Validation of CONTAMW Predictions for Tracer Gas in a Townhouse.
Validation of CONTAMW Predictions for Tracer Gas in a
Emmerich, S. J.; Nabinger, S. J.; Gupte, A.;
Building Simulation 2003, 8th International Building
Performance Simulation Association (IBPSA) Conference.
Proceedings. August 11-14, 2003, Eindhoven,
Netherlands, 299-306 pp, 2003.
tracer gas; validation
To provide additional validation data for the multizone
airflow and contaminant model, CONTAMW, experiments were
performed in an occupied 3-story townhouse in Reston,
VA. A tracer gas, sulfur hexaflouride (SF6), was
manually injected within one room of the house and the
concentration of SF6 was measured in each zone. This
same process was then recreated in CONTAMW and the
resulting predictions were statistically compared to the
measured values. A total of 10 experiments were
conducted and simulated between May 2000 and June 2001.
The tests involved injecting 1500 mL of 1% SF6 in a
single room of the house. In 4 of the 10 cases, the
heating and air-conditioning system fan was operating.
SF6 was injected in the Recreation Room (basement
level), the Kitchen/Dining Room (main level) and the
Master Bedroom (upstairs level). Ambient conditions
ranged from a low outdoor temperature of 5 C to a high
of 29 C. Wind conditions ranged from calm to moderate
with a high average wind speed of 4 m/s. A statistical
comparison of measurements and predictions was performed
per ASTM D5157 (ASTM 1997) for all cases. Comparisons
were made for overall zone average concentrations and
individual zone transient concentrations. The results
for zone average concentrations were very good with many
cases meeting most or all of the D5157 criteria. Several
cases showed a poor to fair correlation between average
measurements and predictions due to discrepancies with a
single zone - the main floor bathroom - but excluding
that zone resulted in these cases meeting or nearly
meeting the D5157 criteria. Comparisons of individual
zone transient concentrations were mixed with many good
to excellent cases but also numerous fair to poor. As
expected, there were frequently large differences
between measured and predicted peak concentrations.
Also, the bathroom zone was a consistently difficult
zone to predict accurately. Other zones had occasional
poor comparisons between predictions and measurements
but no consistent discrepancies. The predicted SF6
concentration averaged over all zones and cases was
within 10% of the average measured concentration.
Excluding the bathroom zone, the overall average
predicted concentration (115 mumg/m3) was essentially
identical to the overall average measured concentration