ACG Member Nathan Culley, TBE, CxA, Penn Air Control, Inc. Discusses Preconstruction HVAC Surveys - HVAC/P Magazine
ACG and AABC Member Nathan Culley, TBE, CxA, Penn Air Control, Inc. published "Setting the Stage" in HVAC Plumbing Product News, Spring 2021.
Over the past several years we have seen a trend in how HVAC upgrade or remodel projects are designed, . mechanical Mechanical engineers have increasingly required a pre-construction survey of the existing HVAC systems when designing new systems or remodeling the existing systems
Air flow at the unit and at each supply return and exhaust grille should be measured and temperatures recorded in heating and cooling modes. For hydronic systems, water flow rates and temperatures should also be measured. Every hospital building is different, as are is each HVAC system, so the engineer of record should request the specific information they need to design a complete and functional system with limited changes during construction. (Note: Chapter 25 of the AABC National Standards for Total System Balance is specifically devoted to testing and balancing of healthcare facilities, and an excellent resource for both engineers and balancing professionals working on these projects.)
In selecting a company to perform this type of work, there are some items that should be considered. The agency conducting the survey should have experience with hospital construction standards, HVAC requirements as well as knowledge of current ASHRAE standards. The technicians should be trained and certified in Testing, Adjusting and Balancing (TAB) of HVAC systems as well as commissioning of HVAC and controls systems. Ideally, the work would be performed by a 3rd party company, independent from the design or construction teams so there is no conflict of interest between parties and the owner. This can assure they are receiving an unbiased report. A reliable guide for reference would be the Associated Air Balance Council (AABC) National Standards which gives specific, detailed procedures for testing of HVAC system components.
The goal of a HVAC system remodel is to improve its function for hospital facility stakeholders. To achieve this, it's imperative to have TAB technicians document the existing conditions prior to the start of a renovation or remodel project. This will ensure the work is communicated clearly to the design team and that the project is completed efficiently with minimal problems.