Natural ventilation potential for gymnasia - Case study of ventilation and comfort in a multisport facility in northeastern United States

- Natural ventilation potential to maintain acceptable air quality and thermal comfort may be significant for gymnasia.
- Wind and buoyancy driven forces can complement or oppose each other depending on the wind direction and opening position.
- Larger net openings that are more evenly distributed performed better.
- Rooftop vents improve ventilation performance, particularly under unfavorable wind conditions.
- More attention is needed to achieve the IAQ-thermal balance of controlled natural ventilation.

The natural ventilation potential to maintain acceptable indoor air quality (IAQ) and thermal comfort in gymnasia was investigated using a university multisport facility in northeastern United States as a case study building. A parametric modeling study was conducted considering the effects of opening configurations and control strategies during the summer months. The thermal accuracy of the model was verified using field measurements during August 2015. Performance metrics for IAQ and thermal comfort were the percentages of occupied hours during which ventilation rate met or exceeded ASHRAE Standard 62.1-2013 and temperature met adaptive thermal comfort criteria of ASHRAE Standard 55-2013, respectively. Wind direction was found having a major effect on cross ventilation rate. Wind and buoyancy driven forces could complement or oppose each other depending on the wind direction and opening position. Relative to the base case, larger net openings that were more evenly distributed performed better. Rooftop vents improved ventilation performance, particularly under unfavorable wind conditions. With improved opening configurations, the acceptable ventilation hours increased from 21.5% to 99.5% of occupied time for the maximum occupancy. The strictest temperature-controlled strategy had the best thermal performance. Thermal comfort conditions could be maintained during 85.3% of the occupied hours. However, the temperature rule largely shortened the opening operation time, and consequently decreased the acceptable ventilation hours to only 47.1%. Continuously natural ventilation during occupied time gave the longest combined IAQ-thermal acceptable hours, 73.9% of the occupied time, although it moderately decreased the thermal comfort hours to 74.2%.