On the case... a forensic investigation
Wednesday, October 3, 2012 at 10:19AM Not a crime scene, but certainly a case of fantastic forensic engineering work.
Hiram College completed a renovation of the dining/multi-purpose facility. Facilities staff noticed the compact fluorescent lamps (cfl) were not illuminated to full brightness. In preparation for a campus meeting, an electrical contractor was brought in to troubleshoot the problem. After checking the wiring for ground faults and replacing lamps, the problem persisted.
Tim Pool, PE, RCDD - Director of Engineering and a licensed electrical safety inspector - was called to assist the contractor. Working with our lighting designer, Ardra Zinkon and the fixture manufacturer, the team eliminated any lamp or ballast problems with the fixtures. On a lift inspecting fixtures, Tim noticed a cool draft of air coming from the plenum space, flowing out of the fixture housings. CFLs lose efficiency in cold conditions, providing lower illumination output. To test this, Tim used a piece of plastic wrap from the kitchen to cover the opening on the fixture housing, forcing the heat from the lamp to remain in the fixture and preventing the cold air from entering. The lamp went to full illumination almost instantly.
It was determined that the kitchen hood exhaust combined with the make-up air unit was under pressurizing the main space and cold air from the air plenum was being dragged across the lamp causing a chill to the lamp envelope and thus not allowing the lamp to burn at full brightness. The College hired an air balancer to adjust air flow and the pressurization between the spaces was normalized.
The solution we developed required an out-of-the box approach to problem solving that crossed disciplines. Who would’ve thought a piece of plastic wrap could be the primary tool to solve an engineering dilemma?
