Retrofit

Retrofitting Strategy	Installation of occupancy/motion sensor for on/off/dimming control of lighting
	Occupancy sensors can be used to operate (switch off or dim) lightings of different zones or individual lights to reduce the energy consumption of the lighting system.
	Consideration
	The amount of energy saving highly depends on the occupancy pattern of the controlled space. Care should be taken to use the lighting sources/lamps that the life expectancy of which is not adversely affected by the frequent on and off operation. The occupancy sensors should be well chosen and adjusted so that they can truly determine if the space is occupied or not. For instance, the sensors should not be affected by people passing by a transparent partition. The legislation requirement on lighting intensity especially for escape route.
	Estimated Saving
	LF_PREå(kW_LGT_i,PRENLGT_i,PREOPHR_i,PRE)yr – å(kW_LGT_i,POSTNLGT_i,POSTLF_i,POSTOPHR_i,POST)yr Where i is the effective zone of building LF_PRE = 1 for ON/OFF control under normal operating time of premises å(kW_LGT_i,PRENLGT_i,PREOPHR_i,PRE)yr = [kW_LGT_1,PRENLGT_1,PREhr₁/dayday₁/wk + …. + kW_LGT_i,PRENLGT_i,PREhr_i/dayday_i/wk]52 å(kW_LGT_i,POSTNLGT_i,POST LF_POSTOPHR_i,POST)yr = [kW_LGT_1,POSTNLGT_1,POSTLF₁* hr₁/dayday₁/wk + …. + kW_LGT_i,POSTNLGT_i,POSTLF_ihr_i/dayday_i/wk]52 LF_i = (1 – 0.33*0.33) = 0.9 for 33% of power reduction (dim-down to 50% lux level) at 33% of time as an example Please click HERE to view the list of terminology.