Loading...
Central Services-CIP presentation on city building performanceBridge Street Jackson Street Leeds Elementary •1915/1953 Wings •Windows: U-.75 •Wall:R-4/6 •Roof:R-36 •1991 Wing •Windows: U-.75 •Wall:R-7/11 •Roof:R-12.5/24 •1953 Wing •Windows: U-0.75 •Wall:R-3 •Roof:R-13 •1976 Wing •Windows: U-0.50 •Wall:R-3 •Roof:R-13 •1953 Wing •Windows: U-1 •Wall:R-4 •Roof:R-16/34 •1991 Wing •Windows: U-.95 •Wall:R-12 •Roof:R-25/33 •2 Dual-fired (gas & oil) hot water boilers – fair condition •Panel & fin-tube hot water radiation •Unit Ventilators in Classrooms •Roof-mounted AHUs for Cafe & Gym – beyond useful life •Unit Ventilators in Library connected to newer roof-mounted air-cooled condensers (4T each) •Out of date pneumatic controls •Very limited cooling (Admin & Library) •2 Gas fired steam boilers (2019 & Old) with heat exchanger •AHU's with steam & hot water coils ducted to 1970's classrooms •Unit ventilators with steam coils for 1950's classrooms •Electric Heat Pumps in Library, Cafeteria & Kitchen •Very old DDC control system (AHU's only), rest of building pneumatic •2 Dual-fired (gas & oil) steam boilers (old) with heat exchanger •Unit ventilators with steam coils for 1952's classrooms •Unit ventilators with hot water coils for 1989 classrooms •2012 ERV and unit ventilators for leased space •AHU with heating and cooling coil Admin/Library/Offices/Computer room •Very old controls – mix of DDC & pneumatic Bridge Street Jackson Street Leeds Elementary Current EUI 67 Target EUI 35 Step 1 – Envelope Improvements at 1915/1953 Wing of building Step 2 – 1915/1953 Mechanical Improvements Step 3 – Envelope Rebuild at 1991 Wing Step 4 – 1991 Mechanical Improvements Current EUI 67 Modeled EUI 37 Step 1 – Envelope Improvements at 1915/1953 Wing of building •Improve R-value of exterior walls and roof •New high-performance windows •Comprehensive air sealing Step 2 – 1915/1953 Mechanical Improvements •Replace unit ventilation with ERV (electric heating coil) •Replace boiler with VRF/Heat Pumps (air or ground source) PV/Electrical Upgrade •Install onsite PV Array and Upgrade Electrical System Capacity Step 3 – Envelope rebuild at 1991 wing •Replace underperforming daylighting •Provide continuous insulation at walls & roof with integrated air sealing •Install high-performance glazing Step 4 – 1991 Mechanical Improvements •Replace unit ventilation with ERV (electric heating coil) •Replace boiler with VRF/Heat Pumps (air or ground source) •Replace hot water with electric boilers •1991 Wing of Bridge is the only steel stud construction within the study (thermal bridging issue) •Existing moisture concerns at Gym, Admin •1915/1950s wing has historic significance •User behavior – an issue with open windows – need staff to understand ventilation system •Daylighting/Glare concerns Current EUI 63 Target EUI 35 Step 1 – Envelope Improvements at 1953 Wing of building Step 2 – 1953 Mechanical Improvements Step 3- 1976 Interim Mechanical Improvements Step 4 – Envelope Improvements at 1976 Wing Step 5 – 1976 Mechanical Improvements Current EUI 63 Modeled EUI 37 Step 1 – 1953 Wing Envelope Improvements •Improve R-value of exterior walls and roof •New high-performance windows •Comprehensive air sealing Step 2 – 1953 Wing Mechanical Improvements •Replace unit ventilation with ERV (electric heating coil) •Replace boiler with VRF/Heat Pumps (air or ground source) PV/Electrical Upgrade •Install onsite PV Array and Upgrade Electrical System Capacity Step 3 – 1976 Interim Mechanical Improvements •Replace unit ventilation with ERV (electric heating coil) •Replace boiler with new gas boiler – 95% eff. Step 4 – 1976 Wing Envelope Improvements •Improve R-value of exterior walls and roof •New high-performance windows •Comprehensive air sealing Step 5 – 1976 Wing Mechanical Improvements •Replace boiler with VRF/Heat Pumps (air or ground source) •Glass block clerestory at 1953 Wing •Important daylighting strategy •Hard to air seal •Stud construction with metal siding •Most complicated geometrical form •Evidence of previous moisture issues at Library Current EUI 72 Target EUI 35 Step 1 – Envelope Improvements at 1953 Wing of building Step 2 – 1953 Mechanical Improvements Step 3- 1991 Interim Mechanical Improvements Step 4 – Envelope Improvements at 1991 Wing Step 5 – 1991 Mechanical Improvements Current EUI 72 Modeled EUI 42 Step 1 – 1953 Wing Envelope Improvements •Improve R-value of exterior walls and roof •New high-performance windows •Comprehensive air sealing Step 2 – 1953 Wing Mechanical Improvements •Replace unit ventilation with ERV (electric heating coil) •Replace boiler with VRF/Heat Pumps (air or ground source) PV/Electrical Upgrade •Install onsite PV Array and Upgrade Electrical System Capacity Step 3 – 1991 Interim Mechanical Improvements •Replace unit ventilation with ERV (electric heating coil) •Replace boiler with new gas boiler – 95% eff Step 4 – 1991 Wing Envelope Improvements •Improve R-value of exterior walls and roof •New high-performance windows •Comprehensive air sealing Step 5 – 1991 Wing Mechanical Improvements •Replace boiler with VRF/Heat Pumps (air or ground source) •Community significance •Largest number of high- volume spaces: Atrium, PreK •Evidence of moisture challenges at PreK •Crawl space foundation below 1953 Wing •Daylighting/Glare concerns – many classrooms are East or West facing If all schools were upgraded today to achieve the City's GHG goals, the cost per school would be: Bridge Street Jackson Street Leeds Elementary 6.48M 8.22M 7.23M 1915/1953 Wall $139,000 Window $950,00 Roof $254,000 HVAC $1,600,000 1991 Wall $225,000 Window $750,000 Roof $454,000 HVAC $1,800,000 1953 Walls $64,800 Window $912,000 Roof $403,000 HVAC $1,256,000 1976 Walls $205,000 Window $1,400,000 Roof $1,142,000 HVAC $2,830,000 1953 Wall $44,439 Window $460,000 Roof $426,000 HVAC $1,600,000 1991 Wall $170,000 Window $1,160,000 Roof $683,000 HVAC $2,688,000 REMINDER: Educational facilities exist to support educational objectives and the efforts of students, teachers and staff to meet those objectives. •Educational priorities and whether they are met by the current buildings •Enrollment projections •Projected operating budgets •Projected maintenance budgets •Transportation costs by school The NNZ study aims to reduce GHG emissions but does not address the larger issues the District should address as a part of a comprehensive Master Plan. How should projects be sequenced? 2022-0324_NNZ Draft Capital Plan Flowchart.vsdx •Integrated approach – roof/window/wall & HVAC per section •Divide each school into sections by age •Address highly vulnerable steam boiler wings first •Buy time for technological advance ment (better hydronic source options in the future?) •Address least insulated/highest EUI next for greatest impact •Keep Bridge Street last because of unfortunate wall condition