Project Delivery Method: Design-bid-build (DBB)

Project Type: Existing infrastructure (kitchen-cafeteria)

Owner Team: University president, owner representative (consultant), project manager of capital projects, facility manager (in-house staff)

Project Delivery Team: HVAC engineer (lead consultant), plumbing, electrical, structural, fire protection, security consultants, and third-party commissioning consultant (CxC)

DBB Project Team: Project manager for HVAC contractor as prime contractor, mechanical-electrical coordinator, piping foreman, ATC subcontractor, and boiler service subcontractor

HVAC Application 2023 ASHRAE Handbook: Chapter 8 Educational Facilities

HVAC Systems and Equipment 2020 ASHRAE Handbook: Chapter 1, HVAC System Analysis and Selection, Chapter 2 Decentralized Cooling and Heating Plants, Chapter 11 Steam Systems, and Chapter 32 Boilers

Other References: Refer to “Codes & Standards” (back of each ASHRAE Handbook for additional reference), ASHRAE Practical Guide to Seismic Restraints, ASHRAE Standard 202 (RE: Commissioning Process for Buildings & Systems), and 2021 ASME Boiler and Pressure Vessel Code


Heating Design Intent:

  • This optimum boiler heating equipment selection and the project’s design intent document is based on the analytical processed outlined in ASHRAE Handbook 2020 Chapter 1 HVAC System Analysis and Selection and includes the following:
    • Owner project requirements (OPR): building program goals and additional goals
    • Finalized system selection shall be to replace a 30-year old firetube boiler with a new 95% efficient gas-fired steam condensing boiler to serve the university’s main campus cafeteria.
    • Automatic controls shall include new system automatic controls interfaced with the existing Building Automation System (BAS) controls, equipment furnished controls, BACnet interface, Internet interface, and populating new equipment data into the existing computerized maintenance management software (CMMS) system from in-house operation and maintenance (O&M) staff.
  • Program and Project Goals:
    • Functional Goals: (refer to chapter 1, 2020 Handbook)
    • Budget Goals: First cost and operating cost
    • Timeline Goal(s): Summer installation and commissioned prior to the fall University schedule
    • Management Goals: Replace antiquated steam boiler and its associated boiler feed unit based on the university’s deferred maintenance budget and master plan, and 3-year service contract for boiler and boiler feed equipment
  • Utility Availabilities: Existing natural gas service, electrical service, and BAS
  • Pipe Distribution: Schedule 40 black iron steel for steam supply and boiler feed piping and schedule 80 black iron steel pipe for condensate return piping with fiberglass insulation (thickness per state energy code) plus insulation of valves, and fittings; stem traps will not be insulated
  • Boiler feed receiver shall have duplex feed pumps serving the new boiler replacement
  • The owner representative shall contract the services of a 3rd party Cx agent to assist in the overseeing of the DBB contract and compliance with the design team’s contract documents


  • The heating BofD design criteria shall be in sync with the project delivery method and owner’ project requirements (OPR) noted above.
  • Utility shall be existing electrical 480/3/60 power and existing natural gas service to serve the new gas-fired 100-boiler horsepower (bhp) unit B-1 to serve existing kitchen equipment for 400-student cafeteria. This boiler replacement project is Phase 1 of a 3-part mechanical equipment replacement project based on the University’s deferred maintenance master plan.
  • New boiler feed receiver with two water pumps sized to operate in lead-lag sequence of operation.
  • New boiler system sequence of operation: the new condensing, high-efficient boiler will operate year-round to provide low pressure steam to kitchen equipment, e.g., dishwasher, 100% kitchen hood make-up air unit, etc.
  • The existing cafeteria building automatic controls shall be reprogrammed to accommodate this be design criteria. The new boiler self-contained automatic controls shall be interfaced with the existing BAS system. Existing controls shall also include interface with the building security system and CMMS work order system.
  • The new lead boiler feed pump shall be sized for 75% with matching lag pump.
  • The new pipe distribution shall be insulated and installed to serve the steam system.
  • Conceptual/Schematic Phase General Notes:
    • HVAC design engineer shall provide system flow diagrams with the three documents (OPR, DID, & BofD) along with ATC sequences of operation that is integrated with the existing BAS and electrical one-line diagram.
    • HVAC design engineer shall include electrical data sheet to coordinate with electrical design engineer, plumbing data sheet to coordinate with plumbing design engineer, and equipment and distribution weights to coordinate with structural design engineer, as well as DID to the security consultant.

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