Project Delivery Method: Construction management at risk (CM) with a guaranteed maximum price (GMP)

Project Type: New construction and infrastructure (central cooling)

Owner’s Team: The dry-air warehouse storage owner, owner’s representative (consultant), project manager of capital projects, leasing agent, and facility manager

Project Delivery Team: CM project manager; mechanical-electrical coordinator; and HVAC, plumbing, electrical, structural, and security consultants

HVAC Project Team: HVAC project manager; automatic temperature control (ATC) technician subcontractor; building automation system (BAS) subcontractor; third-party commissioning consultant (CxC); and third-party testing, adjusting, and balancing (TAB) technician

ASHRAE Handbook-Application 2019: Chapter 3, Commercial and Public Buildings

2020 ASHRAE Handbook-HVAC Systems and Equipment: Chapter 4, Air Handling and Distribution, and Chapter 18, Variable Refrigerant Flow (VRF)

References: 2019 ASHRAE Handbook – HVAC Applications, 2020 ASHRAE Handbook – HVAC Systems and Equipment, and Construction Management Association of America (CMAA)

Other References: Refer to the codes and standards located in the back of each ASHRAE Handbook for additional reference; ASHRAE Humidity Control Design Guide for Commercial and Institutional Buildings; ASHRAE Guide for Buildings in Hot and Humid Climates; ASHRAE Indoor-Air Quality Guide: Best Practice for Design, Construction, and Commissioning Systems; and ASHRAE Standard 202 (Commissioning Process for Buildings and Systems)

DESIGN INTENT DOCUMENT (DID)

  • The optimum HVAC system selection and the project’s design intent is based on the analytical process outlined in ASHRAE Handbook 2020, Chapter 1, HVAC System Analysis and Selection, and includes the following:
  1. Owner’s project requirements (OPRs), building program goals, and additional goals;
  2. The finalized system selection shall incorporate multiple DOAS,  each serving 20,000 square feet of lease space; and
  3. The automatic controls shall include new system automatic controls interfaced with the existing 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:
    1. Functional goals: (refer to Chapter 1, 2020 Handbook);
    2. Budget goals: The life-cycle cost is based on leased space of 200,000 square feet;
    3. Timeline goal(s): The installation due date and prepurchased equipment date; and
    4. Management goals: In-house mechanical and electrical services, service contracts for new equipment, and a five-year financial property management plan.
  • Available utilities: Existing natural gas service, electrical service, and the BAS system.
  • New variable refrigerant flow (VRF) HVAC heat recovery units to maintain space temperature.
  • New DOAS units to limit the space humidification to 45°F relative humidity.
  • All units shall be heat pumps with heat recovery for reheat as needed.

    • BASIS OF DESIGN (BofD) DOCUMENT

    • The HVAC BofD criteria shall be in sync with the project delivery method and (OPRs).
    • The utility shall be existing electrical 480-V power to serve 10 DOAS heat recovery heat pump units and 40 VRF fan coil units.
    • Each 20,000-square-foot leased space shall have a DOAS unit to introduce minimum outdoor air ventilation and dehumidify this outdoor air while fan coil units shall maintain to space temperature of 68° and 30% RH in the heating season and 76° and 45% RH  in the air conditioning season.
    • Standby mode of operation: There shall be no standby redundancy in any of the 10 leased warehouse spaces.
    • The new refrigerant piping shall be insulated based on the unit manufacturer’s requirements.
    • Conceptual/Schematic Phase General Notes:
    1. The design team shall work closely with the owner’s team: dry-air warehouse storage owner, owner representative (consultant), project manager of capital projects, leasing agent, and facility manager to produce the BofD documents;
    2. The CM firm’s project manager, along with the company’s in-house estimating department (general construction, HVAC, plumbing, electrical, structural, and fire protection estimators), shall provide preconstruction estimating and value engineering services in sync with the leasing financial spreadsheet;
    3. The HVAC design engineer shall provide system flow diagrams with the three documents (OPR, DID, and BofD) along with ATC sequences of operation that is integrated with the existing BAS control system and electrical one-line diagram; and
    4. The HVAC design engineer shall include an electrical data sheet to coordinate with the electrical design engineer, a plumbing data sheet to coordinate with the plumbing design engineer, and equipment and distribution weights to coordinate with the structural design engineer as well as the security consultant.
  • The CxC and TAB technicians shall provide design reviews at the end of the schematic phase and design development phase.
  • The CM shall solicit all construction bids and oversee the construction phase of the project.