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English 05/09
ACCURATE AX - AW - AD - AT - AF
CONNECTION TO BRAZED PLATE CONDENSER AW-AT-AF
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AW-AT-AF water-cooled units
The condenser must be connected to the cooling water circuit,
making sure that the water inlet and outlet connections are cor-
rect.
If the water temperature falls below the dew point of the condi-
tioned air, insulate the pipes with closed cell material (e.g.:
Armaflex or equivalent) to prevent condensation; the insulation
must allow access to the valves and the three-piece joints.
Seal the holes where the pipes pass through the base of the air-
conditioner to avoid the bypass of air.
N.B.: the water system of the unit is PN16
WATER CONNECTIONS
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For all the water connections (with the exception of the
condensate drain), the following are recommended:
- flexible connections to avoid transmitting vibrations and
allow small movements of the air-conditioner;
- joints in three pieces, near the fittings, to simplify the
removal of the unit;
- on-off valves to disconnect the unit from the water cir-
cuit: where possible use ball valves with full opening to
minimise pressure drop.
(For AW-AT-AF models) check that the cross-section of
the chilled water pipes and the characteristics of the circu-
lating pump are suitable: an insufficient water flow-rate
affects the performance of the air-conditioner.
Check that the water inlet and outlet connections are cor-
rect. Insulate all the chilled water pipes with closed cell
material (e.g.: Armaflex or equivalent), to prevent conden-
sation; the insulation must allow access to the valves and
the three-piece joints.
(For AW-AT-AFmodels) check that the water circuit has
been filled with an antifreeze mixture containing the right
percentage of ethylene glycol.
To select the pipeline refer to "Pressure Drops on
stainless steel pipes"
CORRECTION FACTORS
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ETHYLENE GLYCOLE
A mix of water plus glycole used has fluid instead of only water cause a cooling capacity reduction of the unit. Multiplay the cooling capacity
for the values reported of the following tables
Iceing temperature
0
-5
-10
-15
-20
-25
% of glycole on tot. charge
0
12%
20%
28%
35%
40%
Flow factor
cQ
1 1,02 1,04
1,075 1,11 1,14
P. drops factor
cdp
1 1,07 1,11
1,18 1,22 1,24
INCROSTATION FACTOR
All datas reported are refered to a complete clean brazed blade condenser (incrostation factor = 1).
For different values of incrostation factor multiplay all datas reported on cooling capacity tables for factors reported on following table.
Incrostation factor
(m
2
°C/W) 4,4
x10-5 0,86x10-4 1,72x10-4
Incrostation factor
f1
--- 0,96 0,93
Compressor factor
fk1
--- 0,99 0,98
Total power factor
fx1
---
0,99 0,98
