A study was proposed by our field engineer modifying a conventional 1x11W CFL mirror optic fitting to LED using 36 nos.
0.2W (SMD 2835) strip LEDs (white) that was procured from open market.
The payback calculation for the same is shown below:
** Note: Since the modification was done by the maintenance staff at site no separate labour cost is added.
Conclusion:
1. Partial replacement (in group of 3) is possible in strip LED whereas CFL needs total replacement.
Kindly furnish your views.
0.2W (SMD 2835) strip LEDs (white) that was procured from open market.
The payback calculation for the same is shown below:
Details | 11 W | 36 x 0.2 W | |||
Type of lamp used | CFL | Strip LED | |||
Cost of modification using 36 x 0.2W strip | |||||
LEDs including LED driver ** (L) | - | 136 | |||
No. of Fittings | 1 | 1 | |||
Wattage (W) | 11 | 7.2 | |||
Operating Hours/ day (h) | 14 | 14 | |||
KWH per day | 0.154 | 0.1008 | |||
KWH per year for 285 days usage | 44 | 29 | |||
Cost per KWH (Rs.) | 8.4 | 8.4 | |||
Energy Cost Per Year (Rs.) | 370 | 244 | |||
Lamp Replacement Cost (Rs.) | 70 | 0 | |||
Total | 440 | 244 | |||
Annual Savings per fitting | 196 | ||||
No. of fittings that can be modified | 66 | ||||
Total savings per year | 12936 | ||||
Investment (L x n) | - | 8976 | |||
Payback Period | 0.69 | years | |||
ie., | 8 | months |
** Note: Since the modification was done by the maintenance staff at site no separate labour cost is added.
Conclusion:
- The average service life of CFL is about 8000-12000 hours. As far as 0.2W LED is concerned, the manufacturer claims that it is more than 30000 hours.
1. Partial replacement (in group of 3) is possible in strip LED whereas CFL needs total replacement.
- The average LUX measured (@1m above floor level) was 43 for CFL lamp while for this modified LED fixture it is 30.
- However, in locations such as restrooms, Toilet lobbies, Fire escape staircase, basement parking areas and all Lift lobbies (except CCTV covered areas) where the lumen requirement is not so critical, this modification can be done.
- To assess the reliability of the strip LED, it's driver and the modification work itself, a reasonable observation period of about 3 months may be required.
- A study on similar lines will be conducted on 2x11W CFL luminaire also.
Kindly furnish your views.