Bulbs, Switches & Wiring

Light Colours & Bulbs

• A light source creates a pool of light, but it also has a secondary effect, which is produced when the light reflects off surfaces. Consider the lighting effect that you are trying to create, bearing in mind the surfaces in the area. Light hitting a highly polished light coloured surface will reflect light back very well, whilst light directed to a matt dark surface will be almost totally absorbed.
• Therefore if you are lighting a room that has dark matt painted walls and dark furnishings and carpet, you will need to add more light to achieve a well illuminated space, likewise a room with high gloss light coloured paint, will require less light to illuminate the same space, due to the reflective capabilities.
• You can create atmosphere in a room by combining types of light, use direct lighting for reading, highlighters to create pools of light to accent pictures or art work and occasional lighting to create cosy areas within the room.
• When choosing the type of light you wish to use, it is necessary to know what type of light is emitted from which lamps.
• Tungsten lighting produces a warm comfortable light, which is ideal for areas to relax in.
• Halogen lighting produces a much whiter crisp light, closer to sunlight, which is especially ideal for kitchens and bathrooms, but can be used in all areas. Halogen lamps also show up true colours, which make them ideal for artwork, craft and reading tasks.
• Low voltage halogen lighting in the dichroic form, produces 30% more light than the mains voltage equivalent and produces a nicer, warmer, ambience of light. When there is an option choose low voltage for performance and ambience.
• Fluorescent lighting can be whiter than tungsten, but not as white or crisp as halogen, but fluorescent light, unlike tungsten and halogen, starts to deteriorate in colour and brightness from the first day of it’s operation. If you want fluorescent lighting for a particular application and you want whiter than white, try to obtain white tubes with a high phosphorous content.
• LED lighting however, is the light of choice, due to its low running costs and longevity, LED lighting can be used for general lighting, marker lighting, feature lighting, ambient mood and task lighting. LED technology is moving fast and is the light source of the present, but you need to ensure that any LED choice is going to give you the desired amount of illumination that you require. The measurement of the light output is denoted in Lumens and the colour temperature of the lamp is measured in degrees Kelvin, the colour temperature of the light gives an indication of the warmth or coolness of the light source, 3000K to 4000K is a warm light suitable for a lounge area, 5000K to 6000K is a cool light more suited to a study or a working environment, where a brighter light is required.

How much light do you need?

• We all require different levels of light to perform different tasks in the home.
• Determining the correct light level is not an easy task, but if you use a simple  “Rule of Thumb” calculation, it is possible to arrive at a figure that can be used as a guide.
• Measure the area of your room in square metres and multiply this figure by; 25 for standard tungsten lighting, 15 for halogen lighting, or 19 for compact fluorescent lighting.
• Example for a Living Room
• If your room measures 26 square metres and you wish to use tungsten lighting, you would require a total wattage of 650wts; you can achieve this by using:

• For Halogen lighting you would use the same calculation, but use the figure 15 as your multiplier.
• For LED lighting the term watts is not used for light output (but is used for electricity consumption) , for LED the unit of light output is measured in Lumens and the unit of light intensity is measured in degrees Kelvin, the range of choice of the degrees Kelvin allows you to choose the colour temperature of the light source, varying from different ranges of warm white to cool white, the higher the number the cooler the light source.
• As a "Rule of Thumb" you can divide the number of Lumens by 10 to arrive at the approximate equivalent number of watts, but the technologies of the different light sources can vary.
• The above can be used as a guide, but some people require more light and some less, it is often better to over estimate the amount of light required by up to 25% and fit a dimmer to give you the most flexibility.

Dimmers

• All tungsten and most halogen (low voltage or mains voltage) domestic light fittings can be dimmed with the correct dimmer.
• A Dimmer unit has to be compatible with: The total wattage and type of lamps that it has to control. If you exceed the maximum wattage capacity, the dimmer will fail.
• All Dimmers have a maximum wattage capacity and a comfortable working range of minimum to maximum, which varies amongst manufacturers. It is important to select the correct dimmer for the task.
• All Dimmers used on LED light sources should have an operating range starting at the minimum of zero.
• All LED Dimmers should only be used with dimmable light sources.
• All Dimmers must to compatible with the electrical components of the light source and fitting.

What Type of Dimmer to use

• For normal tungsten Lighting: Use a Resistive Dimmer
• For LED Lighting: Use a Resistive Dimmer that has a dimming range that starts at zero and only use the dimmer on dimmable LED light sources.
• For mains voltage halogen lighting: Use a Resistive Dimmer, (but read the Dimmer manufacturer’s instruction leaflet, some manufacturers state that: When using their dimmers with mains voltage halogen lamps, you will need to down rate the maximum wattage capacity of their dimmer by a certain percentage).
• For Low voltage lighting with a Leading Edge Electronic Transformer: Use a Leading Edge Resistive Dimmer.
• For Low voltage lighting with a Trailing Edge Electronic Transformer: Use a Trailing Edge / Phase Lagging Resistive Dimmer.
• For Low Voltage lighting with a Wire Wound Transformer: Use an Inductive Dimmer.
• All Dimmers will produce some buzzing noise, either at the dimmer or at the light fitting, this is usual, but should not be audible so as to cause annoyance to someone with a normal quality of hearing.
• If the correct dimmer has been installed and you experience a resonating noise from the light fitting, one should first check to ensure that the fitting has been securely mounted to the ceiling or wall and that there are no loose components on the light fitting, such as loose glass shades, as the resonance will cause these to vibrate.
• Excessive noise and / or pulsations indicate a non compatible dimmer.
• Beware of Dimmers claiming to be suitable for all types of lighting

Lighting your Home

• Use separate switching circuits in all rooms, where you can, to enable you to separate different types of lighting, levels of light and zones within a room, to obtain maximum comfort and diversity of light for your lighting themes.
• Example for a Living Room
• Use a four-gang lighting switch on the wall to control:
  • 1. Central ceiling light; main source of illumination.
  • 2. Uplighter wall lights; mood lighting.
  • 3. Table and Floor lamps; occasional lighting. (Using a 5amp plug and  socket circuit).
  • 4. Recessed Floor lamps; feature lighting.