Switching to Low Voltage Landscape Lighting – Why it Makes Sense.
Lower Energy Cost and Better Illumination than 120-Volt Lighting.
Author: Steve Parrott (Cast Lighting)
A Low Voltage Landscape Lighting System consumes about one-third the energy of a 120-volt security lighting system.
Light Efficacy : When discussing energy consumption in lighting, the term ‘light efficacy’ is often used. This refers to the amount of light (lumens) produced by a unit of energy (watt). ‘Lumens per watt’ is, therefore, the value used to compare how different light sources consume energy.
Of the types of light sources used in outdoor residential lighting, standard 120-volt incandescent lighting has a very low efficacy (about 10 lumens/watt) while 12-volt tungsten halogen lamps have about a 50% greater efficacy (about 15 lumens/watt).
This represents an energy savings of one-third based on the better efficacy of low voltage lamps. The following points add additional savings.
Greater Selection of Low Wattage Lamps: Typical 120-volt outdoor security lighting uses PAR-type flood lamps rated at between 100 and 250 watts. Even lamps used at entry ways and lamp posts are typically between 40 and 60 watts. Compare this to low voltage lighting, where the most effective lamps are between 10 and 35 watts. The availability of these highly efficient low wattage lamps gives the lighting designer great flexibility in design while maintaining energy efficiency.
More Controlled Light Spread and Direction: While 120-volt fixtures are typically designed to flood light in all directions, low voltage fixtures are designed for precise control of the light beam. Instead of wasting light energy, the designer directs the light where it is needed.
Better Control via Timers and Photocells: All low voltage landscape lighting systems are designed to be controlled by timers and photocells. These units can be set to operate lighting fixtures for the precise amount of time needed, rather than operating all night.
Better Safety and Security: Typical 120-volt flood lighting creates pools of extremely bright light while leaving other areas in complete darkness. Low voltage lighting operates on a better principle – the selective low level illumination of various areas throughout the property. This eliminates shadowed areas where prowlers may lurk.
Less Light Trespass: Because the illumination from 120-volt lighting is so poorly controlled, this light can shine into neighboring properties (light trespass). Beyond being an annoyance, many communities have adopted ordinances against this. Low voltage lighting fixtures are designed to precisely control the spread of light.
Better Aesthetics: Perhaps the most compelling reason for switching to low voltage lighting is for its potential to truly transform the homeowner’s nighttime experience.
A talented lighting designer selectively reveals the natural beauty of the landscape and creates beauty through patterns of shadow and light. This is only possible through the use of low voltage lighting.