Natural ventilation control strategy

[shorowit]

Currently natural ventilation is assumed to occur whenever outdoor conditions are favorable for cooling and outdoor HR < 0.0115, per ANSI/RESNET 301-2022, based on the operable window area.

Could allow some additional inputs:

• How often windows are open (e.g., # days/week) Natural Ventilation Availability #1161
• Seasons (heating vs cooling vs swing) Natural ventilation enhancements #2152
• How much an operable window can be opened (e.g., 50% for a double-hung window) Natural ventilation enhancements #2152
• Disallow natural ventilation during certain hours (e.g., overnight)
• Allow diversity of days/week of operation (random, 8760 schedule, etc.)
• For stochastic occupancy, align w/ occupants being home?

[shorowit]

One possibility would be to offer a schedule that represents the percent of operable window area that is open at any given time. For example:

<WeekdayScheduleFractions>0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0</WeekdayScheduleFractions>
<WeekendScheduleFractions>0, 0, 0, 0, 0, 0, 0, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0</WeekendScheduleFractions>

This would mean that windows are never open on weekdays, and on weekends windows can only open between 7am and 11pm, with 10% of the operable window area opened. (10% could represent, e.g., the assumption that 50% of the area of operable windows can be open, and 20% of that openable area is actually opened by occupants.) Of course, natural ventilation would still only occur based on outdoor temperature/humidity constraints, etc.