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Leak Repair

EPA 608 Type 2 Chapter 4 (Take full course for free)


In this module, we will learn about EPA’s classification system and leak rates defined for the particular systems. We will also learn about the process defined by EPA for repairing leaks. Skip to quiz!


1. Leak Repair Categories


Many types of refrigeration systems are used in the market. EPA classifies the different types of systems available into four categories.


The systems are classified based on the purpose they serve. They are:

  • Comfort cooling systems

  • Commercial refrigeration systems

  • Industrial process refrigeration

  • All other appliances

Let us have a look at each category.

Comfort cooling systems are systems used to provide cooling and humidity control in places occupied mostly by humans.


Residential houses, offices, and commercial buildings are few such examples of places having comfortable cooling systems. Examples of such systems include chillers, commercial split systems, and packaged rooftop units.


Commercial refrigeration systems are appliances used in retail food and cold storage sectors.

Some examples include supermarkets, restaurants, other foodservice chains, convenience stores, and cold storage to store goods like meat and dairy products.


Industrial process refrigeration is directly linked to industrial processes. These systems are complex, customized systems used in the chemical, pharmaceutical, petrochemical, and manufacturing industries.


This sector also includes industrial ice machines, appliances used directly in electricity generation, and ice rinks. Note that if one appliance is used for both IPR and other applications, it will be considered IPR equipment if 50% or more of its capacity is used for IPR systems.


Recall that leak rate is the rate at which an appliance is losing refrigerant due to leaks. According to the previous slide classifications, EPA defines the maximum leak rates for these systems.


Just as we say ‘To err is Human,’ no appliance can be made entirely leak-free. Despite all measures to prevent leaks, all systems have a very tiny bit of leakages from them. This leak is acceptable until the leak rate does not exceed the maximum leak rates set by the EPA.


The maximum leak rate is that leak rate above which the system must be repaired for leaks. The maximum leak rate is also called the trigger leak rate or threshold leak rate. Remember these names!


The following are the maximum leak rates for a 12-month period

Appliance Type Leak Rate

Comfort cooling systems 10%

Commercial refrigeration 20%

Industrial Process Refrigeration (IPR) 30%

All other appliances 10%

Remember these numbers!


The leak rates in the table give the maximum leak rate set by the EPA. They apply for all systems having 50 pounds or more amount of refrigerant. If the leak rate of a system exceeds the maximum leak rate given in the table, it must be repaired for leaks.


2. Leak Repair Procedure


Now that we know the maximum leak rates for all types of appliances, we must repair an appliance if it leaks beyond the maximum rate.


If an appliance has a leak rate higher than the maximum leak rate set by EPA, the owner of that appliance has the following options:

  • To repair the appliance.

  • To mothball the appliance or the specific leaking component(s).

  • To retrofit the appliance.

  • To retire the appliance.

Let us look at each of these options in detail.


The owner of an appliance must get the leak repaired after detecting it. After repairing the leak, it is compulsory to verify the results whether the system is still leaking or not.


The EPA states that two leak verification tests are required after repairing an appliance. A leak verification test is the set of steps to confirm that the appliances’ leak rate is below the maximum leak rate.

The two leak verification tests are: Initial Leak Verification Test It should be performed right after the leak is repaired and before filling the system back with refrigerant. Follow-up Leak Verification Test It should be performed after the appliance returns back to normal working conditions. (Usually within 10 days of leak repair)


If any of the two leak verification tests fail, it means that the system is still leaking. In such situations, the owner must further repair the appliance or go for any of the next steps.


Mothballing an appliance means to

  1. Evacuate it to at least atmospheric pressure

  2. Isolate it from the other components and

  3. Temporarily shut it down.

Recall that evacuating equipment means removing all the air out of the system.


Isolating is separating the appliance or a piece of equipment from the rest of the system. Equipment is mothballed if the repair process is taking too long or some replacement piece of equipment is not available at the moment.


Retiring the appliance means to put it out of service and properly dispose of it. If a leak is irreparable, we can retire the appliance and dispose of it.


Recall that retrofitting is when we adapt and make changes to the equipment so that we can use a new refrigerant in it. If a leak is irreparable, we can retrofit the appliance to use a new refrigerant in it.


3. Conclusion


In this module, we discussed EPA’s classification of systems. We also went through the maximum leak rates for these systems. Finally, we also learned about the procedure to be followed while repairing leaks in a system.


Question #1: Which leak repair category does the EPA define as the refrigeration appliances used in the retail food and cold storage warehouse sectors?

  1. Commercial refrigeration

  2. Industrial process refrigeration

  3. Comfort cooling

  4. Ice making refrigeration

Scroll down for the answer...














EPA classifies appliances used in retail food and cold storage warehouse sectors as Commercial Refrigeration Systems.


Question #2: A company uses a chiller that diverts 55% of its cooling capacity to one of its manufacturing lines and 45% of its cooling capacity to air condition the office spaces. Which leak rate category would this chiller be in?

  1. Commercial refrigeration

  2. Industrial process refrigeration

  3. Comfort cooling

  4. Ice making refrigeration

Scroll down for the answer...












If any appliance uses more than 50% of its capacity for industrial processes (manufacturing line in this case), it is classified as Industrial Process Refrigeration System.


Question #3: Starting in 2019, what leak rate triggers the EPA requirement that commercial refrigeration systems containing 50 pounds or more of R-22 be repaired?

  1. 10%

  2. 20%

  3. 30%

  4. 40%

Scroll down for the answer...











The maximum leak rate set by EPA for a commercial refrigeration system is 20%. If a commercial refrigeration system has a leak rate higher than 20%, then it must be repaired.


Question #4: Which of the following is NOT required to mothball an appliance using an ozone-depleting refrigerant?

  1. Shut down the appliance temporarily

  2. Remove the appliance and store it in a warehouse at the facility

  3. Recover the refrigerant from the isolated section or component

  4. Recover refrigerant to at least atmospheric pressure

Scroll down for the answer...










The other options are processes actually involved during the process of mothballing an appliance. Removing the appliance and storing it in a warehouse is not a step included in mothballing an appliance.



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