Calculation Of Compensation Factor - Rinnai Q85SN Installation & Service Instructions Manual

6.7.7 Calculation of compensation factor
i
NOTICE
!
WARNING
32
The compensation factor eliminates or reduces the natural effect of derate of maximum
input caused by the resistance of the vent system and/or the impact of the altitude.
1. Determine the Compensation Factor Vent System CF(V) in the table below.
Eq. length (ft)
min max
0 10
11 20
21 30
31 40
41 60
61 80
81 100
Compensation factor vent system CP(V)
2. Determine the Compensation Factor Altitude CF(A) in the table below.
Altitude (ft)
min max
0 1
1,000 2,000
2,000 3,000
3,000 4,000
4,000 5,000
5,000 6,000
6,000 7,000
7,000 8,000
8,000 9,000
9,000 10,000
Compensation factor altitude CP(A)
Any application or installation above 10,000 must be reviewed by Rinnai's
Engineering group. This is to ensure the product is installed and the overall
system is designed properly and that the units are commisioned properly.
Not involving of Rinnai's Engineering group would result in no support of the
product and no warranty.
3. Calculate the Compensation Factor Total CF(T):
CF(T) = CF(V) + CF(A)
The result is the setting for Parameter 73.
Change parameter 73 according to this result. See Chapter 11.1 how to change
parameters.
Example of calculation:
Q175
Eq. lenth vent system (taken from previous example)
Altitude
Parameter setting (Par. 73) = 52
Do not overcompensate the boiler by setting a higher value than calculated,
otherwise the boiler could be seriously damaged.
Boiler type
Q85 Q130 Q175
CF (V)
0 0
0 0
0 2
1 4
2 6
3 8
4 10
Boiler type
Q85, Q130, Q175, Q205
CF (A)
0
6
12
18
24
30
36
42
48
54
46 ft
7,200ft
Q205
0 0
2 3
4 6
6 10
10 n.a.
15 n.a.
n.a. n.a.
table 10
table 11
CF(V) = 10
CF(A) = 42 +
CF(T) = 52