41 LED Bulbs installed – July 2015
In July 2015, the compact fluorescent bulbs (CFLs) in 37 path-light fixtures at Coffee Creek Condos and 4 fixtures under the bridge were REPLACED with Light Emitting Diodes (LED) bulbs. These 41 fixtures operate 11 hours at night or 4015 hours per year; originally used incandescent bulbs; were upgraded to CFL bulbs; and now have LED bulbs. The following table compares the three types of 40-watt equivalence bulbs:
| Incandescent Bulbs
(originally Installed) |
Compact Fluorescent
(CFLs) |
LED bulbs
(currently installed) |
|
| Total Hours of operation/year
(41 * 11 hrs/day * 365 days/yr) |
164,615 | 164,615 | 164,615 |
| Lumens/bulb | 450 | 450 | 450 |
| Life span (average), hours | 1,200 | 8,000 | 25,000 |
| Number of bulbs changed/year | 137 | 21 | 7 |
| Watts/bulb | 40 | 12 | 6 |
| Total kwh of electricity used | 6,585 | 1975 | 988 |
| Cost/yr (at 10 cents/kwh) | $658 | $198 | $99 |
The cost per CFL bulb is about $1/bulb compared to about $5 per LED bulb. If we assume that the labor costs are $3/bulb (conservative), then the cost of replacing 21 CFL bulbs is $84/year compared to $56/year for 7 LED bulbs. Therefore, the maintenance savings are at least $28/year which when combined with the $99/year energy savings provides a total savings of $127/year.
Back about 30 years ago, 27 3-tier path-light fixtures (black, model Red-Dot cat. No. G30) were installed. Later, an additional 10 path-light fixtures were added (one 4-tier fixture and nine 3-tier fixtures). Since the black Red-Dot G30 was no longer available, green fixtures (3-tier cat. No. model Thomas & Betts Red-Dot K330) were purchased, painted black, and installed. During the recent installation of the LED bulbs, one fixture was found to be damaged and the glass protective bulb missing. After some searching an exact duplicate for the black Red-Dot G30 fixture was found at Home Depot online (http://www.homedepot.com/p/Greenfield-Weatherproof-3-Tier-Path-Light-Black-PL3TBL/202188701?keyword=pl3tbl) for $14.97, purchased and installed.
In addition to installing LED bulbs, the fixtures were cleaned and painted.
