8.1 Filling and venting

1. Make sure that a leak test is performed on the system.
2. Open the vent valves to allow air to get out of the system during filling.
3. Fill the charging/heating circuit using the filling valve of the system.

4. Close the outlet valve when no more air comes out of the outlet valve.

   The pressure starts to pick up after a few minutes.

5. Close the filling valve when the pressure is at the correct level.

6. Carefully vent the system using the vent valves.

7. Repeat the filling and venting process until all air is removed from the system and the pressure is at the correct level.

1. Ground source heat applications: Fill the collector with a mixture of water and geothermal fluid that can withstand a temperature of –15 °C.

   Other applications: Fill the collector with fluid that can withstand a temperature that is 5 °C lower than the lowest collector temperature during use.

   Environmentally friendly bioethanol is recommended for use as a geothermal fluid.

2. Fill the collector via valves A.

   Valve B must be closed during filling so that the collecting liquid circulates through the entire circuit.

3. Fill the system with pure geothermal fluid.

   Be careful not to get debris from the base of the container into the suction hose (strainer).

   If you recycle liquid with an external filling or vent pump, make sure that the liquid is not pumped as foam into the system. It might be difficult to get foamy microbubble liquid out of the system and it may cause malfunctions. If necessary, you can prevent microbubbles from entering the collector by using two large containers.

4. Pressurise the collector using an external booster pump.

   Monitor the collector’s pressure gauge to ensure that the pressure does not exceed the opening pressure of the safety valve.

5. Clean the heat pump’s strainer before the heat pump is started.

The collector can also be vented in two stages. A bypass valve (C) must be installed in the collector so that the internal piping can be vented separately from the well field. When pumping into the well field, the air is mixed with cold collecting liquid, making it more difficult to remove the air. The valve C must be closed during normal operation.

Perform a pressure test on the filled collector as follows:

1. Increase the pressure up to the design pressure and check the pressure after 30 minutes.

   If the pressure drops during these 30 minutes, there is a leak in the system.

2. Repair any leaks and repeat the pressure test.
3. If the test is successful, mark the test as completed in the Commissioning log.