Optimize with P2S - Retro Cx | P2S
Swipe To Continue
Swipe To Continue

Optimize with P2S
Retro Cx

Planning &
Investigation Phases

Retro-Commissioning (RCx) is a systematic process for improving and optimizing a building’s operations and supporting those improvements with enhanced documentation and training. The process seeks to improve how building equipment and systems function together. As owners are moving towards net-zero, improving energy efficiency, and lowering carbon emissions, retro-commissioning can be a cost-effective solution to help diagnose/resolve existing issues and reduce energy consumption.

The process begins with the Planning Phase. P2S works with the client to discuss the project goals during this time. These goals can include reducing energy usage, investigating issues with consistent cold/hot calls, equipment short cycling, etc. Once the goals are identified, P2S works with facilities to collect all of the basic building information (latest drawings and specifications, equipment lists, any O&M documentation, control as-builts detailing the installed sequence of operations, energy bills, maintenance records, etc.). We also conduct walkthrough inspections to review all of the equipment with the facility's staff. P2S then develops a Current Facilities Requirements (CFR) document through a series of meetings. This document includes the latest building occupancy schedules, the intended uses for each space, required zone temperature/humidity ranges for each space, and more. Using the goals, existing documents, building walkthroughs, we then develop a retro-commissioning plan.

Once the planning phase is completed, P2S moves on to the Investigation phase. During the investigation phase, P2S will review project documentation such as drawings, specs, as-builts, installed equipment nameplates, and the building automation system’s trends and programming logic. We would then develop Functional Performance Test (FPT) plans based on the documentation available and the newly developed CFR. The FPT plan with step-to-step procedures will be followed and filled out with test data and findings during our field investigation visits. P2S will physically verify critical sensors locations and operations (temperature, humidity, flow, pressure, airflow measuring stations) and verify their calibration, as well as physically verify the devices (dampers, valves, actuators, VFDs). We will finally test the operation sequences to verify the actual programming of equipment. All issues identified are presented in an issues log that details the faults, and P2S provides recommended solutions. If addressing these items will provide energy savings, these will be defined as Energy Conservation Measures (ECMs). The ECMs are then prioritized as no cost, low cost, or high cost. An RCx Investigation Report is finalized and submitted to the client, including energy savings calculations and simple payback analysis for the ECMs.

Implementation &
Verification Phases

At this point, the project will move on to the Implementation Phase. During this time P2S and the client work together to develop and execute the implementation plan. This plan is focused on implementing the items in the RCx Investigation report. Depending on the level of effort, some ECMs can be implemented without hiring additional sub-contractors while others may require design documents, control upgrades(new sensors or sequences), a contracted controls contractor, etc. The duration of the implementation phase can vary depending on the ECMs identified during the investigation phase and the level of effort required to implement these items.

The final stage will be the Verification Phase. After the implementation phase is complete and the ECM items selected for implementation have been installed/programmed, P2S revisits the site for another round of functional testing and verifications. P2S will verify all of the work completed during the implementation phase was done according to the implementation plan and will verify facilities personnel are adequately trained to ensure the new changes can be properly maintained to facility goals. P2S will verify the ECMs work as intended and confirm energy savings. The Verification Phase will conclude with a final RCx report that includes all activities completed during the RCx process.

Some simple investigations can be done to verify the system's overall performance and identify energy-saving measures. These include:

  • Building and Space Schedule Optimization – Verify equipment is off when not in use
  • Setpoint Verification – Verify system setpoints are programmed properly
  • Setpoint Control – Verify system components control to setpoints properly
  • Economizer Control Operation – Verify minimum ventilation and proper free cooling
  • Heating & cooling leakage – Verify temperature gain across coils
  • Heating and Cooling Control – Verify no simultaneous heating and cooling
  • And more.

The commissioning professional typically includes a more in-depth review of the current system operating condition and makes suggestions for improvements. These include:

  • Safety Protection – Test and verify the safety devices are still operational
  • Control Sequence Improvement – Implement setpoint automatic reset strategy
  • Verify system capacity – Test fan airflow, heating, and cooling capacities
  • Evaluate System Improvement Opportunities – Add occupancy sensor interlock
  • And More

Systemic
Process

Through a systematic process, retro-commissioning can help:

  • Improve building operation and reduce maintenance calls
  • Reduce building energy consumption and lower energy costs
  • Diagnose and resolve existing issues with systems or equipment
  • Improve indoor air quality and occupant comfort
  • Help diagnose and resolve problems that occurred during design or construction
  • Identify the discrepancies between the as-built documents and the installed system
  • and more

Retro-commissioning helps building owners save money in the long run by lowering energy consumption and maintenance costs. The payback period on this investment is usually very short. In fact, some local governments offer incentives for clean building energy that require retro-commissioning and energy audits. These incentives will further shorten the payback period on the investment. P2S has certified commissioning professionals and energy auditors who can guide the building owners through retro-commissioning.

Learn more about our Retro Cx projects below!

Learn more

Form has been submitted successfully!

Bryant Mercado

Group Leader

Contact

CSULB Housing Expansion

P2S Project

View Project

SDSU College of Arts & Letters MBCx

P2S Project

View Project

UCSD Mandesville Hall

P2S Project

View Project

UC Irvine Strategic Energy Plan

P2S Project

View Project