Hello,
I am using EnergyPlus v9.5 for load calculations. The zone we are looking at has an exterior wall area of 221SF and a window area of 75 SF. The design day outdoor air temperature is -1.4F and the room heating setpoint is 75F (deltaT=76.4F). This project is at elevation near Denver.
We are using the ZoneInfiltration:DesignFlowRate object (see image).
image:
The infiltration schedule is a constant value of 1.0.
The resulting hourly variable Zone Infiltration Current Density Volume Flow Rate m3/s = 0.0140250881894948 (29.7174789090896 cfm). The Zone Infiltration Standard Density Volume Flow Rate m3/s = 0.0138260174506981 (29.2956719 cfm). The resulting sensible heat loss is 2530.8 btu/h.
image:
image:
2530.8 btu/h = x * 29.2956719 cfm * (75-(-1.4)) results in x being 1.13 (which is at least close to 1.08).
What I am not understanding is how the infiltration flow rate is calculated. A wall area of 221 SF * 0.11cfm/sf = 24.31 cfm, not 29.3 or 29.7. It is almost as if the calculation is double counting the window and wall area or is using the floor area (270sf) instead of the wall area
I have tried messing with the sizing parameters changing them from 1.25 to 1 and nothing changed. I also thought about adjusting for wind, but it was my understanding that that only mattered for the ACH calculation.
Am I missing something? Could this be a bug?
