Existing Building Commissioning (EBCx) Interpretations

LEED-EBOM v2009 contained three credits: EAc2.1 EBCx Investigation and Analysis, EAc2.2 EBCx Implementation, and EAc2.3 EBCx Ongoing Cx. These credits are structured around understanding current operation, implement measure to improve operation, and develop plan for continue process to address changes in facility performance requirements.

The commissioning credits under LEED EBOM-v4 are similar to v2009 with some changes only to the organization and naming convention: EAc1 Existing Building Commissioning – Analysis, EAc2 Existing Building Commissioning – Implementation and EAc3 Ongoing Commissioning.

LEED-EBOM references a number of ASHRAE publications throughout the requirements and credits as part of the certification. Table 1 lists the references with version updates between v2009 and v4.

Table 1. ASHRAE references in LEED-EBOM versions.

Local municipalities reference applicable construction codes stating specific version(s) often with amendments. For example, the International Energy Conservation Code (IECC) 2018, Chapter 4 Commercial Energy Efficiency, Section C401.2 Application states commercial buildings shall comply with ASHRAE Standard 90.1 or other Sections based on certain conditions. Section C408 Maintenance Information and System Commissioning outlines requirements for functional performance testing of mechanical systems and lighting controls. Furthermore, the International Green Construction Code (IgCC) 2018, Chapter 10 Construction and Plans for Operation, Section 10.3 Mandatory Provisions includes commissioning with reference to Guideline 0-2013 The Commissioning Process.

ASHRAE Standard 90.1-2016 includes HVAC controls commissioning for buildings greater than 50k sqft (6.7.2.4) and lighting functional testing (9.4.3). ASHRAE Standard 90.1-2019 requires Cx Plan and reporting in accordance with ASHRAE Standard 202 Commissioning Process for Buildings and Systems.

ASHRAE publications include a commissioning standard and a series of guidelines (GDL). Standard 202 is meant to be utilized for minimum acceptable practice and has been adopted by many jurisdictions as part of the building code. The standard was originally developed to apply to any project in a new or existing building for commissioning HVAC systems, lighting control, the envelope, plumbing, and any other system in the building. However, changes currently in progress will define the scope of Standard 202 as new buildings and create a second standard to apply to existing buildings.

The guidelines represent best practice methods and are intended to describe in detail the commissioning process for owners, end users, consultants and any other interested parties. They are subdivided between the general commissioning process (GDL 0) and specific to HVAC systems (GDL 1). Within each series exist a document that applies to new buildings (GDL 0, GDL 1.1) and existing buildings (GDL 0.2, GDL 1.2). GDL 1.5 is specific to smoke control systems. The first guideline for a facility type is currently in development as a guideline for commissioning datacenters (GDL 1.6). A major effort underway within the ASHRAE commissioning standards and guidelines committees is to provide a separation between new and existing projects that better represent the different objectives. Currently, no other guidelines are in development, but possible future efforts may include lighting control and envelope.

ASHRAE Standard 202 and Guideline 0 define commissioning as a process to verify and document that the Owners Project Requirements were met in the planning, design, installation, testing, operation and maintenance of all facility systems.

Functional performance testing is an activity within the commissioning process to verify that installed systems meet an acceptance criterion typically defined by the Owners Project Requirements.

ASHRAE Standard 90.1 defines minimum requirements for energy efficiency in new buildings and incorporates the Standard 202 commissioning process. The general commissioning process defined in Standard 202 is the minimum acceptable, whereas Guideline 0 is the best practice and Guideline 1.1 is the best practice for new installations of HVAC systems. Guideline 0 includes everything in Standard 202 with additional activities to ensure the highest quality commissioning process. Guideline 1.1 is and adapted version of Guideline 0 to specifically apply to HVAC systems.

The AABC Commissioning Group (ACG) is an association established in 2004 for independent 3^rd party commissioning professionals. Building Commissioning Association (BCxA) provides guidelines, best practices, tools, industry studies, technical conferences and training.

Example: Building lighting control system upgrade project to replace existing system that no longer meets owner requirements. Upgrades include additional features related to zoning and scheduling; however, without any engineering requirements, a permit or code official was not involved thus there wasn’t any enforcement towards updated code requirements. In this situation, more stringent performance requirements would be enforced by the Owner via the OPR with input from the project team.

The existing ongoing commissioning program was developed in accordance with LEED-EBOM requirements built upon the ASHRAE Guideline 0 Commissioning Process and adapted for an existing facility using ASHRAE Guidelines 0.2 and 1.2 with an emphasis on functional performance testing, issue resolution, and measure development to meet documented owner requirements.

The lighting control system upgrade project represents a new vendor provided/installed system. As such, the proposed commissioning scope is based upon ASHRAE Guideline 0 and tailored to cost effectively meet client expectations by focusing on functional performance testing and reporting. Per Guideline 0, pre-design phase activities include assistance with development of the OPR via updated occupancy schedules and construction phase activities include submittal verification, functional test procedure development, Cx visit/meeting, functional test execution and training verification. The existing ongoing commissioning program will utilize the updated OPR and test documentation from this project to complete occupancy/operations phase activities.

In general, the commissioning scope could be expanded for increased conformance with ASHRAE Guidelines by engaging the commissioning provider earlier in the process to assist with pre-design phase OPR development, design phase submittal reviews and more involvement during the construction phase to ensure proper installation prior to the start of testing through adherence to project Cx Plan.