Last part of this topic that deals with how to design, install, operate and maintain high performance air conditioning systems.
by Camilo Botero *
After having developed the theme of high performance air conditioning, phases of a project, the concept of bEQ (Building Energy Quotient) and the optimization of air conditioning using the main novelties of the industry, now we will analyze processes such as the construction phase, the phase of occupation, operation and maintenance and the final report.
The objectives of the commissioning process should be defined during the construction phase through meetings and precise communications and updating the quality assurance documents. Verification of verification documents is also necessary: checklists and test procedures. Another activity is to define the training needs and verify the construction activities, and to prepare for the delivery to the owner of the work.
It is necessary to verify that the specifications of the construction if they comply with the requirements of the owner and for this are required under conditions:
- Verify the training of the owner's staff.
- Check the systems manual.
- Update the owner's requirements and the commissioning plan.
- Facilitate communications.
- Update the bases of the design.
- Update the owner's requirements.
- Update the commissioning plan.
- Implement the checklists and testing procedures.
- Implement the training plan.
- Prepare the systems manual.
The commissioning team is the means to have effective communications and finally obtain the acceptance of the owner, through official meetings and through the skillful use of the work Log. The members of the commissioning team in this phase are the commissioning management, the owner's representative (Project Manager, operation and maintenance personnel), the design team representatives (including specialized consultants, contractor representatives (including subcontractors, especially adjustment and balancing professionals and controllers) and representatives of the brands of the most important teams, who will review again the following:
- Owner requirements: update according to the owner's orders.
- Basis of the design: update according to the changes of the requirements of the owner.
- Checklists for construction: finalize and implement.
- Test procedures: finalize and implement.
- Manual of the systems: complete and verify.
- Work Log: use
- Commissioning plan: update and expand.
The purpose of the verification is not to provide the contractor with free quality control services, but to provide the owner with assurance that the requirements specified by him are being met. ASHRAE's 202 standard emphasizes the recommendation of strategic sampling where the frequency of the sample will be established by the Commissioning Management.
This is a very controversial issue so commissioning management should establish it with precision. If deviations are found during sampling, responsibilities are established; it is about correcting them and if this is not possible, the activity is rejected. The financial responsibility for these reprocesses must be contractually defined.
The owner's requirements for the project are set, as the benchmark against which the checks should be made, but generally the contractors are bound by the contract documents and not by the owner's requirements. If there are deviations from the contract, they are relatively easy to correct, but if the deviations are presented with respect to the owner's requirements and are not in the contract, the matter is more complicated.
The contingencies to resolve conflicts of the previous nature, must be discussed and taken into account. In theory, in the verification of design documents should prevail the requirements of the owner of the project, versus the contractual.
The elements of the construction checklist and testing procedures that involve starting or activating a device must be done by the contractors under the observation of the commissioning team and other interested parties. The verification of such activities would be based on witnessing the start-ups and elaborating the protocols of tests and starts and documenting them.
Verification of documents, such as the system manual, are usually accompanied by the review of the commissioning team. The verification of the training must be carried out in person, with exams and / or interviews. The commissioning management verifies that a specific sample meets the quality and quantity expectations that appear in the owner's requirements and the verification is made to look for problems and minor deviations that can be resolved via the work's log, but the Major deviations require concerted action with the commissioning team. The owner is responsible for the final acceptance of deviations that impact their requirements.
The commissioning management does some checks, supervises others and verifies that it complies with the owner's requirements regarding quality and quantity, as it appears in the documents for the construction. Its function is to detect the problems, and the deviations are corrected by work log or meetings with those involved. The owner reserves the final responsibility for the acceptance of the solutions. The commissioning team supervises the selected tests and verifies that the test procedure is met.
The commissioning team supervises the selected trainings and verifies that the training activities are carried out in accordance with the commissioning plan. We are looking for possible deficiencies in the training. Minor and major deviations are corrected as explained above. The final responsibility for acceptance of these training will be the owner.
Systems Manual: the commissioning team verifies that the systems manual is complete in accordance with the commissioning plan. We are looking for possible deficiencies in the documentation that should appear in said manual. Minor and major deviations are corrected as explained above. The final responsibility for acceptance of this manual will be made by the owner.
Phase of occupation, operation and maintenance
The objectives of the commissioning process in the occupation & operations phase must be clearly defined. This is defined by the commissioning team, among them are:
- Update of the commissioning documents.
- Workshop of lessons learned.
- Final report of the commissioning team
- Close the commissioning process
- Prepare the owner for a long-term use of the facilities where the project was carried out.
- Complete the tests specified for this phase of occupation and operations.
- Minimize after-sales calls to contractors and suppliers.
- Document the lessons learned
- Give assistance during matters that concern guarantees.
- Provide assistance with accompaniments to the operations of the facility so that they meet the requirements of the owner.
- Closing formally the process, by means of a record of delivery of the Project to the Owner.
- Coordinate calls to contractors.
- Verify the tests that were left for this phase.
- Verify the training during this phase.
- Make sure that the systems manual is complete, careful and accessible.
- Update the requirements and the commisionning plan for file.
- Close the work log and deliver it to the owner.
- Make a workshop of lessons learned.
Complete and submit the final report of the commissioning process, owner requirements and design bases:
- Take into account what and update if necessary:
- Training materials: incorporate them into the systems manual.
- Manual of the systems: verify and use.
- Log of work: close and archive in a place of easy access.
- Commissioning plan: update.
- Develop and deliver the final report of the commissioning process
- Although most participants are ready to move in this phase, everyone can benefit from this exercise.
- The owner can benefit from the information received and compare the results with their initial requirements.
- The design team would benefit by comparing their design criteria with the results.
- Likewise, contractors can see how their assemblies perform.
- And commissioning management can benefit from all these experiences, for future projects.
- Identifies any system or assembly that does not perform according to the owner's requirements and notes the ramifications of such deviations.
- Evaluates the operating conditions of the systems and assemblies after the tests are completed.
- Summarizes the content of the blog.
- Defines the project reference points.
- Record the lessons learned.
- Ideally, it highlights the benefits of the commissioning process.
- Without accusing, it shows the problems solved and the costs abolished, improved performances etc.
Finally, I want to leave the following reflections regarding the assurance of quality in an air conditioning project, because even when all those involved in this project have clear their own functions, they must adopt this methodology that will undoubtedly benefit them greatly.
1 The Owner can benefit from the information obtained from the various parties involved that relate the deliverables, with their requirements, wishes and specifications.
2 The design team can benefit from the topics that relate the design processes to the implementation of them in the construction phase and verify if their premises and assumptions were fulfilled, especially in the phase of occupation, operation and maintenance.
3 The contractors can benefit from the topics that relate the construction processes and equipment used up to them in the construction phase and verify if their processes and techniques were fulfilled, especially in the phase of occupation, operation and maintenance.
4 The ASHRAE 202 standard is a methodologically very convenient and easy to follow guide to achieve high performance air conditioning projects. Its use is recommended.
* Camilo Botero is the current Secretary of the Federation of Latin American Associations Air Conditioning & Refrigeration - FAIAR; he was president of ACAIRE and is president of Camilo Botero Ingenieros Consultores Ltda. He has taught in several Colombian, guilds and now universities in ACAIRE courses graduate air conditioning projects, energy efficiency in air conditioning and refrigeration, cogeneration and trigeneration , psychometrics applied thermodynamics, fluid mechanics, heat transfer and turbomachinery. (Cbg@cbgingenieria.com).