2015-12-22-PBC-min - Laserfiche WebLink

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DiNisco needs to understand community building use especially gym, library, and cafeteria. Lexington Board of Health recommends that Lexington Public Schools follow Massachusetts Department of Public Health guidelines for Co2 air content at 600ppm. Are these State wide school standards necessary to be met? If so, additional ventilation will be needed at additional costs. Must realize total costs involved in all growth at Diamond versus growth at both schools. This is mostly a cost exercise since the Superintendent has advised against this approach. Four options were presented: 4 Pipe Induction: very quiet, used at Estabrook, no filters to change, most cost effective for full AC. 2 Pipe Induction: manual turnover from heating to AC in fall and spring needed, full AC Variable Refrigerant Flow (VRF): noisier, full AC Partial Cooling: is really dehumidification and may not provide comfort the full school year \[the thinking is that there may be 5 days of discomfort during the normal school year\], used at Bowman and Bridge. The spaces occupied year round would receive ac. The HVAC discussion included: Fiske and Harrington use a geothermal system. Life cycle costs given are for Clarke only in the new, 16,000 sf building addition and not for Diamond or any of the renovated spaces at either school. Air-to-air pumps of today are more efficient than the geothermal pumps at Fiske and Harrington. The Co2 discussion included: Currently, there are 3 air exchanges and a fourth may be needed, to meet DPH recommendation of 600ppm. DiNisco is developing costs differences for better Co2 air exchanges. Models of exchange included: o High volume of air exchanged at a low speed o Or increasing the speed which will also increase the noise level o Therefore a larger unit will be needed for this larger air capacity. This will require a higher roof load, unit cost, associated ductwork, and electrical load 3.Value Engineering (VE) Presentation: The discussion included: The master list of proposed VE items was distributed indicating which items were recommended by the Design team with input from school administration and facilities.