Commissioning In Schools

Transcription

1 Commissioning In Schools Why are schools doing commissioning? What challenges do K-12 schools face? How has a School District Approached Cx? Examples LEED Small/Private Chicago Public Schools

2 School Commissioning Drivers LEED for New Schools Energy efficiency Federal Funding Expectations Large Renovation Programs Startup or operational Problems Reduced School Facility Operator Experience

3 Challenges faced by Schools Major Mechanical Renovations School Additions and New Schools Less Experienced Operating Staff Energy Costs continue to rise, with more complicated systems used to save energy IAQ concerns

4 How do Schools Apply Cx Commissioning for LEED Commissioning of Major Mechanical Projects Esp with Building Automation Retro Cx for Existing Buildings

5 LEED Cx LEED vs. ASHRAE Rural vs. Metropolitan When You Start Common Issues Programming In House vs. Contract Based Maintenance Function Accommodating Community

6 Common Issues Design LEED Cx Understanding the Ideal Classroom Space for Operations Basis of Design vs. Specifications Resolving Issues Construction Submittal Quality Understanding Longevity

7 LEED Cx

8 Success Stories LEED Cx Chicago Public Schools Collaborative for High Performance Schools New Orleans Public Schools Hammond School District Los Angeles Unified School District Colorado Springs District 11 Scottsdale School District

9 Private School - Case Study Background 54K Sq.Ft. Single story facility built in two phases Serving K-12 Budget Constraints Aggressive const. schedule (90 days/phase) Comfort complaints students, faculty & parents Project was NOT Commissioned!

10 What s Going On? Brand new building??? Owner solicits help Independent third party to review Conduct a comprehensive field investigation Perform a peer review of design Prepare a report of findings Provide recommendations for correction

11 HVAC Systems 28 Constant Volume gas fired RTUs Optional economizer section provided Single stage cooling (no capacity control) No microprocessor controls basic thermostat DDC system installed expensive thermostat 10 Toilet and General exhaust systems 2 Fume hoods

12 Interview Owner & Staff Main complaint large temperature fluctuations Owner Criteria Warm in Winter, Cool in Summer! Written Design Criteria Virtually non-existent!

13 First Steps Field Investigation Review design drawings BAS trends (not much value, 30 min. int.) Review sequences of operation Set up data loggers (30 second intervals) Inspect all 28 RTUs Spot check readings from T&B report

14 Observations Classrooms (Graph) Two classrooms served by same RTU As much as 4º difference between rooms Setpoint 73º BAS Average of both rooms Air leaving diffusers 72º to 105º (1 st Stage) Four 2X2 diffusers in center of room Burner ON time 8 minutes, total cycle 45 min. Room uncomfortable at DAT of 105º

15 Room 109 Temp Room 102 Temp

16 Room 109 Temp Room 102 Temp RTU-1 DAT

17 Room 109 Temp Room 102 Temp RTU-1 DAT

18 Observations (cont.) Multipurpose Room Room is always cold in winter 16 ft. high ceiling, eight 2X2 diffusers Max. temperature at ceiling 100º Avg. room temp. 68º at 5ft. (32º gradient over 11 ft.) Max. temperature at diffusers 155º

19 RTUs Observations (cont.) All RTUs selected with highest heating capacity available No microprocessor based controls No capacity control for cooling No OA temperature compressor lockout OA min. position not set on all units (No OA) Min. OA will be open in unoccupied mode Dirty and inconsistent type of air filters NSB not programmed on some RTUs

20 Solutions??? No cheap/quick solutions Adjust OA dampers for min. code req. air Replace two, 2X2 diffusers with slot dif. Install elect. reheat for furnace off cycle Use elect. reheat in cooling mode to prevent sub-cooling and control humidity Replace diffusers in multipurpose room Program all units for NSB mode

21 How Do You Avoid This? COMMISSIONING Assist with clear & concise Owner Requirements Ensure that system design meets OPR Verify submitted equipment meets design intent Observe installation of systems Review sequences of operation Prepare pre-functional checklists Perform functional testing *** Be the advocate for the Owner***

22 Chicago Public Schools (CPS) Fourth Largest School district in Nation Nearly 600 school facilities 240 schools are 75 years or older and 100 schools are 50 to 75years old Major Mechanical Renovations w/ BAS New Schools Began commissioning schools in 2002

23 CPS drivers for Cx, 2002 Operation of New and Renovation Schools not as expected, and a few of the school with significant problems Pilot Cx of 5 schools identified many design and construction related issues Number of mechanical renovations to increase over next 10 to 15 years. Limited building operator experience with BAS control systems

24 CPS Commissioning Challenges Design Phase Inconsistent MEP details and methodology Wide variation in control drwgs, specs and sequence Construction Phase Contractor unfamiliar and initially unwilling to follow existing Cx requirement in the specifications New Schools are LEED w/ Enhanced Cx MEP schematic design lags physical design

25 Commissioning at CPS Today Commissioning all renovation projects that include Building automation New Schools LEED Silver Cx representative on MEP Technical Committee MEP Standards Building Control Standards

26 Commissioning Scope at CPS Large Mechanical Renovations Per Year Primary Commissioning focus is controls Nearly all significant functions of HVAC systems demonstrated via the controls commissioning 1-2 New schools per year with 7 in design in 2008 Enhanced Cx for LEED Design has moved from a prototype developed by CPS to a more open Architectural and Mechanical design with greater latitude in MEP systems. This will make Cx even more critical

27 Cx Participation MEP Technical Committee MEP Technical Committee Chaired by CPS Managing Engineer Members include representative from each of the 3 Owners Representative teams and a Commissioning Authority Review topics include specification updates and additions MEP details and schedules updates and additions Lessons learned, from both design and construction Cx representative is responsible for identifying lessons learned from all the Cx s and bringing those to the committee

28 MEP Standards MEP Standard design document Includes much of the MEP information for both the OPR and BOD. MEP Specifications Include detailed startup, training and Cx requirements as well as LEED requirements MEP schedules, & details (+ 200)

29 BAS Drawings and Specs BAS Specifications General requirements including operator training video (CD based), Cheat sheets and complete system manual Exhibits with example Training and Graphics requirements Specifications for devices, interfaces and software Sequence of Operation specification (80 & growing) Entire section for BAS commissioning Detailed control drawings Include logic per written sequence Points list, BOM, Electric ladder diagram for starters.

30 Diagram, Points list, Logic diagrams, Notes,

31 Questions?