Bright Ideas Lighting Co.

My photo Boise lighting maintenance and energy efficient lighting upgrades

Monday, March 28, 2011

pulse-start metal halide lighting

There are two types of metal halide light bulbs - probe start and pulse start
Metal halide light bulbs are used in exterior lighting (parking lot lights, street lights, wallpacks, many exterior lights).   They fall under a type of lighting called HID or high intensity discharge lighting, which includes metal halide, high pressure sodium, and mercury vapor. 

Lower wattage metal halide light bulbs have always been pulse-start.  Only recently have higher wattage bulbs (150 watt and above) become available in pulse-start.

The higher wattage probe-start metal halide fixtures are slowly being phased out.  Per the Energy Independence and Security Act of 2007 new fixtures between 150-500 watt can no longer contain probe-start metal halide ballasts

Pulse start metal halide is superior in quality and performance compared to traditional metal halide lamps which use probe start technology. It optimizes the start up process and evenly distributes heat throughout the lamp. The noticeable benefits are faster start-up time, more energy efficiency, better lumen maintenance and longer life. 

Probe start metal halide lamps use three electrodes in the arc tube to start the lamp: one starter electrode and two operating electrodes. The starter electrode creates a discharge across from an operating electrode. The electrons discharged jumps through the small gap between these two electrodes to start the lamp. A bi-metal switch disconnects the starter electrode from the circuit after the lamp is started. Every start-up of the lamp causes tungsten from the electrodes to sputter and stain the arc tube wall. This cause lumen depreciation which means the light output of the lamp decreases as it is operated. Over time the arc tube wall darkens and reduces the performance of the lamp.

This weakness in probe start metal halide lamps is resolved in the redesign of the lamp into using pulse start technology. Pulse start metal halide lamps use a high voltage ignitor and the ballast to create a series of high voltage pulses which start the lamp. The ignitor reduces the sputtering of tungsten as it heats up electrodes faster in the start-up process. It also allows the reduction of the pinch or seal area at the end of the arc tube thereby reducing heat loss and warm-up time. The immediate benefit of this redesign is higher lumen maintenance which means lamps can provide sufficient illumination and operate for a longer period of time before needing replacement.

The development of the pulse start technology increased lamp life and energy efficiency comparable to high pressure sodium lamps. In addition, it also produces desirable color characteristics.  The extended life of the pulse-start metal halide bulbs will reduce long term lighting maintenance costs

Pulse-start metal halide lamps are now available in a 5000 kelvin color, with a color rendering index of over 90.  This makes pulse-start metal halide an attractive lighting retrofit to both high pressure sodium lighting and traditional probe-start metal halide lamps.

Traditional probe start metal halide ballasts run using electromagnetic ballasts.  While many pulse-start lights also run off electromagnetic ballasts, they are more efficient, and there are some electronic ballasts available for pulse-start metal halide lights.  The electronic ballasts available today are typically only available for the wattage 150 and lower, but higher wattage electronic ballasts are expected to come on the market soon.

In Idaho there are currently incentives from Idaho Power for retrofitting old probe-start metal halide fixtures to pulse-start.  

Pulse-start technology is superior to probe-start lamps in almost every measurable way – longer life, better lumen maintenance, faster start up time, greater lumens per watt.  

At Bright Ideas Lighting Co in Boise Idaho we are your experts in lighting retrofits of all types including pulse-start metal halide.  Call us at 208-378-1889

Tuesday, March 8, 2011

8 foot light fixture upgrade

Recently we had a commercial lighting upgrade project in Boise, Idaho where the customer had 8' T12 fixtures that each had 4 light bulbs in them.  They were big fixtures that looked very dated and they were not very energy efficient.    Each fixture was consuming 276 watts and not producing adequate light.

We looked at a couple of different options and decided that it was not worth it to attempt to retrofit the old fixture to something more energy efficient like T8 8' lamps.  

The better approach was to scrap the old fixture entirely and use a new 8' fixture with tandem 4' T8 light bulbs.  The 4' T8 bulbs last longer than the 8' lamps and are much more energy efficient.  

We used high performance ballasts and high lumen T8 light bulbs.  The new fixtures use 110 watts and produce more light than the old fixtures.  

Also the light quality is better.  The old 8' T12 bulbs had a color rendering index of only 60, while the new T8 4' bulbs have a CRI of 83. 

The old T12 8' light bulbs only had a rated life time of 12,000 hours, while the new high performance T8 light bulbs have a rated life of 24,000 hours.

By using the energy saving fixtures and high performance bulbs and ballasts we were able to get the customer Idaho Power rebates that paid for approximately 70 percent of total project costs. 

The energy savings on each fixture is estimated at approximately $37 per year.   The energy savings in the first year is more than the after rebate cost of each fixture.  

Bright Ideas Lighting Co also warrantied all the bulbs and ballasts on this job for 2 years, thus eliminating lighting maintenance costs!

It is important when doing commercial lighting projects like this to make use you use a licensed electrical contractor who has experience in lighting upgrades.