Installation Instructions

Aqua Systems heat exchangers can operate as either a condenser or an evaporator. We recommend installing a vent and drain plugs where freeze cleaning may be required and fully insulating the unit to improve overall heat transfer performance. 

  • Step 1: Connect refrigerant gas to the top refrigerant port.

  • Step 2: Connect refrigerant liquid to the bottom refrigerant port.

  • Step 3: Configure the unit for either Parallel Water Flow or Series Water Flow.

Parallel Water Flow

  • Commonly used for closed loop installations.

  • Suitable regardless of water or fluid temperatures.

  • Recommended when leaving water temperature may approach freezing.

  • Maximum flow rate is 12 GPM.

Parallel Flow

Series Water Flow

  • Typically used for one pass evaporator installations.

  • Leaving water temperature must remain above freezing with safety margin.

  • Maximum flow rate is 6 GPM.

  • Not recommended for models larger than S-4, S-4R, CN4 or CN4R.

Series Flow

Freeze Cleaning Instructions

  • Set up water piping so that water flow to the heat pump can be turned off.

  • Use boiler drains on the top and bottom water connections ensuring the heat exchanger will vent at the top and drain at the bottom.

  • Shut off water flow to unit and open the vent and drain for the heat exchanger.

  • Configure the heat pump controls so that the heat exchanger is operating as the evaporator.

  • After you have confirmed the heat exchanger has fully drained, manually engage the compressor contactor and allow the compressor to run until the suction pressure drops below 20 PSI.

  • Configure the heat pump controls so that the heat exchanger is operating as the evaporator.

  • Shut down the compressor and allow system pressures to equalize. Close the vent opening. 

  • Restore water flow and flush the heat exchanger through the drain until the discharge runs clear.

  • Close the drain opening and return the system to normal operation.