57
57
Combustion parameters: measuring conditions of useful e
ffi
ciency
(
fl
ow temperature/return temperature
=
80 / 60 °C), ambient tem-
perature reference
=
15°C.
4
TECHNICAL DATA.
4.1 VARIABLE HEAT OUTPUT.
N.B.:
the power data in the table has been obtained with intake-
exhaust pipe measuring 0.5 m in length. Gas
fl
ow rates refer to
net calorific value below a temperature of 15°C and at a pressure
of 1013 mbar.
G20
G31
Supply pressure
mbar (mm H
2
O)
20 (204)
37 (377)
Gas nozzle diameter
mm
5.0
5.0
Flue
fl
ow rate at nominal DHW/heat output
kg/h (g/s)
42 (11.67) - 34 (9.44) 43 (11.94) - 35 (9.72)
Flue
fl
ow rate at min heat output
kg/h (g/s)
6 (1.67)
6 (1.67)
CO
2
at
Q
. Nom./Acc./Min.
%
9.20 / 9.00 / 9.00
(
±
0.2)
10.20 / 10.00 / 10.00
(
±
0.2)
CO with 0
%
O
2
at Nom./Min.
Q
.
ppm
240 / 7
263 / 7
NO
X
with 0
%
O
2
at Nom./Min.
Q
.
mg/kWh
72 / 27
39 / 34
Flue temperature at nominal output
°C
63
63
Flue temperature at minimum output
°C
54
54
Max air combustion temperature
°C
50
50
Intake / exhaust available head F0
=
0
Pa
68
68
Intake / exhaust available head F0
=
1
Pa
103
103
Intake / exhaust available head F0
=
2
Pa
138
138
4.2 COMBUSTION PARAMETERS.
METHANE
(G20)
PROPANE
(G31)
HEAT
THERMAL
MODULATION
GAS FLOW RATE
BURNER
MODULATION
GAS FLOW RATE
BURNER
(kW)
(kcal/h)
(
%
)
(m
3
/h)
(
%
)
(kg/h)
(g/s)
25.0
21500
D.H.W.
99
2.74
99
2.01
0.56
24.0
20640
96
2.63
96
1.93
0.54
23.0
19780
92
2.52
92
1.85
0.51
22.0
18920
88
2.41
88
1.77
0.49
21.0
18060
84
2.30
84
1.69
0.47
20.0
17200
HEAT.
+
D.H.W.
80
2.19
80
1.61
0.45
19.0
16340
76
2.08
76
1.53
0.42
18.0
15480
72
1.97
72
1.45
0.40
17.0
14620
68
1.86
68
1.37
0.38
16.0
13760
63
1.75
63
1.29
0.36
15.0
12900
59
1.64
59
1.21
0.34
14.0
12040
54
1.53
54
1.13
0.31
13.0
11180
50
1.42
50
1.05
0.29
12.0
10320
45
1.32
45
0.97
0.27
11.0
9460
40
1.21
40
0.89
0.25
10.0
8600
35
1.10
35
0.81
0.22
9.0
7740
30
0.99
30
0.73
0.20
8.0
6880
25
0.88
25
0.65
0.18
7.0
6020
20
0.77
20
0.56
0.16
6.0
5160
15
0.66
15
0.48
0.13
5.0
4300
10
0.55
10
0.40
0.11
4.0
3440
4
0.44
4
0.32
0.09
3.5
3010
1
0.39
1
0.28
0.08
