Webel: Psy/MPsy: Psychrometrics for Mathematica: Transferred heat (energy "Q") has field names with lower case 'qTot', 'qSen', 'qLat'. Heat rates (energy per time) have field names 'qDotTot', 'qDotSen', 'qDotLat' (to avoid clashes with Mathematica core)

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CONVENTION
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STRICT
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In most literature, heat exchange is represented by 'Q', and heat exchange rates are represented by 'q' or either q or Q with dot '.' over it. However, Mathematica has an informal rule that custom variables (expressions) should not start with a capital letter, because such are reserved for Mathematica core.

The Webel Pys library uses the following variables for field names (although, in displays and tables it can use rich Mathematica markup):

  • qTot: Total heat exchange (energy).
  • qSen: Sensible heat exchange (energy), which cause a change in dry bulb temperature 'tdb'.
  • qLat: Latent heat due to water vaporisation (water gained by the humid air) or condensation (water lost by the humid air).

For heat rates (energy per time), qDotTot, qDotSen, and qDotLat are used.

Note that this convention is adopted:

Wikipedia: 'Heat released by a system into its surroundings is by convention a negative quantity (Q < 0); when a system absorbs heat from its surroundings, it is positive (Q > 0). '

And in the Webel Psy library and examples, systems are never considered to "contain heat":

Wikipedia: 'A thermodynamic system does not contain heat. Nevertheless, the term is also often used to refer to the thermal energy contained in a system as a component of its internal energy and that is reflected in the temperature of the system.'
Relates to
TRAIL: Air Conditioning Psychrometrics (vs CED Engineering course): Example results (only) in Mathematica and SysML using the Webel Psy package and MPsy class
Example 05: Sensible heating: 'qSen' (+ve): energy transfer TO humid air
Example 06: Sensible heating: 'qSen' per mass (+ve): energy transfer TO humid air
Example 07: Sensible cooling: 'qDotSen' (-ve): energy transfer rate FROM humid air
Example 08a: Humidification: Drying lumber with air: required volumetric air flow rate
Example 08b: Humidification: As a 2-step (3-state) process
Example 09: Moisture added to air: Amount (mass)
Example 10: Condition and dehumidify air by chilling and condensing some moisture: Process table
Example 11: Total (qDotTot), sensible (qDotSen), and latent cooling (qDotLat) required for cooling air
SysML4Mathematica: Example 05: Sensible heating: 'qSen' (+ve): energy transfer TO humid air
SysML4Mathematica: Example 06: Sensible heating: 'qSen' per mass (+ve): energy transfer TO humid air
SysML4Mathematica: Example 07: Sensible cooling: 'qDotSen' (-ve): energy transfer rate FROM humid air
SysML4Mathematica: Example 08a: Humidification: Drying lumber with air: required volumetric air flow rate
SysML4Mathematica: Example 09: Moisture added to air: Amount (mass)
SysML4Mathematica: Example 10: Condition and dehumidify air by chilling and condensing some moisture: Process table
SysML4Mathematica: Example 11 [A] Total (qDotTot), sensible (qDotSen), and latent cooling (qDotLat) required for cooling air: Using CoolProp wrappers and SysML Parametric Diagrams
SysML4Mathematica: Example 11 [B]: Total (qDotTot), sensible (qDotSen), and latent cooling (qDotLat) required for cooling air: Using Webel MPsy objects and SysML Activity Diagrams
The MPsy “one shot” humid air state class
Psychrometrics exercise references (and about some naming conventions)
Psy`Psychrometrics package variables registry
About the Psy` package Psychrometrics exercises slides (in this trail)
CONVENTION: ‘$EQ$’, ‘$E$’, ‘eq$’ and ‘sym$’: Examples from the Psy` Psychrometrics package
Related notes
[CONVENTION]{STRICT} Webel: Psy/MPsy: Psychrometrics for Mathematica: CONVENTION: 'Q' as a quantity symbol in equations indicates the energy GAINED BY the system as heat energy transfer; 'W' indicates the work DONE BY the system on its external surroundings.
[CONVENTION]{STRICT} Webel: Psy/MPsy: Psychrometrics for Mathematica: For Imperial Units (IP), International British Thermal Units (Btu) are assumed
[CONVENTION]{STRICT} Webel: Psy/MPsy: Psychrometrics for Mathematica: Humidity ratio (absolute humidity) is indicated by a lower case 'w' and measured in mass (water) / mass (dry air) units, so the SI and IP representations are equal Real (without an explicit unit system)
[CONVENTION]{STRICT} Webel: Psy/MPsy: Psychrometrics for Mathematica: Relative humidity is indicated by a lower case 'r' and measured as a Real fraction (rather than as a Percentage). [Some tables and plots do SHOW the relative humidity as a Percentage.]
Related notes (backlinks)
Related snippets (extracts)
 Heat released by a system into its surroundings is by convention a negative quantity (Q < 0); when a system absorbs heat from its surroundings, it is positive (Q > 0).
 A thermodynamic system does not contain heat. Nevertheless, the term is also often used to refer to the thermal energy contained in a system as a component of its internal energy and that is reflected in the temperature of the system.
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