Rinnai 37AHB SERIES - Manual (Page 52)

52 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
948
921
891
868
8
4
1
8
1
9
795
772
701
596
567
120
35.
5
34.
5
33
.3
32
.5
31.
5
30.
7
29.
8
28.
9
26.
2
22
.3
21
.2
130
42
40
.8
39
.4
38
.4
37.
2
36.
3
35.
2
34.
2
31.
0
26
.4
25
.1
140
48.
6
47.
2
45
.7
44
.5
43.
1
42.
0
40.
8
39.
6
35.
9
30
.6
29
.1
150
55.
4
53.
8
52
50
.7
49.
1
47.
8
46.
4
45.
1
40.
9
34
.8
33
.1
160
61.
3
59.
6
57
.6
56
.1
54.
4
53.
0
51.
4
49.
9
45.
3
38
.5
36
.7
921
891
864
836
8
1
2
7
8
8
768
742
699
594
559
120
34.
1
33.
0
32
.0
31
.0
30.
1
29.
2
28.
4
27.
5
25.
9
22
.0
20
.7
130
40.
7
39.
4
38
.2
37
.0
35.
9
34.
9
34.
0
32.
8
30.
9
26
.3
24
.7
140
47.
3
45.
8
44
.4
42
.9
41.
7
40.
5
39.
5
38.
1
35.
9
30
.5
28
.7
150
55.
0
53.
2
51
.6
49
.9
48.
5
47.
1
45.
9
44.
3
41.
7
35
.5
33
.4
160
61.
1
59.
1
57
.3
55
.4
53.
8
52.
3
50.
9
49.
2
46.
4
39
.4
37
.1
803
768
740
712
6
8
2
6
5
2
628
596
569
541
510
120
32.
6
31.
1
30
.0
28
.9
27.
7
26.
4
25.
5
24.
2
23.
1
21
.9
20
.7
130
38.
6
36.
9
35
.6
34
.2
32.
8
31.
4
30.
2
28.
7
27.
4
26
.0
24
.5
140
45.
6
43.
6
42
.0
40
.4
38.
7
37.
0
35.
7
33.
8
32.
3
30
.7
29
.0
150
52.
1
49.
9
48
.0
46
.2
44.
3
42.
3
40.
8
38.
7
36.
9
35
.1
33
.1
160
58.
1
55.
6
53
.5
51
.5
49.
3
47.
2
45.
4
43.
1
41.
2
39
.1
36
.9
TB
D
S
ee N
ot
e 6.
37AHB 04508KA 5 + REU- VA 2019FF UD
A
HB4
5
+
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
)
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.
20
A
HB4
5
+
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
HB4
5
+
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
3
(H
)
2.
0
NE
T
HE
A
TI
N
G
CAP
A
CI
TY
(M
B
H
)
13
16
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
.
T
A
B
L
E 5
.2
0
: 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