Abstract:
A method and materials are disclosed for cleaning the internal parts of a refrigeration system while keeping the system on line and operational. The ability to clean the system may bring the energy efficiency of the existing equipment back to or above the original energy efficiency. The ability to also keep the system on line during the cleaning process may avoid extensive down time and may eliminate the need to disassemble and replace system components.

Description:
FIELD OF THE DISCLOSURE 
       [0001]    The present disclosure relates to refrigeration systems. More particularly, the present disclosure relates to cleaning compositions that can be used for cleaning mineral deposits and other contaminants and residues inside refrigeration systems, including the residue from compressor motor burnouts, and to a method for using the same. 
       BACKGROUND OF THE DISCLOSURE 
       [0002]    Refrigeration systems are found in window air conditioning units, central air conditioning units, food coolers, and food freezers, for example. 
         [0003]    Over the years, refrigeration systems have seen major changes in design, refrigerating capacity, and energy efficiency. In recent years, many of the changes have been due to environmental concerns surrounding stratospheric ozone depletion and global warming caused by refrigeration systems and the refrigerating fluids they employ to move heat from one area to another. The phaseout of chlorofluorocarbon (CFC) refrigerants in 1995 was a major step in curbing the environmental damage caused by these substances. World environmental organizations have also begun the phaseout of hydrochlorofluorocarbon (HCFC) refrigerants. A move to refrigerants that do not contain chlorine, such as hydrofluorocarbon (HFC) refrigerants, is underway. 
         [0004]    Much time and effort has also been expended to make refrigeration systems more energy efficient, which will stem environmental damage due to these devices even further. In developed countries, more energy efficient equipment is mandated by law and regulation. An increased efficiency of even 1 to 2 percent is deemed a major step forward. 
         [0005]    The problem now lies with what to do with the millions of pieces of older refrigerating equipment in operation that were made to use the prior CFC and HCFC refrigerants. This older equipment tends to be less efficient than the newer equipment that uses non-chlorine containing refrigerants like HFC. Although this older equipment can be retrofitted to use non-chlorine containing refrigerants, after the retrofit, the older equipment tends to be even less energy efficient than the newer equipment. Another problem with energy efficiency in older equipment is that the CFC and HCFC refrigerant compressors typically used mineral based lubricating oil. When this type of lubricant is heated, it breaks down and leaves carbon deposits on internal valves, motor windings, and other components, requiring the system to use more energy to achieve the same amount of refrigeration capacity. 
         [0006]    Currently, it is not unusual to simply replace system components when a refrigeration system shows a loss of capacity, even though a preferred solution to the problem might be to clean and remove carbon deposits and other contaminants and residues from the inside of the system components. Many smaller systems are hermetically sealed, and cleaning internal components is currently not an option. On larger systems, compressors and components are sometimes disassembled, purged, and flushed clean, but this requires the entire system to be shut down, sometimes for days or weeks if the component has to be shipped to a repair facility for cleaning In many instances food in coolers and freezers must be removed, and on some large air conditioning systems, shutdown is not an option, and components or entire refrigeration units must be replaced because of the time sensitivity of the operation (e.g., hospitals, office buildings). 
       SUMMARY 
       [0007]    The present disclosure relates to a method and materials for cleaning the internal parts of a refrigeration system, while keeping the refrigeration system on line and operational. This method does not require extensive down time, and in many cases eliminates the need to replace system components. Using the method and materials of the present disclosure can bring the energy efficiency of the existing equipment back to or above the original energy efficiency, and in many cases could save thousands of dollars in repair or eliminate the need for equipment replacement. The increase in energy efficiency leads to cost savings and decreased environmental damage by power providers. 
         [0008]    According to an embodiment of the present disclosure, a method is provided for cleaning a sealed refrigeration system. The method includes the steps of: removing a first refrigerant from the refrigeration system; installing a second refrigerant blend in the refrigeration system; contemporaneously cleaning the refrigeration system and operating the refrigeration system with the second refrigerant blend; removing the second refrigerant blend from the refrigeration system; and installing a third refrigerant in the refrigeration system. 
         [0009]    According to an embodiment of the present disclosure, a method is provided for cleaning a sealed refrigeration system. The method includes the steps of: removing a first refrigerant from the refrigeration system; installing a second refrigerant blend of at least one cleaning material and at least one refrigerant in the refrigeration system; operating the refrigeration system with the second refrigerant blend; removing the second refrigerant blend from the refrigeration system; and installing a third refrigerant in the refrigeration system. 
         [0010]    According to an embodiment of the present disclosure, a sealed refrigeration system is provided including a first heat exchanger, a second heat exchanger in communication with the first heat exchanger, and a cleaning refrigerant blend configured to cycle repeatedly through the first and second heat exchangers, the cleaning refrigerant blend being heated in the first heat exchanger and cooled in the second heat exchanger, the cleaning refrigerant blend including at least one cleaning material and at least one refrigerant. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The above-mentioned and other features and advantages of this disclosure, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
           [0012]      FIG. 1  is a schematic view of a refrigeration system of the present disclosure. 
       
    
    
       [0013]    Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate exemplary embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
       DETAILED DESCRIPTION 
       [0014]    A refrigeration system  100  is illustrated schematically in  FIG. 1 . Refrigeration system  100  includes a first heat exchanger in the form of an evaporator  102 , a compressor  104 , a second heat exchanger in the form of a condenser  106 , and an expansion valve  108 . A desired refrigerant cycles repeatedly through the refrigeration system  100 . In the evaporator  102 , the refrigerant takes in heat from a relatively hot input  110  (e.g., ambient air) to produce a relatively cold output  112  (e.g., cooled air). The heated refrigerant from the evaporator  102  vaporizes and continues to the compressor  104 , where the refrigerant is pressurized, and then to the condenser  106 , where the refrigerant condenses and releases heat. The cooled refrigerant from the condenser  106  continues through the expansion valve  108 , where the refrigerant is depressurized. The cooled refrigerant then returns to the evaporator  102  to provide more cooling of the relatively hot input  110 . 
         [0015]    The refrigeration system  100  may be hermetically sealed during normal cooling operations, such that the refrigerant remains inside the refrigeration system  100  and cycles through the refrigeration system  100 . Individual components of the refrigeration system  100  (e.g., compressor  104 ) may also be hermetically sealed. The refrigeration system  100  may include an input port (not shown) to selectively receive refrigerant, such as when installing a new refrigerant into an empty refrigeration system  100  or when “topping off” an existing refrigerant in the refrigeration system  100 . The refrigeration system  100  may also include an output port (not shown) to selectively remove refrigerant, such as when draining or flushing an existing refrigerant from the refrigeration system  100 . Typically, the input port and the output port will be combined into a single port that is capable of both receiving and removing refrigerant. The refrigerant may be introduced into and removed from the refrigeration system  100  with the assistance of pressurized gas or vacuum, for example. 
         [0016]    Over time, the refrigeration system  100  may lose refrigerating capacity and become less energy efficient due to buildup of many materials in the refrigeration system  100 . This buildup of residual material is more common in refrigeration systems  100  that use CFC and HCFC refrigerants, because such refrigeration systems  100  commonly use mineral based oil to lubricate compressor  104 , valves, motors, and other moving parts (not shown) inside the refrigeration system  100 . The buildup of carbon residues created by heat breaking down the mineral based oils inside the refrigeration system  100  may result in higher energy costs and loss of refrigerating capacity. 
         [0017]    Presently, to bring the refrigeration system  100  to full or substantially full capacity and energy efficiency, it is sometimes necessary to disassemble the system  100 , purge the system  100 , flush individual components, and replace expensive components, such as compressors  104  and coils in evaporator  102  and condenser  106 . This is a costly and time consuming process, causing the refrigeration system  100  to be out of service for days or weeks, potentially costing the owner of the equipment thousands of dollars. 
         [0018]    The present disclosure provides cleaning compositions capable of cleaning mineral deposits and other contaminants and residues from inside the refrigeration system  100 . According to an exemplary embodiment of the present disclosure, the cleaning composition includes a blend of (1) one or more cleaning materials that aid in cleaning the refrigeration system  100  and (2) one or more non-chlorine containing HFC refrigerants. Because the cleaning composition includes both (1) cleaning material(s) and (2) refrigerant(s), the cleaning composition may be referred to herein as a cleaning refrigerant blend (CRB). The CRB may contain more HFC refrigerants than cleaning materials. For example, HFC refrigerants may make up as little as 50 wt. %, 60 wt. %, or 70 wt. % of the total CRB and as much as 80 wt. %, 90 wt. %, or more of the total CRB, with cleaning materials and other materials making up the balance of the total CRB. 
         [0019]    Exemplary cleaning materials for use in the CRB of the present disclosure include dichloroethylene (C 2 H 2 Cl 2 ), decafluoropentane (C 5 H 2 F 10 ), pentafluorobutane (C 4 H 5 F 5 ), and pentafluoropropane (C 3 H 3 F 5 ), for example. Such cleaning materials may account for about 0.2 wt. % to about 5 wt. % of the total CRB, either individually or in combination. A suitable cleaning blend is the CLEAN SHOT™ cleaning blend, which is commercially available from ICOR International, Inc. of Indianapolis, Ind. 
         [0020]    Exemplary fluorine-containing HFC refrigerants for use in the CRB of the present disclosure include pentafluoroethane (C 2 HF 5 ) and tetrafluoroethane (C 2 H 2 F 4 ), for example. The HFC refrigerant may also be blended with other non-fluorine containing refrigerants, such as butane and/or isobutane (C 4 H 10 ). In an HFC blend, the quantity of each individual refrigerant may be varied to achieve the desired cooling effect. For example, the HFC blend may contain 17 to 84 wt. % pentafluoroethane, 8 to 82 wt. % tetrafluoroethane, and 0.5 to 5 wt. % butane and/or isobutane. Exemplary refrigerants are low-temperature boiling components. For example, pentafluoroethane has a boiling point of −55.3 degrees F. (−48.5 degrees C.), tetrafluoroethane has a boiling point of −15.3 degrees F. (−26.3 degrees C.), and butane and isobutane have boiling points of about 8 to 16 degrees F. (−13 to 9 degrees C.). 
         [0021]    A first exemplary HFC refrigerant blend is contemplated for medium temperature systems (e.g., 33 to 40 degrees F. discharge temperature). The first HFC refrigerant blend includes about 17 wt. % to about 22 wt. % pentafluoroethane, about 75 wt. % to about 82 wt. % tetrafluoroethane, and about 0.5 wt. % to about 5 wt. % butane. A suitable HFC refrigerant blend is the HOT SHOT2™ refrigerant blend, which is commercially available from ICOR International, Inc. 
         [0022]    A second exemplary HFC refrigerant blend is contemplated for high temperature systems (e.g., 40 to 60 degrees F. discharge temperature). The second HFC refrigerant blend includes about 52 wt. % to about 58 wt. % pentafluoroethane, about 40 wt. % to about 45 wt. % tetrafluoroethane, and about 0.5 wt. % to about 5 wt. % isobutane. A suitable HFC refrigerant blend is the NU-22B® (R-422B) refrigerant blend, which is commercially available from ICOR International, Inc. 
         [0023]    A third exemplary HFC refrigerant blend is contemplated for low temperature systems (e.g., −10 degrees F. discharge temperature). The third HFC refrigerant blend includes about 76 wt. % to about 84 wt. % pentafluoroethane, about 8 wt. % to about 15 wt. % tetrafluoroethane, and about 0.5 wt. % to about 5% isobutane. A suitable HFC refrigerant blend is the ONE SHOT® (C) (R-422C) refrigerant blend, which is commercially available from ICOR International, Inc. 
         [0024]    An exemplary CRB formulation is provided in Table 1 below. This CRB formulation utilizes the third HFC refrigerant blend above, which is configured for low temperature systems, so the resulting CRB formulation may also be configured for low temperature systems. When the cleaning blend and the desired HFC refrigerant blend are combined, the individual components therein may make up smaller, but proportional amounts of, the total CRB compared to the individual blends. 
         [0000]    
       
         
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                   
                 Compositions of 
                 Composition of 
               
               
                   
                 Components 
                 Individual Blends 
                 Total CRB 
               
               
                   
                   
               
             
             
               
                   
                 (1) Cleaning Blend 
                 100.0% 
                 4.5 wt. % 
               
               
                   
                 Trans-dichloroethylene 
                 33.3 wt. % 
                 1.5 wt. % 
               
               
                   
                 Decafluoropentane 
                 22.2 wt. % 
                 1.0 wt. % 
               
               
                   
                 Pentafluorobutane 
                 22.2 wt. % 
                 1.0 wt. % 
               
               
                   
                 Pentafluoropropane 
                 22.2 wt. % 
                 1.0 wt. % 
               
               
                   
                 (2) HFC Refrigerant Blend 
                 100.0 wt. %  
                 95.5 wt. %  
               
               
                   
                 Pentafluoroethane 
                 82.0 wt. % 
                 78.3 wt. %  
               
               
                   
                 Tetrafluoroethane 
                 15.0 wt. % 
                 14.3 wt. %  
               
               
                   
                 Isobutane 
                  3.0 wt. % 
                 2.9 wt. % 
               
               
                   
                 Total 
                 N/A 
                 100.0 wt. %  
               
               
                   
                   
               
             
          
         
       
     
         [0025]    The present disclosure also provides a simple method to clean the mineral deposits and other contaminants and residues from inside the refrigeration system  100  and restore the refrigeration system  100  to at or near its original capacity and energy efficiency, without the refrigeration system  100  having to be taken out of service for an extended period of time. Exemplary method steps are described further below. 
         [0026]    First, the original CFC or HCFC refrigerant is removed from the refrigeration system  100 . The original refrigerant may be removed from the above-described output port (not shown) of the refrigeration system  100 . At this stage of the process, the refrigeration system  100  may contain internal mineral deposits and other contaminants and residues that could dampen the refrigerating capacity of the refrigeration system  100 . 
         [0027]    Next, a suitable CRB, as described above, is introduced into and cycled through the refrigeration system  100 . Although a preferred CRB will be pre-blended before installation in the refrigeration system  100 , it is within the scope of the present disclosure that various ingredients of the CRB may be introduced separately into the refrigeration system  100  and blended once inside the refrigeration system  100 . The CRB may be introduced into the above-described input port (not shown) of the refrigeration system  100 . Because the CRB includes both (1) cleaning material(s) and (2) refrigerant(s), the CRB is configured to clean the inside of the refrigeration system  100  while contemporaneously performing normal cooling operations. The CRB should be a direct replacement for the original refrigerant, in that it should be compatible with the mineral oil used, and it should mimic the operating pressures and densities of the original refrigerant used. After a period of time suitable for cleaning, which may range from at least one hour to a day, a week, or more depending on the state of the refrigeration system  100 , the CRB is removed from the refrigeration system  100 , such as via the above-described output port (not shown). 
         [0028]    Then, an HFC refrigerant replacement is introduced into and cycled through the refrigeration system  100  to resume normal cooling operations. The HFC refrigerant may be introduced into the above-described input port (not shown) of the refrigeration system  100 . The HFC replacement should be very carefully selected, in that it also should be compatible with the mineral oil used, and it should have very close density/temperature relationships and temperature/pressure relationships to the original refrigerant it is replacing. According to an exemplary embodiment of the present disclosure, the HFC refrigerant is similar to the prior CRB, except that the HFC refrigerant need not include the cleaning material(s) of the prior CRB. 
         [0029]    Advantageously, the entire procedure can increase refrigerating capacity and energy efficiency significantly over simply changing the refrigerant without cleaning the refrigeration system  100 . Also, the refrigeration system  100  remains operational during the cleaning phase of the procedure. 
         [0030]    The CRB of the present disclosure differs from known flush products. Flush products are intended for use in individual components of a disassembled and non-operational refrigeration system  100 . The CRB, by contrast, is capable of being cycled through an assembled refrigeration system  100  when the refrigeration system  100  is turned on and operational. Also, flush products are intended for use over a relatively short period of time until the flush product exits the component being cleaned and/or evaporates, which may result in partial or incomplete cleaning. The CRB, by contrast, is capable of being cycled repeatedly through the refrigeration system  100  over a relatively long period of time to achieve more complete cleaning Additionally, because flush products are intended for use in open lines and/or other open components of the refrigeration system  100 , flush products are generally delivered in relatively small quantities. However, because the CRB is contained within an assembled refrigeration system  100 , the CRB may be present in relatively large quantities to achieve more complete cleaning For example, at any given time, a particular component of the refrigeration system  100  may encounter about 3 times, 5 times, or 7 times more CRB than flush product. 
       EXAMPLES 
       [0031]    As descriptive examples, five refrigeration systems were chosen to provide data supporting the conclusion that cleaning the interior components and surfaces of a refrigeration system increases the refrigerating capacity and energy efficiency in three preferred embodiments (e.g., medium temperature systems (Examples 1 and 2), high temperature systems (Examples 3 and 4), and low temperature systems (Example 5)). All of the steps were followed, as the CRB alone does not provide the increased capacity, and adding the higher capacity HFC refrigerant alone does not provide the increased capacity, but the total procedure of cleaning and changing refrigerants provides the increase, all while keeping the refrigeration system online 
         [0032]    The test protocol was as follows: determine coefficient of performance (COP) as a baseline with the original refrigerant (OR) installed, install a HFC refrigerant blend (HFCB) prior to cleaning and determine COP, remove HFCB, install cleaning refrigerant blend (CRB) and determine COP during cleaning, operating system one week with CRB, remove CRB, re-install HFCB and determine COP after cleaning COP is defined by energy consumption/heat transferred. Higher numbers indicated better energy efficiency. The cleaning step with each CRB was performed until the corresponding refrigeration system exhibited at least a slight drop in energy consumption, which suggested that mineral deposits and other contaminants and residues had been removed. In the following examples, the cleaning step was performed for about one week. 
       1. Example #1  
     Medium Temperature Refrigeration System 
       [0033]    A 23 year old CFC-12 walk-in cooler using R-12 as the refrigerant was chosen for a first medium temperature (e.g., 33 to 40 degrees F.) test. The medium temperature CRB consists of between 17 to 22 wt. % pentafluoroethane, 75 to 82 wt. % tetrafluoroethane, 0.5 to 5 wt. % butane, and 0.2 to 5 wt. % of a cleaning material in the form of decafluoropentane. The medium temperature HFCB consists essentially of between 17 to 22 wt. % pentafluoroethane, 75 to 82 wt. % tetrafluoroethane, and 0.5 to 5 wt. % butane, without the cleaning material of the CRB. COP test results are presented in Table 2 below. 
         [0000]    
       
         
               
               
               
             
           
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                 Test 
                 Value 
               
               
                   
                   
               
             
             
               
                   
                 Baseline COP 
                 3.14 
               
               
                   
                 COP with HFCB installed prior to cleaning 
                 3.04 
               
               
                   
                 COP with CRB installed during cleaning 
                 2.99 
               
               
                   
                 COP with HFCB re-installed after cleaning 
                 3.22 
               
               
                   
                   
               
             
          
         
       
     
         [0034]    According to the test results in Table 2, simply installing the HFCB prior to cleaning showed a decrease in COP, which is typically the case when changing from a CFC to an HFC refrigerant. Installing the CRB showed a further decrease in COP, due mainly to the fact that the cleaning chemicals in the CRB are high-temperature boiling components, and add little or nothing to the refrigerating capacity of the refrigerant. However, these decreases in capacity were not severe enough to cause the equipment to have to be taken offline. The cooler was still a usable piece of equipment during the cleaning process, it just used a little more energy to achieve the required refrigerating effect. 
         [0035]    After the cleaning process, the filter/drier on the system was replaced, due to the fact that the cleaning process had pushed carbon deposits and dirt into the filter, and the HFCB was re-installed into the system. According to the test results in Table 2, COP after completion of the cleaning process was higher than the baseline COP with R-12 installed, or simply installing the HFCB without cleaning 
       2. Example #2  
     Medium Temperature Refrigeration System 
       [0036]    A 22 year old CFC-12 beer cooler using R-12 as the refrigerant was chosen for a second medium temperature test. The medium temperature CRB consists of essentially between 17 to 22 wt. % pentafluoroethane, 75 to 82 wt. % tetrafluoroethane, 0.5 to 5 wt. % butane and isobutane, and between 0.2 to 5 wt. % of a cleaning material blend including decafluoropentane, trans-dichloroethylene, and pentafluorobutane. The medium temperature HFCB consists essentially of between 17 to 22 wt. % pentafluoroethane, 75 to 82 wt. % tetrafluoroethane, and 0.5 to 5 wt. % isobutane, without the cleaning material blend of the CRB. COP test results are presented in Table 3 below. 
         [0000]    
       
         
               
               
               
             
           
               
                   
                 TABLE 3 
               
               
                   
                   
               
               
                   
                 Test 
                 Value 
               
               
                   
                   
               
             
             
               
                   
                 Baseline COP 
                 3.72 
               
               
                   
                 COP with HFCB installed prior to cleaning 
                 3.51 
               
               
                   
                 COP with CRB installed during cleaning 
                 3.37 
               
               
                   
                 COP with HFCB re-installed after cleaning 
                 3.77 
               
               
                   
                   
               
             
          
         
       
     
         [0037]    According to the test results in Table 3, simply installing the HFCB prior to cleaning showed a decrease in COP, and installing the CRB showed a further decrease in COP, due mainly to the fact that the cleaning chemicals in the CRB are high boiling components, and add little or nothing to the refrigerating capacity of the refrigerant. However, these decreases in capacity were not severe enough to cause the equipment to have to be taken offline. 
         [0038]    After the cleaning process, similar normal maintenance was performed as described in Example 1. According to the test results in Table 3, COP after completion of the cleaning process was higher than the baseline COP with R-12 installed, or simply installing the HFCB without cleaning 
       3. Example #3  
     High Temperature Refrigeration System 
       [0039]    An 8 year old, 12,000 BTU window air conditioner using R-22 as the refrigerant was chosen as a good candidate for a first high temperature (e.g., 40 to 60 degrees F. discharge temperature) test. The high temperature CRB consists of essentially between 52 to 58 wt. % pentafluoroethane, 42 to 48 wt. % tetrafluoroethane, 0.5 to 5 wt. % isobutane, and between 0.2 to 5 wt. % of a cleaning material blend including trans-dichloroethylene and pentafluoropropane. The high temperature HFCB consists of essentially between 52 to 58 wt. % pentafluoroethane, 40 to 45 wt. % tetrafluoroethane, and 0.5 to 5 wt. % isobutane, without the cleaning material blend of the CRB. COP test results are presented in Table 4 below. 
         [0000]    
       
         
               
               
               
             
           
               
                   
                 TABLE 4 
               
               
                   
                   
               
               
                   
                 Test 
                 Value 
               
               
                   
                   
               
             
             
               
                   
                 Baseline COP 
                 4.06 
               
               
                   
                 COP with HFCB installed prior to cleaning 
                 3.88 
               
               
                   
                 COP with CRB installed during cleaning 
                 3.50 
               
               
                   
                 COP with HFCB re-installed after cleaning 
                 4.10 
               
               
                   
                   
               
             
          
         
       
     
       4. Example #4  
     High Temperature Refrigeration System 
       [0040]    An 18 year old, 18,000 BTU window air conditioner using R-22 as the refrigerant was chosen for a second high temperature (e.g., 40 to 60 degrees F. discharge temperature) test. The high temperature CRB consists of essentially between 52 to 58 wt. % pentafluoroethane, 42 to 48 wt. % tetrafluoroethane, 0.5 to 5 wt. % isobutane, and between 0.2 to 5 wt. % of a cleaning material blend including trans-dichloroethylene and pentafluoropropane. The high temperature HFCB consists of essentially between 52 to 58 wt. % pentafluoroethane, 40 to 45 wt. % tetrafluoroethane, and 0.5 to 5 wt. % isobutane, without the cleaning material blend of the CRB. COP test results are presented in Table 5 below. 
         [0000]    
       
         
               
               
               
             
           
               
                   
                 TABLE 5 
               
               
                   
                   
               
               
                   
                 Test 
                 Value 
               
               
                   
                   
               
             
             
               
                   
                 Baseline COP 
                 4.66 
               
               
                   
                 COP with HFCB installed prior to cleaning 
                 4.22 
               
               
                   
                 COP with CRB installed during cleaning 
                 4.10 
               
               
                   
                 COP with HFCB re-installed after cleaning 
                 4.65 
               
               
                   
                   
               
             
          
         
       
     
       5. Example #5  
     Low Temperature Refrigeration System 
       [0041]    A 21 year old CFC-502 ice cream freezer was chosen as a good candidate for the low temperature (e.g., -10 degrees F. discharge temperature) test. The low temperature CRB consists essentially of between 76 to 84 wt. % pentafluoroethane, 8 to 15 wt. % tetrafluoroethane, 0.5 to 5 wt. % isobutane, and between 0.2 to 5 wt. % of a cleaning material blend including decafluoropentane, pentafluorobutane, and trans-dichloroethylene. The low temperature HFCB consists of 76 to 84 wt. % pentafluoroethane, 8 to 15 wt. % tetrafluoroethane, and 0.5 to 5 wt. % isobutane, without the cleaning material blend. COP test results are presented in Table 6 below. 
         [0000]    
       
         
               
               
               
             
           
               
                   
                 TABLE 6 
               
               
                   
                   
               
               
                   
                 Test 
                 Value 
               
               
                   
                   
               
             
             
               
                   
                 Baseline COP 
                 3.12 
               
               
                   
                 COP with HFCB installed prior to cleaning 
                 2.99 
               
               
                   
                 COP with CRB installed during cleaning 
                 2.79 
               
               
                   
                 COP with HFCB re-installed after cleaning 
                 3.47 
               
               
                   
                   
               
             
          
         
       
     
         [0042]    As demonstrated in the above examples, this novel approach to cleaning the inside of a sealed refrigeration system allows the serviceperson to clean the system without extended periods of the equipment being out of service, change the refrigerant to an ozone safe replacement, not have to change the oil in the system, or system components. As an added benefit, in many cases, this cleaning process increases the energy efficiency of the equipment. In all of the above examples, the energy efficiency was increased by installing an HFCB after cleaning over simply installing an HFCB prior to cleaning. 
         [0043]    While this invention has been described as having exemplary designs, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.