R: Execute MIAQ, an indoor air aerosol model

miaq.aer {heR.IndoorAir}

R Documentation

Execute MIAQ, an indoor air aerosol model

Description

This function executes an aerosol calculation using MIAQ, a Multi-chamber Indoor Air Quality model originally authored by William W. Nazaroff as part of his Ph.D. disseration research in the Environmental Engineering Science Department at the California Institute of Technology, Pasadena, CA.

Usage

miaq.aer(...)

Arguments

`...`	Any of the following arguments or a list containing them:
`dens`	particle density [kg/m^3], real
`ncomp`	no. of aerosol components, integer
`nbins`	no. of aerosol size bins, integer
`nhours`	np. of hours in the simulation, integer
`nchamb`	no. of chambers (rooms), integer
`v`	volumes of each chamber [m^3], real array
`h`	heights of each chamber [m], real array
`nwalls`	number of walls in each chamber, integer array
`bingeo`	automatically set geometric size bins, logical (integer) `FALSE` = manually assign size bins, see `binlim` `TRUE` = automatically assign size bins
`binlim`	bin limits for aerosol diameter (used if `bingeo = FALSE`) [μ m], real array
`minbin`	minimum bin limit [μ m] (used if `bingeo = TRUE`)
`maxbin`	maximum bin limit [μ m] (used if `bingeo = TRUE`)
`surfloss`	type of surface loss model, integer 1 = deposition velocity model 2 = forced laminar flow model 3 = natural convection model 4 = homogeneous turbulence model
`depvel`	aerosol deposition velocity for each chamber and bin (used if `surfloss` = 1) [cm/s], 2d real array Note: Each value is considered a total deposition velocity for a single room and is divided among the surfaces.
`surforien`	orientation of walls (surfaces) in each chamber, 2d integer array 1 = vertical surfaces (VE,VI) 2 = upward isolated surface (UI) 3 = upward enclosed surface (UE) 4 = downward isolated surface (DI) 5 = downward enclosed surface (DE)
`surfarea`	area of each wall in each chamber [m^2], 2d real array
`surflen`	length of each wall in direction of flow in each chamber [m], 2d real array
`surftemp`	surface temperature for each chamber, wall, hour [deg C], 3d real array
`indtemp`	indoor air temperature for each chamber and hour [deg C], 2d real array
`initc`	initial conc for each chamber, component, and size bin [μ g/m^3], 3d real array
`outc`	outdoor conc for each component, size bin, and hour [μ g/m^3], real array
`thermo`	thermophoresis coefficients for each size bin, real array
`turb`	turbulence intensity for each chamber and hour, real array
`coagtype`	use fixed coagulation coefficients, integer 0 = no coagulation effect is included 1 = fixed coagulation coefficients 2 = variable coagulation coefficients
`coagtemp`	temperature of air for coagulation calc [deg C], real dim(2)
`coagturb`	turbulence of air for coagulation calc, real dim(2)
`infilt`	infiltration rate from outdoors for each hour [m^3/min], real array
`exfilt`	exfiltration rate to outdoors for each hour [m^3/min], real array
`recirc`	recirculation rate for each chamber for each hour [m^3/min], 2d real array
`intake`	air intake rate for building for each chamber and hour [m^3/min], 2d real array
`return`	air return rate for each chamber for each hour [m^3/min], 2d real array
`cross`	ventilation between chambers for each hour [m^3/min], 3d real array
`makeup`	make-up air supply rate for each hour [m^3/min], real array
`inteff`	efficiency of the intake vent filter for each bin, real array
`reteff`	efficiency of the return vent filter for each chamber and bin, 2d real array
`receff`	efficiency of the recirculating filter for each chamber and bin, 2d real array
`emiss`	include source emissions in calculation, logical (integer) `FALSE` = do not include emission in the calculation `TRUE` = include emissions, see following variables
`erate`	particle emission rate for each source,component,and bin [μ g/min], 3d real array
`echamb`	the chamber where each source is located, integer array
`etimes`	start and stop times (elapsed min after midnight) for each source, 2d real array
`hourstart`	hour that simulation will start, integer
`minstart`	minute that simulation will start, integer
`hourend`	hour that simulation will end, integer
`minend`	minute that simulation will end, integer
`timeint`	the time interval (step) for the simulation in minutes, real
`write`	write detailed ouput to text files, logical (integer)
`write.freq`	multiple of time interval that data is written
`show.time`	print out the time it took the MIAQ routine to execute, logical

Details

This R function is a front-end to indoor air quality calculations for arbitrary size distributions of aerosols (airborne particles) using the MIAQ program. MIAQ is highly-configurable research software written in Fortran-77. A stand-alone version exists that takes a textual command file as input.

The MIAQ program has the following general features:

1. Multichamber temporal simulation of airborne pollutant concentrations

2. Both aerosol and gas phase contaminants are considered

3. For all species, ventilation, filtration, wall loss, and direct emissions into each chamber are considered

4. For gases, thermal and photolytic reactions are treated

5. For particles, coagulation is treated for any number of particle diameter intervals (bins).

The dimensional limits of the current MIAQ program are as follows:

The maximum number of aerosol components = 2
The maximum number of aerosol bins = 25
The maximum number of chambers = 5
The maximum number of sources = 20
The minimum simulation time step (interval) = 1 min
The maximum number of simulated hours = 24
The maximum number of time steps = 1440
The maximum number of walls per chamber = 5

In the future, another R function miaq.gas will be written to conduct MIAQ calculations for gaseous species.

Value

The function returns a list with the following component arrays:

`cpall`	airborne particle mass concentration [μ g/m^3], 4d array by min, chamber, component, size-bin
`cnall`	airborne particle number concentration no./cm^2, 4d array by min, chamber, component, size-bin
`dpall`	deposited particle mass [μ g/m^2], 5d array by min, chamber, component, size-bin, wall
`elmin`	elapsed minutes, vector of real values

Author(s)

Neil E. Klepeis
nklepeis@uclink.berkeley.edu
http://socrates.berkeley.edu/~nklepeis

References

Nazaroff and Cass (1989) Environmental Science and Technology 23 : 157-165

Nazaroff and Cass (1986) Environmental Science and Technology 20 : 924-934