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I have an issue with a dedicated outdoor air system supply and exhaust flows being unbalanced in OpenStudio 2.4. I am getting a severe error in my heat recovery wheel as a result. The DOAS is set up as shown below and delivers air to dozens of zones.

I am losing most of my air between the supply and return sides. The airflow is consistent from OA intake, through the coils and to the terminal units. The flow from the terminal units through the return from the zone stays consistent, but somewhere between the zone return node and the airloop return node, I am losing 80% of my flow. as shown below. I am showing the standard density volume flow rate in CFM of the supply node where the setpoint manager is located and the return air node immediately before the economizer.

I do not have any exhaust fans at the zone level and can't think of any reason I would be losing air in the loop. I am hard sizing all of the terminal units with flows greater than the required ventilation rate specified in the DesignSpecification:Outdoor air object, but I don't think that would result in unbalanced flows. The larger of the two flows correlates to expected supply air flows specified for terminal units. I have tried switching loop sizing from Ventilation to Total, toggling the DCV option, and autosizing loop flows vs. hard sizing them with no luck. What am I missing?

My OSM is here.

I have an issue with a dedicated outdoor air system supply and exhaust flows being unbalanced in OpenStudio 2.4. I am getting a severe error in my heat recovery wheel as a result. The DOAS is set up as shown below and delivers air to dozens of zones.

I am losing most of my air between the supply and return sides. The airflow is consistent from OA intake, through the coils and to the terminal units. The flow from the terminal units through the return from the zone stays consistent, but somewhere between the zone return node and the airloop return node, I am losing 80% of my flow. as shown below. I am showing the standard density volume flow rate in CFM of the supply node where the setpoint manager is located and the return air node immediately before the economizer.

I do not have any exhaust fans at the zone level and can't think of any reason I would be losing air in the loop. I am hard sizing all of the terminal units with flows greater than the required ventilation rate specified in the DesignSpecification:Outdoor air object, but I don't think that would result in unbalanced flows. The larger of the two flows correlates to expected supply air flows specified for terminal units. I have tried switching loop sizing from Ventilation to Total, toggling the DCV option, and autosizing loop flows vs. hard sizing them with no luck. My zone level system is a four-pipe fan coil with outdoor air set to zero. My assumption is that isolates the fan coil from the DOAS loop. What am I missing?

My OSM is here.

I have an issue with a dedicated outdoor air system supply and exhaust flows being unbalanced in OpenStudio 2.4. I am getting a severe error in my heat recovery wheel as a result. The DOAS is set up as shown below and delivers air to dozens of zones.

I am losing most of my air between the supply and return sides. The airflow is consistent from OA intake, through the coils and to the terminal units. The flow from the terminal units through the return from the zone stays consistent, but somewhere between the zone return node and the airloop return node, I am losing 80% of my flow. as shown below. I am showing the standard density volume flow rate in CFM of the supply node where the setpoint manager is located and the return air node immediately before the economizer.

I do not have any exhaust fans at the zone level and can't think of any reason I would be losing air in the loop. I am hard sizing all of the terminal units with flows greater than the required ventilation rate specified in the DesignSpecification:Outdoor air object, but I don't think that would result in unbalanced flows. The larger of the two flows correlates to expected supply air flows specified for terminal units. I have tried switching loop sizing from Ventilation to Total, toggling the DCV option, and autosizing loop flows vs. hard sizing them with no luck. My zone level system is a four-pipe fan coil with outdoor air set to zero. My assumption is that isolates the fan coil from the DOAS loop. What am I missing?

My OSM is here.