Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
Yes, that's possible, with certain requirements. The simulation assumes neutral pressure unless AirflowNetwork is used. This is because the outdoor air system exhausts an amount equal to the outdoor air. So to ensure that the zones do not result in a negative pressure you need to ensure that the amount of outdoor air equals or exceeds the amount of exhaust air. Exhaust air is accounted for when it occurs in a zone attached to the air loop. For non-air loop zones, a review of the results is required to make sure the air mass balance is correct for this simulation. I would look at the infiltration reporting to see if that amount would offset the toilet zone exhaust. Maybe others have a better solution.
| | 2 | No.2 Revision |
Yes, that's possible, with certain requirements. The simulation assumes neutral pressure unless AirflowNetwork is used. This is because the outdoor air system exhausts an amount equal to the outdoor air. So to ensure that the zones do not result in a negative pressure you need to ensure that the amount of outdoor air equals or exceeds the amount of exhaust air. Exhaust air is accounted for when it occurs in a zone attached to the air loop. For non-air loop zones, a review of the results is required to make sure the air mass balance is correct for this simulation. I would look at the infiltration reporting to see if that amount would offset the toilet zone exhaust. Maybe others have a better solution.
To summarize the conclusion of the below comment discussion:
The additional Fan:ZoneExhaust in the toilet zone is unnecessary. The energy impact of the transfer air on the receiving toilet zone is accounted for by the ZoneMixing object. The toilet exhaust fan power can be accounted for in the Fan:ZoneExhaust that is in the source zone.
| | 3 | No.3 Revision |
Yes, that's possible, with certain requirements. The simulation assumes neutral pressure unless AirflowNetwork is used. This is because the outdoor air system exhausts an amount equal to the outdoor air. So to ensure that the zones do not result in a negative pressure you need to ensure that the amount of outdoor air equals or exceeds the amount of exhaust air. Exhaust air is accounted for when it occurs in a zone attached to the air loop. For non-air loop zones, a review of the results is required to make sure the air mass balance is correct for this simulation. I would look at the infiltration reporting to see if that amount would offset the toilet zone exhaust. Maybe others have a better solution.
To summarize the conclusion of the below comment discussion:
Fan:ZoneExhaust in the toilet zone is unnecessary. The energy impact of the transfer air on the receiving toilet zone is accounted for by the ZoneMixing object. The toilet exhaust fan power can be accounted for in the Fan:ZoneExhaust that is in the source zone. | | 4 | No.4 Revision |
Yes, that's possible, with certain requirements. The simulation assumes neutral pressure unless AirflowNetwork is used. This is because the outdoor air system exhausts an amount equal to the outdoor air. So to ensure that the zones do not result in a negative pressure you need to ensure that the amount of outdoor air equals or exceeds the amount of exhaust air. Exhaust air is accounted for when it occurs in a zone attached to the air loop. For non-air loop zones, a review of the results is required to make sure the air mass balance is correct for this simulation. I would look at the infiltration reporting to see if that amount would offset the toilet zone exhaust. Maybe others have a better solution.
To summarize the conclusion of the below comment discussion: The An additional Fan:ZoneExhaust in the toilet zone is unnecessary. The energy impact of the transfer air on the receiving toilet zone is accounted for by the ZoneMixing object. The toilet exhaust fan power can be accounted for in the Fan:ZoneExhaust that is in the source zone.
