The NYC Energy Conservation Code establishes the minimum energy performance for buildings, and commissioning becomes mandatory in projects that meet certain conditions described in the code. In these cases, commissioning must follow an established procedure and specific documentation requirements.
Normally, the energy code only applies for new constructions and for existing buildings that undergo a major change or renovation. The code does not impose energy retrofits on existing buildings, except in cases where a local law mandates a specific upgrade. An example of this is Local Law 88, which requires code-compliant lighting upgrades for all buildings under its coverage by 2025.
The mandatory commissioning requirements in the energy code are for commercial buildings. However, note that high-rise multifamily constructions are considered commercial under the energy code. Only the following building types are subject to the residential requirements:
- Detached one- and two-family dwellings, up to three stories tall (above grade).
- Buildings with three or more attached townhouses, up to three stories tall.
- Buildings classified as R-2, R-3 or R-4 under the 2015 International Building Code, Chapter 3, up to three stories tall.
- Factory-manufactured homes and mobile homes
If a property is used for residential purposes, but it does not meet any of the conditions above, it is subject to the commercial requirements of the NYC energy code. In many cases, this includes a mandatory commissioning procedure.
Meet the commissioning requirements in the NYC Energy Code
NYC Energy Code Commissioning Process
Buildings subject to commissioning under the NYC Energy Code must follow the procedure described in section C408. Even if all building systems are installed correctly, the project cannot pass the final inspection unless the owner provides evidence of commissioning by an approved agency.
Step 01 - The Commissioning Plan
The first step is developing a plan to guide the process. This plan must be written by an approved agency, covering the following points:
- A list of activities during each step of commissioning. The list must include a narrative description of each activity and the personnel involved.
- Description of the equipment, appliances and systems to be tested. This section must include the sequences of operation for all systems involved, and a detailed description of the tests. If any step in the process has prerequisites or requires specific documentation, it must be pointed out here.
- System functions to test during commissioning. This includes specific calibrations and economizer controls.
- Required conditions for each test. This includes identifying which tests can only be performed during a specific season of the year.
- Measurable performance criteria. The units and metrics used for a quantitative description of system performance are established in this section.
Step 02 - System Adjusting and Balancing
HVAC systems involve airflow, and many configurations also use water to transport thermal energy. To deliver heating and cooling effectively, these air and water flows must be balanced. The NYC Energy Code requires adjustment and balancing according to ASHRAE 111 or any equivalent standard approved by the NYC Department of Buildings.
- Air systems balancing: Ventilation systems must be equipped with air balancing means that meet the NYC Mechanical Code, Chapter 6. The main priority during air balancing should be to minimize throttling loss, and then adjust fan speed to provide design airflow.
- Hydronic systems balancing: Heating and cooling coils must include flow balancing and measurement means. Just like with air systems, the priority is to minimize throttling losses, and then adjust pump speed or trim the impeller to provide design flow. The system must be capable of measuring pressure difference across each pump, or alternatively, pumps can be equipped with test ports at the suction and discharge.
Balancing means are not mandatory for equipment below certain capacity thresholds: fans with motors up to 1 hp, and pumps with motors up to 5 hp. Pumps are also exempt from balancing if throttling does not increase losses by more than 5%, with respect to the power drawn with a trimmed impeller.
Step 03 - Functional Performance Testing
As its name implies, this step ensures building systems are properly installed and configured, so they can offer the performance specified in the design documents.
- Equipment tests verify the installation and operation of components, systems and their interfaces. The tests should cover not only full-load and part-load conditions, but also emergency operation. The procedure also includes maintenance serviceability.
- Control tests ensure that HVAC and hot water control systems are calibrated and adjusted, so the system operates as described in the approved design documents. This includes sequences of operation.
- Economizer tests ensure that air economizers operate as specified by their manufacturer.
- Lighting system tests focuses on automatic controls, ensuring they operated as described in the approved design documents. Specific requirements are provided for each subtype of lighting controls- occupancy sensors, time-switch and daylight responsive.
Step 04 - Preliminary Commissioning Report
The preliminary commissioning report accomplishes two main functions:
- Describing deficiencies found during the testing procedure that are still pending for correction.
- Listing the tests that could not be performed due to climate conditions, and describing the conditions required to perform them correctly.
Once the preliminary commissioning report is delivered to the building owner, and the corresponding code official is notified formally with a letter of transmittal, the building can be subject to the final inspection process.
Step 05 - System Balancing Report
The system balancing report provides a detailed description of the adjustment and balancing procedure for air and hydronic systems, including the measurements carried out.
Step 06 - Final Commissioning Report
Once all deficiencies and pending tests identified in the preliminary commissioning report have been corrected, the final commissioning report can be written and delivered. After a building receives the certificate of occupancy or letter of completion, there is a deadline for final report delivery, which changes based on building conditions:
- 30 months for buildings with at least 500,000 square feet, excluding R-2.
- 18 months for buildings smaller than 500,000 square feet, and all R-2 buildings regardless of area.
Conclusion
Commissioning is a challenging procedure due to the variety of building systems involved, and your building cannot receive a final inspection until you complete commissioning and its preliminary report. However, this is not an issue if you work with qualified professionals who are familiarized with NYC code requirements and the corresponding documentation. As a property developer, it is in your best interest to avoid a long approval process, since it delays tenant occupancy and payments.
