Thanks in advance for any insight. I have a two part question –
1. I want to confirm that all site lighting within the LEED boundary can and should be included in the energy model. Appendix G specifically states parking garages and building facades but does not mention any other lighting included under 90.1 -2007 Table 9.4.5 LPD for Building Exteriors.
I've done it in the past, but the savings is usually small and has little overall effect, but now I'll come across a situation where it could be substantial.
2. In preliminary scoping we have a project that consist of 15,000 sq building with ~ 125,000 sq ft of parking and drives (large overall site with the building set back substantially from the main access point due to function). Utilizing the LED fixtures the preliminary lighting design has shown a substantial decrease in the LPD from the allowed 0.15 w/sf. Given the size of the parking/drive compared to the building and the 24-hr nature of the facility the baseline site lighting is almost as much as the base-line building lighting and is resulting in an estimated ~ 25% energy savings for the building by itself.
Is it reasonable to expect to be able to claim this entire savings for EA credit? It ‘feels’ like I’m gaming the system, but the actual energy use should be realized. am I missing something?
Thanks,
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5868 thumbs up
June 25, 2014 - 10:43 am
1. Yes all the site lighting must be included. The credit language states that all energy in and associated with the project must be included.
2. It is not unusual for savings of 75% or more in exterior lighting when using LEDs. You can legitimately claim large savings. One thing you said struck me as odd - the 24 hour nature of the facility should have almost nothing to do with the energy use. Section 9.4.1.3 requires that the exterior lights are off during the day in most cases.
William Holub
Mead & HuntJune 25, 2014 - 8:22 pm
Marcus,
Thank you for the response. I had always assumed that it was expected to include all site lighting, but when I went to double check it was not as clear as I had anticipated - specifically note parking garages and building facades as opposed to "all" site lighting.
It's also good to hear that we don't appear to be in unknown territory with the savings. Our case might just be a case of the large amount of site parking and drives, driving the site lighting to a larger portion of the overall use.
As for the 24 hr comment, it was meant to say the lights were on full throughout the night for security, rather than at reduced levels after midnight which can often be the case once building are closed. Consequently, we are working at 10 -12 hrs a day of operation for ~ 4,000 FLH compared to retail space which may have closer to 2,000 FLH for the parking lot lighting.
Thank you again, I appreciate the feedback and hopefully this helps some one else as well.