Relative Humidity - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 13.1

Controller Tool Help

Product
Controls > Control Tools > Controller Configuration Tool
Document type
User Guide
Document number
LIT-12011147
Version
13.1
Revision date
2019-12-04

The Relative Humidity logic block calculates the Relative Humidity of air given dry bulb temperature and either the dew point or wet bulb temperature. The following table describes the inputs and outputs of the Relative Humidity logic block.

Table 1. Relative Humidity Block Inputs and Outputs

Name

Data Type

Exposed for Connection by Default

Description

Default Value

Inputs

Dew Point Temperature

Float

No

Indicates the dew point temperature of air, which is the temperature at which moisture condenses out of the air. If the Setup property is DP, this input represents the air dew point temperature that is used to calculate Enthalpy. If the Setup property is WB, this input is ignored.

14 °C,

57 °F

Dry Bulb Temperature

Float

Yes

Indicates the temperature of air as measured with a simple thermometer.

25 °C, 77 °F

Elevation

Float

No

Indicates the distance above or below sea level. Below sea level is represented with a negative value.

0 ft, 0 m

Wet Bulb Temperature

Float

No

Indicates the wet bulb temperature. If the Setup property is WB, this input represents the air wet bulb temperature that is used to calculate Relative Humidity. If the Setup property is DP, this input is ignored.

18 °C,

64.4 °F

Outputs

Relative Humidity 1

Float

Yes

Indicates the relative humidity of air.

50%

Range: 0-100%

Properties

Setup

Enum

N/A

Indicates if the wet bulb or dew point temperature is used as the second independent variable to calculate Relative Humidity.

WB

Unit Set

Enum

N/A

Indicates the units of measurement used by the block.

SI, IP

1 This input or output is the Default Element of the block.