Performance factor N
L
To DIN 4708.
Cylinder storage temperature T
cyl
= cold water inlet temperature
+50 K
+5 K/-0 K
and 70 °C heating water flow temperature
Performance factor N
L
subject to the heating output delivered by the boiler (Q
D
)
Cylinder capacity
l
750
950
Q
D
in kW
N
L
performance factor
15
2.00
3.00
18
2.25
3.20
22
2.50
3.50
27
2.75
4.00
33
3.00
4.60
Information regarding performance factor
The performance factor N
L
depends on the cylinder storage tempera-
ture T
cyl
.
Standard values
■ T
cyl
= 60 °C → 1.0 × N
L
■ T
cyl
= 55 °C → 0.75 × N
L
■ T
cyl
= 50 °C → 0.55 × N
L
■ T
cyl
= 45 °C → 0.3 × N
L
Peak output (over 10 minutes)
Relative to the performance factor N
L
.
DHW heating from 10 to 45 °C and 70 °C heating water flow temper-
ature
Peak output (l/10 min) subject to the heating output delivered by the boiler (Q
D
)
Cylinder capacity
l
750
950
Q
D
in kW
Peak output
15
190
230
18
200
236
22
210
246
27
220
262
33
230
280
Max. draw-off rate (over 10 minutes)
Relative to the performance factor N
L
.
With reheating.
DHW heating from 10 to 45 °C and 70 °C heating water flow temper-
ature.
Max. draw-off rate (l/min) subject to the heating output delivered by the boiler (Q
D
)
Cylinder capacity
l
750
950
Q
D
in kW
Max. draw-off rate
15
19.0
23.0
18
20.0
23.6
22
21.0
24.6
27
22.0
26.2
33
23.0
28.0
Drawable water volume
Cylinder content heated to 60 °C.
Without reheating.
Draw-off rate
l/min
10
20
Drawable water volume
Water with t = 45 °C (mixed temperature)
750 l
255
190
950 l
331
249
DHW cylinders
(cont.)
VITOSOL
VIESMANN
85
5822 440 GB
11