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49
AST 14 C 258/00
The curves indicated above refer to a request of a “fictitious room temperature” of 20°C. In
case of required temperature different from 20°C, all curves are parallely translated.
Example of curve shifting with P10=1.5 and fictitious temperature from 20 to 25°C:
The choice of the curves is a procedure that can be performed with your eyes or a
mathematic formula; in both cases it is necessary to check the temperature variations to
correct and better chose the proper curve.
In the first case take a real value of external temperature as reference and link it to a
desired flow value. Then chose the closest curve.
Example
at an external temp. of -4°C, a flow of 62°C is required; curve: 1.5
In the second case use the following formula:
CURVE
Testmin
20
20
Tmax
Where, Tmax is the maximum flow temperature and Textmin is the minimum external
temperature.
Example
Low temperature: High temperature:
Tmax = 44°C Tmax = 70°C
Test = -10°C Test = -10°C
CURVE
(-10)
20
20
44
CURVE
(-10)
20
20
70
P10 curve = 0.8 P10 curve = 1.7
+5
-5
