Rinnai 37AHB SERIES User Manual
Page 32

32
Rinnai Corporation Hydronic Furnace (37AHB) Manual
0
0
.1
0.
2
0
.3
0.
4
0
.5
0.
6
0
.7
0.
8
0
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1.
0
948
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868
841
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6
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4
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36.
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5
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6
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7
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1
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44.
1
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8
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4
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4
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1
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1
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0
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9
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6
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7
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4
150
50.
9
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4
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8
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6
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2
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0
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7
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4
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6
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160
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9
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2
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4
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864
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50.
2
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3
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9
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4
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58.
4
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5
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8
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803
768
740
712
682
652
628
596
5
6
9
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30.
1
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4
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8
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2
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0
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4
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1
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6
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4
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1
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7
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42.
1
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3
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8
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4
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8
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2
33.
0
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3
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9
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4
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8
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49.
7
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5
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8
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1
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2
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4
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9
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9
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2
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5
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2
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2
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0
16
AI
RF
L
O
W
(CF
M
)
T
A
B
L
E
5
.0
: AI
R D
E
L
IV
E
RY
AN
D
P
E
RF
O
R
M
ANC
E
D
A
T
A
(
B
O
T
T
O
M
O
R
S
ID
E
RE
T
URN
w
/ F
A
C
T
O
R
Y
S
U
P
P
L
IE
D
F
IL
T
E
R
)
13
16
20
UN
IT
SIZ
E
EC
M
SPE
E
D
TA
P
E
W
T (
O
F)
NO
M
INAL
HE
AT
IN
G
CA
P
ACI
T
Y
E
x
te
rn
a
l St
a
tic
Pr
e
ss
u
re
(
E
SP)
20
13
16
20
AI
RF
L
O
W
(CF
M
)
13
A
H
B
4
5 +
R
C
98H
P
i(
e
)
2.
0
TAP
3
(H)
N
E
T
H
EAT
IN
G
C
A
PAC
IT
Y
(M
B
H
)
1.
5
A
H
B
4
5 +
R
C
98H
P
i(
e
)
AI
RF
L
O
W
(CF
M
)
SU
PP
O
R
T
S
CO
O
L
IN
G
CAP
.
RANG
E
(T
O
N
S
)
N
E
T
H
EAT
IN
G
C
A
PAC
IT
Y
(M
B
H
)
TAP
4
(M
)
TAP
5
(L
)
N
E
T
H
EAT
IN
G
C
A
PAC
IT
Y
(M
B
H
)
37A
HB
04508K
A5 +
RE
U-K
A3237FFU
D (
WD
)-U
S
2.
0
A
H
B
4
5 +
R
C
98H
P
i(
e
)
N
um
ber
of
3"
Di
am
et
er
B
ranc
h Legs
appl
ic
ab
le
t
o H
ig
h
V
el
oc
ity
S
ys
tem
s O
nl
y.
U
sed onl
y i
f m
et
hods
ot
her
than T
abl
e 3 i
s us
ed t
o det
er
m
ine duc
t s
iz
es
.
M
in
im
um
Legs
@
60 C
F
M
/Leg
O
pt
im
al
L
egs
@
50 C
F
M
/Leg
Ma
xi
m
um le
gs
@
40 C
F
M
/Leg
M
in
im
um
Legs
@
60 C
F
M
/Leg
O
pt
im
al
L
egs
@
50 C
F
M
/Leg
Ma
xi
m
um le
gs
@
40 C
F
M
/Leg
M
in
im
um
Legs
@
60 C
F
M
/Leg
O
pt
im
al
L
egs
@
50 C
F
M
/Leg
Ma
xi
m
um le
gs
@
40 C
F
M
/Leg
N
O
T
E
S
:
1.
EWT - Entering
Water Temp
erat
ure (
F
).
2.
CFM - Airflo
w
in
(Cubic Feet pe
r
Minute).
3.
Legs - 3 inch diameter flexible du
cts to diffusers.
4.
1 MBH = 1000 B
T
U/H.
5.
Shaded bo
x rep
resents rating point; refer
to
w
iring
diagram for f
actor
y set speed t
aps.
6.
Number of
3” dia
m
eter legs specified
in table above is for rating poi
nt onl
y (i.e. at
E
xternal Static Pressure of 0.5 in.
w
c. and
speed TAP3, TA
P1, TAP2 , TAP2
for AHB45, AHB
60, AHB75, AHB
90 respectively).
Final leg
count is to be determin
ed b
y
the installing con
tractor and is to
be based on the
follow
ing form
ula:
NUMBER
O
F
LE
G
S
= TO
TAL AV
AILABLE CFM
(A
T
T
H
E SPE
CIFIC ES
P)
/ DESIRED CF
M
per LE
G
(40, 50,
or 6
0 C
F
M
)
Example:
Given the design point for AH
B045 of
0.8
ESP, Lo
w
fan sp
eed (Ta
p5).
Fro
m
table 5.0, available CFM is 569
and
the desired CF
M
per leg is 50 CF
M.
Therefo
re, N
umb
er of Legs = 569/
50 = 11.38 ro
und
ed do
w
n to
11.
TBD
See Note 6.
TBD
See Note 6.
TBD
See Note 6.
TBD
See Note 6.
TBD
See Note 6.
TBD
See Note 6.
in. W.C.