16
Monobloc Outdoor Unit Installation Manual
The water supply must be analysed and appropriate filtering, treatment, control devices, shut-off and bleed valves
and circuits built in, to prevent corrosion (example: damage to the protection of the tube surface if the fluid is
polluted), fouling and deterioration of the pump fittings.
Before any start-up verify that the heat exchange fluid is compatible with the materials and the water circuit
coating.
Water quality
In case additives or other fluids, other than those recommended by the manufacturer are used, ensure that the
fluids are not considered as a gas, and that they belong to class 2, as defined in directive 97/23/EC.
Recommendations on heat exchange fluids:
•
No NH4+ ammonium ions in the water, they are very detrimental for copper. This is one of the most
important factors for the operating life of copper piping. A content of several tenths of mg/l will badly
corrode the copper over time.
•
Cl- Chloride ions are detrimental for copper with a risk of perforations by corrosion by puncture. If possible
keep below 10 mg/l.
•
SO4
2
- sulphate ions can cause perforating corrosion, if their content is above 30 mg/l.
•
No fluoride ions (< 0.1 mg/l).
•
No Fe2+ and Fe3+ ions with non-negligible levels of dissolved oxygen must be present. Dissolved iron < 5
mg/l with dissolved oxygen < 5 mg/l.
•
Dissolved silicon: silicon is an acid element of water and can also lead to corrosion risks. Content < 1mg/l.
•
Water hardness: > 0.5 mmol/l. Values between 1 and 2.5 mmol/l can be recommended. This will facilitate
scale deposit that can limit corrosion of copper. Values that are too high can cause piping blockage over
time.
•
Alkalimetric Titre (TAC) below 100mg/l is desirable.
•
Dissolved oxygen: Any sudden change in water oxygenation conditions must be voided. It is as detrimental
to deoxygenate the water by mixing it with inert gas as it is to over-oxygenate it by mixing it with pure
oxygen. The disturbance of the oxygenation conditions encourages destabilisation of copper hydroxides
and enlargement of particles.
•
Electric conductivity: 0.001-0.06 S/m (10-600
μS
/cm)
•
pH: Ideal case pH neutral at 20-25°C (7 < pH < 8).
CAUTION:
Charging, adding, draining and sampling fluid from the water circuit must be done by qualified personnel,
using air vents and materials suitable for the products. Water circuit charging devices are field-supplied.
Charging, sampling or removing heat exchange fluids should be done with devices that must be included
on the water circuit by the installer. Never use the unit heat exchangers to add heat exchange fluid.
CAUTION: The use of units in an open loop is forbidden.
7.2.3 - Operating precautions and recommendations
•
The water circuit should be designed to have the least number of elbows and horizontal pipe runs at
different levels. Below the main points to be checked for the connection:
•
Comply with the water inlet and outlet connections shown on the unit.
•
Install manual or automatic air purge valves at all high points in the circuit.
•
Use a pressure reducer to maintain pressure in the circuit(s) and install a relief valve as well as an
expansion tank. Units with the hydronic module include a relief valve and an expansion tank.
•
Install a water pressure gauge (manometer) to monitor the water pressure in the heating circuit.
•
Install drain connections at all low points to allow the whole circuit to be drained.
•
Install stop valves, close to the entering and leaving water connections.
•
Use flexible connections to reduce vibration transmission.
