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I'm trying to model a residential tower with HRV's in each suite (approximated with one large air loop with air-to-air HX, supply/exhaust fans, and AirTerminal Single Duct Uncontrolled in each zone). Minimum fraction of O/A has been set to 1.0 via a schedule at the air loop Outdoor Air Controller. I have defined People and Design Specification Outdoor Air rates at the Space Type level. I have also tried setting flags in OS:Sizing:System so that "type of load to size on" is set to VentilationRequirement and "System Outdoor Air Method" is set to VentilationRateProcedure. All fans, intakes, terminals etc are autosized.

When I run the model, the resulting airflows are massive (10x what I have defined or more). If I hard-size all the diffusers to the airflow I know I need it works fine. Kind of defeats the purpose of schedules and hierarchies though.

I am at a loss. If anyone is able to assist, would be much appreciated. (tried to upload the OSM file but it wouldn't take)

I'm trying to model a residential tower with HRV's in each suite (approximated with one large air loop with air-to-air HX, supply/exhaust fans, and AirTerminal Single Duct Uncontrolled in each zone). Minimum fraction of O/A has been set to 1.0 via a schedule at the air loop Outdoor Air Controller. I have defined People and Design Specification Outdoor Air rates at the Space Type level. I have also tried setting flags in OS:Sizing:System so that "type of load to size on" is set to VentilationRequirement and "System Outdoor Air Method" is set to VentilationRateProcedure. All fans, intakes, terminals etc are autosized.

When I run the model, the resulting airflows are massive (10x what I have defined or more). If I hard-size all the diffusers to the airflow I know I need it works fine. Kind of defeats the purpose of schedules and hierarchies though.

I am at a loss. If anyone is able to assist, would be much appreciated. (tried to upload the OSM file but it wouldn't take)

I'm trying to model a residential tower with HRV's in each suite (approximated with one large air loop with air-to-air HX, supply/exhaust fans, and AirTerminal Single Duct Uncontrolled in each zone). Minimum fraction of O/A has been set to 1.0 via a schedule at the air loop Outdoor Air Controller. I have defined People and Design Specification Outdoor Air rates at the Space Type level. I have also tried setting flags in OS:Sizing:System so that "type of load to size on" is set to VentilationRequirement and "System Outdoor Air Method" is set to VentilationRateProcedure. All fans, intakes, terminals etc are autosized.

When I run the model, the resulting airflows are massive (10x what I have defined or more). If I hard-size all the diffusers to the airflow I know I need it works fine. Kind of defeats the purpose of schedules and hierarchies though.

I am at a loss. If anyone is able to assist, would be much appreciated. (tried to upload the appreciated.

Edit: Link to download OSM file but it wouldn't take)here (thanks Julien & Jamie). I switched a few diffusers in air loop "Residential HRV Loop" back to autosize, most have been left hard-sized for comparison's sake: https://www.dropbox.com/s/7kxqg0u2kxuma7q/Test%20MURB%20DOAS.osm?dl=0

I'm trying to model a residential tower with HRV's in each suite (approximated with one large air loop with air-to-air HX, supply/exhaust fans, and AirTerminal Single Duct Uncontrolled in each zone). Minimum fraction of O/A has been set to 1.0 via a schedule at the air loop Outdoor Air Controller. I have defined People and Design Specification Outdoor Air rates at the Space Type level. I have also tried setting flags in OS:Sizing:System so that "type of load to size on" is set to VentilationRequirement and "System Outdoor Air Method" is set to VentilationRateProcedure. All fans, intakes, terminals etc are autosized.

When I run the model, the resulting airflows are massive (10x what I have defined or more). If I hard-size all the diffusers to the airflow I know I need it works fine. Kind of defeats the purpose of schedules and hierarchies though.

I am at a loss. If anyone is able to assist, would be much appreciated.

Edit: Link to download OSM file here (thanks Julien & Jamie). I switched a few diffusers in air loop "Residential HRV Loop" back to autosize, most have been left hard-sized for comparison's sake: https://www.dropbox.com/s/7kxqg0u2kxuma7q/Test%20MURB%20DOAS.osm?dl=0

Zone                        ft3     ach     E+ cfm  design cfm  Autosize?   Error
L1 CityHome 1 - Plus        15924   0.716   190.0   62.59       Y           204%
L1 CityHome 3 - Plus        15924   0.238   63.2    62.59       N           1%
L13 NE Unit                 7312    0.871   106.1   62.59       Y           70%
L13 North Unit              7524    0.506   63.5    62.59       N           1%
L1 Corridors                17566   1.756   514.1   585.5       Y           -12%
L1 Manager Office           2424    5.469   220.9   13.87       Y           1493%