Project Delivery Method: Integrated project delivery (IPD)

Owner Team: Building owner, owner representative (consultant), and facility manager (in-house staff)

Project Delivery Team: IPD project manager; job superintendent; mechanical-electrical coordinator; and HVAC, plumbing, electrical, structural, fire protection, and security consultants  

HVAC Project Team: HVAC contractor project manager; automatic temperature controls (ATC) technician (subcontractor); building automation system (BAS) technician (in-house staff); O&M technician (in-house staff); third-party commissioning consultant (CxC); and testing, adjusting, and balancing (TAB) technician  

Application: 2019 ASHRAE Handbook, Educational Facilities, Chapter 8; and Kitchen Ventilation, Chapter 34

Systems & Equipment: 2020 ASHRAE Handbook, Air-Handling and Distribution, Chapter 4; and In-Room Terminal Systems, Chapter 5

Project Type: Infrastructure replacement

References: Refer to the codes and standards located in the back of each ASHRAE Handbook for additional reference

Other References: ASHRAE Indoor-Air Quality Guide: Best Practice for Design, Construction, and Commissioning; ASHRAE Practical Guide to Seismic Restraints; ASHRAE Standard 55 (Thermal Environmental Conditions for Human Occupancy); ASHRAE Standard 62.1 (IAQ); and ASHRAE Standard 202 (Commissioning Process for Buildings and Systems)

DESIGN INTENT DOCUMENT (DID)

The HVAC system selection and design intent is based on the process outlined in ASHRAE Handbook 2020, Chapter 1, HVAC System Analysis and Selection, and includes the following:

  • Owner’s building program and additional goals
  • System and constructability constraints
  • Finalized system selection shall be decentralized HVAC systems with terminal units
  • Automatic controls shall include temperature controls, equipment furnished controls, a BACnet interface, an internet interface, an existing BAS interface, and the in-house O&M firm’s existing computerized maintenance management software (CMMS) system interface
  • Program & Project Goals:
  1. Budget goals: First cost and operating cost
  2. Timeline goals: an occupancy move-in date of Aug. 15
  3. Management goals: School facilities management and in-house mechanical and electrical services
  • Available Utilities:
    1. Natural gas, electricity, and the BAS system
  • Existing Conditions:
    1. Replace existing central air system to serve the kitchen hood exhaust and adjacent toilet exhaust
    2. Reuse the existing hot water heating system
    3. Reuse the existing air-cooled chiller system
    4. Reuse the existing sheet metal: low-velocity and galvanized sheet metal with volume and fire dampers
    5. Reuse the existing end suction primary/secondary pumping with a variable frequency drive (VFD)     

    DESIGN CRITERIA DOCUMENT

    • The HVAC design criteria shall be in sync with the project delivery method and the owner’s project requirements
    • The design criteria shall be based on ASHRAE 90.1 and state energy code compliance for outdoor air temperature compliance
    • Reuse existing utilities and central heating and chilled water systems
    • The new automatic controls shall be interfaced with the existing BAS
    • The existing central plants shall provide heating in the winter to maintain 68°F, and, in the air conditioning season, 76° via a single duct, thermostatically controlled, providing ventilation air maintaining a positive cafeteria pressure of 0.05 inch gage and negative pressure in kitchen of 0.05 inch gage
    • The existing central air system shall be replaced with a new, 100% outdoor air unit with energy recovery of the cafeteria exhaust that is not kitchen hood exhaust
    • A new central air system should include MERV-7 prefilters and MERV-14 final filters on the supply air side and MERV-14 filters on the energy recovery wheel intake side
    • Existing variable air volume (VAV) and fan-powered air terminals shall be replaced with VAV primary air fan-powered air terminals, operating to provide positive space pressure in the cafeteria and kitchen
    • Conceptual/schematic phase general notes: The HVAC design engineer shall provide system flow diagrams with these three documents (OPR, DID, & basis of design [BOD]) along with ATC sequences of operation

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