CoolProp: Mathematica wrapper: Psychrometrics (humid air): When obtaining the dew point temperature 'Tdp' at the pressure 'P', humidity ratio 'W', and dry bulb temperature 'Tdb', the 'Tdb' value will be "ignored" but MUST be within a sensible range!
Webel: Psy/MPsy: Psychrometrics for Mathematica: The default newPsy[tdb] builder accepts the pressure 'p' as an option, which defaults to sea level atmospheric pressure.
Webel: Psy/MPsy: Psychrometrics for Mathematica: The CoolProp "wrappers" of the Psy library in fact wrap lower-level wrappers (bindings) for CoolProp for Mathematica
Webel: Psy/MPsy: Psychrometrics for Mathematica: The default MPsy class is a readonly one-shot class that pre-builds many frequently used psychrometric properties (offered as public fields) using CoolProp, and also offers some value-adding methods.
Webel: Psy/MPsy: Psychrometrics for Mathematica: The default newPsy[tdb] builder requires the dry bulb temperature 'tdb', and one (only) of the relative humidity 'r', the humidity ratio 'w', or the wet bulb temperature 'twb' (as options).
Webel: Psy/MPsy: Psychrometrics for Mathematica: Most CoolProp wrappers can be invoked with the dry bulb temperature 'tdb', the pressure 'p', and one (only) of the relative humidity 'r', the humidity ratio 'w', or the wet bulb temperature 'twb'
On [a] psychrometric chart, this process is represented as [a] line sloping downward and to the left. This process is assumed to occur as simple cooling first and then condensation. While the moisture is condensing the air is assumed to remain saturated. Source CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'
Mathematica: v13.2+: Division of one temperature by another will result in a numeric ratio given by the value of both temperatures in Kelvin. Source Wolfram Language (Mathematica) online help reference
Mathematica: v13.2+: Division by temperature units will produce a quantity equivalent to the temperature converted to Kelvin before division, with results canonically given in Kelvin. Source Wolfram Language (Mathematica) online help reference
GOTCHA: Mathematica v13.2+: Operations on "DegreesFahrenheit" °F and "DegreesCelsius" °C are now performed using Kelvins (K). CASE: Naive percentage operation gives answer relative to Kelvins. Use "DegreesCelsiusDifference"/"DegreesFahrenheitDifference"!
Example 11: Total (qDotTot), sensible (qDotSen), and latent cooling (qDotLat) required for cooling air Gallery Tutorial TRAIL: Air Conditioning Psychrometrics (vs CED Engineering course): Example results (only) in Mathematica and SysML using the Webel Psy package and MPsy class Section Slide kind plot table
Determine the total, sensible and latent cooling required cooling 20,000 cfm of air from a temperature of 90 F and a relative humidity of 60% to a temperature of 55 F and 100% relative humidity. Source CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'
Hot humid day 90°F and 90% RH. Condition the air to 70°F at about 50% RH. Chill the air to condense out enough moisture to dehumidify it: goal is air with absolute humidity not exceeding 0.008 lbs of moisture per pound of air. Show processes. Source CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'
Example 10: Condition and dehumidify air by chilling and condensing some moisture: Process table Gallery Tutorial TRAIL: Air Conditioning Psychrometrics (vs CED Engineering course): Example results (only) in Mathematica and SysML using the Webel Psy package and MPsy class Section Slide kind plot table
Example 09: Moisture added to air: Amount (mass) Gallery Tutorial TRAIL: Air Conditioning Psychrometrics (vs CED Engineering course): Example results (only) in Mathematica and SysML using the Webel Psy package and MPsy class Section Slide kind plot table
How much moisture is added to 20 lb of air going from 50°F, 50% RH to 80°F, 60% RH? Source CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'
Example 08b: Humidification: As a 2-step (3-state) process Gallery Tutorial TRAIL: Air Conditioning Psychrometrics (vs CED Engineering course): Example results (only) in Mathematica and SysML using the Webel Psy package and MPsy class Section Slide kind plot table
Determine the amount of sensible heat needed to increase the temperature of air from 50°F and 50% RH to 90°F. Source CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'
Ninety cubic-ft of lumber is dried at 140°F 'tdb' and 125.6°F 'twb'. The drying rate of the lumber is 5.68 lb of water per hour. If outside air is at 80.6°F 'tdb' and 80% relative humidity how much outside air is needed per min to carry away the moisture? Source CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'
Example 08a: Humidification: Drying lumber with air: required volumetric air flow rate Gallery Tutorial TRAIL: Air Conditioning Psychrometrics (vs CED Engineering course): Example results (only) in Mathematica and SysML using the Webel Psy package and MPsy class Section Slide kind plot table
Determine the cooling required to sensibly cool 20,000 cfm of air from a temperature of 90 F and a relative humidity of 60% to a temperature of 75 F. Source CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'
Example 07: Sensible cooling: 'qDotSen' (-ve): energy transfer rate FROM humid air Gallery Tutorial TRAIL: Air Conditioning Psychrometrics (vs CED Engineering course): Example results (only) in Mathematica and SysML using the Webel Psy package and MPsy class Section Slide kind plot table
Example 06: Sensible heating: 'qSen' per mass (+ve): energy transfer TO humid air Gallery Tutorial TRAIL: Air Conditioning Psychrometrics (vs CED Engineering course): Example results (only) in Mathematica and SysML using the Webel Psy package and MPsy class Section Slide kind plot table
Calculate the amount of sensible heat that must be added to 100lb of air at 85°F dry bulb and 75°F wet bulb to raise the temperature of air to 100°F dry bulb. Source CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'
Example 05: Sensible heating: 'qSen' (+ve): energy transfer TO humid air Gallery Tutorial TRAIL: Air Conditioning Psychrometrics (vs CED Engineering course): Example results (only) in Mathematica and SysML using the Webel Psy package and MPsy class Section Slide kind plot table
Example 04: Values from dry bulb temperature 'tdb' and wet bulb temperature 'twb' Gallery Tutorial TRAIL: Air Conditioning Psychrometrics (vs CED Engineering course): Example results (only) in Mathematica and SysML using the Webel Psy package and MPsy class Section Slide kind plot table
Example 03b: Values from dry bulb temperature 'tdb' and wet bulb temperature 'twb' Gallery Tutorial TRAIL: Air Conditioning Psychrometrics (vs CED Engineering course): Example results (only) in Mathematica and SysML using the Webel Psy package and MPsy class Section Slide kind plot table
The dry bulb reading is 85°F and the wet bulb is 60F. Using the chart determine the following values. Using the chart determine the following values: Relative humidity; Dew Point; Absolute humidity; Specific volume; [Specific] enthalpy. Source CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'
The dry bulb reading is 70°F and the wet bulb is 54°F. Using the chart determine the following values. Using the chart determine the following values: Relative humidity; Dew Point; Absolute humidity; Specific volume; [Specific] enthalpy. Source CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'
The dry bulb reading is 78°F and the wet bulb is 58°F. Using the chart determine the following values: Relative humidity; Dew Point; Absolute humidity; Specific volume; [Specific] enthalpy. Source CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'
Example 03a: Values from dry bulb temperature 'tdb' and wet bulb temperature 'twb' Gallery Tutorial TRAIL: Air Conditioning Psychrometrics (vs CED Engineering course): Example results (only) in Mathematica and SysML using the Webel Psy package and MPsy class Section Slide kind plot table
Example 02: Values from dry bulb temperature 'tdb' and wet bulb temperature 'twb' (sling psychrometer) Gallery Tutorial TRAIL: Air Conditioning Psychrometrics (vs CED Engineering course): Example results (only) in Mathematica and SysML using the Webel Psy package and MPsy class Section Slide kind plot table
An air-conditioned room at sea level has an indoor design temperature of 75°F and a relative humidity of 50%. Determine the humidity ratio, enthalpy, density, dew point, and thermodynamic wet bulb temperature of the indoor air at design condition. Source CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'
A sling psychrometer gives a dry-bulb temperature of 78°F and a wet-bulb temperature of 65°F. Determine other moist air properties from this information. Source CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'
Example 01: Values from 'tdb' and relative humidity 'r' Gallery Tutorial TRAIL: Air Conditioning Psychrometrics (vs CED Engineering course): Example results (only) in Mathematica and SysML using the Webel Psy package and MPsy class Section Slide kind plot table
When calibrated to ITS-90, where one must interpolate between the defining points of gallium and indium, the boiling point of VSMOW water is about 10 mK less, about 99.974 °C. Source Wikipedia
Precise measurements show that the boiling point of VSMOW water under one standard atmosphere of pressure is actually 373.1339 K (99.9839 °C) when adhering strictly to the two-point definition of thermodynamic temperature. Source Wikipedia
Fun fact: The normal boiling point of water isn't exactly 100 °C (at least not since 2019 when the definition of the Kelvin scale was changed to use the Boltzmann constant and decoupled from the triple point of water)
Webel vs SysPhS-1.1: Annex A.5: Humidifier: The water temperature from TemperatureIncreaseConstraint and HeatingCalculationConstraint starts at 0 °C (should probably be the environment temperature 20 °C). Needs an additional parameter and initial value.
Figure 31: Elements for physical interaction Gallery Tutorial TRAIL: SysPhS-1.1 specification body figures in MagicDraw/Cameo SysML vs Modelica [using Wolfram SystemsModeler] Section Slide kind SysML Package Diagram
