Revision history [back]
DOAS input Problem
I have started my simulation and It shows the following warning and I am not sure what is it and what to do about it. I have trying to set up a DOAS System
First of all, I am not very sure what are these errors come from and how can I solve it?
** Warning ** SimHVAC: Maximum iterations (20) exceeded for all HVAC loops, at HONG KONG SAR CHN CityUHK-45007 WMO#=450070, 01/01 03:15 - 03:30
** ~~~ ** The solution for one or more of the Air Loop HVAC systems did not appear to converge
** ~~~ ** Air System Named = DOAS did not converge for mass flow rate
** ~~~ ** Check values should be zero. Most Recent values listed first.
** ~~~ ** Demand-to-Supply interface mass flow rate check value iteration history trace:
0.421904,0.571668,0.774595,1.049554,1.422117,4.239839,0.421904,0.571668,0.774595,1.049554,
** ~~~ ** Supply-to-demand interface deck 1 mass flow rate check value iteration history trace:
0.421904,0.571668,0.774595,1.049554,1.422117,0.311375,0.421904,0.571668,0.774595,1.049554,
** ~~~ ** Air System Named = DOAS did not converge for temperature
** ~~~ ** Check values should be zero. Most Recent values listed first.
** ~~~ ** Demand-to-Supply interface temperature check value iteration history trace:
3.462632E-002,2.555499E-002,1.886016E-002,1.391922E-002,1.027269E-002,0.103233,3.462632E-002,2.555499E-002,1.886016E-002,1.391922E-002,
** ~~~ ** Supply-to-demand interface deck 1 temperature check value iteration history trace:
2.555499E-002,1.886016E-002,1.391922E-002,1.027269E-002,0.103233,3.462632E-002,2.555499E-002,1.886016E-002,1.391922E-002,1.027269E-002,
** ~~~ ** Air System Named = DOAS did not converge for energy
** ~~~ ** Check values should be zero. Most Recent values listed first.
** ~~~ ** Demand-to-Supply interface energy check value iteration history trace: 9612.881052,13025.189533,17648.773708,23913.603146,32402.274792,96602.722233,9612.881052,13025.189533,17648.773708,23913.603146,
** ~~~ ** Supply-to-demand interface deck 1 energy check value iteration history trace: -9612.881052,-13025.189533,-17648.773708,-23913.603146,-33006.735202,-7094.521112,-9612.881052,-13025.189533,-17648.773708,-23913.603146,
My next warnings are the following. As This is a DOAS System I am not sure how to adjust the input to Energyplus
Yes, !- Use Outdoor Air DX Cooling Coil
7.2; !- Outdoor Air DX Cooling Coil Leaving Minimum Air Temperature {C}
The maximum Outdoor Air DX Cooling Coil Leaving Minimum Air Temperature is 7.2C But What If my leaving air temperature is larger than 7.2? Can it still be a DOAS Coil?
** Warning ** CalcDoe2DXCoil: Coil:Cooling:DX:SingleSpeed "DOAS COOLING COIL 1" - Full load outlet air dry-bulb temperature < 2C. This indicates the possibility of coil frost/freeze. Outlet temperature = -1.12 C.
** ~~~ ** ...Occurrence info = HONG KONG SAR CHN CityUHK-45007 WMO#=450070, 01/02 08:00 - 08:04
** ~~~ ** ... Possible reasons for low outlet air dry-bulb temperatures are: This DX coil
** ~~~ ** 1) may have a low inlet air dry-bulb temperature. Inlet air temperature = 16.701 C.
** ~~~ ** 2) may have a low air flow rate per watt of cooling capacity. Check inputs.
** ~~~ ** 3) is used as part of a HX assisted cooling coil which uses a high sensible effectiveness. Check inputs.
** Warning ** CalcDoe2DXCoil: Coil:Cooling:DX:SingleSpeed "DOAS COOLING COIL 2" - Full load outlet air dry-bulb temperature < 2C. This indicates the possibility of coil frost/freeze. Outlet temperature = -0.27 C.
** ~~~ ** ...Occurrence info = HONG KONG SAR CHN CityUHK-45007 WMO#=450070, 01/04 08:00 - 08:03
** ~~~ ** ... Possible reasons for low outlet air dry-bulb temperatures are: This DX coil
** ~~~ ** 1) may have a low inlet air dry-bulb temperature. Inlet air temperature = 12.178 C.
** ~~~ ** 2) may have a low air flow rate per watt of cooling capacity. Check inputs.
** ~~~ ** 3) is used as part of a HX assisted cooling coil which uses a high sensible effectiveness. Check inputs.
DOAS input Problem
I have started my simulation and It shows the following warning and I am not sure what is it and what to do about it. I have trying to set up a DOAS System
First of all, I am not very sure what are these errors come from and how can I solve it?
** Warning ** SimHVAC: Maximum iterations (20) exceeded for all HVAC loops, at HONG KONG SAR CHN CityUHK-45007 WMO#=450070, 01/01 03:15 - 03:30
** ~~~ ** The solution for one or more of the Air Loop HVAC systems did not appear to converge
** ~~~ ** Air System Named = DOAS did not converge for mass flow rate
** ~~~ ** Check values should be zero. Most Recent values listed first.
** ~~~ ** Demand-to-Supply interface mass flow rate check value iteration history trace:
0.421904,0.571668,0.774595,1.049554,1.422117,4.239839,0.421904,0.571668,0.774595,1.049554,
** ~~~ ** Supply-to-demand interface deck 1 mass flow rate check value iteration history trace:
0.421904,0.571668,0.774595,1.049554,1.422117,0.311375,0.421904,0.571668,0.774595,1.049554,
** ~~~ ** Air System Named = DOAS did not converge for temperature
** ~~~ ** Check values should be zero. Most Recent values listed first.
** ~~~ ** Demand-to-Supply interface temperature check value iteration history trace:
3.462632E-002,2.555499E-002,1.886016E-002,1.391922E-002,1.027269E-002,0.103233,3.462632E-002,2.555499E-002,1.886016E-002,1.391922E-002,
** ~~~ ** Supply-to-demand interface deck 1 temperature check value iteration history trace:
2.555499E-002,1.886016E-002,1.391922E-002,1.027269E-002,0.103233,3.462632E-002,2.555499E-002,1.886016E-002,1.391922E-002,1.027269E-002,
** ~~~ ** Air System Named = DOAS did not converge for energy
** ~~~ ** Check values should be zero. Most Recent values listed first.
** ~~~ ** Demand-to-Supply interface energy check value iteration history trace: 9612.881052,13025.189533,17648.773708,23913.603146,32402.274792,96602.722233,9612.881052,13025.189533,17648.773708,23913.603146,
** ~~~ ** Supply-to-demand interface deck 1 energy check value iteration history trace: -9612.881052,-13025.189533,-17648.773708,-23913.603146,-33006.735202,-7094.521112,-9612.881052,-13025.189533,-17648.773708,-23913.603146,
My next warnings are the following. As This is a DOAS System I am not sure how to adjust the input to Energyplus
Yes, !- Use Outdoor Air DX Cooling Coil
7.2; !- Outdoor Air DX Cooling Coil Leaving Minimum Air Temperature {C}
The maximum Outdoor Air DX Cooling Coil Leaving Minimum Air Temperature is 7.2C But What If my leaving air temperature is larger than 7.2? Can it still be a DOAS Coil?
** Warning ** CalcDoe2DXCoil: Coil:Cooling:DX:SingleSpeed "DOAS COOLING COIL 1" - Full load outlet air dry-bulb temperature < 2C. This indicates the possibility of coil frost/freeze. Outlet temperature = -1.12 C.
** ~~~ ** ...Occurrence info = HONG KONG SAR CHN CityUHK-45007 WMO#=450070, 01/02 08:00 - 08:04
** ~~~ ** ... Possible reasons for low outlet air dry-bulb temperatures are: This DX coil
** ~~~ ** 1) may have a low inlet air dry-bulb temperature. Inlet air temperature = 16.701 C.
** ~~~ ** 2) may have a low air flow rate per watt of cooling capacity. Check inputs.
** ~~~ ** 3) is used as part of a HX assisted cooling coil which uses a high sensible effectiveness. Check inputs.
** Warning ** CalcDoe2DXCoil: Coil:Cooling:DX:SingleSpeed "DOAS COOLING COIL 2" - Full load outlet air dry-bulb temperature < 2C. This indicates the possibility of coil frost/freeze. Outlet temperature = -0.27 C.
** ~~~ ** ...Occurrence info = HONG KONG SAR CHN CityUHK-45007 WMO#=450070, 01/04 08:00 - 08:03
** ~~~ ** ... Possible reasons for low outlet air dry-bulb temperatures are: This DX coil
** ~~~ ** 1) may have a low inlet air dry-bulb temperature. Inlet air temperature = 12.178 C.
** ~~~ ** 2) may have a low air flow rate per watt of cooling capacity. Check inputs.
** ~~~ ** 3) is used as part of a HX assisted cooling coil which uses a high sensible effectiveness. Check inputs.
DOAS input Problem
I have started my simulation and It shows the following warning and I am not sure what is it and what to do about it.
I have trying to set up a DOAS System


**
My This is my next warnings are the following. following
As This is a DOAS System I am not sure how to adjust the input to Energyplus
Energyplus
Yes, !- Use Outdoor Air DX Cooling Coil
7.2; !- Outdoor Air DX Cooling Coil Leaving Minimum Air Temperature {C}
The maximum Outdoor Air DX Cooling Coil Leaving Minimum Air Temperature is 7.2C But What If my leaving air temperature is larger than 7.2? Can it still be a DOAS Coil?
**
*
Warning