Climate Wizard CW-P exhaust fan behaviour in Cool and Vent mode


The speed of the exhaust fan is governed by the pressure differential between the supply and exhaust. The pressure is measured by a set of 4mm tubes, 2 tubes each for supply and exhaust. 

 

The end of the supply pressure sensor tube is located behind the exhaust fan and passes through the plenum into the space between after the cores and before the supply fan.

The end of the exhaust pressure sensor tube is located on the exhaust fan mounting bracket, under the exhaust fan.

The ambient lines both pass through the cooler and come out behind the air filters on the right side of the cooler.

 

The exhaust fans will behave differently in Cool mode compared to Vent mode. 

  • In Cool mode the exhaust will try to maintain the correct supply / exhaust ratio by ramping the exhaust fan up and down.
  • In Vent mode the exhaust fan will maintain a 20Pa difference to prevent unfiltered air passing backwards through the cores.

 

TESTING

  • Remove the Ambient lines from the pressure sensor PCB in the control enclosure. Be careful though as the pressure sensors can easily be broken. DO NOT try and pull tubes straight off the sensors. Use a knife to make a vertical cut where the tube attaches to the barb of the sensor.
  • Does this improve the operation of the exhaust fan?
  • Next you need to check the end of the tubes of the supply and exhaust lines behind the exhaust fan and look for blockages

 

See page 30 of the attached manual.