New building owners might want to double check the performance of their ventilation systems before accepting the door keys from their contractors. A National Institute of Standards and Technology (NIST) analysis* of a recent Environmental Protection Agency (EPA) survey of 100 representative U.S. public and commercial buildings found that actual post-construction ventilation conditions are often different than expected based on the building design.
The analyzed data showed frequent instances of underventilation, a condition that can cause poor air quality, occupant discomfort and even illness, as well as overventilation, a situation that can boost energy costs dramatically. The NIST researchers said such findings highlight the importance of early testing of a ventilation system's ability to achieve design intent. The differences between actual versus the predicted ventilation rates also argue for subsequent regular maintenance checks. They noted instances where building engineers could not find ventilation systems plans or found the ventilation system equipment itself inaccessible and urged building designers and operators to remedy the situations.
A key goal of the U.S. EPA Building Assessment Survey and Evaluation (BASE) study was to define the status of the existing U.S. building stock with respect to indoor air quality, ventilation and occupant perceptions of environmental conditions. NIST's analysis and the original data should be useful for establishing standardized protocols for future indoor air quality studies, examining the relationship between symptoms reported by occupants and building characteristics, and developing guidance on building design, construction, operation and maintenance.
* A. Persily, J. Gorfain, Analysis of Ventilation Data from the U.S. Environmental Protection Agency Building Assessment Survey and Evaluation (BASE) Study, NISTIR 7145, is available at http://www.bfrl.nist.gov/pdf/BASE-final.pdf.
The above story is based on materials provided by National Institute Of Standards And Technology (NIST). Note: Materials may be edited for content and length.
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