and LED light color.

This isn’t just a matter of deciding on a color such as white, blue, red, green, yellow and so on, although that choice is also available. It is more to do with what is known as “color temperature” – whether the light appears “cool” or “warm” which depends on the sort of effect you are trying to create and is fundamentally a matter of personal taste.

There are some basic rules of thumb though. To create a “dramatic” look use very bright, pure white (if anything slightly on the “cool” side); this is especially effective on water and architectural garden features as you will get a sharply defined, quite sparkly effect. For plant foliage and flowers it’s more common to want to enhance natural colors so warm white or even yellow or amber spotlights can be used to uplight both leaves and branches.

How To Get The Best From LED Outdoor Lights

When installed in bollards and spikes – frequently for the purpose of illuminating pathways – outdoor LED lighting can be used to either replace normal garden lighting used for this type of application or to introduce interesting new effects. Conventional lighting simply can’t come close to matching the jewel-like quality of LEDs with their crystal sharp definition and rich colors.

Scatter a mixture of different colored LED garden spikes around your borders and also maybe use some diffusers to vary the intensity and your garden will be as colorful at night as during the day, if not more so. Which brings up another key point related to garden lighting, namely that artificial lighting really comes into its own when you let it be what it is – artificial.

Trying to recreate how your garden looks during the daytime is a) never going to come close to how your garden really does look in daylight and b) wasting an opportunity to take advantage of all the wonderful effects that artificial light brings to the outdoor night time garden party. Once you understand this you quickly realize another key factor in successful garden lighting – light intensity.

Human eyes adjust to night time conditions and simply banishing the darkness with a blaze of flood lights is most definitely not the route to a beautifully lit garden. Use lots of different types of LED garden light fixtures (spot lights, colored lights, accent lights etc) and vary the brightness to create effects that contrast, complement and generally work together with each other and your garden area. Blur the boundaries between house lighting and the garden by graduating the light levels rather than having an abrupt transition.

Above all, don’t make the common mistake of over illuminating your garden; keep the light levels relatively subdued when lighting outdoors (you’re not performing surgery out there) and leave large areas of darkness – you need a canvas to paint on and with garden lighting the darkness is that canvas. This works well with smaller gardens which can easily become overwhelmed by lighting, but it’s also effective in larger gardens. Rather than use brighter lights outside, just use more lights.

Because with outdoor LED lighting you can. As a general rule you can install 10 LED garden lights for 1 halogen fixture – that’s an awful lot more light fixtures to play with! But if you do want to mix and match between LED garden lights and regular halogen bulbs, you can easily do that too, with a few simple caveats as described below.


Planning Your Landscape Lighting

The best way to approach anything new is to become familiar with it first. If you’ve not installed a garden lighting system before then go look at some examples. It has to said that photographs never quite capture garden lighting very well, but you shouldn’t have to search too far to come across some real-life installations in your neighborhood that might serve as a template (or a terrible warning!). There are also many quite impressive examples of municipal landscape lighting these days.

Unlike interior lighting, the outdoor variant is mostly about mood and decorative effects. As a general rule you don’t need ambient light (ironically, since you do want ambience) or task light. You don’t (in fact, can’t) light up a garden in the same way as you can a room; it doesn’t have a ceiling or proper walls for a start. Whatever you do illuminate though will stand out very effectively against the overall backdrop of darkness, which means you don’t in fact need to light anywhere near as much as you might think.

Although there are always perfectly good exceptions, if you work on a rough guide that spacing lights less than a meter apart is too close, and more than two meters apart might be spread too thin, then you shouldn’t go far wrong. Clearly there are going to be areas where you want to use more lighting and other, perhaps quite large, spaces that you deliberately want left in total darkness. I don’t for example draw any attention to the part of the garden where the shed is, but do use clusters of very small lights packed fairly densely (maybe 5 per shrub) close up to the deck, which when mixed in with the foliage creates a “cloud” effect. This at least should make it easy to approximate how many lights, and therefore what size transformer and length of cable, will be required.

When it comes to individual light fittings, there are two basic techniques to consider. Some lights are the decorative effect themselves and others are there in order to illuminate something else. The former is straightforward enough – not too bright (you don’t want to hurt your eyes), probably colorful, and eye-catching. These can also serve a function, such as path lights (solar powered LEDs set into paving slabs, for example) and bollards, or maybe simple spikes that suggest real or illusory boundaries.

Fixtures whose purpose is to light something else can be deployed in essentially one of four basic ways. You can light something from above (downlight), below (uplight), behind (backlight) and from in front. The latter has a number of further variants since you can obtain quite different effects depending on whether the light is used to “wash” over the subject, place it in relief or casting shadows, or to catch it at an angle.

So how to choose? Well, many features in a garden themselves suggest the best approach, simply by their very nature. If you have, say, a reasonably large tree that has an interesting structure then a powerful uplight will really bring this to life at night. You might, according to the size of the tree, need 100 watts or more, otherwise all you’ll do is get a bit of reflected glow off the trunk, which is not very impressive at all. Be careful though when using powerful outdoor lights that you don’t upset your neighbours – as always, a friendly chat about your plans first and being open to any concerns could help defuse potential problems before they arise.

For the more common or garden shrub and sculptural feature, one of the easiest ways to figure out how best to light it is to use a regular handheld torch (or several) and go out of an evening and try different effects. Typically you will eventually be using lamps of 10w to 20w, which most household torches should be capable of reasonably emulating. As you proceed, take notes to record what seemed to work best where (or lay some form of marker on the ground). Clearly you can’t get a good feel for the overall effect, but you’re not really going to get that until you connect it all together and switch it on for the first time. It does help however to have at least a basic outline plan to work to.

Having an approximate idea of the number and type of lights you need, and the physical area they are intended to cover will tell you how much (and what thickness) cable to buy plus the size of transformer that will be needed. If your proposed installation isn’t that large then your best bet might be to purchase an all in one kit since you can guarantee that everything will work together properly and it should be very easy to install. Otherwise you will need to buy a suitably sized transformer and length of cable (more on this below) as separate components, but the trade-off is that you will have total flexibility in terms of the individual light fittings. Assuming of course that they are all of the same basic type (i.e. LED or incandescent) and that the sum of the individual wattages is within the total load that the transformer will support.

Lastly, where planning is concerned you’re almost certainly not done even once you have wired it all up and switched it on. There’s a good chance you will have guessed wrong about a few things, got a few lights in the wrong places, that sort of thing. For this reason, don’t be tempted to immediately bury the cable in order to tidy everything away. It won’t do any harm laying on the surface for a day or so until you feel the layout is as it should be. Digging up and working with damp, soil covered wiring is best avoided if possible.

Typical Low Voltage Garden Lighting Installation

Many, if not most, home DIY garden lighting kits use a 12v (low voltage) transformer that has capacity to run a given number of watts. You simply run a cable around the areas where you might want to install lighting, connect one end to the transformer (indoors of course) and you may then attach outdoor garden lighting fittings to any point on the cable. So long as the total number of watts loaded onto the cable (i.e. the combined wattage rating of all your garden lights) is within the capacity of the transformer then you’re good to go.

It is sometimes possible to mix LED garden lights and incandescent lights on the same circuit, but this generally only applies in one direction; namely adding suitable LED units to a standard 12v circuit normally used for incandescent (typically low wattage halogen) lamps. An LED garden light that can be powered this way will have this noted somewhere on the packaging.

Normally however, you should power LED outdoor lights using only an LED transformer (these are guaranteed to supply a constant 12 volts) and similarly use ordinary 12v transformers (which may vary their output voltage in response to the load) only with incandescent bulbs.

In short, the best and safest way to mix incandescent and LED outdoor lights is to lay two circuits, one powered by an LED driver and the other a regular low voltage transformer. If you put LED garden lights on a regular circuit you will very likely shorten the life of the LED bulb (to a matter of weeks) and likewise, attaching incandescent lamps to an LED driver is almost certain to wreck the driver.

Having said all that, there is no doubt that using both forms of garden lighting can produce a truly magical effect. Add in softer solar lighting (see below) and the mix of light quality, level and color gives you plenty to paint with. You can also, within limits, modify the brightness of individual light fittings by using bulbs of greater or lesser wattage.

A quick technical note here. In a 12v low voltage system, the cable itself applies a load to the transformer which you also have to account for. This is usually stated on the packaging and depends upon the length of the cable. It also means that lights furthest away from the transformer will tend to appear slightly dimmer than those nearer.

One way to both boost the current levels and spread them uniformly across the cable is to ensure the cable forms a loop, either all the way back to the transformer or to some point reasonably close. This latter technique is specifically called the T method of cabling. You create a continuous hub, or loop, that runs around the area to be lit and attach each of the light fixtures to this cable. A second cable (the upright of the T) then intersects this loop and runs back to the transformer.

Obviously be sure to observe polarity if doing this (the cable is actually a pair of wires – do not cross connect the two wires) While most outdoor light fittings don’t care about polarity and can have the wires attached either way round, this is most definitely not the case when looping the cable back on itself. For this reason there is usually either embossed writing or a colored band on one of the wires – if you never connect a marked wire with an unmarked one you won’t go wrong. If your lights flicker or seem unreasonably dim or bright then chances are you have a case of crossed polarity somewhere in the circuit.

Another way to help reduce the line loss (or voltage drop) that is an inherent issue with all low voltage systems is to use a thicker cable, i.e. buy a 10 gauge instead of 12 gauge cable. Wire gauges units decrease as cable thickness increases. There is a difference between the American and British Wire Gauge scales – here’s a graphic of the standard wire gauge. As a general rule of thumb, you should anyway increase the cable thickness in proportion to the total load on the system – a thinner cable may be fine powering say 150 watts, but for a larger installation with a total load of say 500 watts then a thin cable will suffer badly from line loss.

If you’re still having problems with lights being dimmer than expected than it’s possible you simply have too much load for the transformer and need a more powerful version. To reiterate, the total load as calculated in watts, and including all lights plus the cable runs, should be as close as possible to, but without exceeding, the stated output of the transformer.

Low Voltage Garden Lighting Applications

LED outdoor lights are ideal for garden water features – ponds, fountains, and running water – thanks to their safe low voltage; LED garden light units themselves are very robust and run cool, and the pure, sharp quality of LED light complements water perfectly with dazzling reflections.

There are all manner of outdoor LED garden light fixtures that are suitable for enhancing outdoor water features at night, depending on whether you want to uplight, downlight, backlight or actually immerse LED lights in the water itself. There are for example, LED pond lights commonly available that can either float on the surface or be submerged and provide internal illumination from the bottom of the pond. But even the common or garden LED spot light can be installed to produce brilliant effects in combination with water.

Nor is there anything really to stop you using standard indoor 12 volt LED light bulbs as part of the outdoor lighting system. If any of your outdoor fittings accept a bi-pin lamp base (as commonly found on GU4 capsules and MR11 spots for example) then you’re in business. What you might have to do though, since many LED garden lights are sealed and have no serviceable parts, is cannibalize old, cheap or non-functioning regular halogen fixtures since these will have the right sort of fitting. The advantage to be gained here is that you can frequently source much brighter LEDs than those commonly found in garden lighting products. You can also make colors of your own choosing using colored cellophane or similar transparent materials. These would normally melt or catch on fire if used close to a halogen lamp, but LEDs scarcely warm them up.

So, as well as lighting pathways, patios and ponds, and bringing key garden features and plants to life (some plants really lend themselves to artificial light and look far more dramatic by night than they do in the daylight), what else can you do with outdoor LED lighting? Well, there’s the obvious use of outdoor color changing LEDs in the garden. Used sparingly this can look really effective (though if over done it can make your garden look like Santa’s Grotto).

You can also play with outdoor LED wall wash effects – got a boring wall or fence or side of a shed? – bounce LED lights off it and turn it into a colorful backdrop. You can also use LED wall wash lighting to good effect on areas of well manicured lawn, raked gravel or any other relatively even surface.

Of course, some outdoor LED lighting fixtures, rather than be used to illuminate something else, almost beg to be the center of attention themselves. LED garden lights comprising small 1w single color LED bulbs work well as individual focal points – in a similar way that gardeners use bright colorful plants to draw the eye during the day time. Installed either with or without simple diffusers screens, the effect resembles a garden studded with rich blue sapphires, pure green emeralds, deep red rubies and a myriad other vibrant gemstones through every colour in the spectrum.

Some of the most stunning LED garden lighting designs at the moment are garden ornaments that complement their surroundings and look great by day, but that steal the show come the evening. Popular examples of these are LED tree lights that resemble regular garden sculpture during the day and are typically the size of a small maple tree (though size – and of course cost – are variable). At night and once lit however, they can mimic pink cherry blossom or bronze autumn leaves and are simply gorgeous, eye-catching centre pieces.

And finally, one other great benefit of outdoor LED lighting – the power consumption of LED garden lights is so low that you don’t necessarily even need to purchase a 12v transformer and lay a low voltage cable system. There are many choices available for solar garden lighting these days, not least with solar powered LED garden lights.

The downside to solar LED lighting is that it is in general not so controllable (i.e. you can’t turn the whole system on and off with a conveniently situated switch).

There are, however, solar powered garden lighting systems whereby you can hook up a number of outdoor LED lighting fixtures to a single solar panel, which has two advantages: you can place the solar panel somewhere nice and sunny regardless of where the light fittings are situated, and you can turn a set of outdoor LED lights on and off from a single place.

The great thing about mixing low voltage electricity and solar power is that provides a bit more flexibility to position outside LED lights exactly where you want in your garden without necessarily having to wire up the whole garden.

So there you have it: the perfect complement to home LED lighting – outdoor LED lighting.

6 comments:

  1. Hi,
    Thanks for sharing such a wonderful post.I read it and enjoy it.It is very entertaining.The use low voltage garden lighting is very safe.The application describes in it is good.

    Done a great Job............Thanks once again.........

    ReplyDelete
  2. Hi, im trying to fine some water save lights for my water features, they will need to be completely water proof because i want to place them at the bottom of the feature is this possible?

    ReplyDelete
  3. led pond lights very nice blog you have written dear author i like your blog about led technology so carry on dear for further improvement

    ReplyDelete
  4. Hi,

    The LED lights have replaced light bulbs and they are being used in commercial as well as residential premises. LED is defined as a semiconductor, which has the capabilities of emitting light with the aid of electric current.Thank you.

    Explosion proof light fixtures




    ReplyDelete
  5. HI!
    This LED garden light has beautiful!

    Not only long life LED lamps, energy-saving and environmental protection shows more advantages.

    ReplyDelete
  6. Thank you for explaining the difference between LED Outdoor Lights and Conventional Outdoor Lighting.

    flood light fixtures

    ReplyDelete

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