Symbol	Units	Description
AL	m2	cross-sectional area of exhaust duct
E	J/kg	heat released per unit amount of oxygen consumed (= 13.1 × 106 J/kg O2)
k1,k2		proportional constant (<< 1)
M	kg/mol	molecular weight
n	mol/s	material flow rate
${\widehat{n}}_{\text{T},\text{L}}$	mol/s	total material flow rate in L-stream with tracer
p	Pa	pressure
pvap	Pa	vapor pressure
q	W	heat release rate
RH		relative humidity (%)
S		combustion product species
T	K	temperature
vL	m/s	gas velocity in the exhaust duct
y	mol/mol	amount-of-substance fraction
α		expansion factor, defined in Eq. (15)
β		ratio of amount of substance of combustion products formed to that of oxygen consumed, defined in Eq. (12)
v		stoichiometric coefficient
ρ	mol/m3	density
ϕ		oxygen depletion factor, defined in Eq. (2)

Subscript
A	pertaining to A-stream (to analyzers)
CO	carbon monoxide
CO2	carbon dioxide
D	pertaining to D-stream (to stack)
E	pertaining to E-stream (entering stream)
fuel	fuel
H2O	water
i	combustion product species i (= 1, 2,…, m)
L	pertaining to L-stream (leaving stream)
m	total number of combustion product species
N2	Nitrogen
rxn	Reacted
S	pertaining to S-stream (sampling stream)
tr	tracer gas
T	Total
W	pertaining to W-stream (water analyzer)
Superscript
*	background (no fire under collection hood)