14
3.3 WATER CONTENT OF THE SYSTEM
The compressors often work intermittently as the user cooling request does not generally coincide with that supplied by the
compressor. A compressor start-up or shutdown delay can generate a carrier fluid temperature drift from the storage ideal
temperature. The system must be be built in such a way that this drift does not cause damage to the hydraulic circuit.
There is a substantial difference between units that operate on pure water and water with a glycol content.
NO GLYCOL UNITS:
These units do not have an on-board tank and the system must be built to guarantee a minimum amount of water in the
primary circuit. The amount in question can be identified by following the requirements provided in the documentation for the
associated chiller, as it depends directly on the power of the chiller unit, on the type of installed compressors and on the
number of envisioned power steps. The associated chiller can be selected with or without an on-board tank, as long as the
required minimum amount of water is observed. The associated chiller must be selected with at least one on-board pump.
GLYCOL UNITS
An on-board AQUA Link tank is always included as part of the standard supply of these units. The associated chiller must, in
turn, be selected with an on-board tank. This choice is based on the possibility of exploiting a complete system that is not
dependent on external accessory elements. The sum of the water-glycol content from the two tanks is, in fact, enough to
avoid damage to the circuit due to possible fluctuations in temperature.
The Chiller series, with or without glycols, that AQUA Link can be associated with are:
-
Teal
-
Teal FC (Basic – Custom – Extra)
-
Teal A
-
Teal A FC (Basic – Custom – Extra)
-
Teal SLN
-
Teal SLN FC (Basic – Custom – Extra)
-
Teal A SLN
-
Teal A SLN FC (Basic – Custom – Extra)
-
Teal A+
-
Teal A+ FC (Basic – Custom – Extra)
-
Teal W
-
Oxford
-
Oxford FC
-
Oxford A
-
Oxford SLN
-
Cyan
-
Cyan SLN
-
Kappa V EVO
-
Kappa V EVO SLN
-
Kappa V Evo A
-
Kappa V Evo A HT
-
Kappa V Evo A SLN
-
Kappa V Evo A HT SLN
-
Omega V Echos
-
Omega V Echos A
TABLE 1 - FREEZING POINT FOR WATER-ETHYLENE GLYCOL MIXTURES
AMBIENT MINIMUM TEMPERATURE (°C)
+0°
-5°
-10°
-15°
-20°
-25°
-30°
-35°
-40°
FREEZING POINT (°C)
-5°
-10°
-15°
-20°
-25°
-30°
-35°
-40°
-45°
ANTI-FREEZE
% IN WEIGHT
ETHYLENE GLYCOL
6
22
30
36
41
46
50
53
56
3.4 RECOMMENDATIONS FOR OUTDOOR UNIT INSTALLATION
Units with gycols for outdoor installation are always accessorised by an electrical heating element to protect the heat
exchanger, otherwise the chilled beams circuit will not be protected from frost. The heating element switches on when the
critical temperatures are reached.
The installer is responsible for protecting any pipe sections that connect the secondary hydrualic circuit (chilled beams) to
the plate exchanger.
