The reason we need to be recovering refrigerants from systems prior to repairs or decommissioning is for a number of reasons. Firstly you need to depressurise the system if changing out any faulty valves, compressors or repair leaks.
Secondly we do not want to be venting refrigerant to the atmosphere as
CFC/HCFC refrigerants have damaging chlorine which destroys the ozone layer and HFC will contribute to greenhouse effects.
Click Here for information in regards to the phaseout of certain refrigerants.
There are common methods of recovering refrigerant. these are the vapour, liquid and push pull methods.
The vapour method recovers refrigerant from the systems low side (suction port) as a vapour and the recovery unit in turn changes the state of the refrigerant to a liquid before discharging this into the recovery tank.
The liquid method recovers the refrigerant in its liquid state and is a much faster way of reclaiming refrigerant. You can connect your gauges or digital manifolds to both high and low sides and slowy meter the refrigerant into your recovery unit. Most modern recovery machines are perfectly ok with recovering liquid.
The push pull method is a method of recovering refrigerant extremely fast. There are a number of restrictions though and it cannot be used on all systems. The basic idea behind this method is that the recovery or reclaim unit uses vapour from the recovery cylinder and this creates a high pressure vapour that pushes the liquid refrigerant out of the system and back into the recovery tank.
Do not use this method if your system has less the 5kg of refrigerant, has a reversing valve or is a heat pump or if you have an accumulator in between the ports used for the recovery. You have to have a steady flow of liquid refrigerant.
All modern machines will come with a diagram of how to connect all these different methods of recovery to your HVAC-R system.
See our range of recovery / reclaim units HERE
Remember you are required to weigh in and out all refrigerant and keep a log of when and where refrigerant was used.
If you don't already have a set of quality digital scales check out our range HERE