Project Delivery Method: Performance Contract (PC)
Owner Team: The pharmaceutical building manager, owner representative consultant, and facility manager (in-house staff)
Project Delivery Team: The performance contract (PC) project manager; utility company representative; and HVAC project delivery team, including an HVAC energy engineer (outsource staff), HVAC supervisor (in-house), ATC technician (outsource), and operations and maintenance (O&M) technician (outsource)
Owner Performance Requirements (OPR): 2019 ASHRAE Handbook HVAC Application, “Commercial and Public Buildings,” Chapter 3, and “Industrial Air-Conditioning,” Chapter 15; and 2020 ASHRAE Handbook, “HVAC Systems and Equipment, Condenser Water Systems,” Chapter 14; Cooling Towers, Chapter 40; and “Heat Exchangers,” Chapter 48
Project Type: Infrastructure (central process cooling), energy audit and retrofit, and facility audit and capital project master planning
References: 2019 ASHRAE Handbook, “HVAC Applications,” and 2020 ASHRAE Handbook, “HVAC Systems and Equipment”
Other References: Cooling Technology Institute (cooling towers), ASHRAE Instrumentation for Monitoring Central Chilled Water Plant Efficiency, ASHRAE Fundamentals of Design and Control of Central Chilled-Water Plants, ASHRAE Standard 202 (commissioning process for buildings and systems), and the National Association of Energy Service Companies (NAESCO)
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 Energy Service Co.’s (ESCO’s) Energy Engineering Evaluation of the Pharmaceutical Company’s Existing Condenser Water System Serving the Process Chilled Water System. The performance contracting project shall include system constraints and constructability constraints. Specialized equipment shall include a new plate and frame heat exchanger, evaporative cooling tower, and end-suction pump with each standby pump operating with variable-speed drives. Automatic controls shall include temperature controls, BACnet interface, and an internet interface that connects to the existing BAS interface.
The project shall include energy performance goals and budget goals (first cost, operating cost, life cycle cost, and return on investment). The timeline shall be completed during heating season and include pre-purchasing equipment.
Management intends to outsource the mechanical, electrical operation, and maintenance management to easier achieve environmental and net-zero energy goals.
Available utilities include electric power and emergency power with an existing process cooling and heating system that includes a condenser water system, process chilled water system, and BAS. The system includes a 2,000-ton open cooling tower with six condenser water pumps and four 500-ton centrifugal electric chillers with two condenser water pumps for process chilled water cooling. The condenser water pipe distribution is schedule 80 steel without insulation and chilled water pipe distribution is schedule 40 steel with insulation.
DESIGN CRITERIA DOCUMENT
- The HVAC design criteria shall be in sync with the project delivery method, energy retrofit based on performance contract operation, and maintenance return on investment.
- The design criteria shall be based on an energy audit of the pharmaceutical’s process chilled water system performance during the heating season.
- The existing cooling tower system functioned year-round with one cooling tower having an electric sump pan heater and pump head pressure control on heating season process cooling via one winter chiller and the associated chilled water and condenser water pumps.
- Condenser water pipe distribution shall be insulated and include electrical heat tracing on winter outdoor pipe distribution.
- An energy retrofit shall function on waterside economizer mode operation with a new evaporative cooling tower plate and frame heat exchanger separating process chilled water from condenser water system. A new heating season process chilled water pump and condenser water pump should each be equipped with a standby pump and VFD motors.
- The addition of a new BAS computer system with remote monitoring and management shall be interfaced with the existing process chilled water system to reduce operating cost and enhance operation and maintenance of this year-round application.
- The performance contractor’s HVAC design and energy engineers shall provide system flow diagrams with associated automatic energy management control and sequence of operation.
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