EPA 608 Type 1 Chapter 7 (Take full course for free)
In this module, we will take a look at how to recover refrigerant and ways to speed up our recovery process. Skip to quiz!
1. Recovery Overview
Before recovering any refrigerant, we need to first identify the refrigerant in the appliance. Then, we need to use a recovery cylinder that is used for that type of refrigerant. For example, if we are recovering from an appliance that contains R-22, we need to use a recovery cylinder that is exclusively used for R-22.
Recall that each recovery cylinder can only be used to recover one type of refrigerant. We need to keep recovery cylinders separate for different refrigerants to avoid mixing refrigerants and making the refrigerants unusable.
When recovering refrigerant into a recovery cylinder, we also need to make sure we do not fill more than 80% of the cylinder’s capacity.
We can monitor the fill of the recovery container by using one of the following:
Mechanical float devices,
Electronic shut off devices, or
Gross cylinder weight
Mechanical float devices, are sometimes also called internal float devices. They work by turning the motor off on the recovery machine when a certain fill level has been reached.
But even if the motor is off, refrigerant can still flow into the cylinder, leading to a fill of more than 80%. If you then warm up the cylinder, it can then even explode or blow out a relief valve.
For these reasons, the industry has largely shifted away from mechanical or internal float devices and even electronic shut off devices. But technically, these methods can still be used according to the EPA.
Using the cylinder weight is the most accurate method of monitoring fill level. This method forces technicians to be more vigilant and get recovery done in a more timely fashion, which reduces risk of accidental venting.
2. Recovery Speed
Recall that we want to minimize our recovery time because the longer we take in recovering refrigerant, the more likely it is that an accident can happen. We want to prevent accidents like releasing refrigerant or equipment malfunction.
There are special cases where we have to take additional measures to recover refrigerant faster. This includes if we are doing passive recovery and the compressor stops working.
One of the methods we can use to recover refrigerant faster is to install both low and high side access valves. This way, refrigerant can flow through both sides, allowing us to recover refrigerant faster.
In frost-free refrigerators, we can also utilize the defrost heater component to help us speed up recovery of refrigerant. The defrost heater is a component in frost-free refrigerators that melts ice off evaporator coils so that the coils can be exposed to air.
Turning on the defrost heater will increase the temperature of the refrigerant so that we can recover it faster.
3. Conclusion
In this module, we took a look at recovery practices including:
Identifying the refrigerant inside an appliance,
Methods to prevent overfilling recovery cylinders, and
How to increase recovery speed so we minimize recovery time.
Next we’ll take a look at equipment we need for refrigerant recovery.
Question #1: We need separate recovery cylinders for each class of refrigerants (e.g. HCFCs).
For example, we cannot use the same cylinders to recover CFC and HCFC refrigerants. But we can use the same cylinder to recover different HCFC refrigerants.
True
False
Scroll down for the answer...
False!
All different refrigerants need to recovered in separate containers.
R-32 and R-134a are both HFC refrigerants. But they would need to be recovered in separate cylinders because they are different refrigerants.
Question #2: You are servicing an appliance that contains R-134a. Which of the following can you use to recover the refrigerant?
A recovery cylinder used for HCFC-22
A recovery cylinder used for HFC-134a
A disposable cylinder used for R-134a
A disposable cylinder used for R-22
Scroll down for the answer...
A recovery cylinder used for HFC-134a
We must use recovery cylinders to recover refrigerant. We cannot use disposable cylinders to recover refrigerant.
We also need to make sure that the recovery cylinder is used for the same refrigerant as the appliance we are recovering from.
And since R-134a is the same as HFC-134a, the correct answer would be (b).
Question #3: Which methods are approved by the EPA to monitor fill level of recovery cylinders?
Mechanical/ Internal Float Devices
Electronic Shut Off Devices
Gross cylinder weight
All of these
Scroll down for the answer...
All of these
These are all acceptable methods of monitoring the fill level for recovery cylinders, according to the EPA.
Question #4: Which method of monitoring fill level is most accurate?
Gross cylinder weight
Mechanical float device
Electronic shut off device
None of these
Scroll down for the answer...
Gross cylinder weight
The most accurate method of monitoring fill level uses the gross cylinder weight to see how much refrigerant has been charged.
Question #5: Installing both high and low side access valves will increase recovery time.
True
False
Scroll down for the answer...
False!
This is false.
Installing both high and low side access valves will increase recovery speed, not recovery time. In fact, because it is faster, it will decrease recovery time.
Question #6: Defrost heaters: (Select all that apply)
Can be used to increase the temperature of refrigerant
Can be used to increase refrigerant recovery speed
Are available in all Type I appliances
None of these
Scroll down for the answer...
Can be used to increase the temperature of refrigerant
Can be used to increase refrigerant recovery speed
Defrost heaters are only available in frost-free refrigerators. They are not available in all appliances so (c) is incorrect.
Both (a) and (b) are correct.
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