One of the primary goals of Engineered Air Balance is to be an industry leader in providing quality Total System Balance services to the Texas area and beyond. To achieve this objective, we rigorously train our technicians and engineers in the processes and techniques of HVAC Testing, Adjusting, and Balancing as well as provide our customers and construction teams organized, comprehensive documentation to communicate our process and results.
EAB’s TAB technicians and engineers strive to ensure that the engineering design intent of a project is realized at project completion. This is accomplished by taking precise measurements and by making calculated adjustments to every component of the heating and cooling system on a project. The data taken during the air balancing process is documented in a Test and Balance report and submitted at the completion of a project; however, this is only the result of our work, and does not communicate the planning steps required to successfully complete all HVAC testing and balancing tasks before the project deadline.
While smaller projects can be easily managed using simple notes and verbal communication, medium to large projects require the construction team and the TAB team to coordinate well in advance of the TAB team stepping foot on site. This is best done by supplying the construction team with a concise document containing all relevant information needed integrate the TAB process into the project schedule.
This concise document is often referred to as a TAB Plan and should contain several key pieces of information. At minimum, a TAB plan should contain a detailed list of all equipment on a project with a context specific list of prerequisites for the TAB process to begin. Additionally, the plan should include a description of the HVAC TAB process for each piece of equipment, and an estimated timeline, with manpower requirements, for completing each test.
HVAC Test and Balance Prerequisites
It is important that the construction team is aware of the requirements for Testing, Adjusting, and Balancing for HVAC so that a project can be prepared before the TAB team arrives. Below is a short list that includes some of the HVAC TAB prerequisites and why they are important.
Building Access
Building access seems straight forward on paper, but depending on the project, specific areas can be access limited, particularly if the building is partially active like a hospital. Therefore, it is extremely important for the construction team to have building access coordinated before the HVAC Test and Balance team steps foot on a project. This will prevent a situation in which hours or days are lost simply because the TAB team cannot access the equipment or control system.
Installation and Startup Complete
Incomplete equipment startup is likely the biggest hinderance to the TAB process on a project. With the complexity of today’s HVAC systems, many trades must complete their work before a piece of equipment is completely started up. If one link in the chain of communication is broken, startup for that equipment can easily fall through the cracks if not well tracked. Often the TAB team will be told that equipment is ready for TAB, but something seemingly innocuous is missing, derailing the TAB process.
Controls Installed and Functioning
Assuming equipment startup is complete, HVAC system balancing still requires the control system to be installed and functioning. While its occasionally true that the TAB process can be started with no controls functioning, it is far more efficient to balance equipment when it is running in automatic, controlled completely by the building control system.
Building Envelope Complete
An HVAC system’s function is to control the air moving into and out of a space. If the space in question is full of holes, the ability of the HVAC system to control the temperature, pressure, or indoor air quality of that space efficiently, or even at all, becomes nearly impossible to attain. Therefore, it is important that penetrations are sealed, and doors and windows are installed properly. This particularly true when pressure control is important to a space like operating theatres or isolation rooms.
Testing Adjusting and Balancing Process and Timeline
To make it easier for the construction team to make informed decisions while integrating TAB into the construction schedule, it is important to communicate the testing and balancing tasks and the estimated timeline and manpower requirements for each. All too often, incorrect assumptions are made about the scalability or workflow of the test and balance process. This can lead to unrealistic windows for the TAB team to complete work before a deadline like a city or state inspection. Information should include the specific steps the TAB team plans to take for each piece of equipment, the estimated time for each step, the estimated manpower required to complete the step in that time, and any steps that are required to be complete before the next step is started. This information will allow the construction team to understand how long TAB will take, whether some tasks can be done in parallel, and whether the TAB team can be scaled efficiently to complete the test and balance process in a shorter period.
EAB’s TAB Plan Outline
The typical TAB plan that EAB provides is comprised of a minimum of 4 sections. These sections are “Pretesting Requirements”, “Testing, Adjusting, and Balancing (TAB)”, “TAB Plan Outline”, and “TAB Report Outline”.
The Pretesting Requirements section contains a list of requirements that must be completed before TAB can begin. This includes items as simple as “supply, return, and outside air ductwork installation must be complete”, but also more complex items pertaining to specific pieces of equipment on the project that have special requirements.
The Testing, Adjusting and Balancing (TAB) section details the general TAB workflow for the project including the estimated duration and manpower requirements for the project. This section might also mention TAB tests that can be done in parallel vs tests that must be completed before other tests can begin.
The Tab Plan Outline section includes all types of equipment and balancing steps specific to that equipment. This will include any Pre-Balancing steps, like presetting damper positions, in addition to the Final Balancing steps required for each piece of equipment.
The TAB Report Outline section contains a sample report table of contents or outline, and sample field data forms with the intention of giving the reader a sense of what to expect from EAB’s final TAB report. The final TAB report will contain 3 main sections. The “Front End” contains a Title page, Table of Contents, a summary of the project, including any outstanding deficiencies, certificates required for the TAB team, and a list of the instrumentation used on the project. The “Report Data” section is the meat of the report and contains all data recorded on the project during the TAB process. This section is organized by System. A system includes all equipment that is directly connected or operates as a cohesive unit. For example, an air handling unit with all terminal units and grilles, reheat coils, and control systems controlling that equipment would be included in one system. The final section is the “Appendix”. The Appendix contains all project documentation relevant to the TAB process including schedules created by EAB, submittal, drawings, and correspondence. Additionally, the complete Deficiency Resolution Log containing all open and closed deficiencies from the project.
Deficiency Resolution Process
The final section of the TAB report, mentioned in the previous section, is the DRL. EAB Records Deficiencies for a project based on Engineering Document requirements. Deficiencies are recorded on the Deficiency Resolution Log (DRL). A DRL is periodically submitted to the customer or directly to the construction team depending on the project requirements. The construction team replies when deficiency is resolved and EAB backchecks the deficiency. If the deficiency is resolved, it is marked complete. If the deficiency is unresolved, it is marked as incomplete, and the cycle starts again. Each unresolved backcheck is documented on the DRL. Any unresolved deficiencies are included in the final TAB report as Action Items or Info items based on the project document requirements. As mentioned in the previous section, a complete copy of the DRL, including all open and closed items, is included in the final TAB report appendix.
Conclusion
Testing, Adjusting, and Balancing is an important service relevant to many construction projects. The best way to integrate the TAB process into the project schedule is to provide a well-documented plan to the construction team during the planning phase, well before the TAB team sets foot on the project. A TAB Plan is an organized document designed to provide all pertinent information to assist the construction team with integrating TAB into the project schedule. When done well, a TAB plan can have a positive impact on the outcome of a project.