A t the heart of professional landscaping is the enjoyment of a natural setting in proximity to where we live and work. Much of this benefit is lost with today?s two-income lifestyle. The only time to enjoy being home or out on the town falls at night.
The hours we have to view outdoor amenities and landscaping is when it is dark. As William Locklin, a pioneer in low-voltage lighting puts it, "Lighting the natural visual elements of landscaping and architecture at night dramatically enhances and extends the optimum viewing hours of property"
Night lighting overcomes an objection to investing in landscaping -- lack of time to enjoy it. Nightscaping, as Locklin calls both the field and his company, is as important to the landscape contractor who installs it on his projects as to the person enjoying the end result. And, because the power source is low-voltage electricity, additional licensing and permits are usually unnecessary.
Like irrigation, another closely-linked specialty of landscape construction and maintenance, low-voltage lighting requires a core of knowledge. An understanding of electrical resistance, transformers, types and location of light fixtures, waterproof connections, and light intensity is required to successfully design and install low-voltage lighting systems. Once you acquire this knowledge, the extent to which you work with licensed electricians is no greater than that of locating and supplying power to irrigation controllers.
DESIGN
One tremendous advantage of low-voltage lighting is its flexibility. As landscapes mature, low-voltage fixtures can be relocated or adjusted without a great deal of trouble. Whether fixtures are placed on walls, suspended from trees, buried in the soil, or staked in the open, they must be located with both maintenance and light effect in mind. Access to the fixtures for cleaning, adjustment and lamp replacement is critical. If exposed to traffic and landscape maintenance equipment, the fixture should be durable and protected from tampering.
The skilled lighting designer uses a number of effects to achieve a dramatic result. Professional installations usually include a combination of effects and fixtures. Among them are:
Accenting - This technique directs beams of light to highlight particular elements of the landscape, such as a prized ornamental shrub or statue.
Downlighting - As simple as illuminating a path or walkway with low fixtures, or as complex as a floodlight mounted on a pole, building or tree, this technique lights a larger area than accenting.
Uplighting - More dramatic and the reverse of downlighting. Fixtures on the surface or well lights shine upward to highlight leaves, bark, or statues.
Silhouetting - Lights located behind and beneath a landscape feature to show the general shape or silhouette without revealing details.
Shadowing - Lights located in front and beneath a landscape feature to throw a shadow on a wall, fence or building behind the feature.
Moonlighting - A type of downlighting using soft diffused light from fixtures located in a tree or pole to resemble the glow of the moon through the plant canopy.
Grazing - This technique shines light on surfaces to reveal interesting textures, such as brick, rough wood or tree bark.
The purpose of lighting is frequently safety as well as maximizing a landscape investment. The two goals can work together to help you sell low-voltage lighting systems. For a small additional expense, you can turn your customer?s safety system into an effective landscape system. Illumination of paths, steps and walls for safety purposes can and should be balanced with the techniques listed previously to disguise the practical safety aspects of the system. Such measures might also lower or control liability insurance costs for your customers.
POWER SOURCE
The heart of a low-voltage system is the transformer that converts 110-120 line voltage to a safer 12 volts. Transformers are available in a range of sizes, generally from 100 to 600 watts. Picking the right size of transformer for a project entails adding up the wattages of all the fixtures. The sum of these fixture wattages is called the total nominal wattage. You also need to consider the power lost to the resistance of the wire based on its gauge and length. Connections are important because poor ones will sap the voltage of the transformer.
An analogy is irrigation. Each sprinkler (fixture) has an application rate (wattage). The size of the pipe (gauge) restricts the amount of water (wattage) available to the sprinklers (lamps). If too many heads (fixtures) are in a zone, the application rate (wattage) will be below design specifications and the coverage will be poor. Extremely long lengths of pipe (wire) also result in a loss of pressure because of the friction (resistance) of the inside pipe wall (wire) to the water flow (electricity). Leaks also reduce the performance of an irrigation (lighting) system.
Plan for future expansion when selecting a transformer. However, do not install a transformer that exceeds the total nominal wattage of the fixtures by more than a third. Excessive wattage can shorten the life of the lamps in the fixtures. If the transformer is too small for the TNW of the lamps, there is a good chance it will overheat and trip circuit breakers. The light(s) furthest down the wire will also be noticeably dimmer than the others.
If a customer intends to significantly expand his low-voltage lighting system in a second phase of work, you might want to recommend a two-circuit transformer. Use one circuit for the first phase and save the second circuit for the next phase.
Experienced low-voltage lighting installers will place the transformer in the middle of a chain of lights rather than on one end. Cable can also be looped to begin and end at the transformer. Pros typically avoid straight cable runs more than 100 feet long and looped runs over 150 to 200 feet. Twelve gauge double wire is standard, however 10-gauge and 8-gauge cable is handy where cable runs or fixture numbers might present resistance problems.
Low-voltage cable can be buried directly in the soil without conduit. It should be deep enough to avoid damage from traffic or maintenance equipment. Conduit or PVC pipe is recommended where surface disturbance is likely or under pavement where additional cable lines might need to be installed in the future. Waterproof connectors are strongly advised for buried cable.
CONTROLLERS
A controller can be as simple as a wall switch regulating a socket or as complex as a motion or light detector. Remote control is also available on some controllers. You might consider the possibility of hooking a lighting system into a central home or office security system.
Many controllers are a combination of a transformer and a clock timer. The customer might want the system to come on at dusk and shut off at midnight. He may also want it to come on before dawn and turn off at daybreak. You could use a light sensor to turn the system on and off. The customer is the one who will operate the system, so select controllers that are easy to understand and are accessible. Part of a professional lighting installation job is mounting the controller and/or transformer so it isn?t an eyesore and won?t be subject to vandalism or tampering.
TYPES OF FIXTURES
There are four major considerations with fixtures. The first is does the fixture provide the type of lighting effect you planned for in the design? Secondly, what type of lamp does the fixture have? Also, is the design of the fixture suitable to the customer and does it blend into the design of the landscape? Finally, is the fixture durable and relatively tamperproof?
In most cases, you will be installing a variety of fixtures on the same site. They should be compatible from both appearance and power consumption standpoints. An assortment of well-chosen fixtures is more effective than a large number of one or two types of fixtures.
Make a list of priorities for the installation, and match the fixtures to these priorities. Go through catalogs and contact a distributor who specializes in low-voltage lighting fixtures. Evaluate the fixtures you will recommend before you present the customer with your plan. Show the customer sample fixtures and photographs of the lighting effect from the them at night. Some contractors have small light systems to give customers demonstrations. All these costs must be recouped in the price of the system.
Generally, a fixture will be able to operate a range of lamps, depending upon the capacity of the system, the intensity of light desired, and the type of lamp used. Low-voltage systems use incandescent and halogen lamps. Both of these types of lamps generate large amounts of heat. Keep this in mind when locating fixtures. Avoid placing them in areas where leaf debris collects or near sensitive plants. There is a difference in the appearance of plants when they are illuminated with incandescent lamps or halogen lamps. It depends upon the effect sought by you and your customer.
Lamp life varies considerably based on conditions and power supply. When operated at the manufacturer?s rated wattage, bulbs should last 1,000 hours or more. Lamp life is shortened when wattage is above the rated level. Halogen lamps can last longer than incandescent under ideal conditions.
MAINTENANCEAn annual spring lighting system checkup is recommended. Wait for the plants to leaf out so you can evaluate whether adjustments in direction and location are needed. If you maintain the system, consider changing out all similar lamps after one or two have burned out. You don?t want to run to the job every time a lamp burns out. Information on how long the lamps burn each night is helpful in planning replacement.
Use the maintenance call to promote system expansion, controller upgrades (like light sensors), and highlighting a few dramatic landscape features. Leave behind a brochure that shows model night landscapes, extras like step lights and moonlighting, and related landscape elements, such as water features and outdoor furniture. It?s all part of landscaping. Night lighting can be a profitable added income stream.
