- Removed 8 lamps from the wall sconces: 8*13W each = 104W
- I removed an extra fixture in the back: 2*13W lamps = 26W
- I removed an extra fixture in the basement: 2*13W lamps = 26W
- Replaced a 3 lamp fixture with the extra 2 lamp fixture: 1*13W lamp = 13W
- Replaced any 18W lamps found with the 13W: 6*(18W-13W) = 30W
- Total wattage reduction of: 199W or 0.199kW.
- These lights run 24hr/day/365days/year: 8760 hours
- Total reduction in consumption is 0.199kW * 8760hours = 1743kWH
- Based on the average of $0.09/kWH we will save $156.89/yr on our utility bill. *Note: These are simple calcs and do not address ballast efficiency or consumption.
Sunday, April 17, 2011
De-Lamping: Bringing work home
It's another weekend and I brought some work home with me again. Our condo building has two stairwells, front and back, that have a ceiling fixture at every landing and a wall sconce between levels. These lights are on 24 hours a day, 7 days a week, 52 weeks a year. Being an engineer that works on projects to use controls to reduce energy, this drives me crazy. We also perform energy audits for clients. We walk around looking at things like how their mechanical systems are functioning and recommend updates. Lighting is a great place to save money. I do lighting surveys where you count lamps and fixtures, take light level readings, and find smart ways to reduce energy. Our home and the building we live in is not immune to these efforts. I tried not to, but I brought more work home with me. Why not. My skills can be used to hopefully trim a few bucks off our condo associations operating expenses. We recently updated old busted fixtures with three CFL lamps on both the walls and ceilings to two lamp fixtures. However, I felt there was still more that could be done. I had decided to de-lamp the wall sconces since there was adequate light in the stair with one lamp. Some of the lamps were already burned out, so I got an idea of lighting levels in the space. Most often people just remove a lamp and move on. You can see in the picture this would not be acceptable. The light is clearly coming from one side of the fixture and it gives an uneven bright spot. As much as I want to save energy, this would drive me crazy. So I did some investigating. Turns out I was in luck. Taking the diffuser (glass piece) off the fixture it became apparent I had two lamp holders and two ballasts. They were all bolted into place on the flat metal back. I decided I would remove one ballast and lamp holder. I could then relocate the remaining one into the center of the fixture. Take a look at behind the glass before.....