E93.1001EN.C Manual CD
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52
9.8
Elaborated examples
To work out the examples in this section, the rules of page 45 ff. are given again:
1. Codes to a one water heater installation:
−
There’s only one flow pipe and one return pipe, both encoded D1. For the right diameter value see
table
A
in § 9.5.1. The main pipe diameter D equals this value.
2. Codes for cascades: two or more water heaters connected:
−
First number the water heaters: water heater-1 is the one whose hot water connection is situated the
furthest away from the tank(s).
−
Connections directly to the water heaters: D1 = 54
1,5 (mm
mm).
−
Number the horizontal hot water pipes between water heaters: from D1 at water heater-1 to D at
water heater-number-last (values: table
B
−
Number the horizontal cold-water return pipes between water heaters ‘reversely’: from D1 at water
heater-number-last to D at water heater-1.
3. Codes for tank connections:
-
Pipes between the connections: D. Values from the water heater table
C
-
Tank connections: D
T
(entrance and exit). The values are found in the tank table
D
O
NE
CD
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120
WATER HEATER WITH ONE
EWD450
TANK
Water heater and tank connections:
For this system rule 1 must be applied, so only one pipe size is needed.
No numbering of water heaters, tanks and connections is required.
From table
A
: for 1 water heater is D1=D = 54
1,5 [mm
mm]
From table
D
: for 1 tank is D
T
= 54
1,5 [mm
mm]
For this system, pipes sized at least 54
1,5 [mm
mm] are required for all connections.
Length of the connecting pipes water heaters
↔
tanks
From table
E
:
The maximum total length of flow and return pipes 54
1.5 [mm
mm] is 24,2 m.
So when 54
1,5 [mm
mm] is applied, the physical distance between water heaters and tanks may be half of
this, so ~ 12 m, at max. In case bends and/or valves are used, this distance becomes less than 12 m. Use table
E.
Pump
From table
F
: Use pump
P2
.
D1
(=D)
D
D
D1
(=D)
1
D
D
KOUD IN
D
T
D
T
tank
EWD450
water heater
CD
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120
COLD IN
Example 1
