MECHANICAL/ELECTRICAL FAMILY ELDERLY ACTION = REPLACE 50+ = "long-lived" systems CONSTR. CONSTR. UNLESS NOTED Central Unit Exhaust, roof mtd 15 15 Chilled Water Distribution 50+ 50+ Chilling Plant 15 25 Compactor 15 15 Cooling Tower 25 25 Electrical Switchgear 50+ 50+ Electrical Wiring 30 30 Elevator, Controller, dispatcher 15 20