Multizone Modeling Approaches to Contaminant-Based Design.
Multizone Modeling Approaches to Contaminant-Based
Musser, A.; Persily, A. K.
ASHRAE Transactions 2002 Annual Meeting. Proceedings.
2002, Honolulu, HI, 1-8 pp, 2002.
ASHRAE Transactions, Vol. 108, No. 2,
air quality; source control; contaminant; volatile
organic compounds; ventilation; depressurization fan
Indoor air quality is currently addressed in the design
process primarily through prescriptive building codes
based on specified flow rates. However, a
contaminant-based design approach opens the door to
design innovation, offering opportunities for improved
indoor air quality, energy conservation, and reduced
environmental impact. This paper discusses current
design approaches, and some possibilities for the future
of contaminant based design. Techniques and modeling
approaches that could be used today are demonstrated
using examples from a case study building. A multizone
network airflow model is used to stimulate airflow
rates, pressure relationships, and contaminant transport
to support the design. These simulations are utilized to
specify minimum ventilation rates to control
non-occupied related contaminants for a system with
carbon dioxide demand control. Contaminant buildup
during an overnight shutdown is also studied, and
strategies for a pre-occupancy purge are developed. The
model is also used to size an exhaust fan to negatively
pressurize an enclosure housing a biological process.
The case study identifies the critical, or design
conditions that must be addressed, and discusses
strategies that could be used to meet them with