Table 1 describes the attributes used by the Economizer Availability module.
|
Name |
Type 1 |
Description |
Default Value |
|---|---|---|---|
|
Bypass Percent |
Provides the percent of air passing through the coil that is unaffected by the coil [%]. This is used for the Model-Based Economizer Type. |
20% |
|
|
Discharge Air Temperature |
Provides the effective discharge air temperature for the cooling coil. This is used for the Model-Based Economizer Type. |
12 °C, 55 °F |
|
|
ECON-AVAILABLE (Free Cooling Available) |
G, V |
Displays a value of True when increasing the volume of outside air can reduce the cooling coil load. This attribute contains a value of False when the volume of outside air should be at the minimum required for ventilation. |
|
|
Economizer Type |
Use to select the type of economizer logic. |
Temperature&Enthalpy Set Name: Free Cooling Method |
|
|
ECONSWO-SP (Change Over Temperature) |
Specifies the change over dry bulb temperature used to determine if free cooling is available for the Dry Bulb Temperature economizer option. |
20 °C, 68 °F |
|
|
Elevation |
Contains the distance above or below sea level [m or ft]. This is used in the psychrometric calculations performed for Economizer Type = Temperature & Enthalpy or Model Based. |
0 m, 0 ft |
|
|
Hardware Free Cooling Available |
Provides an input that can be used to determine whether the economizer is suitable or not. The failsoft property on this attribute is set to True. If this input becomes unreliable, the default value of Not Available is used. Hardware Free Cooling Available is typically connected to the ECON-EN hardware input (BI). |
Not Available Set Name: Not Available/Available |
|
|
Minimum OA Percent |
Provides the percent of maximum supply fan flow rate required for the minimum amount of ventilation air. |
20% |
|
|
Network Free Cooling Available |
Provides an input to this module that can be used to determine whether the economizer is suitable or not. True means suitable and False means not suitable. The failsoft property on this attribute is set to True. If this input becomes unreliable, the default value of False is used. Network Free Cooling Available is typically connected to the ECON-EN Network Input. |
False |
|
|
OA Humidity |
Provides the relative humidity of the outdoor air and is used when the Economizer Type is Temperature & Enthalpy or Model Based. OA Humidity is typically connected from a Network Input or hardware input (OA-H). |
50.0%RH |
|
|
OA Temperature |
Contains the dry bulb temperature of the outside air. |
25 °C, 77 °F |
|
|
Return Air Humidity |
Provides the relative humidity of the return air and is used when the Economizer Type is Temperature & Enthalpy or Model Based. Return Air Humidity is typically connected from the RA-H hardware input. |
50.0%RH |
|
|
Return Air Temperature |
Provides the dry bulb temperature of the return air and is used when the Economizer Type is Temperature & Enthalpy or Model Based. Return Air Temperature is typically connected from the RA-T hardware input. |
20 °C, 68 °F |
|
|
Suitability Selection |
Defines the method for determining the suitability. Suitability may be a function of network suitability, hardware suitability, or humidity and temperature. |
Local Sensors Set Name: Free Cooling Select |
|
|
Supply Fan Status |
Provides the operating status of air-handling unit supply fan. When the fan is off, ECON-AVAILABLE is immediately set to False. When the fan turns on, the conditions are immediately evaluated to determine the economizer status. Running = True, Off = False. |
True |
|
|
Unit Set |
Specifies whether this module should operate in Metric or Imperial units. |
SI, IP Set Name: Unit Set |