6. Piping installation
Installer reference guide / Mono tank integrated type
55
6.1 Preparing water piping
Water circuit requirements
Before installing the unit, make sure to check the following points:
• The maximum water pressure of the unit is 2.9 bar static pressure.
• The operating range of leaving water temperature is 15~70˚C at heating conditions and 5~25˚C at cooling conditions.
• The minimum required water flow rate for operation is 16 liters/min.
Otherwise, the unit can stop due to a lack of water and display error (E911). The design of the installation should meet
with the nominal flow in order to achieve the efficiencies as declared by our TDB.
• The water quality must be according to EN directive 98/83 EC.
• If the unit and the pipes are exposed to freezing temperature, it can cause damage to the hydraulic system.
Special care must be taken to prevent freezing of the total water system.
• The unit is designed to be used in a closed-loop system. Do not use any other components which are designed only for
an open-loop system.
• Never use uncoated parts in the water circuit. Because it can cause excessive corrosion
• All hydraulic parts including field piping must be insulated to reduce heat loss and condensation.
• It is recommended to install the water inlet combination valve to feed small quantities of water to the system
automatically, replacing the minor water losses and maintaining the system pressure.
• Drain taps must be provided at all low points of the system to permit complete drainage of the circuit for maintenance use.
• Make sure that the check valves are correctly installed in the system (field supply).
• Flush pipes out with clean water to remove contaminants in pipes during installation.
• The strainer (water filter) must be cleaned after flushing the pipes, and it should be cleaned periodically. Replace
strainer when necessary.
• Charge the water until a pressure of 1.5~2.0bar by using the inlet combination valve (Field supply). (The water pressure
indicated on the manometer will vary depending on the water temperature) The nominal water pressure in the system
should remain about 1.0 bar at all times to avoid air entering the water system.
• Make sure that air should be vented from the system at start-up or after installing/ servicing.
The air vent valve must be opened during charging the water (at least 2 turns) in order to remove all air in the circuit,
and an inlet combination valve allows water into the system continuously.
• Provide air vents at all high points of the system, which must also be easily accessible for servicing.
• Always use materials which are compatible with water used in the system and with the materials used on the indoor unit.
• Select piping diameter in relation to required water flow and available ESP of the pump.
• Use chemical cleaning agents (begin with acid , finish with alkali).
• Do not operate the system with closed valves because it results in damaging the heat pump.
• It is recommended to avoid long runs of piping between the DHW tank and the hot water end point (shower, bath,…)
and to avoid dead ends.