These are the most efficient room lights currently available. Compact-fluorescents are available in 12 volt DC versions or 120 volts AC. They are suitable when large areas need to be illuminated. Recent developments have produced more pleasing lighting colours. They do not perform well under very cold conditions.
Light Emitting Diodes (LEDs) technology has developed substantially over the last 5 years with the introduction of the White LED, producing >100 lumens per watt. LEDs sustain a long lifetime – 100,000 hours with 80% Lumen Maintenance. LEDs require low power (350-700 mAmps. They are typically configured for 12 or 24v DC to operate making them an ideal choice to use with batteries. They are not impacted by temperature (designed to withstand -40 to +85°C). They are also vibration resistant.
LEDs are most suitable for task lighting, but can be adjusted easily to provide ambient lighting. The quality of light can be adjusted to suit the environment and aesthetic preferences of the designer.
Light Up The World Foundation, Calgary, AB
Tubular skylights, or sun tunnels, are an efficient way to provide natural lighting, reducing the need for electric lighting. Generally, tubular skylights have a roof-mounted light collector and a reflective sun scoop in the rooftop assembly that directs sunlight into a highly reflective metal or plastic tube. Sunlight is then guided through the tube to a diffuser lens mounted on the interior ceiling surface. This light diffusion sets tubular skylights apart from standard skylights because it allows the light to be distributed more evenly throughout the room and reduces potential UV ray damage to interior finishes. Tubular skylights also minimize heat loss in the winter and heat gain in the summer since the system is well sealed and the rooftop solar collector has a small surface area. The performance of tubular skylights varies among brands, but tests have shown that one 13-inch tubular skylight has the light output equivalent of one 700 watt incandescent bulb in December and one 1200 watt bulb in June.