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EPA 608 Certification & Trade School Diplomas designed to get you into a job in less than 4 weeks. 

Recovery Requirements

EPA 608 Type 1 Chapter 6 (Take full course)


In this module, we will take a look at the two main methods of recovering refrigerants and discuss the different requirements for each method.


1. System Dependent Recovery


System Dependent Recovery requires the pressure of a functioning compressor to recover refrigerant. This is also called passive recovery.


Recall that in any system, matter will flow from high pressure to low pressure. Since the refrigeration system is pressurized and the compressor increases its pressure, we can use that pressure as our “high” point.


If we connect a non-pressurized refrigerant container to the system, the pressure of the container is lower than the pressure inside the system. The refrigerant will naturally flow from high to low, helping us recover our refrigerant. This is how system-dependent recovery works.


Passive recovery is limited to appliances with 15 lbs or less of refrigerant. This includes small appliances with 5lbs or less of refrigerant, like household refrigerators. These are appliances which we cover in Type I.


2. Self-Contained Recovery

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Self Contained Recovery is the use of a recovery device that operates independently of the system you are recovering from. They have their own compressor, pump, or other mechanism to recover refrigerant. This is also called active recovery.


When recovering from small appliances, first identify the refrigerant that you are about to recover. Older refrigerators, particularly those built before 1950, may contain non-fluorocarbon refrigerants, which cannot be recovered with current recovery equipment.


Active recovery does the job much quicker than passive recovery. Recall that as time to recovery increases, the chances of venting increase. So we want to minimize time spent recovering refrigerants.


Active recovery is required for systems containing more than 15 lbs of refrigerant.


3. Recovery Levels


There are different required levels depending on whether the appliance’s compressor is working.

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When the compressor in Type I appliances is not working, the EPA Section 608 rules require recovering 80 percent of the charge amount on the appliance nameplate.


For appliances with working compressors, the EPA Section 608 rules require either:

  • Recovery of 90 percent of the nameplate charge, or

  • Recovery of the appliance to 4 inches mercury (in Hg)

For example, with a charge of 5 lbs on the appliance nameplate and a non-functional compressor, you would need to recover 80% of the charge, or 4 lbs of refrigerant. For the same appliance with 5 lbs of refrigerant, we would need to recover 4.5 lbs of refrigerant if the compressor is working.


4. Operating Compressor


With an operating compressor, there should be a big enough pressure difference between the system and your recovery container. The pressure difference makes the refrigerant naturally flow from high to low pressure, into the recovery container.


Because there is sufficient pressure, you only need to have one access valve to recover refrigerant. For a system with an operating compressor and a completely restricted capillary tube, we would attach one access valve on the high side of the system.


5. Non-Operating Compressor


If the compressor does not work in the appliance, there may be refrigerant trapped in the compressor oil. Technicians need to take measures to help release trapped refrigerant. This is especially important in passive recovery, since the recovery process relies on the system pressure.


It is essential to take measures to help release trapped refrigerant when performing passive recovery and the compressor is not working. Since refrigerant is miscible in refrigerant oil, it can get trapped in the oil, but when we heat it up, the refrigerant vaporizes, separating it from the oil. This is how we can release trapped refrigerant.

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These measures for releasing trapped refrigerant include:

  • Warming the system (with a heating blanket or a heat gun), and

  • Tapping the compressor bottom with rubber mallet to release refrigerant

Make sure we are only warming up the system with a heating blanket and not an open flame. Recall from Core that this can cause an explosion since refrigerant cylinders are pressurized and refrigerants may be highly flammable.


If we tap the compressor to release trapped refrigerant, make sure we are using a rubber mallet. We need to make sure that we are not damaging the appliance. If we use a metal mallet, this may damage the appliance and release refrigerant, damage equipment, or worse.


When performing passive recovery and the compressor is not working, we need to access the system from both the high and low side to recover as much refrigerant as possible.


Because we are performing passive recovery, the recovery process depends on the compressor. With a non-operating compressor, we need to access both high and low sides to try to get to the 80% required level of recovery.


Technicians need to take measures like this to make sure that we can recover the required level of 80% of the nameplate charge when the compressor doesn’t work.


6. Conclusion


In this module, we discussed the requirements for recovering refrigerants in Type I appliances. For appliances with non-functional compressors we need to recover 80% of the nameplate charge. This is required for both passive and active recovery.


And for active recovery on appliances with working compressors, we need to recover either 90% of the nameplate charge or to a 4 inch vacuum.




Other References:


 
 
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