Temperature Control Sysems And Why They Dont Work
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Temperature Control Sysems And Why They Dont Work



Tech 3 - Harry Demetrulias

Tech 3 - Harry Demetrulias
Technical Session from the 2006 ASHRAE Region VI CRC



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Temperature Control Sysems And Why They Dont Work Temperature Control Sysems And Why They Dont Work Presentation Transcript

  • Temperature Controls “Why Don’t They Work? Harry Demetrulias
  • Top 5 Reasons Control Systems Don’t Work 1. Many Controls Contractors ARE Crooks! 2. Mechanical Design Problems 3. Mechanical Installation Problems and Equipment Malfunction 4. Operator Errors and Overrides 5. Controls Installations: Misapplied Field Devices, Sensor Locations, Lack of Calibration, and PID Loop Tuning
  • Blame the Owners “Owners are too demanding and unrealistic in their cost expectations” Lower! How Low?
  • Blame The Architects “Architects are too focused on aesthetics, and do not allow adequate space for building systems: Mechanical Rooms and Interstitial Space”
  • Blame the Generals General Contractors punch out projects without scheduling adequate time for Start-up, Checkout, Test & Balance, and Commissioning activities
  • Blame the Engineers “Mechanical Engineers Overworked and Underpaid!”
  • Blame the Suppliers “Equipment Suppliers Just SELL STUFF and Don’t Support it!”
  • Blame the Balancer “Do you really trust those Test & Balance Reports?”
  • “Should we blame those Design/Build Mechanical Contractors?
  • Finger-pointing is easy Working toward Solutions Requires Professional COLLABORATION
  • Function or Malfunction is without exception a collaborative effort between Consultant, Mechanical Contractor, Controls Contractor and Facility Operations.
  • Temperature Control is simple. Building Automation is complex… How can we promote Collaboration?
  • Delivering Truly Integrated Building Systems To Owners Requires Collaboration - Engineers - Controls Contractors - Mechanical Contractors - Equipment Suppliers - Facility Operations
  • When Temperature Control Becomes Complicated • Economizer Mode • Variable Volume/Flow • Dynamic Resets • Warm-up/Cool-down Modes • Building Pressurization Control • Smoke Control •Underfloor Systems • IAQ • Load Shedding Programs •TOD Scheduling • PRAC Self-Tuning • Integrations to 3rd Parties • Validated Systems
  • Controls Contractor’s Perspective: The Consultant as PROBLEM…or Solution
  • Market Pressure & the Design Community • Hyper-competition • Below Market Design Fees • Allotted Billable hours for quality designs and specifications • Lack of onsite Project Engineering • Reliance on draftsmen to incorporate last minute changes • Addenda Ad Infinitum
  • The Key: Publish Quality Documents Installation is only as good as the design Errors on P&S result in problems in the field Malfunction begins in the mind of the designer Unedited Master Specifications Lower engineering cost but… Many Change Orders/retrofit corrections
  • Example #1: Nonspecific Specifications • “DDC controllers shall be BACnet. Lonmark AND N2 Open Protocol compliant…” • “Acceptable manufacturers are Alerton, Andover, Delta, Honeywell, Invensys, Johnson Controls, Siemens, Staefa Controls, Trane, or approved equal.”
  • 2. Electric, Electronic, and DDC Systems: a. Alerton Technologies, Inc. Example #2: b. Andover Controls Corp. c. Automated Logic Corporation. Healthcare project… d. Auto-Matrix, Inc.; Auto-Flow Division. e. CSI Control Systems International, Inc. f. Danfoss Automatic Controls. g. Delta Controls Inc. h. EDA Controls Corp. i. Electronic Systems USA, Inc. j. G C Controls, Inc. k. Honeywell, Inc.; Home & Building Control. I. Impact Energy Controls Corp m. Johnson Controls, Inc.; Controls Group. n. KMC Controls/Kreuter Manufacturing Company. o. Landis & Staefa, Inc. p. Luwa Bahnson Inc. q. McQuay Intemational. r. Neles-Jamesbury. LOWEST TOTAL COST OF OWNERSHIP s. Pneuline Controls Co.; National Energy Controls Corp. t. Scientific-Atlanta, Inc.; Control Systems Div. u. Siebe Environmental Controls; Barber-Coleman/Robertshaw Anyone Products v. Solidyne Corp. w. TCS/BASYS Controls Missing? x. Teletrol Systems Inc. y. Trane Co. (The); North American Commercial Group. z. Triangle MicroSystems, Inc. aa. Uni-Line North America; Robertshaw Division. 3. Systems must interface seamlessly with existing front end control system
  • Damper Control: When the unit is commanded on, the Example #3: outside air damper shall fully open. When the unit is commanded off, the outside air damper shall close. The exhaust damper shall remain closed and the mixed air damper shall remain open. 8 RF1ISO-S RA-F1 NC RA-SD RA-T (Div. 16) RA-H VSD NC EA RA 10 RF2ISO-S RA-F2 HSP1-A Set @4" NC H L VSD SF-F1 SF1ISO-S 7 HUM-O NO 0-7.5" 10-27 PFILT-A NC FFILT-A SA-P Set @ 1" Set @ 1" H L H L H L LT-ALM VSD MA-T HSP2-A SA-SD 3 DPR-O (38 Deg F) HUM-HL SA-T Set @4" (Div. 16) C OA NC C H L SA 4 SF-F2 SF2ISO-S 9 4 CLG-O HUM-VLV RETURN NC NO STM NC SUPPLY VSD Discharge Air Temperature Control: When the unit is commanded on, the outside air damper, return air damper, and relief air damper will be open. Discharge temperature sensor SA- T through the DDC Controller will modulate the cooling coil 2-way control valve CLG-O to maintain setting. The discharge air temperature will be controlled to maintain a 55°F setpoint.
  • Specify SPECIFICS… Specify limited qualified bidders that are suitable for • market type LOWEST TOTAL COST OF OWNERSHIP • product application • contractor expertise Balance First Cost with Operating Cost
  • BAS Cross- FIRE VIDEO- ON- Referencing DEMAND HOTEL ELEVATOR OPERATING SYSTEM IT NETWORK LIGHTING PABX Write Specifications that refer to other sections and technologies. CENTRAL PLANT PAGING Detail the responsibilities CCTV Furnished by… SECURITY CMMS Installed by… 15 BUILDING Wired by… SERVICES
  • Sequence of Operation EXHAUST SYSTEM: EF-1 and EF-2 EF- EF- Isolation Exhaust Fans EF-1 and EF-2: EF- EF- On command from the BAS, the fans shall start. If Include at Minimum: for any reason the fan status does not match its commanded value, an alarm will be generated. ISOLATION ROOM MONITORS Flow Diagrams System Description: The Isolation Rooms shall be monitored by a Space Pressure Monitor as described in controls specification at minimum and shall generate an Point Charts alarm at the BAS upon general alarm or deviation from space pressurization setpoint (adj). adj). Sequences
  • P.E. Professional Enforcer Enforce your specifications Guard against cheating in hyper-competitive market Get involved in checkout, functional testing and commissioning Specify Commissioning Expectations Review Checkout Sheets Verify that field devices match the specification
  • Resist De-Value Engineering 10. Delete lab VAV: Constant volume labs 9. Delete DDC from FCUs 8. Delete SAT Sensors on VAV w/RH 7. Delete DPs across filter racks 6. Delete interfaces to Chillers, Boilers and VFDs 5. Delete AFMS from AHUs SA/RA/OA 4. Delete VAV zones and combine multiple zones 3. Delete Custom Controls on RTUs in lieu of packaged 2. Delete RH Coils in lieu of Cooling Only VAV 1. Delete DDC from VAV/CAV terminals
  • Technology Capabilities of Technology Cost of Technology Technology is more affordable than ever. But it has made building controls more complicated for 1990 2006 Specifying Engineers
  • Get Help from Your Local Controls Experts and Sales Engineers The System Selection Tool was designed to help specifying engineers quickly develop detailed, accurate plans and specifications for heating, ventilation and air conditioning (HVAC)
  • Summary: A New Level of Engineering Value $ Step 1 Publish Quality Documents Step 2 Resist De-Value Engineering Step 3 List Qualified Bidders Step 4 Enforce Specifications Step 5 Get Support and Consultation from Reputable Controls Companies
  • Less quality in More value out Design/Build and Value Engineering Exploiting Owner’s Lowest First Cost Demands?
  • “We can do it cheaper and faster!” Less quality in More value out Hyper/Competitive Market and the D/B Model: Contractors Control Design - Reliance on Equipment Suppliers for TC - Packaged systems w/canned programs
  • Slam it in Commission it later Hard Bid/Design/Build Can this building be fixed?
  • Problem: Mechanical Design & Controls Issues – Building Pressurization Problems – Toggling RTU Modes – Uneven Underfloor Distribution – Overly cool interior zones – Overly warm exterior zones Symptoms – No humidity control Building # 1 – Energy Hog—could not qualify for Energy D/B Debacle Star rating ASHRAE Temperature Controls: “Why Don’t They Work?” Don’ Work?”
  • Problem: Mechanical Design & Controls Issues – VAV w/General Exhaust System – No trunks to distribute UFS Causes – Improperly placed pressure sensing devices – No calibrated primary T/H devices Building # 1 – Cooling mode problems D/B Debacle – Dueling PID Loop Control on RTU – Inability to alter or augment canned RTU program—limitations ASHRAE Temperature Controls: “Why Don’t They Work?” Don’ Work?”
  • Problem: Mechanical Design & Controls Issues – Hire a COMMISSIONING AGENT! – Add return fans – Add trunks to distribute UFS Solutions – Relocate pressure sensing devices Building # 1 – Calibrate primary T/H devices D/B Debacle – Replace misapplied DDC hardware – Reprogram and recommission – Work with commissioning agent ASHRAE Temperature Controls: “Why Don’t They Work?” Don’ Work?”
  • Manual Control Automation does not work well in the “HAND” position
  • “It’s always a Controls Problem!” …often times it is… The Controls Contractor as Part of the Solution…
  • Controls Industry Boilers as the Problem: Pumping & VFDs Chiller Absorption Power Generators Today’s Technology is less expensive Fan Systems But the Labor is not Margin Expectations Continue to Rise Fire Alarm Competition is driving the quality out Surgical Suites Lighting Fume Hood
  • Today’s Technicians often know computers but lack understanding of basic mechanical systems Application Engineering & Commissioning Challenges Decreased skill sets in controls software engineering Protocols do NOT control buildings Software illiteracy Reliance on automated Person at Metasys processes workstation Lack of Quality Management processes What is Commissioning?
  • COMPLEXITY Building Technology Has Complicated Simple Temperature Controls Comfort Lighting Security Scheduling Access control Fire safety Communications Fuel conservation Power load management Maintenance management
  • Controls Industry as the Problem: Value Added Services? Phase 1 Low First cost Phase 2 Prices just went up! Phase 3 Delivering less value over time
  • Solution 1: Can we consider a new Level of Value? Phase 1 Low First cost Phase 2 Open Book Pricing Phase 3 Pricing Agreements Phase 4 Meet the Specifications Phase 5 Exceed Customer Expectations
  • Solution 2: Expert Services Provide support and educational services to the engineering community Offer design review services and provide input on sequences, points lists and specifications Review Bid Documents and write good clear RFIs early in the process
  • Solution 3: Customer & Design Team Deliver as Promised General Behave more like consulting experts, less like the proverbial Crooks Be professional and deliver on Performance Mechanical Electrical Windows Raised Floor Specifications Contractor Contractor etc Submit proper Controls HVAC Lighting Fire checkout and commissioning documentation to Power Consultants Security Mgmt Make Buildings Work
  • Quality Assurance… Apply ASHRAE Standards Due diligence on installations and checkout practices Tune loops and set up trends during checkout and commissioning Work with Designers as fellow engineers, not combative contractors Review Checkout Sheets Verify that field devices match the specification
  • Working Together we can deliver better design and construction projects and the High Performance Buildings that Owners are paying for.
  • Temperature Controls “Why Don’t They Work? Q&A