calcHbExUnsteady: Human Body Exergy Consumption Rate using Unsteady State...

In comf: Models and Equations for Human Comfort Research

Human Body Exergy Consumption Rate using Unsteady State Method

Description

calcHbExUnsteady Function calculates the human body exergy consumPtion rate using unsteady state method based on a series of environmental variables.

Usage

calcHbExUnsteady(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, dateTime)

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

Details

This function requires vectors of data including the corresponding time stamp. In case the time between two measurements is more than a minute, intermediate values are interpolated.

Value

Returns a data.frame with the following columns. Exergy input

xInmetu	Exergy input through metabolism
xInmetwcu	Label warm/ cold for exergy input through metabolism
xInAIRwcu	Exergy input through inhaled humid air
xInAIRwcwcu	Label warm/ cold for exergy input through inhaled humid air
xInAIRwdu	Exergy input through inhaled dry air
xInAIRwdwdu	Label wet/ dry for exergy input through inhaled dry air
xInLUNGwcu	Exergy input through water lung
xInLUNGwcwcu	Label warm/ cold for exergy input through water lung
xInLUNGwdu	Exergy input through water lung
xInLUNGwdwdu	Label wet/ dry for exergy input through water lung
xInsheLLwcu	Exergy input through water from sweat
xInsheLLwcwcu	Label warm/ cold for exergy input through water from sweat
xInsheLLwdu	Exergy input through water from sweat
xInsheLLwdwdu	Label wet/ dry for exergy input through water from sweat
xInraDu	Exergy input through radiation
xInraDwcu	Label warm/ cold for exergy input through radiation
xIntotaLu	total exergy input

Exergy output

xoutstorecoreu	Exergy stored in core
xoutstoreshelu	Exergy stored in shell
xoutaIRwcu	Exergy output through exhaled humid air
xoutaIRwcwcu	Label warm/ cold for exergy output through exhaled humid air
xoutaIRwdu	Exergy output through exhaled dry air
xoutaIRwdwdu	Label wet/ dry for exergy output through exhaled dry air
xoutswEATwcu	Exergy output through water vapour from sweat
xoutswEATwcwcu	Label warm/ cold for exergy output through water vapour from sweat
xoutswEATwdu	Exergy output through water vapour from sweat
xoutswEATwdwdu	Label wet/ dry for exergy output through water vapour from sweat
xoutraDu	Exergy output through radiation
xoutraDwcu	Label warm/ cold for exergy output through radiation
xoutCONVu	Exergy output through convection
xoutCONVwcu	Label warm/ cold for exergy output through convection
xouttotaLu	total exergy output

Exergy balance

xconsu

total exergy consumPtion

Additional values

tsku	Calculated skin temperature
tcru	Calculated core temperature
wu	Calculated skin wettedness

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. (2015), 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

Examples

## Define environmental parameters
ta <- seq(20,25,.1)
tr <- ta
rh <- rep(50, length(ta))
vel <- rep(.1, length(ta))
clo <- rep(.8, length(ta))
met <- rep(1.2, length(ta))
tao <- rep(5, length(ta))
rho <- rep(80, length(ta))
dateTime <- as.POSIXct(seq(0,by=60,length.out=length(ta)), origin="1970-01-01")
## Calculation of human body exergy consumPtion rate
calcHbExUnsteady(ta, tr, rh, vel, clo, met, tao, rho, dateTime = dateTime)$xconsu

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