Minutes - Public Works Committee - 01/17/2012

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Case 5.3 Consider Lighting Retrofit for Parking Ramp Project Public Works Director Olson reviewed in the staff report that attached to the case are a number of options to consider, one is to perpetuate the decision that was made in 2005 to continue with the metal halide lamps. The second is switch out the metal halide lights in the new ramp with fluorescent T5 lamps and the third option is to move forward with retrofitting the existing parking facility as well as changing the design to include new lights that are fluorescent. Councilmember Elvig asked do you recall what savings were from when we first started the structure. Public Works Director Olson responded he went back through the last 12 months of electric bills and priced it out based on how much we spent on electricity on that ramp today. He stated 45% of the total cost is lighting, the remainder is the HVAC system. Councilmember Elvig asked what percentage of lighting was turned off. Public Works Director Olson responded probably one third on the outside lights but there was a building code requirement that we have to maintain a certain level of lights for emergency purposes. Leo Offerman from Connexus Energy was present and informed the Committee that what Connexus uses is the IES which is Illuminating Engineers Society of North America. Mr. Offerman reviewed the RP2098 which is lighting for parking facilities and gave the short version of the standards. He stated this is what they used when they reviewed the plans and what is the recommended maintained illuminance values for parking garages from the report which is attached to the case. What they are asking for is a minimum of one footcandle for basic light. There is actually two footcandle for daytime so we are allowing some day lighting as well, but for night is one footcandle. Mr. Offerman stated LED works different and that changes the way they look at lighting all together, it is more important if they are meeting the minimums with good uniformity, and when we look at the plans for T5 lights, the uniformity is very good and it meets the minimums. The average is not quite as high, but that is okay, you can get the averages up by having hot spots. He went on to explain that what they do is put the whole ramp on a point by point grid, he highlighted where the minimum requirement wasn't met, the only case is by the stairwell where there is going to be other light, so he explained they were able to meet the entire area of the lamp at the minimum level and uniformities were there. Director of Public Works/Principal City Engineer Olson reviewed as part of his energy analysis, Public Works Committee / January 17, 2012 Page 3 of 8