The general lighting of commercial buildings typically consists of light fixtures installed in multiple lamp configurations (two, three, four, six or eight). The light level in the working space will be determined by the number of lamps in the fixture, the light output of the lamps, and the spacing of the fixtures. Consequently, correction for overlighting could be made by removing lamps or changing the location and number of fixtures. It is, however, much easier to reduce the number of lamps per fixture than it is to change the spacing of the fixtures. This is called “delamping“. Delamping is a simple and inexpensive way to reduce over-illumination, save energy, and increase occupant comfort.
What are Delamping Benefits?
A growing number of businesses are taking strides to create a more healthy viewing environment for employees and visitors. From increased eye comfort to a healthier bottom line, delamping can improve life at the office for workers. Here are just a few of the reasons why business owners are strategically reducing the amount of light provided in their facilities.
— Energy Saving
Today’s businesses are more focused than ever on energy efficiency. Delamping is a great way for virtually all types of businesses to reduce energy, helping businesses lower their electric bills and bolstering eligibility for tax credits that are awarded to energy efficient businesses
— Increased Sale and Productivity
Studies show that sales and productivity increase are higher when employees are exposed to natural lighting as opposed to standard fluorescent lighting found in department stores and offices. Delamping can help bolster productivity by allowing any natural light to shine through.
— Reduced eye Discomfort
A rising number of Americans are being diagnosed with photophobia, a condition marked by eye discomfort that develops as a result of exposure to light. Overexposure to fluorescent light, LED bulbs, and glare can all worsen the effects of this condition. Delamping alleviates this discomfort by reducing the amount of light per square foot.
Common Errors During Delamping
Clearly, delamping offers many benefits. However, sometimes facility managers attempt to forge ahead with the delamping process without considering alternatives to bulb removal. In some cases, the delamping process is undertaken without examining the ballast wiring. Essentially, a person simply begins removing lamps without considering the structure of the fixture. This can cause the following problems:
— Unevenly distributed light
— Flickering among remaining lamps
— A shortened life span of the lamps that remain
One of the largest universities in Florida rolled out its energy-efficient lighting pilot project after awarding to a third-party dual-mode T8 LED tube vendor that had touted a 10-year warranty and its broad ballast compatibility. The facilities head was dumbfounded when one of three LED tubes in the fixture failed on almost all fixtures, just three weeks after the installation. The manufacturer couldn’t offer any explanation on the massive failure. So much for its 10-year warranty and ballast compatibility claims.
A closer examination of the situation revealed that the fixture had been de-lamped. The fixture used a 4-lamp ballast, and only three LED tubes were used. As a result, the 4-lamp ballast was overdriving the three LED lamps, and burned out the LED driver prematurely over a short period of time.
“The ballast-compatible LED tube (Type A or Type A+B) are known to have four disadvantages: ballast incompatibility, ballast energy consumption, and ballast maintenance cost. The fourth problem is overdrive of LED tube under de-lamping scenarios.”
— Dr. Matthew Maa, VP of Aleddra LED Lighting
Delamping Performance in Tested
To understand LED tube performance in delamped fixtures, California Lighting Technology Center (CLTC) partnered with Pacific Gas&Electric Company (PG&E) on a series of linear lamps assessments. CLTC completed photometric and electrical evaluations of 11 commercial available linear LED products and one standard linear fluorescent system, which served as the baseline. Selected products included Type A, Type B, Type C, Type AB and Type AC. The full report on this study is published by PG&E on the Emerging Technologies Coordinating Council website.
The linear fluorescent performed as expected under the delamped scenario for both the instant-start and programmed start ballasts. Input power and light output were reduced by roughly half. When operating with rapid-start ballast, which requires lamps to be wired in series, a delamped scenario does not work.
For linear LED products, delamping may or may not be suitable. Some linear LED tubes can operate in a delamped scenario, others cannot. Product literature may or may not speak to this point. Few manufacturers included delamping information on product specification sheets. CLTC strongly suggest that LED tube manufacturer should explicitly call out information on delamping and bring that information out of the footnotes and into the main body of publications.
Which is Better Delamping Way?
A delamping operation can be conducted with two general approaches, the common approach (simply but not necessarily the most effective) is to remove the appropriate number of lamps in fixtures. Hold back these lamps and keep them in stock in case any of the new lamps have premature failure, so that you have a stocked lamp that could be replaced in. In this approach you should manage these stocked lamps well.
The other approach would be the simplest. You can adjust the light to appropriate level by using our ConnSet® wire connector in related fixtures. Set and Forget until one day you need further adjusting light level, simply by using another wire connector. You don’t need keep and manage any lamp in stock.
