According to ASHRAE Standard 90.1-2010 <mandatory prescription 9.4.1.3 Parking Garage Lighting Control>, “lighting shall be controlled by one or more devices that automatically reduce lighting power of each luminaries by a minimum of 30% when there is no activity detected within a lighting zone for no more than 30 minutes”. As it is not acceptable to turn-off all luminaries during opening-hours in car parks due to security and safety reasons, this requirement implies the installation of dimmable luminaries - which is expensive.
The same energy efficiency level can be achieved with the following less expensive solution: occupancy sensors automatically shutting-off one-third of the lamps <33% energy saving> when there is no activity detected for no more than 30 minutes and time-clock control for the remaining two-thirds of the lamps. If lamps controlled by occupancy sensors are evenly distributed within the zone, lighting quality and energy efficiency will be equivalent to the solution prescribed by ASHRAE with lower initial investment.
Do you think that this is an acceptable solution for a LEED project to comply with this requirement?
