ads ENGINEERS through its Sustainable Service Group, SSG, is prepared to assist building owners in developing and implementing a program reflecting these City mandates.  A brief description of each critical component of Local Law 0967, energy audit, retro-commissioning, and verification of corrective measures is discussed below.  The law requires an energy audit be performed to identify both low cost operational improvements and potential capital improvement projects to the base building systems that provide an attractive return on investment.   The energy audit must be performed in accordance with the requirements of a Level II audit as described by ASHRAE’s Procedures for Commercial Building Energy Audits.  This is a fairly detailed engineering study that includes a review the mechanical and electrical system design and operation, site survey, energy analysis, and identification of corrective and operational measures.  The energy efficiency report shall identify potential capital improvements along with estimated energy savings, costs, and their payback.

Prior to filing the energy efficiency report the building must be retro-commissioned.  Retro-commissioning is the systematic process using testing protocols for optimizing the energy efficiency of existing mechanical and electrical systems through the identification and correction of system deficiencies, adjusting and calibrating of controls, and making modifications in operational and control sequences.    The process includes identifying the system requirements, developing and performing customized functional tests to determine if systems and equipment are performing properly and in an energy-efficient manner, confirming that repair work has been done, evaluating the adequacy of operator training, and system documentation.

While the energy audit and retro-commissioning efforts can be seen as discrete projects they really represent a continuous process culminating with the filing of the energy efficiency report with the City.   Part of this process is identifying, performing, and documenting that a number of corrective measures have been completed prior to the report being filed.  These types of corrective measures are usually low in first cost and have excellent payback.  These measures can include verification of the following:

•           Control devices must be calibrated.

 •           Appropriate temperature and humidity set points have been incorporated in the control sequences, economizer controls are functioning, there is no simultaneous heating and cooling, and reset functions are operating properly.

 •           Permits for all HVAC, electrical, and plumbing equipment are in order.

 •           Ventilation rates are appropriate for the current facility requirements.

 •           Airside and waterside HVAC distribution systems are properly balanced.

 •           Lighting levels are appropriate to the task and lighting controls are operating properly.

 •           Water leaks have been identified and corrected.

 •           HVAC equipment ducts, vents, and coils are cleaned.

 •           Boilers tuned and steam traps operating properly.

 •           Exposed steam, hot, and chilled water pipes are insulated.

 •           Appropriate weather stripping and sealants installed.

 •           Operating staff is adequately trained in their system operation and general energy conservation techniques.

 •           System documentation including Operation and Maintenance Manuals are up to date.

Clearly the energy audit, retro-commissioning, and the corrective measures described above will take time and money.  The good news is that implementing these measures can result in significant energy cost savings.  However, owners will need to start the process of complying with the new law as early as practicable.  SSG is ready to sit down with you to discuss the best approach to complying with the new law.   

Energy Audit

The law requires that an approved energy auditor perform an energy audit on the building.  The intent is to identify both low cost operational improvements and capital projects with an attractive payback that will results in reduced energy consumption and reduced energy costs.   The energy audit must be performed in accordance the requirements of a Level II audit as described by ASHRAE’s Procedures for Commercial Building Energy Audits.   This is a fairly detailed engineering study and includes the following as a minimum:

 •           Review the mechanical and electrical system design and operation through a review of drawings, building survey, measurement of key operating parameters, and interviews with operating personnel.

 •           Using the energy bills, floor area calculations, and its functional use breakdown, the building’s energy use shall be bench marked so the building can be compared with other similar buildings.

 •           Provide a breakdown of the building energy use by end-use components.

 •           Identify corrective measures that need to be addressed to allow systems to perform as designed.

 •           Identify low cost operational changes and low cost measures that can reduce energy use.

 •           Evaluate potential energy efficiency measures and capital improvements.  For each measure calculate energy saving potential, capital cost, additional operation and maintenance costs and simple payback.  The analysis may be done using either manual or computerized calculations.

 •           Recommend measurement and verification procedures to determine the effectiveness of the recommended measure.

 •           Identify capital intensive measures that may require a more detailed engineering analysis.

 Retro-Commissioning

Prior to filing the energy efficiency report the building must be retro-commissioned.  Retro-commissioning is the systematic process using testing protocols for optimizing the energy efficiency of existing mechanical and electrical systems through the identification and correction of system deficiencies, adjusting and calibrating controls, and making changes in operational and control sequences.  Following is a description of the retro-commissioning process:

•           Along with the Owner, building management, and operations staff create the Current Facilities Requirements document.

•           Develop a retro-commissioning plan that outlines the organization, schedule, allocation of resources, and documentation requirements of the retro-commissioning process.

•           Develop customized functional performance test procedures to determine if equipment is operating in accordance with the original design intent and control sequences.

•           Perform functional tests that include operating the systems and components through each of the written sequences of operation including start up, shutdown, unoccupied mode, manual mode, staging, reset, miscellaneous alarms, etc.

•           Maintain a master issues log and a separate record of functional testing.

•           Identify repairs and minor corrective measures such as changing control set points, modifying reset schedules, or adjusting sequences of operation as well as identifying more substantial measures requiring re-design and equipment modifications.  Prepare estimates of potential energy savings for each measure as appropriate.

•           Confirm that equipment repairs have been made, that the operations staff is adequately trained in their system operation and general energy conservation techniques, and that system documentation including Operation and Maintenance Manuals are up to date.

•           Prepare a retro-commissioning report that documents and certifies the findings for filing with the City.

                                                        ads ENGINEERS is a member of the US Green Building Council and the Building Commissioning Association. 
                                                        For more information contact Lorey Flick, PE at Lorey.Flick@adsce.com or visit our website www.adsce.com.