12
ORIGINAL INSTRUCTIONS
VES Andover Ltd Eagle Close Chandlers Ford Ind. Est Eastleigh Hampshire SO53 4NF
Tel: 08448 156060 Fax: 02380 261204 E-mail: [email protected] Web: www.ves.co.uk
Heat Recovery Unit
Installation, Operation and Maintenance Manual
®
Continued
This differential pressure compares the static pressure in front of the fan inlet ring with the static pressure
in the inlet ring of the narrowest point. The differential pressure between the static
pressures is related to the air volume via the energy conservation rate as per the graph below.
Simply read across from the pressure measurement to the appropriate fan curve and down to
calculate the resultant air volume.
For example:
Measured differential pressure: 550Pa
Unit: EVX616
Reading from graph: 1.0
Air Volume: 1.0m³/s
700
750
800
850
900
950
1000
1050
1100
1150
1200
0
50
100
150
200
250
300
350
400
450
500
550
600
650
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3
E
V
X1
E
VX2
EVX3
E
VX6
E
V
X4
E
V
X
7
EVX5
EV
X
8
Th
i
s m
ea
su
re
m
ent
c
an
al
s
o
b
e
e
xp
re
ss
ed
in
t
h
e
f
ollowin
g c
al
cu
lation
:
w
h
ere
q
i
s
t
h
e
air
vol
um
e
in
m³
/
s
k
i
s
t
h
e
f
an
nozzle
c
oe
ff
i
c
ient
(EVX143
=
68
,
EVX244
=
86
,
EVX345
=
96
,
EVX447
=
172
,
EVX549
=
274
,
EVX616
=
154
,
EVX717
=
197
,
EVX819
=
308)
p
i
s
t
h
e
m
ea
su
red
di
ff
erential
p
re
ssu
re
in
Pa
E
x
a
mp
le
:
Mea
su
red
di
ff
erential
p
re
ssu
re
:
550
Pa
Unit
:
EVX616
q =
(154
550)
/
3600
q =
(154
x
23.452)
/
3600
q =
3611
/
3600
q =
air
vol
um
e
=
1.003
m³
/
s
q =
(k
p
)
/
3600
V
W
Δ
V
W
Δ
√
V
V
V
V
q
Air
Vol
um
e
m³
/
s
v
Δ
p
Di
ff
er
en
tial
Pr
e
ssu
re
P
a
w
Standard Wiring
& Fan Installation
5
Differential pressure curves
Fig.
