I do not think you need all those set point managers. They do not make sense to me, because the controllers are not given.
For example, the setpoint manager:MixedAir sense the MixedAir Node, and control the cooling or heating coil monitoring the temperature at the reference node. It used three controllers, OA, cooling coil and heating coil. These need to be programmed.
I do not think that the RH can be control from one point at the OA inlet.. The traditional method cools the air to 16°C or 18°C and feed into the zone. The warming up of the air at the zone generally provide sufficient moisture reduction. The HE will not always save energy.
I have assumed that the mixer is an OA mixer. If it is not, then the relief air node air flow rate will not be the same as that of the OA inlet node. In the customed case, the return air may not need to be mixed with the OA, than the exhaust fan is required, simply as a device to control the air flow volume.
I have not read any ASHRAE or LEED guide lines, so my comment may not apply to those working on baseline buildings.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: jim@xxxxxxxxxxxxxxxxxxxxxxxxxxx
Date: Mon, 21 May 2012 11:55:06 -0400
Subject: [EnergyPlus_Support] Setpoint Managers are driving me crazy!
Dear forum,
Apologies in advance for a messy question?..
Below is a schematic of an air loop.
· Note that there is a pre-cooling coil upstream of the Mixing Box.
· Also note that all of the numbers (e.g., 1200, 1204, etc.) are ?shorthand? for a node name.
I want the pre-cooling coil to operate solely as a dehumidification device to maintain a specific humidity ratio. Everything else should operate in a fairly typical fashion for heating and cooling control, except that there is no economizer.
I show below the SetPointManagers and related mixed air NodeList that I am using with no success for dehumidification. Can you offer a suggestions to make this work?
Thanks!
| SetpointManager:MixedAir |
Name | SPMgr_MixAir_AHU-1 |
Control variable: | Temperature |
reference set point node name | 1210 (Node name equivalent) |
fan inlet node name | 1208 |
fan outlet node name | 1210 |
Name of the set point Node or Node List | MANodeLIST_AHU-1 |
| |
| SetPointManager:Warmest |
Name | SPMgr_DischAir_AHU-1-warmest |
Control Variable | Temperature |
HVAC Air Loop Name | AirLoop_AHU-1 |
Minimum Setpoint Temperature | 12.8 |
Maximum Setpoint Temperature | 26.7 |
Strategy | MaximumTemperature |
Setpoint Node or NodeList Name | 1210 |
| |
| SetpointManager:SingleZone:Humidity:Maximum |
Name | SPMgr_ZoneRH_AHU-1 |
Control Variable | MT |
Schedule Name | MT |
Setpoint Node or NodeList Name | 1210 |
Control Zone Air Node Name | Node_MainStore |
| |
| SetPointManager:Scheduled |
Name | SPMgr_Sched_AHU-1 |
Control Variable | Temperature |
Schedule Name | SchCpct_Always70F |
Setpoint Node or NodeList Name | 1204.5 ß E+ complains if I don?t have a temperature setpoint for the pre-cooling coil |
| |
| SetPointManager:OutdoorAirPretreat |
Name | SPMgr_OAdehum_AHU-1 |
Control Variable | MaximumHumidityRatio |
Minimum Setpoint Temperature | 10 |
Maximum Setpoint Temperature | 30 |
Minimum Setpoint Humidity Ratio | 0.0008 |
Maximum Setpoint Humidity Ratio | 0.0091 |
Reference Setpoint Node Name | 1205 |
Mixed Air Stream Node Name | 1205 |
Outdoor Air Stream Node Name | 1204.5 |
Return Air Stream Node Name | 1200 |
Setpoint Node or NodeList Name | 1204.5 |
| NodeList |
Name | MANodeLIST_AHU-1 |
Node Name1 | 1205 |
| 1207 |
| 1208 |
| 1204.5 |
Making me think?.
"He who is kind is free, even if he is a slave. He who is evil is a slave, even if he is king."
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