calcHbExSteady: Human Body Exergy Consumption Rate Using Steady State Method

In comf: Models and Equations for Human Comfort Research

Human Body Exergy Consumption Rate Using Steady State Method

Description

calcHbExSteady calculates the human body exergy consumption rate in W/m2 using steady state method based on a set of environmental variables.

Usage

calcHbExSteady(ta, tr, rh, vel, clo, met, tao, rho, frad = 0.7, eps = 0.95, 
ic = 1.085, ht = 171, wt = 70, tcr = 37, tsk = 36, basMet = 58.2, warmUp = 60, 
cdil = 100, sigmatr = 0.25)

Arguments

ta	a numeric value presenting air temperature in [degree C]
tr	a numeric value presenting mean radiant temperature in [degree C]
rh	a numeric value presenting relative humidity [%]
vel	a numeric value presenting air velocity in [m/s]
clo	a numeric value presenting clothing insulation level in [clo]
met	a numeric value presenting metabolic rate in [met]
tao	a numeric value presenting outdoor air temperature in [degree C]
rho	a numeric value presenting outdoor relative humidity [%]
frad	a numeric value presenting the fraction of body exposed to radiation 0.7(for seating), 0.73(for standing) [-]
eps	a numeric value presenting emissivity [-]
ic	a numeric value presenting permeability of clothing: 1.084 (average permeability), 0.4 (low permeability)
ht	a numeric value presenting body height in [cm]
wt	a numeric value presenting body weight in [kg]
tcr	a numeric value presenting initial value for core temperature in [degree C]
tsk	a numeric value presenting initial value for skin temperature in [degree C]
basMet	a numeric value presenting basal metabolic rate in [met]
warmUp	a numeric value presenting length of warm up period, i.e. number of times, loop is running for HBx calculation
cdil	a numeric value presenting value for cdil in 2-node model of Gagge
sigmatr	a numeric value presenting value for cdil in 2-node model of Gagge

Value

Returns a data.frame with the following columns

Exergy input
xInmets Exergy input through metabolism [W/m2]
xInmetwcs Label warm/ cold for exergy input through metabolism [W/m2]
xInAIRwcs Exergy input through inhaled humid air [W/m2]
xInAIRwcwcs Label warm/ cold for exergy input through inhaled humid air [W/m2]
xInAIRwds Exergy input through inhaled dry air [W/m2]
xInAIRwdwds Label wet/ dry for exergy input through inhaled dry air [W/m2]
xInLUNGwcs Exergy input through water lung [W/m2]
xInLUNGwcwcs Label warm/ cold for exergy input through water lung [W/m2]
xInLUNGwds Exergy input through water lung [W/m2]
xInLUNGwdwds Label wet/ dry for exergy input through water lung [W/m2]
xInsheLLwcs Exergy input through water from sweat [W/m2]
xInsheLLwcwcs Label warm/ cold for exergy input through water from sweat [W/m2]
xInsheLLwds Exergy input through water from sweat [W/m2]
xInsheLLwdwds Label wet/ dry for exergy input through water from sweat [W/m2]
xInraDs Exergy input through radiation [W/m2]
xInraDwcs Label warm/ cold for exergy input through radiation [W/m2]
xIntotaLs total exergy input [W/m2]

Exergy output
xoutstorecores Exergy stored in core [W/m2]
xoutstoreshels Exergy stored in shell [W/m2]
xoutaIRwcs Exergy output through exhaled humid air [W/m2]
xoutaIRwcwcs Label warm/ cold for exergy output through exhaled humid air [W/m2]
xoutaIRwds Exergy output through exhaled dry air [W/m2]
xoutaIRwdwds Label wet/ dry for exergy output through exhaled dry air [W/m2]
xoutswEATwcs Exergy output through water vapour from sweat [W/m2]
xoutswEATwcwcs Label warm/ cold for exergy output through water vapour from sweat [W/m2]
xoutswEATwds Exergy output through water vapour from sweat [W/m2]
xoutswEATwdwds Label wet/ dry for exergy output through water vapour from sweat [W/m2]
xoutraDs Exergy output through radiation [W/m2]
xoutraDwcs Label warm/ cold for exergy output through radiation [W/m2]
xoutCONVs Exergy output through convection [W/m2]
xoutCONVwcs Label warm/ cold for exergy output through convection [W/m2]
xouttotaLs total exergy output [W/m2]

Exergy balance
xconss total exergy consumption [W/m2]
xConsumption total exergy consumption [W/m2]

Additional values
tsks Calculated skin temperature [degree C]
tcrs Calculated core temperature [degree C]
ws Calculated skin wettedness [degree C]

Note

According to Gagge's paper (1973), the value of 'cdil' may vary between 75 and 225 and 'sigma-tr' between 0.25 and 0.75. There is a note in the appendix of his paper saying two things: 1) whatever the values taken for cdil and sigma-tr, there must be no significant change in resulting thermal equilibrium. But, the values taken for cdil and sigmaTr do affect time to equilibrium. According to the analysis of Schweiker et al. (2016), the values of 100 and .25 lead to the best fit of calculated and observed skin temperature.

Author(s)

This function is based on a VBA code developed by Masanori Shukuya. transformation of VBA-code and Excel procedures into R syntax by Marcel Schweiker.

References

Schweiker, Kolarik, Dovjak & Shukuya (2016) <doi:10.1016/j.enbuild.2016.01.002>

Shukuya (2015) Calculation of human body-core and skin-layer temperatures under unsteady-state conditions-for unsteady-state human-body exergy analysis-, internal report of exergy-research group, Tech. rep.

See Also

see also calcComfInd, calcHbExUnsteady

Examples

## Calculation of human body exergy consumption rate 
calcHbExSteady(22, 24, 50, .1, .8, 1.2, 5, 80)

## Calculation of multiple values
dfData <- data.frame(ta=c(20:25), tr=c(20:25))
dfResult <- calcHbExSteady(22, 24, 50, .1, .8, 1.2, 5, 80) 
for(i in 1:nrow(dfData)){
dfResult[i,] <- calcHbExSteady(dfData$ta[i], dfData$tr[i], 50, .1, .5, 1.1, 5, 80)
}

comf documentation built on May 29, 2024, 8:02 a.m.