Pumping Down an AC or Refrigeration System ​

To remove refrigerant from an air conditioning system, a technician has to perform a recovery and pump down procedure. This document will ensure that you have a basic understanding of the important concepts and basic steps involved with recovery and pump down.Pumping down an AC or Refrigeration system is both important and a legal requirement. With recent refrigerant prices increasing, recovering the refrigerant to reuse is just common sense. It is illegal to release into the environment and can result in fines in New Zealand.The best way to handle the refrigerant is by utilising a recovery unit or recovery machine that is connected to a storage cylinder. It’s important that all technicians know how to pump down an air conditioning or refrigeration system. Some air conditioning systems have built in receiver (storage) for convenient pumping down, however a similar process still must be followed.You will need specialised refrigeration tools for completing the pump down correctly, including a recovery machine, manifold gauges, and a torque wrench set.There are many different steps in the recovery and pump down operation depending on the unit and set up. A technician should have previous experience or specialised training before attempting a recovery and pump down process by themselves. This document will ensure that you have a basic understanding of the important concepts and items associated with recovery and pump down.Outline of steps for pumping down an air conditioning and refrigeration unit:
  1.    Switch off the air conditioning unit
  2.    Connect the manifold to the low pressure service valve
  3.    Using your refrigeration service tools, release the nut on the service valve, to a mid-way position between fully opened and fully closed. You should see that that the pressure gauge reading will increase on the manifold gauge.
  4.    Operate the air conditioning unit for 3 to 5 minutes,
  5.    Isolate the liquid line by closing off the liquid line service valve. You should start to see the reducing pressure reading on the manifold gauge.
  6.    Once the pressure reads zero, isolate the vapour line service valve by closing the service valve off,
Refrigerant within the low-pressure side of the air conditioning system should be very minimal at this point. So, you can do necessary repair work, or parts replacement work on the unit.Important: You can not perform repairs on the condenser or compressor as they will still contain refrigerant.If you use a separate refrigerant cylinder, then you can pump down the entire system into your cylinder and then perform maintenance on all air conditioning parts. But this is the quicker method.  If your air conditioning unit has a built in receiver, maintenance on your AC/R system can be carried out anywhere except for the receiver.
  1.    Evacuate the system after the repair and maintenance work by using a high performance Javac Vacuum Pump to 25 microns or less. This step is very important otherwise your system will not operate correctly. This is to remove the moisture and oxygen.
  2.    Next open the service valves and wait for 5 minutes for the refrigerant to disperse.
  3.    You may now turn of the air conditioning or refrigeration unit.
  4. It is suggested that you use a Hand Held Leak Detector to check for any leaks around any new joins or changes to the refrigerant piping.
Just remember that pumping down any air conditioning system requires training and in some cases certification to handle refrigerants. Please consider our environment and the safety of those around you when working with air conditioning systems. If you have not pumped down a refrigeration system before we recommend having an experienced refrigeration service professional do this for you. 

Got Questions?

Contact us anytime using the chatbox at the bottom of the page or signup to our mailing list to be the first to know when we offer our next great deal on a full range of NZ HVAC TOOLS. Or call us NZ Free Call 0800 483 353.

HVAC TOOLS Limited is a NZ GST registered company New Zealand NZ BN 9429046513991.

Browse our HVAC NZ Service Tools range :

Need something else? Get in touch :

Call us NZ Free Call 0800 483 353

Email us : info@hvactools.co.nz

or chat with us