Rinnai 37AHB SERIES - Manual (Page 56)

56 Rinnai Corporation Hydronic Furnace (37AHB) Manual
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
S
P)
/ 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
43.
6
42.
8
42
.1
41
.2
40.
5
39.
8
38.
8
37.
9
36.
0
33
.3
28
.8
130
50.
9
49.
9
49
.1
48
.1
47.
3
46.
4
45.
3
44.
3
42.
0
38
.8
33
.7
140
59.
5
58.
4
57
.4
56
.3
55.
3
54.
3
53.
1
51.
8
49.
2
45
.4
39
.4
150
68.
6
67.
4
66
.2
64
.9
63.
8
62.
6
61.
2
59.
7
56.
7
52
.4
45
.4
160
75.
2
73.
8
72
.6
71
.2
69.
9
68.
6
67.
1
65.
4
62.
1
57
.4
49
.8
11
48
112
8
1103
1072
1045
1012
984
955
937
908
690
120
40.
3
39.
6
38
.7
37
.6
36.
7
35.
5
34.
5
33.
5
32.
9
31
.9
24
.2
130
48.
0
47.
2
46
.1
44
.8
43.
7
42.
3
41.
2
40.
0
39.
2
38
.0
28
.9
140
56.
2
55.
2
54
.0
52
.5
51.
2
49.
5
48.
2
46.
7
45.
9
44
.4
33
.8
150
65.
1
64.
0
62
.5
60
.8
59.
3
57.
4
55.
8
54.
2
53.
1
51
.5
39
.1
160
72.
9
71.
6
70
.0
68
.1
66.
4
64.
3
62.
5
60.
6
59.
5
57
.7
43
.8
971
942
911
880
8
4
7
8
1
7
784
751
715
680
642
120
39.
6
38.
4
37
.2
35
.9
34.
6
33.
3
32.
0
30.
6
29.
2
27
.7
26
.2
130
46.
8
45.
4
43
.9
42
.4
40.
8
39.
4
37.
8
36.
2
34.
5
32
.8
31
.0
140
54.
6
52.
9
51
.2
49
.5
47.
6
45.
9
44.
1
42.
2
40.
2
38
.2
36
.1
150
62.
6
60.
7
58
.7
56
.7
54.
6
52.
7
50.
5
48.
4
46.
1
43
.8
41
.4
160
70.
1
68.
0
65
.8
63
.6
61.
2
59.
0
56.
6
54.
2
51.
6
49
.1
46
.4
844
810
777
734
6
9
8
6
6
5
626
581
533
504
466
120
37.
6
36.
1
34
.6
32
.7
31.
1
29.
6
27.
9
25.
9
23.
8
22
.5
20
.8
130
44.
3
42.
5
40
.8
38
.6
36.
7
34.
9
32.
9
30.
5
28.
0
26
.5
24
.5
140
51.
4
49.
3
47
.3
44
.7
42.
5
40.
5
38.
1
35.
4
32.
4
30
.7
28
.4
150
57.
8
55.
4
53
.2
50
.2
47.
8
45.
5
42.
8
39.
8
36.
5
34
.5
31
.9
160
64.
1
61.
5
59
.0
55
.7
53.
0
50.
5
47.
5
44.
1
40.
5
38
.3
35
.4
TB
D
S
ee N
ot
e 6.
A
HB6
0
+
R5
0
L
Si
A
IRFLOW
(
C
FM
)
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
TA
P
5
(L
)
1.
5
NE
T
HE
A
TI
N
G
CAP
A
CI
TY
(M
B
H
)
TB
D
S
ee N
ot
e 6.
TB
D
See
N
ot
e 6.
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.
TB
D
See
N
ot
e 6.
TB
D
S
ee N
ot
e 6.
TB
D
S
ee N
ot
e 6.
A
HB6
0
+
R5
0
L
Si
A
IRFLOW
(
C
FM
)
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
A
HB6
0
+
R5
0
L
Si
A
IRFLOW
(
C
FM
)
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
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.
TB
D
See
N
ot
e 6.
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
TA
P
1
(H
)
3.
0
NE
T
HE
A
TI
N
G
CAP
A
CI
TY
(M
B
H
)
20
24
30
T
A
B
L
E 5
.2
4
: 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
.
37AHB 06012K A5 + R EU -V A2019 FF UD
A
HB6
0
+
R5
0
L
Si
A
IRFLOW
(
C
FM
)