Psychrometric (BPsychrometricBlock)
Mode property determines the calculation to perform: Dew Point Temperature, Enthalpy (default), Saturation Pressure, Vapor Pressure
or Wet Bulb Temperature.
Figure 139. Psychometric properties
To view these properties, double-click the block on the Wire Sheet or the block name in the Nav tree.
| Property | Value | Description |
|---|---|---|
| Out | read-only value slot | Outputs a calculated value based on the Temperature In, Humidity In values and the Mode properties.
|
| Temperature In | required value slot | Links from the output of other logic blocks or data sources to supply degrees of temperature.
NOTE: Make sure the
Units property matches the units of this property.
|
| Humidity In | required value slot | Links from the output of other logic blocks or data sources to supply the percentage of humidity.
|
| Units | drop-down list | Identifies the units: Metric or English (default) for both Temperature In and Out.
The unit the system uses to display temperature values depends on this property and on your selection for |
| Mode | drop-down list | Identifies the psychrometric calculation to perform: Dewpoint Temp, Enthalpy (default), Saturation Pressure, Vapor Pressure or Wetbulb Temp.
|
Metric and English units
Use this table to determine the correct units for inputs and outputs based on the configuration of the Mode and Units properties.
Mode units in Metric and English
| Mode property | Units = Metric | Units = English |
|---|---|---|
| Dewpoint Temp (Dewpoint Temperature) | °C (degrees Celsius) | °F (degrees Fahrenheit) |
| Enthalpy | kj/kg (kilo joule per kilo gram) | BTU/lb (British thermal unit per pound) |
| Saturation Pressure | kPa (kilo Pascal) | lbs (pounds) |
| Vapor Pressure | hPa (hectopascals) | inHg or in.Hg (inch of mercury) |
| Wetbulb Temp (Wetbulb Temperature) | °C (degrees Celsius) | °F (degrees Fahrenheit) |
Example
An algorithm may be configured with DataSourceBlocks for temperature (hs:outsideAirTempSensor) and humidity (hs:outsideAirHumiditySensor), which are linked to the Psychrometric block inputs.
Figure 140. Psychrometric block algorithm
A numeric point with an analytic proxy extension may be used to calculate real time enthalpy values using numeric points in the station with outside air temperature (hs:outsideAirTempSensor and a:a marker tags) and outside air humidity (hs:outsideAirHumiditySensor and a:a marker tags).
Figure 141. Psychrometric configuration
