3.1.1.1 - 3.1.19.1 AHU Rules
3.1.1.1 - AHU Simultaneous Heating and Cooling
Summary
This unit is heating and cooling at the same time.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Cooling Command |
ClgCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Heating Command |
HtgCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
15 |
The delay represents a span of time in minutes during which the ahu must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Cooling Command Threshold |
Numeric |
1 |
This number is the cooling command threshold indicating the command is “On.” If the ahu’s cooling command is greater than or equal to the cooling command threshold at the same time the ahu’s heating command is greater than or equal to the heating command threshold for a period longer than the delay in order for a fault condition to exist. |
| Heating Command Threshold |
Numeric |
1 |
This number is the heating command threshold indicating the command is “On.” If the ahu’s heating command is greater than or equal to the heating command threshold at the same time the ahu’s cooling command is greater than or equal to the cooling command threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.3.1 - Free Cooling is not Maximized
Summary
Free Cooling is not being fully utilized. Mechanical cooling is being used and the outside air damper is not fully open. The economizer should be used as the first stage of cooling.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Temperature |
OaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Damper Command (open/closed) |
OaDmprCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Cooling Command |
ClgCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
30 |
The delay represents a span of time in minutes during which the ahu must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Economizer Outside Air Enable Setpoint |
Numeric |
67 |
This number (in Fahrenheit) is the maximum allowed value of the outside air temperature. The entering outside air temperature must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Outside Air Damper High Setpoint |
Numeric |
95 |
This number (in Fahrenheit) is the maximum allowed value of the outside air temperature. The entering outside air temperature must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Cooling Command Minimum |
Numeric |
1 |
This number (in Fahrenheit) is the minimum allowed value of the cooling command. The cooling command must exceed or be equal to the cooling command minimum for a period longer than the delay in order for a fault condition to exist. |
3.1.4.1 - Outside Air Damper Position is Greater Than Minimum Setpoint During Heating Mode
Summary
Excess outside air is being brought into the building. The Outside Air Damper is greater than the minimum position setpoint.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Outside Air Temperature |
OaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Damper Command (open/closed) |
OaDmprCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Cooling Command |
ClgCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Heating Command |
HtgCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Scalar |
| Outside Air Damper Minimum Position Setpoint |
OaDmprMinPosSp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
30 |
The delay represents a span of time in minutes during which the ahu must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Economizer Outside Air Temperature Setpoint |
Numeric |
70 |
This number (in Fahrenheit) is the maximum allowed value of the outside air temperature. The entering outside air temperature must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Outside Air Damper Minimum Position Setpoint |
Numeric |
20 |
This number is the minimum outside air damper position needed for ventilation when an ahu is operating. |
| Outside Air Damper Position Threshold |
Numeric |
5 |
The outside air damper position must be greater than the minimum position setpoint by this amount (in percent command) for a fault condition to exist. |
| Cooling Command Limit |
Numeric |
1 |
This number is the cooling command threshold indicating the command is “On.” If the ahu’s cooling command is greater than or equal to the cooling command threshold at the same time the ahu’s heating command is greater than or equal to the heating command threshold for a period longer than the delay then a Fault is generated. |
3.1.4.2 - Outside Airflow is Greater Than Minimum Setpoint During Heating Mode
Summary
Excess outside air is being brought into the building. The outside airflow is greater than the outside airflow minimum position setpoint.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Outside Air Temperature |
OaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Cooling Command |
ClgCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Heating Command |
HtgCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Scalar |
| Outside Air Flow |
OaFlow |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Flow Minimum Setpoint |
OaFlowMinSp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
30 |
The delay represents a span of time in minutes during which the ahu must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Cooling Command Limit |
Numeric |
1 |
This number is the cooling command threshold indicating the command is “On.” If the ahu’s cooling command is greater than or equal to the cooling command threshold at the same time the ahu’s heating command is greater than or equal to the heating command threshold for a period longer than the delay in order for a fault condition to exist. |
| Heating Command Limit |
Numeric |
1 |
This number is the heating command threshold indicating the command is “On.” If the ahu’s heating command is greater than or equal to the heating command threshold at the same time the ahu’s cooling command is greater than or equal to the cooling command threshold for a period longer than the delay in order for a fault condition to exist. |
| Outside Airflow Threshold |
Numeric |
500 |
This number (in cfm) is the outside airflow threshold. The outside airflow must exceed the outside airflow minimum setpoint added to the outside airflow threshold for a period longer than the delay in order for a fault condition to exist. |
| Economizer Outside Air Temperature Setpoint |
Numeric |
70 |
This number (in Fahrenheit) is the maximum allowed value of the outside air temperature. The entering outside air temperature must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.4.3 - Outside Air Damper Position is Greater Than Minimum Setpoint During Mechanical Cooling Mode
Summary
Excess outside air is being brought into the building. The Outside Air Damper is greater than the minimum position setpoint during mechanical cooling mode.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
1. OaTemp associated with this equipment 2. OaTemp at the building level (on prem) 3. OaTemp of the off prem weather station |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Da Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Damper Command (open/closed) |
OaDmprCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Damper Minimum Position Setpoint |
OaDmprMinPosSp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Cooling Command |
ClgCmd |
This point must be a direct child of the equipment that the rule is attached to |
Mandatory |
Scalar |
| Heating Command |
HtgCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Temperature |
Oatemp |
This point must be a direct child of the equipment that the rule is attached to |
Optional |
Scalar |
| Outside Air Temperature |
OaTemp |
This point must be a direct child of the equipment that the rule is attached to. Point u son prem at the building level. |
Optional |
Scalar |
| Outside Air Temperature |
OaTemp |
This point must be a direct child of the equipment that the rule is attached to. Point is off prem at weather station. |
Optional |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
30 |
The delay represents a span of time in minutes during which the ahu must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Economy Outside Air Temperature Setpoint |
Numeric |
70 |
The economy outside air temp setpoint. The outside air temperature must be greater than this constant for a period longer than delay in order for a fault to exist. |
| Outside Air Damper Position |
Numeric |
0 |
The position of the outside air damper. The outside air damper position plus this constant must be less than the outside air damper command for a period longer than delay in order for a fault to exist. |
| Cooling Command |
Numeric |
0 |
The cooling command. The cooling command must be greater than this constant for a period longer than delay in order for a fault to exist. |
| Heating Command |
Numeric |
0 |
The heating command. The heating command must be equal to than this constant for a period longer than delay in order for a fault to exist. |
3.1.4.4 - Outside Airflow is Greater Than Minimum Setpoint During Mechanical Cooling Mode
Summary
Excess outside air is being brought into the building. The outside airflow is greater than the outside airflow minimum setpoint during mechanical cooling mode.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
OaTemp OaTempOnPremWS OaTemoOffPremWS |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| DA Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Damper Command (open/closed) |
OaDmprCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Damper Minimum Position Setpoint |
OaDmprMinPosSp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Cooling Command |
ClgCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Heating Command |
HtgCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Temperature |
OaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Scalar |
| Outside Air Temperature |
OaTemp |
This point must be a direct child of the equipment that the rule is attached to. Point is off prem at weather station. |
Optional |
Scalar |
| Outside Air Temperature |
OaTemp |
This point must be a direct child of the equipment that the rule is attached to. Point is off prem at weather station. |
Optional |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
30 |
The delay represents a span of time in minutes during which the ahu must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Economy Outside Air Temperature Setpoint |
Numeric |
70
|
The economy outside air temp setpoint. The outside air temperature must be greater than this constant for a period longer than delay in order for a fault to exist. |
| Outside Air Percent |
Numeric |
0 |
The outside air percent. The outside air flow must be greater than this constant plus 100 and divided by 100 for a period longer than delay in order for a fault to exist. |
| Cooling Command |
Numeric |
0 |
The cooling command. The cooling command must be greater than this constant for a period longer than delay in order for a fault to exist. |
| Heating Command |
Numeric |
0 |
The heating command. The heating command must be equal to this constant for a period longer than delay in order for a fault to exist. |
3.1.5.1 - Outside Air Damper Does Not Meet the Minimum Position Setpoint
Summary
The outside air damper is less than the minimum position setpoint and sufficient ventilation may not be provided.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Damper Command (open/closed) |
OaDmprCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Damper Minimum Position Setpoint |
OaDmprMinPosSp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Mixed Air Temperature |
MaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
60 |
The delay represents a span of time in minutes during which the ahu must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Mixed Air Temperature Low Limit Setpoint |
Numeric |
40 |
This number (in Fahrenheit) is the minimum allowed value of mixed air temperature. The mixed air temperature must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.6.1 - Percent Outside Air Calculated is Greater Than Outside Air Damper Command
Summary
Excess outside air is being brought into the building, increasing heating and cooling costs. The calculated outside air percent is greater than the outside air damper command plus a threshold. Calculated OA% = 100 X [(RaTemp-MaTemp) / (RaTemp-OaTemp)].
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Return Air Temperature |
RaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Mixed Air Temperature |
MaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Temperature |
OaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Damper Command (open/closed) |
OaDmprCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
60 |
The delay represents a span of time in minutes during which the ahu must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Damper Position Threshold |
Numeric |
15 |
This number (as a percentage) is the damper position threshold. The value of mixed air temperature subtracted from the return air temperature times 100 divided by outside air temperature subtracted from the return air temperature must exceed the value of outside air damper command added to the damper position threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.6.2 - Outside Air Fraction is Too High Compared to Minimum Outside Airflow Setpoint
Summary
Outside air fraction too high; should equal %OA min during heating and cooling operating state.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
OaTemp OaTempOnPremWS OaTempOffPremWS |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Return Air Temperature |
RaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Mixed Air Temperature |
MaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Temperature |
OaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Heating Command |
HtgCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Cooling Command |
ClgCmd |
i This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
15 |
The delay represents a span of time in minutes during which the ahu must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Minimum Temperature Differential |
Numeric |
10 |
Minimum temperature differential threshold. This constant must be less than or equal to the absolute value of return air temp minus outside air temp for a period longer than delay in order for a fault to exist. |
| Airflow Error Threshold |
Numeric |
30 |
Airflow error threshold. |
| Minimum Outside Air Percentage Threshold |
Numeric |
20 |
Minimum outside air percentage threshold. |
| Heating Command |
Numeric |
0 |
Heating command threshold. This constant must be less than the heating command for a period longer than delay in order for a fault to exist. |
| Cooling Command |
Numeric |
0 |
Cooling command threshold. This constant must be less than the cooling command for a period longer than delay in order for a fault to exist. |
3.1.7.1 - Percent Outside Air Calculated is Less Than Outside Air Damper Command
Summary
The calculated outside air percent is less than the outside air damper command minus a threshold, indicating the actual damper position is less than the command. Calculated OA% = 100 X (RaTemp-MaTemp) / (RaTemp-OaTemp)
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Return Air Temperature |
RaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Mixed Air Temperature |
MaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Temperature |
OaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Damper Command (open/closed) |
OaDmprCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
60 |
The delay represents a span of time in minutes during which the ahu must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Damper Position Threshold |
Numeric |
15 |
This number (as a percentage) is the damper position threshold. The value of mixed air temperature subtracted from the return air temperature times 100 divided by outside air temperature subtracted from the return air temperature must not exceed the value of outside air damper command added to the damper position threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.7.2 - Outside Air Fraction is Too Low Compared to Minimum Outside Airflow Setpoint
Summary
Outside air fraction too low; should equal %OA min during Heating or Mechanical Cooling Operating State
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
OaTemp OaTempOnPremWS OaTempOffPremWS |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Return Air Temperature |
RaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Mixed Air Temperature |
MaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Temperature |
OaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Heating Command |
HtgCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Cooling Command |
ClgCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
15 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Minimum Temperature Differential Threshold |
Numeric |
10 |
Minimum temperature differential threshold. This constant must be less than or equal to the absolute value of return air temp minus outside air temp for a period longer than delay in order for a fault to exist. |
| Airflow Error Threshold |
Numeric |
30 |
Airflow error threshold. |
| Minimum Outside Air Percentage Threshold |
Numeric |
20 |
Minimum outside air percentage threshold. |
| Heating Command |
Numeric |
0 |
Heating command threshold. This constant must be less than the heating command for a period longer than delay in order for a fault to exist. |
| Cooling Command |
Numeric |
0 |
Cooling command threshold. This constant must be less than the cooling command for a period longer than delay in order for a fault to exist. |
3.1.7.3 - Outside Airflow is Less Than Minimum Setpoint During Heating Mode
Summary
Less outside air is being brought into the building than what is required by code. The outside airflow is less than the outside airflow minimum setpoint during heating mode.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Flow |
OaFlow |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Flow Minimum Setpoint |
|
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Heating Command |
HtgCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Cooling Command |
ClgCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
30 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Outside Airflow Percentage Threshold |
Numeric |
10 |
Minimum temperature differential threshold. This constant must be less than or equal to the absolute value of return air temp minus outside air temp for a period longer than delay in order for a fault to exist. |
| Cooling Command Threshold |
Numeric |
30 |
Airflow error threshold. |
| Heating Command Threshold |
Numeric |
20 |
Minimum outside air percentage threshold. |
3.1.7.4 - Outside Airflow is Less Than Minimum Setpoint During Cooling Mode
Summary
Less outside air is being brought into the building than what is required by code. The outside airflow is less than the outside airflow minimum setpoint during cooling mode.
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Flow |
OaFlow |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Flow Minimum Setpoint |
OaFlowMinSp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Cooling Command |
ClgCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Heating Command |
HtgCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
30 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Outside Airflow Percentage Threshold |
Numeric |
10 |
|
| Cooling Command Threshold |
Numeric |
0 |
|
| Heating Command Threshold |
Numeric |
0 |
|
3.1.8.1 - Operating Outside of Schedule
Summary
The air handling unit is operating outside of the defined occupied schedule.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
DaFanSts || DaFanCmd |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Return Air Temperature |
DaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Scalar |
| Discharge Air Fan Status |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Scalar |
| Discharge Air Fan Command |
DaFanCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
120 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Sunday Schedule Start Time |
Numeric |
8 |
|
| Sunday Schedule Stop Time |
Numeric |
12 |
|
| Saturday Schedule Start Time |
Numeric |
8 |
|
| Saturday Schedule Stop Time |
Numeric |
16 |
|
| Weekday Schedule Start Time |
Numeric |
6 |
|
| Weekday Schedule Stop Time |
Numeric |
18 |
|
| Unoccupied Heating Temperature Setpoint |
Numeric |
62 |
|
| Unoccupied Cooling Temperature Setpoint |
Numeric |
80 |
|
3.1.9.1 - Discharge Air Temperature Sensor Failure
Summary
The temperature sensory point does not change by more than a tolerance of (0.01) or is outside the range (250 - -40).
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Temperature |
DaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
120 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| High Threshold |
Numeric |
250 |
This number (in Fahrenheit) is the maximum allowed value of the discharge air temperature. The discharge air temperature must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Low Threshold |
Numeric |
-40 |
This number (in Fahrenheit) is the minimum allowed value of the discharge air temperature. The discharge air temperature must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
0.01 |
This number (in Fahrenheit) is the variance threshold. The difference value of the high threshold and low threshold must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.9.2 - Mixed Air Temperature Sensor Failure
Summary
The temperature sensor point does not change by more than a tolerance of (0.01) or is outside the range (150 - -40).
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Mixed Air Temperature |
MaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
120 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| High Threshold |
Numeric |
150 |
This number (in Fahrenheit) is the maximum allowed value of the mixed air temperature. The mixed air temperature must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Low Threshold |
Numeric |
-40 |
This number (in Fahrenheit) is the minimum allowed value of the mixed air temperature. The mixed air temperature must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
0.01 |
This number (in Fahrenheit) is the variance threshold. The difference value of the high threshold and low threshold must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.9.3 - Return Air Temperature Sensor Failure
Summary
The temperature sensor point does not change by more than a tolerance of (0.01) or is outside the range (130 - 20).
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Return Air Temperature |
RaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
120 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| High Threshold |
Numeric |
130 |
This number (in Fahrenheit) is the maximum allowed value of the return air temperature. The return air temperature must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Low Threshold |
Numeric |
20 |
This number (in Fahrenheit) is the minimum allowed value of the return air temperature. The return air temperature must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
0.01 |
This number (in Fahrenheit) is the variance threshold. The difference value of the high threshold and low threshold must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.9.4 - Outside Air Temperature Sensor Failure
Summary
The temperature sensor point does not change by more than a tolerance of (0.01) or is outside the range (130 - -60).
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Outside Air Temperature |
OaTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
120 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| High Threshold |
Numeric |
130 |
This number (in Fahrenheit) is the maximum allowed value of the outside air temperature. The outside air temperature must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Low Threshold |
Numeric |
-60 |
This number (in Fahrenheit) is the minimum allowed value of the outside air temperature. The outside air temperature must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
0.01 |
This number (in Fahrenheit) is the variance threshold. The difference value of the high threshold and low threshold must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.9.5 - Zone Temperature Sensor Failure
Summary
The zone temperature sensor has failed. The temperature sensor point is invariant or is outside the expected range.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Zone Temperature |
ZoneTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
120 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| High Threshold |
Numeric |
150 |
This number (in Fahrenheit) is the maximum allowed value of the zone temperature. The zone temperature must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Low Threshold |
Numeric |
30 |
This number (in Fahrenheit) is the minimum allowed value of the zone temperature. The zone temperature must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
0.01 |
This number (in Fahrenheit) is the variance threshold. The difference value of the high threshold and low threshold must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.10.1 - Discharge Air Pressure Sensor Failure
Summary
The pressure sensor point does not change by more than a tolerance of (0.001) or is outside the range (7.0 - -2.0).
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Pressure |
DaPress |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
60 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| High Threshold |
Numeric |
7.0 |
This number (in inches of water) is the maximum allowed value of the discharge air pressure. The discharge air pressure must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Low Threshold |
Numeric |
-2.0 |
This number (in inches of water) is the minimum allowed value of the discharge air pressure. The discharge air pressure must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
0.001 |
This number (in inches of water) is the variance threshold. The difference value of the high threshold and low threshold must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.10.2 - Building Air Pressure Sensor Failure
Summary
The pressure sensor point does not change by more than a tolerance of (0.001) or is outside the range (1.0 - -1.0).
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Building Static Pressure |
BldgPress |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
60 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| High Threshold |
Numeric |
1.0 |
This number (in inches of water) is the maximum allowed value of the building static pressure. The building static pressure must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Low Threshold |
Numeric |
-1.0 |
This number (in inches of water) is the minimum allowed value of the building static pressure. The building static pressure must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
0.001 |
This number (in inches of water) is the variance threshold. The difference value of the high threshold and low threshold must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.10.3 - Return Air Pressure Sensor Failure
Summary
The pressure sensor point does not change by more than a tolerance of (0.001) or is outside the range (5.0 - -3.0).
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Return Air Pressure |
RaPress |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
60 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| High Threshold |
Numeric |
5.0 |
This number (in inches of water) is the maximum allowed value of the return air pressure. The return air pressure must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Low Threshold |
Numeric |
-3.0 |
This number (in inches of water) is the minimum allowed value of the return air pressure. The return air pressure must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
0.001 |
This number (in inches of water) is the variance threshold. The difference value of the high threshold and low threshold must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.10.4 - Zone Pressure Sensor Failure
Summary
The pressure sensor point does not change by more than a tolerance of (0.001) or is outside the range (1.0 - -1.0).
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Zone Pressure |
ZonePress |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
60 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| High Threshold |
Numeric |
1.0 |
This number (in inches of water) is the maximum allowed value of the zone pressure. The zone pressure must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Low Threshold |
Numeric |
-1.0 |
This number (in inches of water) is the minimum allowed value of the zone pressure. The zone must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
0.001 |
This number (in inches of water) is the variance threshold. The difference value of the high threshold and low threshold must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.11.1 - Discharge Air Humidity Sensor Failure
Summary
The humidity sensor point does not change by more than a tolerance of (0.001) or is outside the range (100 - 0).
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Humidity |
DaHumidity |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
120 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| High Threshold |
Numeric |
100 |
This number (as a percentage) is the maximum allowed value of the discharge air humidity. The discharge air humidity must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Low Threshold |
Numeric |
0 |
This number (as a percentage) is the minimum allowed value of the discharge air humidity. The discharge air humidity must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
0.001 |
This number is the variance threshold. The difference value of the high threshold and low threshold must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.11.2 - Return Air Humidity Sensor Failure
Summary
The humidity sensor point does not change by more than a tolerance of (0.001) or is outside the range (100 - 0).
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Return Air Humidity |
RaHumidity |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
120 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| High Threshold |
Numeric |
100 |
This number (as a percentage) is the maximum allowed value of the return air humidity. The return air humidity must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Low Threshold |
Numeric |
0 |
This number (as a percentage) is the minimum allowed value of the return air humidity. The return air humidity must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
0.001 |
This number is the variance threshold. The difference value of the high threshold and low threshold must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.11.3 - Outside Air Humidity Sensor Failure
Summary
The humidity sensor point does not change by more than a tolerance of (0.001) or is outside the range (100 - 0).
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Outside Air Humidity |
OaHumidity |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
120 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| High Threshold |
Numeric |
100 |
This number (as a percentage) is the maximum allowed value of the outside air humidity. The outside air humidity must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Low Threshold |
Numeric |
0 |
This number (as a percentage) is the minimum allowed value of the outside air humidity. The outside air humidity must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
0.001 |
This number is the variance threshold. The difference value of the high threshold and low threshold must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.11.4 - Zone Humidity Sensor Failure
Summary
The humidity sensor point does not change by more than a tolerance of (0.001) or is outside the range (100 - 0).
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Zone Humidity |
ZoneHumidity |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
120 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| High Threshold |
Numeric |
100 |
This number (as a percentage) is the maximum allowed value of the zone humidity. The zone humidity must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Low Threshold |
Numeric |
0 |
This number (as a percentage) is the minimum allowed value of the zone humidity. The zone humidity must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
0.001 |
This number is the variance threshold. The difference value of the high threshold and low threshold must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.12.1 - Discharge Airflow Sensor Failure
Summary
The discharge airflow sensor has failed. The airflow sensor point is invariant or is outside the expected range.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Discharge Air Flow |
DaFlow |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
30 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| High Threshold |
Numeric |
150,000 |
This number (in cfm) is the maximum allowed value of the discharge airflow. The discharge airflow must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Low Threshold |
Numeric |
20 |
This number (in cfm) is the minimum allowed value of the discharge airflow. The discharge airflow must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
1.0 |
This number (in cfm) is the variance threshold. The difference value of the high threshold and low threshold must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.12.2 – Return Airflow Sensor Failure
Summary
The return airflow sensor has failed. The airflow sensor point is invariant or is outside the expected range.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Return Air Flow |
RaFlow |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
30 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| High Threshold |
Numeric |
150,000 |
This number (in cfm) is the maximum allowed value of the return airflow. The return airflow must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Low Threshold |
Numeric |
20 |
This number (in cfm) is the minimum allowed value of the return airflow. The return airflow must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
1.0 |
This number (in cfm) is the variance threshold. The difference value of the high threshold and low threshold must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
Rule 3.1.12.3 - Outside Airflow Sensor Failure
Summary
The outside airflow sensor has failed. The airflow sensor point is invariant or is outside the expected range.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Flow |
OaFlow |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
30 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| High Threshold |
Numeric |
150,000 |
This number (in cfm) is the maximum allowed value of the outside airflow. The outside airflow must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Low Threshold |
Numeric |
20 |
This number (in cfm) is the minimum allowed value of the outside airflow. The outside airflow must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
1.0 |
This number (in cfm) is the variance threshold. The difference value of the high threshold and low threshold must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.12.4 - Exhaust Airflow Sensor Failure
Summary
The exhaust airflow sensor has failed. The airflow sensor point is invariant or is outside the expected range.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Exhaust Air Flow |
EaFlow |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
30 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| High Threshold |
Numeric |
150,000 |
This number (in cfm) is the maximum allowed value of the exhaust airflow. The exhaust airflow must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Low Threshold |
Numeric |
20 |
This number (in cfm) is the minimum allowed value of the exhaust airflow. The exhaust airflow must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
1.0 |
This number (in cfm) is the variance threshold. The difference value of the high threshold and low threshold must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.13.1 - Discharge Air Temperature Setpoint Could Be Raised
Summary
All zones served by this air handling unit are in a heating or minimum cooling mode, zone temperature is being met, and return air humidity (if available) is at or below return air high relative humidity setpoint, indicating the discharge air temperature setpoint could be raised.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Reheat Command |
RhtCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Vector |
| Discharge Air Flow Setpoint |
DaFlowSp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Vector |
| Discharge Air Flow Minimum Setpoint |
DaFlowMinSp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Vector |
| Discharge Air Flow Maximum Setpoint |
DaFlowMaxSp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Vector |
| Effective Cooling Setpoint |
EffCoolSp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Vector |
| Occupied Cooling Setpoint |
OccCoolSp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Vector |
| Zone Temperature Setpoint |
ZoneTempSp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Vector |
| Return Air Humidity |
RaHumidity |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Vector |
| Return Air High Humidity Setpoint |
RaHighHumiditySp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Vector |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
60 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Zone Temperature Threshold |
Numeric |
0.5 |
|
3.1.13.2 - Discharge Air Temperature Setpoint Could be Lowered
Summary
One or more zones served by this air handling unit are at a 100% cooling mode and zone temperature is not being met, or return air humidity (if available) is above return air high relative humidity setpoint, indicating the discharge air temperature setpoint could be lowered.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Cooling Command |
ClgCmd |
This point must be a direct child of the equipment that the rule is attached to. |
|
|
| Reheat Command |
RhtCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Vector |
| Discharge Air Flow Setpoint |
DaFlowSp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Vector |
| Zone Temperature |
ZoneTemp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Vector |
| Discharge Air Flow Maximum Setpoint |
DaFlowMaxSp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Vector |
| Effective Cooling Setpoint |
EffCoolSp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Vector |
| Occupied Cooling Setpoint |
OccCoolSp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Vector |
| Zone Temperature Setpoint |
ZoneTempSp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Vector |
| Return Air Humidity |
RaHumidity |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Vector |
| Return Air High Humidity Setpoint |
RaHighHumiditySp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Vector |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
15 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Zone Temperature Threshold |
Numeric |
0.5 |
|
| Maximum Cooling Command Threshold |
Numeric |
90 |
|
3.1.14.1 - Discharge Air Fan VFD Invariant
Summary
The discharge air fan VFD is invariant and may be overridden or in Hand.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Discharge Air Fan Speed (single or common) |
DaFanSpd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Discharge Air Pressure |
DaPress |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Scalar |
| Discharge Air Pressure Setpoint |
DaPressSp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
60 |
The delay represents a span of time in minutes during which the fan must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Maximum VFD Speed |
Numeric |
99 |
This number (as a percentage) is the maximum allowed value of the discharge fan VFD speed. The discharge fan VFD speed must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Pressure Setpoint Threshold |
Numeric |
0.1 |
This number (in inches of water) is the minimum allowed value of the discharge air pressure. The discharge air pressure must exceed this threshold added to the discharge air pressure setpoint or the discharge air pressure must not exceed this threshold subtracted from the discharge air pressure setpoint for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
1.0 |
This number is compared to the value of the difference between the maximum discharge air fan speed and the minimum discharge air fan speed. The difference value must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.14.2 - Discharge Air Fan VFD Invariant
Summary:
The discharge air fan VFD is invariant and may be overridden or in Hand.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Discharge Air Fan Frequency (single or common) |
DaFanFreq |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Discharge Air Pressure |
DaPress |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Scalar |
| Discharge Air Pressure Setpoint |
DaPressSp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
60 |
The delay represents a span of time in minutes during which the fan must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Maximum VFD Frequency |
Numeric |
58 |
This number (in Hz) is the maximum allowed value of the discharge fan VFD frequency. The discharge fan VFD frequency must not exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
| Pressure Setpoint Threshold |
Numeric |
0.1 |
This number (in inches of water) is the minimum allowed value of the discharge air pressure. The discharge air pressure must exceed this threshold added to the discharge air pressure setpoint or the discharge air pressure must not exceed this threshold subtracted from the discharge air pressure setpoint for a period longer than the delay in order for a fault condition to exist. |
| Variance Threshold |
Numeric |
0.1 |
This number is compared to the value of the difference between the maximum discharge air fan speed and the minimum discharge air fan speed. The difference value must not exceed the variance threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.15.1 - Discharge Fan Static Pressure Setpoint is Greater Than High Limit
Summary
The discharge fan static pressure setpoint is greater than the high limit and may be overridden. Excessively high fan static pressure increases fan energy and operating costs. ASHRAE Energy Standard 90.1 2016, section 6.5.3.2.2 VAV Static Pressure Sensor Location, limits the static pressure setpoint to 1.2 in. of water.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Discharge Air Pressure Setpoint |
DaPressSp |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
30 |
The delay represents a span of time in minutes during which the fan must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| High Static Pressure Limit |
Numeric |
2 |
This number (in inches of water) is the maximum allowed value of the discharge fan static pressure. The discharge fan static pressure must exceed this threshold for a period longer than the delay in order for a fault condition to exist. |
3.1.16.1 - Discharge Fan Static Pressure is Greater Than Setpoint
Summary
The discharge fan static pressure is greater than the static pressure setpoint and may be overridden or experiencing inefficient control, increasing fan energy and operating costs.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Discharge Air Pressure |
DaPress |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Discharge Air Pressure Setpoint |
DaPressSp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
30 |
The delay represents a span of time in minutes during which the fan must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Static Pressure Threshold |
Numeric |
0.15 |
This number (in inches of water) is the maximum allowed value of the discharge fan pressure. The discharge fan pressure must exceed this threshold added to the discharge air pressure setpoint or the discharge fan pressure must exceed this threshold added to the default static pressure setpoint for a period longer than the delay in order for a fault condition to exist. |
| Default Static Pressure Setpoint |
Numeric |
2.0 |
This number (in inches of water) is the default value of the discharge fan static pressure setpoint. The discharge fan pressure must exceed this threshold added to the default static pressure setpoint for a period longer than the delay in order for a fault condition to exist. |
3.1.17.1 - Discharge Fan Static Pressure is Less Than Setpoint
Summary
The discharge fan static pressure is less than the static pressure setpoint and may be experiencing inefficient control or mechanical failure, and may lead to comfort complaints.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Discharge Air Pressure |
DaPress |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Discharge Air Pressure Setpoint |
DaPressSp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
30 |
The delay represents a span of time in minutes during which the fan must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Static Pressure Threshold |
Numeric |
0.25 |
This number (in inches of water) is the maximum allowed value of the discharge fan pressure. The discharge fan pressure must not exceed this threshold subtracted from the discharge air pressure setpoint or the discharge fan pressure must not exceed this threshold subtracted from the default static pressure setpoint for a period longer than the delay in order for a fault condition to exist. |
| Default Static Pressure Setpoint |
Numeric |
0.6 |
This number (in inches of water) is the default value of the discharge fan pressure setpoint. The discharge fan pressure must not exceed this threshold subtracted from the default static pressure setpoint for a period longer than the delay in order for a fault condition to exist. |
3.1.17.2 - Low Cold and Hot Deck Static Pressure
Summary
When the cold and hot deck static pressure is less than a maximum error allowed.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Cold Deck Static Pressure |
ColdDeckStPrs |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Cold Deck Static Pressure Setpoint |
ColdDeckStPrsSp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Scalar |
| Hot Deck Static Pressure Setpoint |
HotDeckStPrsSp |
This point must be a direct child of the equipment that the rule is attached to. |
Optional |
Scalar |
| Hot Deck Static Pressure |
HotDeckStPrs |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
30 |
The delay represents a span of time in minutes during which the sensor must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
| Cold Deck Static Pressure Threshold |
Numeric |
0.15 |
|
| Hot Deck Static Pressure Threshold |
Numeric |
0.15 |
|
| Default Cold Deck Static Pressure Setpoint |
Numeric |
2.0 |
|
| Default Hot Deck Static Pressure Setpoint |
Numeric |
2.0 |
|
3.1.19.1 Outside Damper Open When Unit is Off
Summary
The outside air damper is open and the supply fan is off, allowing air infiltration. The damper should be shut when the unit is off.
| Equipment Type |
Equipment Tag Constraints |
Tuple Constraints |
| ahu |
-- |
-- |
Input Points
| Name |
Point Template |
Positional Requirements |
Optionality |
Multiplicity |
| Discharge Air Fan Status (single or common) |
DaFanSts |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
| Outside Air Damper Command (open/closed) |
OaDmprCmd |
This point must be a direct child of the equipment that the rule is attached to. |
Mandatory |
Scalar |
Input Constants
| Name |
Data Type |
Default Value |
Description |
| Delay |
Numeric |
15 |
The delay represents a span of time in minutes during which the damper must be in a fault state before the rule starts to actually report that it is in a fault state. The intent of the delay is to reduce the level of alert noise by ensuring that the system does not alert until the fault condition has been in effect for some minimal interval of time. |
