Third-party peer review can be a profitable business if done correctly both technically and professionally. It is a niche business that not all engineers are qualified to perform and/or have the mindset to do. There is a distinct difference between an anal engineer and an analytical engineer. I must admit I’ve always struggled with being pleasant to anal HVAC engineers because our business is not right up there with rocket science and the +/-10% accuracy philosophy (see last month’s column on this topic). I think there is a saying, “Can’t see the forest from the trees,” that applies to this type of engineer. At the same time, I admire an analytical engineer, just as long as she is also cost-effective in the process.
So, having identified two types of HVAC engineers, we will continue on with the third-party peer review discussion assuming this work is being completed by a cost-effective analytical engineer. My process recommendations for a peer review engineer (PRE) are based on completing a design review before the project goes into construction. Troubleshooting, a discussion for next month, is a third-party review after the installation has been completed and problems continue to nag the project.
PRE Step 1: Remember this is a review of the design and not of the designer.
PRE Step 2: Use standardized checklists that are continuously improved on with each job (e.g., duct distribution checklist, budget values to spot check equipment capacity, etc.).
Comment: Checklists are a time-tested quality control tool, and by standardizing the use of checklists, they inherently help to insure the reviewer will be consistent with each third-party peer review.
PRE Step 3: Create a system flow diagram for each system if the design engineer had not already provided such a document. A “picture is worth a 1,000 words” and so a system flow diagram provides such a picture.
Comment: With a system flow diagram in hand, the reviewer can replicate the document for estimating system static pressure, estimating pump head pressure calculation, and interface with electrical data (e.g., show electrical interlock wiring, type of starter, who furnishes starter, who installs and wires the starter, which starters/systems are on emergency power, and which started are only on normal power).
PRE Step 4: Using the system flow diagram, review the written sequence of operation in sync with the flow diagram to make sure the system has all the ATC components specified and shown on the contract drawings.
Comment: It is also important to ask the question, “Who is responsible for sizing the air dampers and steam and water ATC valves?”
PRE Step 5: Inventory all supply air, return air, and exhaust air at minimum and maximum air flows and during the air-conditioning season, heating season, and 100% airside economizer season.
Comment: My recommendation is to design the HVAC to maintain each floor and the overall building at 5% positive air pressure.
PRE Step 6: Review and compare Division 1 General Conditions to the HVAC contract specification to assure consistency.
Comment: So often, these two sections of the contract documents do not get coordinated and the HVAC contractor will base his bid on the HVAC contract document, but as the construction project begins to close out, the prime contractor will be expecting her subcontractors to follow Division1 requirements.
PRE Step 7: Review the HVAC equipment layouts to assure adequate space for the building O&M crews to perform their job long after the builder has left the site.
Comment: Go back to June, July, and August 2013 columns for more information on this topic as well as additional information when completing a peer review.
In the end, it is important that the review has been completed based on the design and not on the design engineer.