46
4A
1P
C
-T
V2
.1
NM
V
-D2
M
-EN
11
-02
-04.
d
o
c
P
M
V
A
V
- S
u
bje
c
t t
o t
e
c
hnic
a
l c
ha
nge
s
VAV
– Module NMV-D2M
N-D2 Formulae
- Formulae for converting units
m
3
/h -> l/s
Volumetric flow [m
3
/h]
/
3.6
m
3
/h -> cfm
Volumetric flow [m
3
/h]
/
1.6990107955
l/s -> m
3
/h
Volumetric flow [l/s]
*
3.6
l/s -> cfm
Volumetric flow [l/s]
*
2.1188800033
cfm -> m
3
/h
Volumetric flow [cfm]
*
1.6990107955
cfm -> l/s
Volumetric flow [cfm]
/
2.1188800033
-
Formulae for calculating area
Area, circle
A = 0.785 x d
2
Area, rectangle
A = l x b
-
Formulae for calculating volumetric flow
Volumetric flow [m
3
/h] = (A [m
2
] x V [m
3
]) x 3600
-
Formulae for calculating velocity
Velocity [m/s]
= Volumetric flow [m
3
/h] / Area [m
2
]
-
Formulae for volumetric flow and differential pressure
-
Volumetric flow [m
3
/h]
c - Constant differential pressure sensor,
manufacturer
‘s value,
see manufacturer’s data
-
Differential pressure from measuring orifice (cross, bar) [Pa]
-
Density [kg/m
3
]; 1.2 kg/m
3
at 1013 hPa and 20°C
- Formulae for pressure
calculations
1 mbar
=
0,001 bar
=
100 Pa
1 mmH
2
O =
9,80665 Pa
V
p
V
p
c
=
p
=
2
c
V
