China
Africa
Explore chapters and articles related to this topic
Choosing Lamp Types & Sources
Published in Michael Stiller, Quality Lighting for High Performance Buildings, 2020
The term luminous efficacy as it applies to electric lighting sources refers to the amount of light energy generated per unit of electrical energy used. We usually express the luminous efficacy of a particular electric lighting source as a ratio of lumens to watts. A lumen, as you will recall from Chapter 2, is a unit of energy in the form of visible light. A watt is a unit of energy in the form of electrical current. So the higher the ratio of lumens to watts, the more efficient the source is at converting electrical energy into visible light. One of the first things to look for in a sustainable lighting source is the ability to create a lot of light with a little bit of electrical energy, or a high ratio of lumens produced to wattage used. But as we will discuss later in this section, the luminous efficacy of a source is not, by itself, a good indicator of the amount of light, or the effective lumens, a luminaire incorporating that source will actually deliver to the target area. The natural distribution of light produced by the source, and the efficiency of the luminaire in harnessing that light and projecting it to the target area, are both contributing factors. To complement luminous efficacy ratings for sources, a new metric that has been developed in the last few years is the TER, or Target Efficacy Rating (NEMA LE 6-2009), which measures the ratio of lumens emitted from a luminaire that contribute to the illumination of a target area per watt of power used.
Intelligent Lighting: Meeting Your Projects Sustainable Goals
Published in Scott C. Dunning, Albert Thumann, Efficient Lighting Applications and Case Studies, 2020
Energy Conservation: An effective sustainable lighting strategy integrates daylight design and architectural elements with electrical lighting and lighting controls to provide illumination. If this system uses the most efficient sources and luminaires currently available and these systems are designed to deliver illumination levels appropriate to the various visual tasks, then very large energy savings can be anticipated in both energy usage for illumination and energy for space cooling.1
Quantitative analysis of sustainable housing energy systems based on Estidama pearl rating system
Published in International Journal of Green Energy, 2018
Abdalla Mahmoud Salim, Saleh Abu Dabous
In term of energy performance, it is concluded that the cooling system is the main energy consumer in the domestic villa sector in Emirate of Sharjah in UAE, requiring around 90% of the total energy needs. The analysis estimated the energy saving attained through implementing sustainable cooling systems compared to the conventional ones. In the One Pearl rated villa, the selected duct split system reduced cooling energy consumption by almost 15%; in the Two Pearls rated villa, the VRF system produced 40% reduction in cooling energy consumption. Additional energy saving can be achieved by implementing sustainable lighting system. The One and Two Pearls systems reduced lighting electricity consumption by 29% and 51%, respectively. Finally, the solar water heating system showed significant saving in terms of energy consumption with a yearly reduction of 78% compared to the electric water heater.