At first glance, LED technology appears to be very friendly with dimming control, with dimmable integrated LED lamps available. However, the given integrated lamp must be rated as compatible with the given line-voltage dimmer. This whitepaper describes current LED dimming issues and offers application guidance to avoid unwanted performance.
Researchers at the National Research Council Canada – Institute for Research in Construction (NRC-IRC) conducted a study to determine how far, how fast and over what period lighting can be dimmed before occupants notice and are adversely affected. The results suggest a role for dimmable lighting in demand response programs.
Green construction codes and standards are beginning to emerge on the national code stage. The standards go beyond energy standards such as 90.1 and the International Energy Conservation Code (IECC) to cover additional areas such as site sustainability, water efficiency, indoor environmental quality and materials and resources. The first is ASHRAE Standard 189.1, Standard for the Design of High-Performance, Green Buildings Except Low-Rise Residential Buildings, published by ASHRAE in January 2010 in conjunction with the USGBC and the Illuminating Engineering Society.
This construction outlook reviews the year’s topline construction numbers, examines the directions that leading construction and electrical industry indicators are pointing, and provides a summary of the latest AIA Consensus Construction Forecast for 2010.
Daylight harvesting’s value proposition is fairly simple: As daylight levels increase in a space, electric light levels can be automatically reduced to maintain a target task light level and save energy. All automatic daylight harvesting control systems need a device that can measure light levels and signal a controller to dim or switch the lights in response to daylight contribution. This device is called a photosensor. The photosensor is a small device that can include a light-sensitive photocell, input optics and an electronic circuit used to convert the photocell signal into an output control signal, all within a housing and with mounting hardware.
Here are 15 examples of LED lighting in application, with a brief description of the controls strategy used to achieve the desired results.
In July 2009, the Department of Energy issued new energy efficiency standards for commercial general-service fluorescent lamps and incandescent (and halogen) reflector lamps. The new rules take effect July 14, 2012 and will basically eliminate products with the lowest efficiency and lowest cost. In the case of fluorescent lamps, equivalent-performance products are readily available, such as T8 lamps, and the market is expected to shift to that and other technologies. In the case of incandescent reflector lamps, only a few equivalent-performance products are readily available that comply, such as infrared-coated halogen lamps, and manufacturers are expected to develop new substitutes.
While general-service incandescent lamps have received the most attention in media coverage of the Energy Independence and Security Act (EISA) of 2007, with provisions beginning to take effect in 2012, many popular incandescent reflector lamps are being outlawed this month.
An additional 30-80 percent energy savings using occupancy sensors and 10-30 percent savings using daylighting controls can be achieved in a hi-bay fluorescent upgrade.
Building automation systems (BAS) provide automatic control of electrical loads, such as HVAC, lighting and electric motors, and functions not related to energy management, such as security and fire safety systems. Energy management systems (EMS) provide automatic control of electrical loads to manage energy consumption either as a stand-alone system or as part of a BAS. While EMS may be capable of provide automatic switching of large blocks of lighting loads, only a fraction of installed EMS actually control lighting, according to the U.S. Department of Energy (2003). EMS that control HVAC are installed in about 5.6% of commercial buildings representing 24% of commercial floorspace—most commonly >100,000 sq.ft. office and education buildings—while EMS that control lighting are installed in 1.3% of buildings covering 7.4% of floorspace.