Indoor Lightings for High-end Commercial Building
This is a lighting reformation project t for a high-end commercial building located in the financial centre in town. It involved replacement of traditional light fitting for lift lobby, corridor, public toilet, tubular troffer and lift cabin illumination, etc.
The contents of this webpage contains analysis of the existing luminaires and the proposed LED replacement. It includes luminous compatibility and power saving before and after the proposed replacement for project evaluation purposes.
1.00 Project Outline
1.01 General
This project is mainly referred to the replacement of LED luminaires from level 10 to 30 which include:
(a) Passenger lift lobby lightings | Total 168 units of 5 inches recessed downlight fitted with 1 x 18W CFL would be replaced by 9W LED recessed downlight without modification of the existing cut-out of the ceiling board. |
(b) Main corridor lightings | There are three types of fluorescent troffer proposed for replacement of LED luminaires, namely · Total 142 units of 36W fluorescent tube fitted to 71 sets of twin-tube recessed troffer may be replaced by 20W tubular LED lamps; · Total 82 units of 36W fluorescent lamp together with emergency battery pack fitted to 42 sets of twin-tube recessed troffer may be replaced by 20W tubular LED lamps together with DENKO L1330 battery pack (TUC/PSB certified model); · Total 4 units of 18W fluorescent lamps fitted to 2 sets of recessed troffer may be replaced by 10W tubular LED lamp. |
(c) Public toilets | Total 179 units of 5 inches recessed downlight fitted with 1 x 18W CFL would be replaced by 9W LED recessed downlight without modification of the existing cut-out of the ceiling board. |
(d) Fireman’s lift | Total 42 units of 5 inches recessed downlight fitted with 1 x 18W CFL would be replaced by 9W LED recessed downlight without modification of the existing cut-out of the ceiling board. |
1.02 Lift lobby lightings
Both passenger and fireman lift lobbies as well as public washroom are uniformly configured with 5 inches recessed downlight fitted with 1 x 18W CFL lamp of E27 base. According to the site survey, the plastic trim and frameworks of the existing fixture are mostly aged and not recommended for reused. In this respect, 9 watts LED recessed downlight with 120mm cut-out size are recommended as replacement that approximately 56% saving of electrical power could be expected.
1.03 Corridor lightings
Generally, there are three types of recessed troffer being configured for corridor, namely
- 71 sets of 4 feet twin-tube standard fluorescent troffer;
- 41 sets of 4 feet twin-tube fluorescent troffer fitted with 2 hours battery pack, and
- 2 sets of 2 feet twin-tube standard fluorescent troffer.
2.00 Luminous compatibility
- 18W CFL Recessed downlights
The existing light source of recessed downlights are uniformly fitted with 1 x 18W Osram Delux Superstar CFL (2900K). It could be simply replaced by NOVETE® 510B slim-line recessed LED downlight. A mock-up sample had been fitted at site for evaluation purposes. The table below exhibits the basic data showing the luminous compatibility:
Basic Data | 51048-115W09K3 | 1 x 18W CFL | LED advantages |
System power per lamp | 9.47W | 21.18W | 55.29% lower |
Rated luminous efficacy per lamp | 900 lumen | 946 lumen | 4.86% lower |
Luminous efficiency per lamp | 810 lumen | 568 lumen | 42.61% higher |
Color rendering index | CRI=85 | CRI=82 | Higher by 3.53 |
Life span | >30000 hours | ≈ 4000 hours | 7.5 times longer |
Warranty | 2 years | NIL | Zero maintenance |
2.02 4 feet twin-tube fluorescent recessed troffer
Generally, fluorescent lamps could be simply replaced by NOVETE® 20W tubular LED lamps on one-to-one replacement basis. Simply remove the starter and fit the tubular LED lamp to the existing T8 holders provided by the fixture to accomplish the installation. The table below exhibits the basic technical data of fluorescent and tubular LED lamp for comparison.
Basic Data | NOVETE® 20W D83100S-W20 | T8 36W fluorescent | LED advantages |
System power per lamp | 21.00W | 42.35W | 50.41% lower |
Luminous efficacy per lamp | 2000 lumen | 2300 lumen | 28% lower |
Luminous efficiency per lamp | 1960 lumen | 1265 lumen | 28% higher |
Life span | >50000 hours | ≈ 4000 hours | 12.5 times longer |
Warranty | 2 years | NIL | Zero maintenance |
3.00 Energy saving evaluation
3.01 Operation schedule
According to the MCST directive, half of the public area lighting within the building are operating 24 hours. That means to say the operation hour insofar as this project is concerned may be scheduled for an average of 18 hours daily throughout the year.
3.02 The proposed replacement
By scrutinizing the finding of the existing lighting, essentially three types of luminaire would be required for replacement, namely
[a] 5” 18W CFL recessed downlight (2900K)
· Passenger lift lobby | 168 units |
· Public washroom | 179 units |
· Fireman’s lift | 42 units |
TOTAL | 389 units |
[b] 4 feet twin-tube 2 x 36W fluorescent troffer
· Troffer with standard feature | 71 units | 142 tubes |
· Troffer with battery pack | 41 units | 82 tubes |
TOTAL | 112 units | 224 tubes |
[c] 2 feet twin-tube 2 x 18W fluorescent troffer
· Troffer with standard feature | 2 units | 4 tubes |
This luminaire may be omitted as it is insignificant insofar as this project is concerned.
3.03 Power consumption of 5” recessed downlight
Total 389 units of NOVETE® 51048-115W09K3 compact LED recessed downlight is proposed for replacement same quantity of 1 x 18W CFL downlights (see section 4.02(a) above) .
Basic data | 1 x 18W CFL | |
Total quantity of lamps | 389 units | |
System power per lamp | 9.47W | 21.18W |
Operation hour per annum (see section 4.01) | 6570 hours (365 days @18 hour daily) | |
Annual power consumption | 24202.76kW | 54130.36kW |
Saving of electrical power per annum | 29927.60kW (55.29%) | |
3.04 Power consumption of 4 feet twin-tube troffer
It is proposed that the 20W tubular LED lamp (model #D83100S-W20K5) may be used for one-to-one replacement of 36W fluorescent lamp currently fitted to the 112 units of twin-tube troffer (see section 4.02[b] above). Simply disable the fluorescent lamp starter and positioning the tubular LED lamp to the existing T8 holders without going through the hassle of re-wiring works.
Basic data | 20W tubular LED | 36W fluorescent lamp |
Total quantity of lamps | 224 units | |
System power per lamp | 21.00W | 42.35W |
Operation hour per annum (see section 4.01) | 6570 hours (365 days @18 hour daily) | |
Annual power consumption | 30905.28kW | 62325.65kW |
Saving of electrical power per annum | 31420.37kW (50.41%) | |
4.0 Payback of investment
Obviously, there are two basic elements for justifying the payback of investment, i.e. (a) saving of power consumption and (b) cost of maintenance.
4.01 Capital expenditure
For the purposes of this project, the following luminaires may be put up for bidding:
[a] 398 units of 9W LED recessed downlight of ≥850 lumen each (PF=0.95) for replacement of 1 x 18W CFL 5 inches recessed downlight for the following areas: | ||
· Passenger’s lift lobby | 168 units | |
· Public washroom | 179 units | |
· Fireman’s lift lobby | 42 units | |
[b] 224 units of 4 feet (1.2meter) 20W tubular LED lamps of ≥1800 lumen each (PF=0.95) for replacement of 2 x 36W T8 fluorescent lamp fitted in the existing 4 feet recessed troffer | ||
· 4 feet troffer with standard configuration | 142 units | |
· 4 feet troffer configure with battery pack | 82 units | |
[c] 41 units of emergency battery pack with 2 hours rated duration of TUV/PSB approved type. | ||
[d] 4 units of 2 feet (0.6meter) 10W tubular LED Lamp of ≥550 lumen each (PF0.95) for replacement of 2 x 18W fluorescent lamp fitted in the existing 2 feet recessed troffer | ||
4.02 Saving of electrical power
Total 61347.97kW of electrical power saving could be expected after the replacement, which include
· Saving after replacement of LED recessed downlight | 29927.60kW |
· Saving after replacement of tubular LED lamp | 31420.37kW |
TOTAL SAVING OF THE PROJECT PER ANNUM | 61347.97kW |
Further energy saving measure would be possible if half of the luminaires are configured with NOVETE® microwave dimming sensor (model #TR-D811). The dimming device could is programmable. Luminance of luminaires may be reduced by 50% if no moving objects being detected within the coverage area of approximately 5 meters radius.
4.03 Saving of maintenance cost
The warranty period provided by the LED lighting supplier will be two years from date of completion for replacement. Therefore, it is suggested to set two years as maintenance cycle. In this respect, there would be zero cost incur for repair and replacement of LED light source. Whereas, the following assumption may be made for maintenance cost projection of the existing light source, which include:
- 18W CFL: The life span could be as short as 6000 hours if it is frequently turn-on and turn-off. Practically, lamp of this kind may have to be replaced minimum once in a year. The cost of maintenance in this respect may be projected @$6.00 per units, thus a budget of $4,668 may have to be provided for the repair and replacement during the maintenance cycle.
- T8 36W fluorescent tube: It usually requires replacement after 3000~4000 hours due to either quick attenuation or damage of the built-in filament (black end of tube). Thus, it may cost approximately $15.00 per tube within the maintenance cycle inclusive of manpower cost. In this case, the cost of maintenance relating to T8 fluorescent tube may be project for an estimated total of $3,360 for the total of 224 units of tubes within the maintenance cycle of two years.
- In conclusion, the cost of maintenance may be projected approximately $8,136 during the maintenance cycle for the purposes of justifying the investment.