Rinnai 37AHB SERIES User Manual
Page 55

Rinnai Corporation Hydronic Furnace (37AHB) Manual
55
N
O
T
E
S
:
1.
E
W
T
- En
teri
ng
W
ater Tempe
ratur
e (F)
.
2.
CFM - Air
flow
in (C
ubic Feet per
Minute).
3.
Legs - 3
in
ch
diame
ter
flex
ible du
cts to
diffu
ser
s.
4.
1 MBH =
1000
BTU/H.
5.
Shaded b
ox
represents ra
ting
poin
t; re
fer
to
w
iring diagra
m
for
factory
se
t sp
eed
taps.
6.
Number of 3”
diam
eter
leg
s
spe
cifi
ed i
n ta
ble a
bov
e is
fo
r
rating
poin
t o
nly
(i.e
. a
t Ex
ternal S
ta
tic
Pres
sure
of
0
.5
in. w
c. and
speed
TAP3, TAP1, TAP2
, TAP2
for
AHB45
, AH
B60, AHB75, A
H
B90 re
spe
ctiv
ely
). Final
leg
count i
s
to b
e de
termined
b
y the in
stalli
ng
con
tractor
and i
s to
be
based
on
the
follow
ing formula:
NUMBER OF LEG
S
= TOTAL
AVA
IL
ABLE CFM
(A
T THE S
P
ECI
F
IC
E
SP)
/ DESI
RED CFM per LEG
(40, 50, or 60 CF
M)
Ex
ample: Giv
en the
design
point
for
A
H
B045 o
f 0
.8
ESP
, Low
fan
speed
(Ta
p5). From
tabl
e 5
.0
, av
ailable CFM i
s
569 and
the d
esir
ed CFM per
leg
is 50
CFM.
Therefore,
Number of Leg
s =
569/50
= 11
.38
rou
nded dow
n to
11
.
0
0
.1
0.
2
0
.3
0.
4
0
.5
0.
6
0
.7
0.
8
0
.9
1.
0
13
43
131
8
1296
1270
1248
1225
1
197
11
68
110
9
1025
889
120
41.
5
40.
7
40
.0
39
.2
38.
5
37.
8
37.
0
36.
1
34.
2
31
.6
27
.4
130
49.
6
48.
6
47
.8
46
.9
46.
1
45.
2
44.
2
43.
1
40.
9
37
.8
32
.8
140
57.
8
56.
7
55
.8
54
.6
53.
7
52.
7
51.
5
50.
2
47.
7
44
.1
38
.2
150
65.
9
64.
7
63
.6
62
.4
61.
3
60.
1
58.
8
57.
3
54.
5
50
.3
43
.6
160
73.
9
72.
5
71
.3
69
.9
68.
7
67.
4
65.
9
64.
3
61.
0
56
.4
48
.9
11
48
112
8
1103
1072
1045
1012
984
955
937
908
690
120
38.
9
38.
2
37
.4
36
.3
35.
4
34.
3
33.
3
32.
3
31.
7
30
.8
23
.4
130
46.
4
45.
6
44
.6
43
.3
42.
2
40.
9
39.
8
38.
6
37.
9
36
.7
27
.9
140
54.
3
53.
4
52
.2
50
.7
49.
4
47.
9
46.
6
45.
2
44.
3
43
.0
32
.6
150
63.
0
61.
9
60
.5
58
.8
57.
3
55.
5
54.
0
52.
4
51.
4
49
.8
37
.9
160
70.
5
69.
3
67
.8
65
.9
64.
2
62.
2
60.
4
58.
7
57.
6
55
.8
42
.4
971
942
911
880
8
4
7
8
1
7
784
751
715
680
642
120
38.
2
37.
1
35
.9
34
.6
33.
3
32.
2
30.
9
29.
6
28.
1
26
.8
25
.3
130
45.
3
43.
9
42
.5
41
.0
39.
5
38.
1
36.
5
35.
0
33.
3
31
.7
29
.9
140
52.
8
51.
2
49
.5
47
.8
46.
0
44.
4
42.
6
40.
8
38.
9
37
.0
34
.9
150
60.
4
58.
6
56
.7
54
.8
52.
7
50.
9
48.
8
46.
7
44.
5
42
.3
40
.0
160
67.
9
65.
9
63
.7
61
.5
59.
2
57.
1
54.
8
52.
5
50.
0
47
.5
44
.9
844
810
777
734
6
9
8
6
6
5
626
581
533
504
466
120
36.
3
34.
8
33
.4
31
.5
30.
0
28.
6
26.
9
25.
0
22.
9
21
.7
20
.0
130
42.
8
41.
0
39
.4
37
.2
35.
4
33.
7
31.
7
29.
4
27.
0
25
.5
23
.6
140
49.
8
47.
8
45
.8
43
.3
41.
2
39.
2
36.
9
34.
3
31.
4
29
.7
27
.5
150
55.
9
53.
6
51
.5
48
.6
46.
2
44.
0
41.
5
38.
5
35.
3
33
.4
30
.9
160
61.
9
59.
4
57
.0
53
.8
51.
2
48.
8
45.
9
42.
6
39.
1
36
.9
34
.2
T
A
B
L
E 5
.2
3
: A
IR
D
E
L
IVER
Y A
N
D
PE
R
F
O
R
M
A
N
C
E D
A
T
A
(
B
O
T
T
O
M
O
R
S
ID
E
R
E
T
U
R
N
w
/ F
A
C
T
O
R
Y
SU
PPL
IE
D
F
IL
T
ER
)
UNI
T
SI
Z
E
EC
M
S
PEE
D
TA
P
SUP
P
ORT
S
C
OOL
IN
G C
A
P
.
RA
NG
E (
T
O
N
S)
EW
T
(
O
F)
NO
M
INA
L
HEA
T
IN
G
CA
P
A
CI
TY
Ex
te
rn
a
l
St
a
ti
c
Pr
es
sur
e
(
E
S
P
) i
n
. W
.C
.
N
um
ber
of
3"
di
am
et
er
br
an
ch
le
gs
appl
ic
abl
e t
o
H
ig
h
V
el
oc
ity
S
yst
em
s on
ly
.
U
ded o
nl
y i
f
m
et
hods ot
her
th
an
Tabl
e
3 i
s used t
o
det
er
m
ine du
ct
s
izes
.
TB
D
See
N
ot
e 6.
TB
D
S
ee N
ot
e 6.
37
AH
B06012
KA
5 +
R
EU
-V
A2024WD(
A)-U
C
A
H
B6
0
+
R6
3
L
S
e
2
A
IRFLOW
(
C
FM
)
TA
P
1
(H
)
3.
0
NE
T
HE
A
TI
N
G
CAP
A
CI
TY
(M
B
H
)
20
24
A
H
B6
0
+
R6
3
L
S
e
2
A
IRFLOW
(
C
FM
)
TA
P
2
(M
H
)
2.
5
NE
T
HE
A
TI
N
G
CAP
A
CI
TY
(M
B
H
)
TB
D
S
ee N
ot
e 6.
A
H
B6
0
+
R6
3
L
S
e
2
A
IRFLOW
(
C
FM
)
TA
P
4
(M
L)
2.
0
NE
T
HE
A
TI
N
G
CAP
A
CI
TY
(M
B
H
)
TB
D
S
ee N
ot
e 6.
M
ini
m
um
Legs
@
60 C
F
M
/Leg
A
H
B6
0
+
R6
3
L
S
e
2
A
IRFLOW
(
C
FM
)
TA
P
5
(L
)
1.
5
NE
T
HE
A
TI
N
G
CAP
A
CI
TY
(M
B
H
)
M
ini
m
um
Legs
@
60 C
F
M
/Leg
O
pt
im
al
Legs
@
50
C
F
M
/L
eg
M
ax
im
um
Legs @
40 C
F
M
/Leg
M
ini
m
um
Legs
@
60 C
F
M
/Leg
O
pt
im
al
Legs
@
50
C
F
M
/L
eg
M
ax
im
um
Legs @
40 C
F
M
/Leg
30
O
pt
im
al
Legs
@
50
C
F
M
/L
eg
M
ax
im
um
Legs @
40 C
F
M
/Leg
M
ini
m
um
Legs
@
60 C
F
M
/Leg
O
pt
im
al
Legs
@
50
C
F
M
/L
eg
M
ax
im
um
Legs @
40 C
F
M
/Leg
TB
D
See
N
ot
e 6.
TB
D
S
ee N
ot
e 6.
TB
D
See
N
ot
e 6.
TB
D
S
ee N
ot
e 6.
TB
D
S
ee N
ot
e 6.