IAQ 2016 Defining Indoor Air Quality: Policy, Standards and Best Practices Co-Organized by ASHRAE and AIVC

The potential of natural ventilation to maintain acceptable air quality and thermal comfort in gymnasia was investigated via a case study and parametric modeling of a multisport facility at a university campus in the northeastern United States. Indoor temperatures at multiple locations were recorded for six days during August 2015 to verify the thermal accuracy of this model. Model and measurements differed on average by 0.5 degree C. A parametric modeling study considered the effect of a range of natural ventilation opening configurations, sizes. Simulations covered the summer months June, July, and August. Metrics for performance were hours during which at least the minimum ventilation flow rate required by ASHRAE Standard 62.1-2013 was maintained and hours during which temperature fell with an acceptable range as defined by the adaptive thermal comfort model in ASHRAE Standard 55-2013. Ventilation opening alternatives included increasing opening size or opening effective ventilation area of existing wall vents and adding rooftop vents.

With the focus on low energy and sustainable buildings today, building designers, engineers and researchers alike increasingly attempt to incorporate natural ventilation in innovative building practices. Despite the interests and collective effort, one key component of natural ventilation, the wind, has proven to be a difficult riddle to solve due to its unsteady nature. One difficulty with predicting wind-driven airflow is the determination of the amount of wind power available as a driving force for ventilation purposes. While it is common practice to assume the wind is steady and often hourly averages from TMY3 weather data are used for wind estimation, such assumption could be error prone due to variability of wind within the one-hour interval provided by the TMY3 data.To specifically investigate this issue, this study incorporates the much finer wind data from the National Oceanic and Atmospheric Administration (NOAA) National Weather Service (NWS) Automated Surface Observing System (ASOS), location-specific weather datasets with 1-minute resolution. Incorporation of such small time steps allows a probabilistic interpretation of how wind would have impact the nature ventilation design. Furthermore, computational fluid dynamics (CFD) was used to investigate the potential wind-driven ventilation flow rate based on this new statistics based wind data, and a comparison to the current state of the art estimation is provided.

In churches, intentional airing may be a measure to evacuate temporarily high levels of contaminants that are emitted during services and other occasions. Crucial contaminants include moisture and other emissions that may deteriorate and/or soil surfaces of paintings and other precious artefacts. Most churches do not have any mechanical ventilation system or any purpose provided openings for natural ventilation, but the ventilation is governed by air infiltration. Enhanced airing may be achieved by opening external windows or doors. Thus, models provided in energy simulation programs should predict this kind of air flows correctly, also in order to get a proper estimation of the total energy use. However there might be some limitations for airing in historical ancient buildings regarding moisture transfer, since at some conditions the outdoor air might be too humid. IDA-ICE is examined here and the models for humidity used in the program are investigated. In the present study, field measurements are performed for airing rate and moisture transfer in a historical church and the results are compared with modelled results from IDA-ICE energy simulation program.