List of TriHumidAir Worksheet Functions

The tables below give a complete list of TriHumidAir worksheet functions.
The rows that are shaded blue describe input parameters to the functions listed below.
All functions use the SI system of units.
The term 'Mixing Ratio' is used instead of 'Humidity Ratio'.

General

Moist Air Properties from Pressure and Temperature

Moist Air Mass Flows

Moist Air Temperature from Enthalpy

Specific Enthalpy of Water (Any Phase) in Equilibrium With Saturated Air at 101,325 Pa

Specific Enthalpy of Saturated Steam

Moist Air Properties from Pressure, Temperature and Relative Humidity

Moist Air Properties from Pressure, Temperature and Mixing Ratio

Moist Air Properties from Pressure, Temperature and Wet Bulb Temperature

Heating and Cooling of a Moist Air Flow

Adiabatic Mixing of Two Streams of Moist Air

Adiabatic Mixing of Moist Air with Injected Water or Steam

General

General: Moist Air Properties from Pressure and Temperature

Property

Formula

Unit

Pressure

P

Pa

Dry Bulb Temperature

T

°C

Relative Humidity

RH

Water Vapour at Saturation Pressure (H2O Only)
Pws0 = f(T) [Pa]

WSatP0(t)

Pa

Water Saturation Pressure (In Air at Given Pressure)
Pws = f(P, T) [Pa]

WSatP(P,t)

Pa

Saturation Mixing Ratio
Ws = f(P, T) [kg/kg]

SatMixRatio(P,t)

kg/kg

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General: Moist Air Mass Flows

Property

Formula

Unit

Mass Flow of Moist Air Mixture (Air + Water)

M

kg/s

Mixing Ratio

W

kg/kg

Mass Flow of Air
Ma = f(M, W) [kg/s]

MassFlowAir_M(m,W)

kg/s

Mass Flow of Water
Mw = f(M, W) [kg/s]

MassFlowWater_M(m,W)

kg/s

Mass Flow of Air

Ma

kg/s

Mixing Ratio

W

kg/kg

Mass Flow of Moist Air Mixture (Air + Water)
M = f(Ma, W) [kg/s]

MassFlowMix_Ma(Ma,W)

kg/s

Mass Flow of Water
Mw = f(Ma, W) [kg/s]

MassFlowWater_Ma(Ma,W)

kg/s

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General: Moist Air Temperature from Enthalpy

Property

Formula

Unit

Pressure

P

Pa

Mixing Ratio

W

kg/kg

Enthalpy of Moist Air per Unit of Mass of Dry Air

H

kJ/kg dry air

Moist Air Temperature from Enthalpy
T = f(P, W, H) [°C]

Temp_H(P,W,H)

°C

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General: Specific Enthalpy of Water (Any Phase) in Equilibrium With Saturated Air at 101,325 Pa

Property

Formula

Unit

Pressure

P

Pa

Dry Bulb Temperature

T

°C

Calculate for Ice

CalcIce

Specific enthalpy of water (any phase) in equilibrium with saturated air at 101,325 Pa
Formulas derived from ASHARE Fundamentals Book, Chapter 6, Table 1.
This function should be expanded to cover pressures other than 101,325 Pa. Therefore, the pressure is used as an input parameter if CalcIce is True, Hw is calculated for ice at triple point (saturation) (T=0.01°C)
H = f (P, T) [kJ/kg]

Hw_P_T(P,T,Optional:CalcIce)

kJ/kg

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General: Specific Enthalpy of Saturated Steam

Property

Formula

Unit

Pressure

P

Pa

Specific enthalpy of saturated steam for a given pressure
H = f(P) [kJ/kg]

Hg_P(P)

kJ/kg

Temperature

T

°C

Specific enthalpy of saturated steam for a given temperature
H = f(T) [kJ/kg]

Hg_T(T)

kJ/kg

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Moist Air Properties from Pressure, Temperature and Relative Humidity

Property

Formula

Unit

Pressure

P

Pa

Dry Bulb Temperature

T

°C

Relative Humidity

RH

Partial Pressure of Water Vapour
Pw = f(P, T, RH) [Pa]

WPartP_RH(P,t,RH)

Pa

Degree of Saturation
µ = f(P, T, RH) [-]

DegreeOfSat_RH(P,t,RH)

-

Density of Moist Air
Rho = f(P, T, RH) [kg/m³]

DensMoistAir_RH(P,t,RH)

kg/m³

Volume of Moist Air Mixture (per Unit Mass of Dry Air)
v = f(P, T, RH) [m³/kg]

VolMoistMix_RH(P,t,RH)

m³/kg dry air

Enthalpy of Moist Air per Unit of Mass of Dry Air
h = f(P, T, RH) [kJ/kg dry air]

EnthalpyMoistAir_RH(P,t,RH)

kJ/kg dry air

Enthalpy of Moist Air per Unit of Mass of Mixture
hm = f(P, T, RH) [kJ/kg mix]

EnthalpyMix_RH(P,t,RH)

kJ/kg mix

Dewpoint of Moist Air
Td = f(P, T, RH) [°C]

DewPoint_RH(P,t,RH)

°C

Wet Bulb Temperature of Moist Air
Twb = f(P, T, RH) [°C]

WetBulb_RH(P,t,RH)

°C

Mixing Ratio
W = f(P, T, RH) [kg/kg]

MixRatio_RH(P,t,RH)

kg/kg

Relative Humidity

RH

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Moist Air Properties from Pressure, Temperature and Mixing Ratio

Property

Formula

Unit

Pressure

P

Pa

Dry Bulb Temperature

T

°C

Mixing Ratio

W

kg/kg

Partial Pressure of Water Vapour
Pw = f(P, T, W) [Pa]

WPartP_W(P,t,W)

Pa

Degree of Saturation
µ = f(P, T, W) [-]

DegreeOfSat_RH(P,t,W)

-

Density of Moist Air
Rho = f(P, T, W) [kg/m³]

DensMoistAir_W(P,t,W)

kg/m³

Volume of Moist Air Mixture (per Unit Mass of Dry Air)
v = f(P, T, W) [m³/kg]

VolMoistMix_W(P,t,W)

m³/kg dry air

Enthalpy of Moist Air per Unit of Mass of Dry Air
h = f(P, T, W) [kJ/kg dry air]

EnthalpyMoistAir_W(P,t,W)

kJ/kg dry air

Enthalpy of Moist Air per Unit of Mass of Mixture
hm = f(P, T, W) [kJ/kg mix]

=EnthalpyMix_W(P,t,W)

kJ/kg mix

Dewpoint of Moist Air
Td = f(P, T, W) [°C]

DewPoint_W(P,t,W)

°C

Wet Bulb Temperature of Moist Air
Twb = f(P, T, W) [°C]

WetBulb_W(P,t,W)

°C

Mixing Ratio

W

Relative Humidity
RH = f(P, T, W) [-]

RelHumidity_W(P,t,W)

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Moist Air Properties from Pressure, Temperature and Wet Bulb Temperature

Property

Formula

Unit

Pressure

P

Pa

Dry Bulb Temperature

T

°C

Wet Bulb Temperature

Twb

°C

Duct Inside Wall Temperature

Too

°C

Duct velocity

V

m/s

Wet Bulb Diameter, default 0.007 m (7 mm)

Dwb

m

Wet Bulb Emmittance [0 to 1], default 0.85

Ewb

-

Lewis Number [0.85 to 1], default 0.85

Le

-

Partial Pressure of Water Vapour
Pw = f(P, T, Twb) [Pa]

WPartP_Twb(P,t,Twb)

Pa

Degree of Saturation
µ = f(P, T, Twb) [-]

DegreeOfSat_Twb(P,T,Twb)

-

Density of Moist Air
Rho = f(P, T, Twb) [kg/m³]

DensMoistAir_Twb(P,t,Twb)

kg/m³

Volume of Moist Air Mixture (per Unit Mass of Dry Air)
v = f(P, T, Twb) [m³/kg]

VolMoistMix_Twb(P,t,Twb)

m³/kg dry air

Enthalpy of Moist Air per Unit of Mass of Dry Air
h = f(P, T, Twb) [kJ/kg dry air]

EnthalpyMoistAir_Twb(P,t,Twb)

kJ/kg dry air

Enthalpy of Moist Air per Unit of Mass of Mixture
hm = f(P, T, Twb) [kJ/kg mix]

EnthalpyMix_Twb(P,t,Twb)

kJ/kg mix

Dewpoint of Moist Air
Td = f(P, T, Twb) [°C]

DewPoint_Twb(P,t,Twb)

°C

Wet Bulb Temperature

Twb

°C

Mixing Ratio
W = f(P, T, Twb) [kg/kg]

MixRatio_Twb(P,T,Twb)

kg/kg

Mixing ratio from Twb calculated for mass and heat transfer
W = f(P, T, Twb, Too, V, Dwb, Ewb, Le) [kg/kg]

MixRatio_Twb1(P,T,Twb,Too,V, Dwb,Ewb,Le)

kg/kg

Relative Humidity
RH = f(P, T, Twb) [-]

RelHumidity_Twb(P,T,Twb)

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Heating and Cooling of a Moist Air Flow

Property

Formula

Unit

Pressure

P

Pa

Mass Flow of Air

Ma

kg/s

Dry Bulb Temperature at Inlet

T1

°C

Mixing Ratio at Inlet

W1

kg/kg

Heating or Cooling Power Between Inlet and Exit

Q

kW

Temperature After Heating or Cooling Moist Air Flow
T2 = f(P, Ma, T1, W1, Q) [°C]

Temp2_Q(P,Ma,T1,W1,Q)

°C

Mixing Ratio After Heating or Cooling Moist Air Flow
W2 = f(P, Ma, T1, W1, Q) [kg/kg]

MixRatio2_Q(Ma,P,T1,W1,Q)

kg/kg

Condensate Water Flow Rate After Cooling Moist Air Flow
'Mc = f(P, Ma, T1, W1, Q) [kg/s]

CondensateFlow_Q(Ma,P,T1, W1,Q)

kg/s

Pressure

P

Pa

Mass Flow of Air

Ma

kg/s

Dry Bulb Temperature at Inlet

T1

°C

Dry Bulb Temperature at Exit

T2

°C

Mixing Ratio at Inlet

W1

kg/kg

Required Power for Heating or Cooling Moist Air Flow
Q = f(P, Ma, T1, T2, W1) [kW]

Power_T2(P,Ma,T1,T2,W1)

kW

Mixing Ratio After Heating or Cooling Moist Air Flow
T2 = f(P, Ma, T1, T2, W1) [kg/kg]

MixRatio2_T2(P,Ma,T1,T2,W1)

kg/kg

Condensate Water Flow Rate After Cooling Moist Air Flow
'Mc = f(P, Ma, T1, T2, W1) [kg/s]

CondensateFlow_T2(P,Ma,T1, T2,W1)

kg/s

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Adiabatic Mixing of Two Streams of Moist Air

Property

Formula

Unit

Pressure

P

Pa

Mass Flow of Dry Air - Inlet Stream 1

Ma1

kg/s

Mass Flow of Dry Air - Inlet Stream 2

Ma2

kg/s

Dry Bulb Temperature - Inlet Stream 1

T1

°C

Dry Bulb Temperature - Inlet Stream 2

T2

°C

Mixing Ratio - Inlet Stream 1

W1

kg/kg

Mixing Ratio - Inlet Stream 2

W2

kg/kg

Enthalpy of Mixed Airstream
H3 = f(P, Ma1, Ma2, T1, T2, W1, W2) [°C]

Enthalpy3_mix(P,Ma1,Ma2,T1,T2,W1,W2)

kJ/kg dry air

Temperature of Mixed Airstream
T3 = f(P, Ma1, Ma2, T1, T2, W1, W2) [°C]

Temp3_mix(P,Ma1,Ma2,T1,T2,W1,W2)

°C

Mixing Ratio of Mixed Airstream
W3 = f(P, Ma1, Ma2, T1, T2, W1, W2) [kg/kg]

MixRatio3_mix(P,Ma1,Ma2,T1,T2,W1,W2)

kg/kg

Condensate Water Flow Rate with Mixed Airstream
Mw3 = f(P, Ma1, Ma2, T1, T2, W1, W2) [kg/s]

CondensateFlow3_mix(P,Ma1,Ma2,T1,T2, W1,W2)

kg/s

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Adiabatic Mixing of Moist Air with Injected Water or Steam

Property

Formula

Unit

Pressure

P

Pa

Mass Flow of Air

Ma

kg/s

Mass Flow of Injected Water

Mw1

kg/s

Dry Bulb Air Temperature at Inlet

Ta1

°C

Temperature of Injected Water

Tw1

°C

Mixing Ratio at Inlet

W1

kg/kg

Equivalent bypass factor (0<=B<=1)
B=1-Mu, where Mu is Humidification efficiency
For Steam injection specify B as:
B = -1 (Steam Enthalpy based on pressure P)
B = -2 (Steam Enthalpy based on temperature Mw1)

B

Factor that determines where Tdap lies between Twb1 and Tw2 (0<=C<=1)
(for C=0 Tadp=Tw1; for C=1 Tadp=Tw2; C->1 for B->0)

C

Exit Air Temperature after injecting water into moist airflow
Ta2 = f(P, Ma, Mw1, Ta1, Tw1, W1, B, C) [°C]

AirTemp2_WI(P,Ma,Mw1, Ta1,Tw1,W1,B,C)

°C

Exit Water Temperature after injecting water into moist airflow
Tw2 = f(P, Ma, Mw1, Ta1, Tw1, W1, B, C) [°C]

WaterTemp2_WI(P,Ma,Mw1, Ta1,Tw1,W1,B,C)

°C

Apparatus Dewpoint Temperature (injecting water into moist airflow)
Tadp = f(P, Ma, Mw1, Ta1, Tw1, W1, B, C) [°C]

Tadp_WI(P,Ma,Mw1,Ta1,Tw1, W1,B,C)

°C

Exit Mixing Ratio after injecting water into moist airflow
W2 = f(P, Ma, Mw1, Ta1, Tw1, W1, B, C) [kg/kg]

MixRatio2_WI(P,Ma,Mw1,Ta1, Tw1,W1,B,C)

kg/kg

Exit Relative Humidity
RH2 = (P,Ta2,W2)

RelHumidity_W(P,Ta2,W2)

Evaporated Injected Water
Mwe = f(P, Ma, Mw1, Ta1, Tw1, W1, B, C) [kg/s]

WaterEvap_WI(P,Ma,Mw1,Ta1, Tw1,W1,B,C)

kg/s

Exit Water Flow after injecting water into moist airflow
Mw2 = f(P, Ma, Mw1, Ta1, Tw1, W1, B, C) [kg/s]

WaterFlow2_WI(P,Ma,Mw1,Ta1, Tw1,W1,B,C)

kg/s

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