CIBSE L7 Standards: 4.1 Assessing Illuminance Levels
4 Results and Discussions
4.1 Assessing illuminance levels
The detailed measurements of illuminance are shown in Appendix 3.Point illuminance recorded for each of the area mentioned in this chapter is presented on the AutoCAD plans in Appendix 4.
4.1.1 Average illuminance Figure 4 1: Illuminance levels measured in different areas As illustrated in Figure 4-1, the general illuminance for the different areas in the building are satisfying the benchmarks imposed by CIBSE L7 regulations and ISO standards, (300-500 lux). Therefore light levels are meeting the legal requirements. 4.1.2 Illuminance measurement for a task/activity Figure 4 2 :Assessment of task illuminance using CIBSE L7 standards
From the bar chart Figure 4-2:
The …show more content…
Consequently, it can be seen that depending on the benchmarks levels set; illuminance levels can be compared and assessed. However it is to be noted that the illuminance levels must fulfill the minimum criteria and objective of a lighting system which is to allow the users of a space to carry out their work quickly, accurately and without any discomfort. The correct illuminance must be provided for visual comfort and thus able the users to perform their work effectively.
The benchmarks taken to design or assess any lighting system are believed to be better if most recent, recurrent and international ones are used. This ensures reliability and up to date results.
4.2 Survey analysis
The light levels for different activities were also investigated among the users through the survey conducted and it was seen that the majority of the users rated the light level for writing, reading and typing purposes as 4 and 3 respectively on a scale of 6. (See appendix 6.4). Other activities were rated as 5 out of 6 .This shows that the occupants are quite satisfied with the lighting levels even though they do not show full …show more content…
This study has identified three factors influencing the cost effectiveness of installing energy efficient lighting technology. These are (a) operating hours, (b) cost of labor (c) cost of luminaries.
The results indicate that there is a large potential to reduce the amount of electricity used by fluorescent lighting fixtures. In addition, achieving this potential would result in a substantial reduction in carbon dioxide emissions associated with the building’s electricity usage.
Using the simple payback analysis, we have found that the cost of installation of the LED system can be recovered in only 1 year which makes it a very cost effective option. This shows that LED system is indeed very benefit for commercial usage.
4.4 DIALux Simulation
The illuminance levels and patterns in the different rooms analysed are presented in appendix 7.3.
4.4.1 Comparison of measured illuminance values with DIALux simulation for LED system
Table 4 3 : comparison of measured values with simulation values
LED system Measurement values
Using luxmeter (lx) DIALux simulation values (lx)
Average illuminance Room 4 413 495 Kitchen 333
4.1 Assessing illuminance levels
The detailed measurements of illuminance are shown in Appendix 3.Point illuminance recorded for each of the area mentioned in this chapter is presented on the AutoCAD plans in Appendix 4.
4.1.1 Average illuminance Figure 4 1: Illuminance levels measured in different areas As illustrated in Figure 4-1, the general illuminance for the different areas in the building are satisfying the benchmarks imposed by CIBSE L7 regulations and ISO standards, (300-500 lux). Therefore light levels are meeting the legal requirements. 4.1.2 Illuminance measurement for a task/activity Figure 4 2 :Assessment of task illuminance using CIBSE L7 standards
From the bar chart Figure 4-2:
The …show more content…
Consequently, it can be seen that depending on the benchmarks levels set; illuminance levels can be compared and assessed. However it is to be noted that the illuminance levels must fulfill the minimum criteria and objective of a lighting system which is to allow the users of a space to carry out their work quickly, accurately and without any discomfort. The correct illuminance must be provided for visual comfort and thus able the users to perform their work effectively.
The benchmarks taken to design or assess any lighting system are believed to be better if most recent, recurrent and international ones are used. This ensures reliability and up to date results.
4.2 Survey analysis
The light levels for different activities were also investigated among the users through the survey conducted and it was seen that the majority of the users rated the light level for writing, reading and typing purposes as 4 and 3 respectively on a scale of 6. (See appendix 6.4). Other activities were rated as 5 out of 6 .This shows that the occupants are quite satisfied with the lighting levels even though they do not show full …show more content…
This study has identified three factors influencing the cost effectiveness of installing energy efficient lighting technology. These are (a) operating hours, (b) cost of labor (c) cost of luminaries.
The results indicate that there is a large potential to reduce the amount of electricity used by fluorescent lighting fixtures. In addition, achieving this potential would result in a substantial reduction in carbon dioxide emissions associated with the building’s electricity usage.
Using the simple payback analysis, we have found that the cost of installation of the LED system can be recovered in only 1 year which makes it a very cost effective option. This shows that LED system is indeed very benefit for commercial usage.
4.4 DIALux Simulation
The illuminance levels and patterns in the different rooms analysed are presented in appendix 7.3.
4.4.1 Comparison of measured illuminance values with DIALux simulation for LED system
Table 4 3 : comparison of measured values with simulation values
LED system Measurement values
Using luxmeter (lx) DIALux simulation values (lx)
Average illuminance Room 4 413 495 Kitchen 333