Abstract:
An apparatus and method wherein potential ozone layer-damaging dichlorodifluoromethane (Refrigerant R-12) is substituted with a mix of less environmentally damaging refrigerants Chlorodifluoroethane and Tetrafluoroethane in dichlorodifluoromethane-based air-cooling systems, in particular HVAC and refrigeration applications. While less environmentally damaging than dichlorodifluoromethane, the substitute refrigerant is less flammable than presently available refrigerants, yet still has a temperature-pressure relationship close enough to that of dichlorodifluoromethane, making the substitute refrigerant suitable for use with dichlorodifluoromethane-based air-cooling systems. In this event, it is mixed with a lubricating oil that is compatible with both the unit refrigerant and typical R-12 system design.

Description:
RELATED APPLICATIONS 
     This application is a continuation-in-part of application Ser. No. 10/980,977 filed Nov. 4, 2004 now abandoned that claims priority to and the benefit of provisional applications, Ser. No. 60/517,028 filed Nov. 4, 2003, Ser. No. 60/571,977 filed May 18, 2004 and Ser. No. 60/599,673 filed Aug. 5, 2004. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the replacement of Refrigerant R-12 (dichlorodifluoromethane) with a blend refrigerant that is less damaging to the ozone layer in systems designed to use Refrigerant R-12 (dichlorodifluoromethane). More particularly, the present invention relates to an improved refrigerant composition, method and apparatus for refrigeration wherein two non-R-12 refrigerants are mixed in a defined ratio to balance the objectives of providing a temperature-pressure relationship of the mix approximating that of Refrigerant R-12 (dichlorodifluoromethane), while at the same time being less flammable than other replacement refrigerants, for HVAC, refrigeration and automotive applications. The mixture is compatible with Refrigerant R-12 (dichlorodifluoromethane) so that it can supplement and replace Refrigerant R-12 (dichlorodifluoromethane). A further particularity of the instant invention relates to an improved method and apparatus for refrigeration wherein refrigerant mixture is mixed with a lubricating oil compatible with the lubricating oil(s) placed in the equipment during manufacture or assembly. 
     2. General Background 
     R-12 refrigerant dichlorodifluoromethane (hereinafter sometimes called “Refrigerant R-12 (dichlorodifluoromethane)”) was once the major, if not sole refrigerant, used in residential air-conditioners, refrigerators, freezers and automobiles. Refrigerant R-12 (dichlorodifluoromethane) is also known as Freon 12 a trademark of E. I. du Pont de Nemours &amp; Co. Inc. for dichlorodifluoromethane. Hereinafter, “Refrigerant R-12 (dichlorodifluoromethane)” is used in this specification to denote dichlorodifluoromethane, regardless of the source. 
     Refrigerant R-12 (dichlorodifluoromethane) came under attack both nationally and internationally as an ozone layer-damaging chemical with a high global warming factor. Both the national and international scientific communities linked Refrigerant R-12 (dichlorodifluoromethane) with damage to the earth&#39;s protective ozone layer. Air-conditioners, refrigerator/freezers and auto units containing R-12 are believed to be a global source of ozone-damaging material and a direct cause of global warming. 
     In response to scientific concern and a national and global outcry over the use of Refrigerant R-12 (dichlorodifluoromethane) in air-conditioning and refrigeration, the United States Congress acted to first reduce and then ban the use of Refrigerant R-12 (dichlorodifluoromethane) in units. 
     Prior to banning the sale of quantities of Refrigerant R-12 (dichlorodifluoromethane), owners of equipment with Refrigerant R-12 (dichlorodifluoromethane)-based air-conditioning units were able to purchase the level of refrigerant in their equipment with only the need of a refrigerants license as required by the Clean Air Act. Millions of units containing refrigerant R-12 (dichlorodifluoromethane) were sold in the United States prior to the start of mandatory phase out set forth by Congress and the international community. 
     Refrigerant R-12 (dichlorodifluoromethane) recharging typically involves 30 lb. cans or cylinders used in the HVAC/R and auto industry. The cylinders are fitted with a dispensing outlet compatible with a commercially available refrigeration manifold. In order to recharge an air-conditioning system, a customer need to only fit the can or cylinder to the manifold and discharge, or “add to” the refrigerant charge directly into the air conditioning system. 
     Following Congress&#39;s limitations on the sale of Refrigerant R-12 (dichlorodifluoromethane) millions of equipment owners with Refrigerant R-12 (dichlorodifluoromethane)-based air-conditioning units were left with no choice other than to reclaim or seek replacement refrigerants to service these units. Intentionally mixing of refrigerants is currently illegal by standards set forth by the Clean Air Act. 
     In response to Congress&#39;s ban on the use of Refrigerant R-12 (dichlorodifluoromethane) in air-conditioning, service dealers retrofitted existing Refrigerant R-12 (dichlorodifluoromethane)-based air-conditioning units with new, non-R-12 refrigerants. 
     Other refrigerants were developed to replace the prior, now banned R-12 refrigerant, or dichlorodifluoromethane. For example, Tamura et al. (U.S. Pat. No. 4,983,312) discloses a refrigerant consisting essentially of R134a (1,1,1,2-tetrafluoroethane) and R142b (chlorodifluoroethane). Tamura et al., however, makes no teaching or suggestion of a lubricant. 
     Wilczek (U.S. Pat. No. 5,384,057), Gorski (U.S. Pat. No. 4,971,712), and Anton of DuPont (U.S. Pat. No. 5,145,594) disclose other R-12 replacements in the form of a blend of certain synthetic lubricants in various R134a and R134a/R125 refrigerant systems. The DuPont patents discuss a gas known as R125 (pentafluoroethane). R125 is five fluorine atoms bonded to an ethane molecule. This is a very large molecule for a refrigerant. It is currently being produced for refrigeration only. Anton discloses the use of a lubricant comprising at least one cyanocarbon compound. Wilczek discloses a fluorosiloxane as a lubricant. Gorski discloses a polyakylene glycol as a lubricant. 
     Begeman, et al. (U.S. Pat. No. 3,092,981) disclose the use of a fluoro halo derivative of an aliphatic hydrocarbon as a refrigerant in combination with alkylbenzene of 1 to 50 carbons and a viscosity of 50 to 2000 SUS (Saybolt Universal Seconds) at 100° F. Olund (U.S. Pat. No. 3,642,634) discloses a lubricating oil for refrigeration equipment consisting essentially of a high viscosity alkylbenzene having a viscosity in the range of 3000 to 1,000,000 SUS at 100° F. and a refrigerant containing a halongenated alkyl working fluid and this high viscosity alkylbenzene. (U.S. Pat. No. 3,733,850 and U.S. Pat No. 4,046,533). Kaneko (U.S. Pat. No. 5,520,833) discloses the use of a lower viscosity (viscosity of 2 to 50 cst at 100° C.) alkylbenzene or alkylnapthelene with a substitute flon compound as a refrigerant. Generally, synthetic oils, such as alkylbenzene, and mineral oils have not been used in conjunction with R134a (1,1,1,2-tetrafluoroethane). As noted by Fukuda, et al (U.S. Pat. No. 5,417,872) R134a has unique properties due to its special chemical structure, so that it is not miscible in refrigerating machine oils used in the refrigeration systems of R-12 refrigerant, e.g. mineral oils (naphthenic oils, paraffinic oils) and synthetic oils such as alkylbenzene. 
     Systems that contain R-12 are still in use today. These older systems have common components: R-12, R-12 mineral oil lubricant, and water that is sequestered into the dryer. If R134a (1,1,1,2-tetrafluroethane) were added to the system, it would damage the system as follows: (1) if no lubricant is added to the R134a (as in U.S. Pat. No. 4,953,312 to Tamura et al.), then the R-12 system would be starved for lubricant, since the R134a gas is not miscible with the mineral oil lubricant; (2) if a synthetic lubricant is added to the R134a (as in Thomas et al., U.S. Pat. No. 5,254,280), then there is a different problem—that of moisture. Older systems can have water trapped in their dryers. Synthetic lubricants such as polyglycol or polysiloxane-based lubricants are hydrophilic. They are not only miscible with R-12 and R134a; they are also partially or completely miscible with water. Thus, if they are introduced into an R-12 system, they will pull this water out of the dryer into the refrigerant flow, possibly initiating corrosion and damage to pressure switches and the TX valve and possible other system components. This is why Elf Atochem and DuPont, to name a few publish elaborate flushing procedures and high efficiency dryer change-outs to prevent damage to the cooling system. 
     Weber (U.S. Pat. No. 5,492,643, U.S. Pat. No. 5,942,149, and U.S. Pat. No. 6,565,766) discloses yet another R-12 replacement consisting of a blend of R-142b (chlorodifluoroethane) in the amount of about 15% to about 40%, R-134a (tetrafluoroethane) in the amount of about 60% to about 85%, and a napthenic lubricating oil (Royco 783C, 783D). Weber generally teaches away from use of synthetic lubricants for the reasons mentioned above. Weber also teaches away from use of higher amounts of R-134a (tetrafluoroethane) noting that at higher temperature ranges, the pressure of R-134a in pure form is well above that of Freon 12 so that it would pose a hazard if used in equipment designed for using Freon 12. Further, Weber&#39;s replacement has the disadvantage of being relatively flammable because of its aerosoling tendency. In the Weber patents the preferred composition contains 79% R134a (tetrafluoroethane), 19% R142b (chlorodifluoroethane) and 2% (lubricant, Royco 783C or 783D) blend that is recognized by Refleak and Refprop (accepted industry computer modeling programs for fractionation analysis) to be flammable in the worst case formulation (WCF) temperature ranges of refrigeration uses as described in ASHRAE Standard 34 and accepted in industry. Proprietary computer modeling and bench top testing from DuPont and Honeywell also show flammability problems and concerns during worst-case fractionation (WCF) preventing acceptance in refrigeration applications. Thus, the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE) has been unwilling to grant a designation for Weber&#39;s refrigerant blend, in particular his preferred blend of 79%/19% and 2% lubricant. The focus of Weber&#39;s patents is directed to automobile applications, an industry that monitors less closely than the HVAC/R industry. 
     Thus, there exists a need for an R-12 refrigerant replacement having reduced flammability which meets ASHRAE&#39;s requirements for designation while at the same time providing lubrication. 
     SUMMARY OF THE PRESENT INVENTION 
     The present disclosure provides a method and apparatus that are environmentally sound alternatives to the use of Refrigerant R-12 (dichlorodifluoromethane) as a refrigerant. More particularly, the disclosure herein provides a mixture of at least two refrigerants that are miscible with each other, and compatible with Refrigerant R-12 (dichlorodifluoromethane) and its equipment while at the same time providing a good compromise between temperature-pressure profile with similar thermodynamic properties that approximates that of Refrigerant R-12 (dichlorodifluoromethane) over the operating range of ambient temperatures usually encountered by air conditioning and refrigeration units or other apparatus utilizing Refrigerant R-12 (dichlorodifluoromethane) as a refrigerant and while at the same time reducing the flammability of the mixture to levels acceptable to ASHRAE Standard 34 and UL2182 among others. In fact in August of 2003 an exemplary embodiment of the present disclosure received an ASHRAE designation of R420A rated A1 in its safety classification. The present disclosure also provides a lubricant, that is compatible with the mixture of the environmentally sound refrigerants described herein and with Refrigerant R-12 (dichlorodifluoromethane), so that mixtures of the refrigerant according to the invention and Refrigerant R-12 (dichlorodifluoromethane) may be utilized with this lubricant in the refrigeration systems without deleterious effect upon moving parts of the refrigerating apparatus that require lubrication from the refrigerant. 
     More particularly, the present disclosure provides a mixture of chlorodifluoroethane and tetrafluoroethane in specific proportions that provide the aforesaid compromise over the range of ambient temperature operating conditions in which Refrigerant R-12 (dichlorodifluoromethane) is a useful refrigerant. For example, the tetrafluoroethane can include either 1,1,1,2-tetafluoroethane (R-134a) or 1,1,2,2-tetrafluoroethane (R134) and the chlorodifluoroethane can include either 1-chloro-1,1-difluoroethane (R142b) or 2-chloro-1, 1-difluoroethane. In an exemplary embodiment, the refrigerant according to the invention comprises a ratio of from about 5% to about 40% weight percent chlorodifluoroethane and from about 60% to about 95% tetrafluoroethane, based upon the combined weight of tetrafluoroethane and chlorodifluoroethane. In another exemplary embodiment, the refrigerant according to the invention comprises a ratio of from less than 13% to above 10% weight percent chlorodifluoroethane and to above 87% to less than 90% tetrafluoroethane, based upon the combined weight of tetrafluoroethane and chlorodifluoroethane. In a further exemplary embodiment, the refrigerant includes 12.0%-11.0% by weight chlorodifluoroethane and 88.0%-89.0% by weight tetrafluoroethane. In yet a further exemplary embodiment, the refrigerant includes the ratio of about 12 weight percent chlorodifluoroethane to about 88 weight percent tetrafluoroethane. 
     In addition, the refrigerant includes a lubricating oil that is soluble in the mixture of the chlorodifluoroethane and tetrafluoroethane. In an exemplary embodiment, the percentage by weight of lubricant in the refrigerant mixture is from about 0.5 to about 20 weight percent (based on the combined weight of chlorodifluoroethane and tetrafluoroethane), more preferably 1-2%, even more preferably 1.25-2%, and most preferably 1.5-1.75% (based on the combined weight of chlorodifluoroethane and tetrafluoroethane). In another exemplary embodiment about 0.5% to about 2% by weight of the refrigerant is a hydrophobic naphthenic lubricating oil that is miscible with the cholordifluoroethane and tetrafluorethane. 
     Suitable lubricants are hydrophobic (immiscible with water) lubricants. Preferably no more than 5% by weight of the lubricant is hydrophilic lubricant (some aliphatic hydrocarbon solvents can absorb up to 5% by weight water and still maintain lubricating integrity). More preferably, no more than 2% by weight of the lubricant is hydrophilic lubricant. Most preferably, the refrigerant blend contains no hydrophilic lubricant. 
     In an exemplary embodiment, the lubricant is a man-made, synthetic alkyl aromatic lubricant. Suitable synthetic lubricants include alkylated benzene lubricants. The lubricant can be either alkylbenzene alone or a mixture of alkylbenzene and mineral oil or a mixture of alkylbenzene and polyol ester (POE). 
     In a further exemplary embodiment, the lubricant can be a naphthenic or a paraffinic based lubricating oil that is soluble in dichlorodifluoromethane, chlorodifluoroethane, and tetrafluoroethane, or mixtures thereof. For example, the lubricant can be selected from those lubricants sold by Anderol, Inc., East Hanover, N.J., an affiliate of Royal Lubricants Company, under the trademark ROYCO® 2302. It should be understood, however, that other lubricating oils might also be used, as long as they are compatible with chlorodifluoroethane, tetrafluoroethane, and Refrigerant R-12 (dichlorodifluoromethane) and hydrophobic. 
     ROYCO® 2302 is a naphthenic oil lubricant having the following composition: 
     65-85% hydrotreated light naphthenic distillate, 
     10-20% solvent refined light naphthenic distillate petroleum, 
     &lt;0.5% butylated triphenyl phosphate, and 
     &lt;2% minor additive. 
     The ROYCO® 2302 lacks the barium dinonylnapthalene sulfonate additive of Royco 783C and 783D. 
     Various additives can be included in the lubricant. Examples include a corrosion inhibitor, such as for anhydrous systems, and/or a surfactant or foaming agent. Phosphated additives add corrosion resistance in the presence of acids and salts and increase wear resistance. Calcium additives help the lubricant resist rust and the effects of corrosion; calcium salts reduce the corrosive effects of hydrochloric acid that is formed in the presence of water and the chlorinated gases present in the refrigerant systems of the present invention. 
     The ROYCO® 2302 lubricant mentioned above contains the corrosion inhibitors mentioned above and can also contain acrylic polymer. It is believed that the function of the acrylic polymer is to increase wear resistance under severe conditions. Acrylics can help film formation, and the ability of the lubricant to coat metal and soft parts and stay in place. 
     While it is intended that the substitute refrigerant according to the present disclosure may be utilized to replace or as a substitute for Refrigerant R-12 (dichlorodifluoromethane) that has escaped from apparatus, the substitute refrigerant of the invention may also be utilized to completely refill apparatus that have been designed for use with Refrigerant R-12 (dichlorodifluoromethane), since the refrigerant has a temperature-pressure profile close enough to that of Refrigerant R-12 (dichlorodifluoromethane), particularly for HVAC and refrigeration (HVAC/R) applications. Thus, when the refrigerant is used as a complete replacement for Refrigerant R-12 (dichlorodifluoromethane), it is no longer necessary that the lubricant be compatible with dichlorodifluoromethane but only that it should be compatible with tetrafluoroethane and chlorodifluoroethane and the lubricants typically used in R-12 systems. In another embodiment of the present disclosure, the refrigerant can be used as the original refrigerant in the apparatus. 
     In further specifics, the present disclosure provides a canister, such as an aerosol can, containing a mixture of tetrafluoroethane and chlorodifluoroethane with a synthetic lubricating oil that may be fitted with an outlet manifold that is compatible with a Refrigerant R-12 (dichlorodifluoromethane) recharging manifold that is typically used to recharge an apparatus with the latter refrigerant. Refrigerant may then be allowed to flow from the container through the manifold and into the apparatus to replace Refrigerant R-12 (dichlorodifluoromethane) refrigerant that has been lost from the refrigeration system. Significantly, there is no need to flush an existing system to use the refrigerant with the lubricant of the present disclosure. 
     When mixing the components of the refrigerant blend of the present disclosure, one should first mix the lubricant with the chlorodifluoroethane, then mix that mixture with the tetrafluoroethane in the proportions afore mentioned. Otherwise, the product may not mix properly. When adding the refrigerant blend of this disclosure to a refrigerant system, one should leave the greatest amount of lubricant in the system if one for some reason takes out the Refrigerant R-12. 
     The present disclosure is designed to be utilized as a R-12 replacement in refrigeration systems. It is designed as a replacement, in which little or no modifications including parts are used to adapt the system for the refrigerant of the present disclosure. 
     The lubricants of the present disclosure are miscible with the chlorodifluoroethane and tetrafluoroethane refrigerant blend and with R-12 refrigerant. This allows for mixing of residual R-12 refrigerant and the refrigerant of the present disclosure, without the release of residual water in the dryer and subsequent system damage (as will happen if the synthetic lubricants disclosed in Thomas et al. and the DuPont patents are used). 
     The present refrigerant mixture can be used as a replacement for R-12 refrigerant, typically deminimus without retrofitting the air conditioning system or flushing it out. It is recommended that a full vacuum be obtained before adding the refrigerant. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The present refrigerant will hereinafter be described and more readily understood from a reading of the following description and by reference to the accompanying drawings. 
         FIG. 1  is a graph comparing the temperature-pressure profiles of various R-142/R-134a blends versus the profile for R-12. 
         FIG. 2  is a graph of a fractionation analysis on various R-142/R-134a blends. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present refrigerant is a mixture of non-Refrigerant R-12 refrigerants that are less damaging to the Earth&#39;s ozone layer with a lower global warming factor and that are recommended by the U.S. Environmental Protection Agency for use in HVAC/R and also by ASHRAE. The refrigerant mixture is compatible with Refrigerant R-12 (dichlorodifluoromethane) and can be used to replace existing Refrigerant R-12 (dichlorodifluoromethane) in existing R-12 based systems. The present refrigerant replaces Refrigerant R-12 (dichlorodifluoromethane) in Refrigerant R-12 (dichlorodifluoromethane) based air-cooling and refrigeration systems, without the need to retrofit existing Refrigerant R-12 (dichlorodifluoromethane) based systems for non-Refrigerant R-12 replacement refrigerants and without the need to flush the system. 
     Specifically, the present refrigerant includes a mixture of chlorodifluoroethane and tetrafluoroethane and a lubricant provided under pressure in a can or cylinder equipped with an outlet compatible with existing Refrigerant R-12 (dichlorodifluoromethane) recharging kit manifolds, so that the refrigerant and lubricant mixture can be added to existing Refrigerant R-12 (dichlorodifluoromethane) based coolant systems. Also, the present refrigerant provides the possibility of using new refrigerant systems, originally designed for “Refrigerant R-12 (dichlorodifluoromethane),” by supplying an EPA-approved refrigerant so that retrofitting to new equipment use is not required. 
     In an exemplary embodiment, a cylinder can like the standard 25 or 30 lb. can formerly used for containing Refrigerant R-12 (dichlorodifluoromethane) is provided, but containing from about 60% to about 95% by weight tetrafluorethane (R-134 refrigerant) and from about 5% to about 40% by weight chlorodifluoroethane (R-142 refrigerant). The can also contains a lubricant in solution with the refrigerant mixture at a percent by weight of in the range of about 0.5% up to about 20% by weight of the combined weight of the refrigerants. 
     In another exemplary embodiment, a cylinder can like the standard 25 or 30 lb. can formerly used for containing Refrigerant R-12 (dichlorodifluoromethane) is provided, but containing less than 90% to more than 87% by weight tetrafluorethane (R-134 refrigerant) and more than 10% to less than 13% by weight chlorodifluoroethane (R-142 refrigerant). The can also contains a lubricant in solution with the refrigerant mixture at a percent by weight of in the range of about 0.5% up to about 2% by weight of the combined weight of the refrigerants. 
     Such lubricants are preferably hydrophobic (immiscible with water) lubricants. Preferably no more than 5% by weight of the lubricant is hydrophilic lubricant (some aliphatic hydrocarbon solvents can absorb up to 5% by weight water and still maintain lubricating integrity). More preferably, no more than 2% by weight of the lubricant is hydrophilic lubricant. Most preferably, the refrigerant blend contains no hydrophilic lubricant. 
     One exemplary lubricant is the aforementioned Royco 2302 naphthenic lubricant. The lubricant can have a viscosity of 5-500 centistokes. In another embodiment the lubricant can has a viscosity of 5-10 centistokes. 
     Another exemplary lubricant is a synthetic alkylate hydrocarbon, such as a man-made, synthetic alkyl aromatic lubricant. One example of such a lubricant is a synthetic alkylbenzene sold under the product name Zerol 30 by Shrieve Chemical products. Zerol 30 is an extra low viscosity, high quality, synthetic alkylbenzene composition having a boiling point of greater than 240° C. at atmospheric pressure, a specific gravity at 15° C. of 0.86-0.88, a viscosity of 4-8 cSt at 40° C. (typically about 5.5 cSt), a pour point of −35° C. max (typically −40° C.), and a water content of 30 ppm in bulk. Such a synthetic alkylate hydrocarbon lubricant can also include a minor portion of either mineral oil or polyol ester (POE) mixed with the synthetic lubricant. By minor portion we mean less than 50% by weight of the total lubricant present. 
     The present disclosure provides lubricants that are compatible with the invention mixture of tetrafluoroethane and chlorodifluoroethane, and with “Refrigerant R-12 (dichlorodifluoromethane),” and that are suitable for lubricating refrigerant compressors and other air-conditioner component parts. While alkylbenzene alone is considered not miscible with tetrafluoroethane (in particular R134a), it is sufficiently soluble in the present tetrafluoroethane/chlorodifluoroethane mixture. This solubility allows the replacement refrigerant blend to lubricate the system, preventing damage to the compressor and component parts of the system. 
     EXAMPLE 1 
     1,1,1,2-tetrafluoroethane and dichlorofluoroethane refrigerants are mixed with a suitable lubricant, such as either the Royco 2302 naphthenic lubricant or an alyklbenzene synthetic lubricant (such as L30 or L35 from Shrieve Chemical Company, The Woodlands, Texas, or Zerol 150 from Nu-Calgon Wholesale, Inc., St. Louis, Mo., or AB 150 from Virginia KMP Corporation, Dallas, Tex.) at set ratios such that the temperature-pressure profile of the mixture is compared to that of Refrigerant R-12 (dichlorodifluoromethane), over the normal operating range of air conditioning and refrigeration systems of from about −60° F. to 160° F. The set ratios range from 80% to 90% 1,1,1,2-tetrafluoroethane and 10% to 20% chlorodifluoroethane. A similar temperature-pressure profile was obtained for Refrigerant R-12 (dichlorodifluoromethane). The results were plotted and compared in  FIG. 1 .  FIG. 1  shows that as the amount of tetrafluoroethane increases in the blends, the temperature-pressure profile of the blends has a greater divergence from the temperature-pressure profile of R-12 at the higher temperatures. 
     A fractionation analysis was conducted for three of the blends found in  FIG. 1 , namely blends having ratios of 86/14, 88/12 and 90/10 by weight percent of tetrafluoroethane to chlorodifluroethane. The results of this fractionation analysis are illustrated in  FIG. 2 . The purpose of this test is to determine the effect on the refrigerant mixture should a leak occur in the refrigeration or air conditioning system. The lubricant used has no effect on this analysis. Since tetrafluoroethane evaporates at lower temperatures than chlorodifluroethane, when a leak occurs more tetrafluoroethane evaporates than chlorodifluoroethane. Thus, for example, for an 86/14 blend of tetrafluoroethane to chlorodifluoroethane when 95% of the initial mass of blend has leaked, the remaining liquid refrigerant comprises 52.91% R142b (chlorodifluroethane). A liquid refrigerant having that much R142b (chlorodifluroethane) is considered flammable. In general, the refrigerant mixture needs to have less than about 48% R142b in the liquid to be considered to have a reduced level of flammability acceptable to ASHRAE Standard 34 and to receive an ASHRAE designation rated A1 in its safety classification. 
     The most preferred ratio is about 12% by weight chlorodifluoroethane to about 88% by weight 1,1,1,2-tetrafluoroethane. This is the ratio of chlorodifluoroethane to 1,1,1,2-tetrafluoroethane with the lubricant where the mixture of the invention shows the best compromise between greatest similarity to “Refrigerant R-12 (dichlorodifluoromethane)” over most operating temperatures with no flame propagation. At this ratio, the fractionation study of  FIG. 2  shows a residual concentration of R-142 (chlorodifluoroethane) at 95% mass leaked of 47.3%, just below the concentration of R-142 considered to be flammable. 
     In the most preferred embodiment of the composition, the most preferred ratios of 1,1,1,2-tetrafluoroethane and chlorodifluoroethane are mixed with a range of from 0.5% to 2% by weight of lubricant as aforementioned. 
     A pressure temperature comparison of 12% chlorodifluorethane to 88% tetrafluoroethane to R-12 and R-134a is provided below in Table 1. 
     
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                   
                 Choice-R420A 
                   
                   
               
               
                   
                 ° F. 
                 Refrigerant 
                 R-12 
                 HFC-134a 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 −40 
                 17.8* 
                 11.0 
                 14.8 
               
               
                   
                 −35 
                 15.0* 
                 8.4 
                 12.5 
               
               
                   
                 −30 
                 12.1* 
                 5.5 
                 9.8 
               
               
                   
                 −25 
                 9.0* 
                 2.3 
                 6.9 
               
               
                   
                 −20 
                 5.8* 
                 0.6 
                 3.7 
               
               
                   
                 −15 
                 2.2* 
                 2.4 
                 0.0 
               
               
                   
                 −10 
                 0.7 
                 4.5 
                 1.9 
               
               
                   
                 −5 
                 2.7 
                 6.7 
                 4.1 
               
               
                   
                 0 
                 4.9 
                 9.2 
                 6.5 
               
               
                   
                 5 
                 7.3 
                 11.8 
                 9.1 
               
               
                   
                 10 
                 9.9 
                 14.6 
                 12.0 
               
               
                   
                 15 
                 12.8 
                 17.7 
                 15.0 
               
               
                   
                 20 
                 15.8 
                 21.0 
                 18.4 
               
               
                   
                 25 
                 19.2 
                 24.6 
                 22.1 
               
               
                   
                 30 
                 22.8 
                 28.5 
                 26.1 
               
               
                   
                 35 
                 26.6 
                 32.6 
                 30.4 
               
               
                   
                 40 
                 30.8 
                 37.0 
                 35.0 
               
               
                   
                 45 
                 35.4 
                 41.7 
                 40.0 
               
               
                   
                 50 
                 40.2 
                 46.7 
                 45.3 
               
               
                   
                 55 
                 45.5 
                 52.0 
                 51.0 
               
               
                   
                 60 
                 51.0 
                 57.7 
                 56.4 
               
               
                   
                 65 
                 57.0 
                 63.8 
                 63.7 
               
               
                   
                 70 
                 63.4 
                 70.2 
                 70.7 
               
               
                   
                 75 
                 70.2 
                 77.0 
                 78.5 
               
               
                   
                 80 
                 77.4 
                 84.2 
                 86.4 
               
               
                   
                 85 
                 85.1 
                 91.8 
                 95.3 
               
               
                   
                 90 
                 93.3 
                 99.8 
                 104.2 
               
               
                   
                 95 
                 102.0 
                 108.3 
                 114.1 
               
               
                   
                 100 
                 111.1 
                 117.2 
                 124.3 
               
               
                   
                 105 
                 120.8 
                 126.6 
                 135.4 
               
               
                   
                 110 
                 131.1 
                 136.4 
                 146.8 
               
               
                   
                 115 
                 141.9 
                 146.8 
                 159.2 
               
               
                   
                 120 
                 153.2 
                 157.7 
                 171.9 
               
               
                   
                 125 
                 165.2 
                 169.1 
                 185.7 
               
               
                   
                 130 
                 177.7 
                 181.0 
                 199.8 
               
               
                   
                 135 
                 190.9 
                 193.5 
                 215.0 
               
               
                   
                 140 
                 204.7 
                 206.6 
                 230.5 
               
               
                   
                 145 
                 219.2 
                 220.3 
                 247.3 
               
               
                   
                 150 
                 234.3 
                 234.6 
                 264.4 
               
               
                   
                   
               
               
                   
                 (*= in.Hg vacuum) 
               
             
          
         
       
     
     EXAMPLE 2 
     A temperature glide example of a mixture of 12% chlorodifluoroethane and 88% afluoroethane refrigerants was conducted at a temperature of 80° F. The exemplary mixture had a temperature glide of 2.5° F. as compared to 4° F. for R-12. The resulting temperature glide chart is in Table 2 below. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 Temp 
                 P Bubble 
                 P Dew 
               
               
                 (° F.) 
                 (psia) 
                 (psia) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 −40 
                 6.941 
                 6.641 
               
               
                 −39 
                 7.165 
                 6.855 
               
               
                 −38 
                 7.389 
                 7.069 
               
               
                 −37 
                 7.613 
                 7.283 
               
               
                 −36 
                 7.837 
                 7.497 
               
               
                 −35 
                 8.061 
                 7.711 
               
               
                 −34 
                 8.285 
                 7.925 
               
               
                 −33 
                 8.509 
                 8.139 
               
               
                 −32 
                 8.733 
                 8.353 
               
               
                 −31 
                 8.957 
                 8.567 
               
               
                 −30 
                 9.181 
                 8.781 
               
               
                 −29 
                 9.460 
                 9.048 
               
               
                 −28 
                 9.739 
                 9.315 
               
               
                 −27 
                 10.018 
                 9.582 
               
               
                 −26 
                 10.297 
                 9.849 
               
               
                 −25 
                 10.576 
                 10.116 
               
               
                 −24 
                 10.855 
                 10.383 
               
               
                 −23 
                 11.134 
                 10.650 
               
               
                 −22 
                 11.413 
                 10.917 
               
               
                 −21 
                 11.692 
                 11.184 
               
               
                 −20 
                 11.971 
                 11.451 
               
               
                 −19 
                 12.314 
                 11.779 
               
               
                 −18 
                 12.657 
                 12.107 
               
               
                 −17 
                 13.000 
                 12.435 
               
               
                 −16 
                 13.343 
                 12.763 
               
               
                 −15 
                 13.686 
                 13.091 
               
               
                 −14 
                 14.029 
                 13.419 
               
               
                 −13 
                 14.372 
                 13.747 
               
               
                 −12 
                 14.715 
                 14.075 
               
               
                 −11 
                 15.058 
                 14.403 
               
               
                 −10 
                 15.401 
                 14.731 
               
               
                 −09 
                 15.817 
                 15.130 
               
               
                 −08 
                 16.233 
                 15.529 
               
               
                 −07 
                 16.643 
                 15.928 
               
               
                 −06 
                 17.059 
                 16.327 
               
               
                 −05 
                 17.475 
                 16.726 
               
               
                 −04 
                 17.891 
                 17.125 
               
               
                 −03 
                 18.307 
                 17.524 
               
               
                 −02 
                 18.723 
                 17.923 
               
               
                 −01 
                 19.139 
                 18.322 
               
               
                 0.0 
                 19.555 
                 18.721 
               
               
                 1.0 
                 20.056 
                 19.201 
               
               
                 7.0 
                 23.062 
                 22.081 
               
               
                 8.0 
                 23.563 
                 22.561 
               
               
                 9.0 
                 24.064 
                 23.041 
               
               
                 10.0 
                 24.565 
                 23.521 
               
               
                 11.0 
                 25.161 
                 24.093 
               
               
                 12.0 
                 25.757 
                 24.665 
               
               
                 13.0 
                 26.353 
                 25.237 
               
               
                 14.0 
                 26.949 
                 25.809 
               
               
                 15.0 
                 27.545 
                 26.381 
               
               
                 16.0 
                 28.141 
                 26.953 
               
               
                 17.0 
                 28.737 
                 27.525 
               
               
                 18.0 
                 29.333 
                 28.097 
               
               
                 19.0 
                 29.929 
                 28.669 
               
               
                 20.0 
                 30.525 
                 29.241 
               
               
                 21.0 
                 31.229 
                 29.916 
               
               
                 22.0 
                 31.933 
                 30.591 
               
               
                 23.0 
                 32.637 
                 31.266 
               
               
                 24.0 
                 33.341 
                 31.941 
               
               
                 25.0 
                 34.045 
                 32.616 
               
               
                 26.0 
                 34.749 
                 33.291 
               
               
                 27.0 
                 35.453 
                 33.966 
               
               
                 28.0 
                 36.157 
                 34.641 
               
               
                 29.0 
                 36.861 
                 35.316 
               
               
                 30.0 
                 37.565 
                 35.991 
               
               
                 31.0 
                 38.389 
                 36.782 
               
               
                 32.0 
                 39.213 
                 37.573 
               
               
                 33.0 
                 40.037 
                 38.364 
               
               
                 34.0 
                 40.861 
                 39.155 
               
               
                 35.0 
                 41.685 
                 39.946 
               
               
                 36.0 
                 42.509 
                 40.737 
               
               
                 37.0 
                 43.333 
                 41.528 
               
               
                 38.0 
                 44.157 
                 42.319 
               
               
                 39.0 
                 44.981 
                 43.110 
               
               
                 40.0 
                 45.805 
                 43.901 
               
               
                 41.0 
                 46.762 
                 44.822 
               
               
                 42.0 
                 47.719 
                 45.743 
               
               
                 43.0 
                 48.676 
                 46.664 
               
               
                 44.0 
                 49.633 
                 47.585 
               
               
                 45.0 
                 50.590 
                 48.506 
               
               
                 46.0 
                 51.547 
                 49.427 
               
               
                 47.0 
                 52.504 
                 50.348 
               
               
                 48.0 
                 53.461 
                 51.269 
               
               
                 54.0 
                 59.791 
                 57.367 
               
               
                 55.0 
                 60.895 
                 58.431 
               
               
                 56.0 
                 61.999 
                 59.495 
               
               
                 57.0 
                 63.103 
                 60.559 
               
               
                 58.0 
                 64.207 
                 61.623 
               
               
                 59.0 
                 65.311 
                 62.087 
               
               
                 60.0 
                 66.415 
                 63.751 
               
               
                 61.0 
                 67.680 
                 64.972 
               
               
                 62.0 
                 68.945 
                 66.193 
               
               
                 63.0 
                 70.210 
                 67.414 
               
               
                 64.0 
                 71.475 
                 68.635 
               
               
                 65.0 
                 72.740 
                 69.856 
               
               
                 66.0 
                 74.005 
                 71.077 
               
               
                 67.0 
                 75.270 
                 72.298 
               
               
                 68.0 
                 76.535 
                 73.519 
               
               
                 69.0 
                 77.800 
                 74.740 
               
               
                 70.0 
                 79.065 
                 75.961 
               
               
                 71.0 
                 80.506 
                 77.354 
               
               
                 72.0 
                 81.947 
                 78.747 
               
               
                 73.0 
                 83.388 
                 80.140 
               
               
                 74.0 
                 84.829 
                 81.533 
               
               
                 75.0 
                 86.270 
                 82.926 
               
               
                 76.0 
                 87.711 
                 84.319 
               
               
                 77.0 
                 89.152 
                 85.712 
               
               
                 78.0 
                 90.593 
                 87.105 
               
               
                 79.0 
                 92.034 
                 88.498 
               
               
                 80.0 
                 93.475 
                 89.891 
               
               
                 81.0 
                 95.108 
                 91.472 
               
               
                 82.0 
                 96.741 
                 93.053 
               
               
                 83.0 
                 98.374 
                 94.634 
               
               
                 84.0 
                 100.007 
                 96.215 
               
               
                 85.0 
                 101.640 
                 97.796 
               
               
                 86.0 
                 103.273 
                 99.377 
               
               
                 87.0 
                 104.906 
                 100.958 
               
               
                 88.0 
                 106.539 
                 102.539 
               
               
                 89.0 
                 108.172 
                 104.120 
               
               
                 90.0 
                 109.805 
                 105.701 
               
               
                 91.0 
                 111.645 
                 107.487 
               
               
                 92.0 
                 113.485 
                 109.273 
               
               
                 93.0 
                 115.325 
                 111.059 
               
               
                 94.0 
                 117.165 
                 112.845 
               
               
                 95.0 
                 119.005 
                 114.631 
               
               
                 2.0 
                 20.557 
                 19.681 
               
               
                 3.0 
                 21.058 
                 20.161 
               
               
                 4.0 
                 21.559 
                 20.641 
               
               
                 5.0 
                 22.060 
                 21.121 
               
               
                 6.0 
                 22.561 
                 21.601 
               
               
                 101.0 
                 130.269 
                 125.568 
               
               
                 102.0 
                 132.333 
                 127.575 
               
               
                 103.0 
                 134.397 
                 129.582 
               
               
                 104.0 
                 136.461 
                 131.589 
               
               
                 105.0 
                 138.525 
                 133.596 
               
               
                 106.0 
                 140.589 
                 135.603 
               
               
                 107.0 
                 142.653 
                 137.610 
               
               
                 108.0 
                 144.717 
                 139.617 
               
               
                 109.0 
                 146.781 
                 141.624 
               
               
                 110.0 
                 148.845 
                 143.631 
               
               
                 111.0 
                 151.150 
                 145.878 
               
               
                 112.0 
                 153.455 
                 148.125 
               
               
                 113.0 
                 155.760 
                 150.372 
               
               
                 114.0 
                 158.065 
                 152.619 
               
               
                 115.0 
                 160.370 
                 154.866 
               
               
                 116.0 
                 162.675 
                 157.133 
               
               
                 117.0 
                 164.980 
                 159.360 
               
               
                 118.0 
                 167.285 
                 161.607 
               
               
                 119.0 
                 169.590 
                 163.854 
               
               
                 120.0 
                 171.895 
                 166.101 
               
               
                 121.0 
                 174.458 
                 168.606 
               
               
                 122.0 
                 177.021 
                 171.111 
               
               
                 123.0 
                 179.584 
                 173.616 
               
               
                 124.0 
                 182.147 
                 176.121 
               
               
                 125.0 
                 184.710 
                 178.626 
               
               
                 126.0 
                 187.273 
                 181.131 
               
               
                 127.0 
                 189.836 
                 183.636 
               
               
                 128.0 
                 192.399 
                 186.141 
               
               
                 129.0 
                 194.962 
                 188.646 
               
               
                 130.0 
                 197.525 
                 191.151 
               
               
                 131.0 
                 200.364 
                 193.933 
               
               
                 132.0 
                 203.203 
                 196.715 
               
               
                 133.0 
                 206.042 
                 199.497 
               
               
                 49.0 
                 54.418 
                 52.190 
               
               
                 50.0 
                 55.375 
                 53.111 
               
               
                 51.0 
                 56.479 
                 54.175 
               
               
                 52.0 
                 57.583 
                 55.239 
               
               
                 53.0 
                 58.687 
                 56.303 
               
               
                 134.0 
                 208.881 
                 202.279 
               
               
                 135.0 
                 211.720 
                 205.061 
               
               
                 136.0 
                 214.559 
                 207.843 
               
               
                 137.0 
                 217.398 
                 210.625 
               
               
                 138.0 
                 220.237 
                 213.407 
               
               
                 139.0 
                 223.076 
                 216.189 
               
               
                 140.0 
                 225.915 
                 218.971 
               
               
                 141.0 
                 229.048 
                 222.051 
               
               
                 142.0 
                 232.181 
                 225.131 
               
               
                 143.0 
                 235.314 
                 228.211 
               
               
                 144.0 
                 238.447 
                 231.291 
               
               
                 145.0 
                 241.580 
                 234.371 
               
               
                 146.0 
                 244.713 
                 237.451 
               
               
                 147.0 
                 247.846 
                 240.531 
               
               
                 148.0 
                 250.979 
                 243.611 
               
               
                 149.0 
                 254.112 
                 246.691 
               
               
                 150.0 
                 257.245 
                 249.771 
               
               
                 151.0 
                 260.690 
                 253.170 
               
               
                 152.0 
                 264.135 
                 256.569 
               
               
                 153.0 
                 267.580 
                 259.968 
               
               
                 154.0 
                 271.025 
                 263.367 
               
               
                 155.0 
                 274.470 
                 266.766 
               
               
                 156.0 
                 277.915 
                 270.165 
               
               
                 157.0 
                 281.360 
                 273.564 
               
               
                 158.0 
                 284.805 
                 276.963 
               
               
                 159.0 
                 288.250 
                 280.362 
               
               
                 160.0 
                 291.695 
                 283.761 
               
               
                 161.0 
                 295.470 
                 287.501 
               
               
                 162.0 
                 299.245 
                 291.241 
               
               
                 163.0 
                 303.020 
                 294.981 
               
               
                 164.0 
                 306.795 
                 298.721 
               
               
                 165.0 
                 310.570 
                 302.461 
               
               
                 166.0 
                 314.345 
                 306.201 
               
               
                 96.0 
                 120.845 
                 116.417 
               
               
                 97.0 
                 122.685 
                 118.203 
               
               
                 98.0 
                 124.525 
                 119.989 
               
               
                 99.0 
                 126.365 
                 121.775 
               
               
                 100.0 
                 128.205 
                 123.561 
               
               
                 167.0 
                 318.120 
                 309.941 
               
               
                 168.0 
                 321.895 
                 313.681 
               
               
                 169.0 
                 325.670 
                 317.421 
               
               
                 170.0 
                 329.445 
                 321.161 
               
               
                 171.0 
                 333.569 
                 325.267 
               
               
                 172.0 
                 337.693 
                 329.373 
               
               
                 173.0 
                 341.817 
                 333.429 
               
               
                 174.0 
                 345.941 
                 337.585 
               
               
                 175.0 
                 350.065 
                 341.691 
               
               
                 176.0 
                 354.189 
                 345.797 
               
               
                 177.0 
                 358.313 
                 349.903 
               
               
                 178.0 
                 362.437 
                 354.009 
               
               
                 179.0 
                 366.561 
                 358.115 
               
               
                 180.0 
                 370.685 
                 362.221 
               
               
                 181.0 
                 375.176 
                 366.658 
               
               
                 182.0 
                 379.667 
                 371.095 
               
               
                 183.0 
                 384.158 
                 375.532 
               
               
                 184.0 
                 388.649 
                 379.969 
               
               
                 185.0 
                 393.140 
                 384.406 
               
               
                 186.0 
                 397.631 
                 388.843 
               
               
                 187.0 
                 402.122 
                 393.280 
               
               
                 188.0 
                 406.613 
                 397.717 
               
               
                 189.0 
                 411.104 
                 402.154 
               
               
                 190.0 
                 415.595 
                 406.591 
               
               
                 191.0 
                 420.468 
                 411.510 
               
               
                 192.0 
                 425.341 
                 416.429 
               
               
                 193.0 
                 430.214 
                 421.348 
               
               
                 194.0 
                 435.087 
                 426.267 
               
               
                 195.0 
                 439.960 
                 431.186 
               
               
                 196.0 
                 444.833 
                 436.105 
               
               
                 197.0 
                 449.706 
                 441.024 
               
               
                 198.0 
                 454.579 
                 445.943 
               
               
                 199.0 
                 459.452 
                 450.862 
               
               
                 200.0 
                 464.325 
                 455.781 
               
               
                   
               
             
          
         
       
     
     The apparatus and method of the preferred embodiment encompass the use of a mixture of refrigerants tetrafluoroethane and chlorodifluoroethane at preferred ranges, as discussed above, with lubricant at preferred ranges, as discussed above (0.5-20% by weight) in the operation of an HVAC/R system, wherein the coolant-oil mixture replaces Refrigerant R-12 (dichlorodifluoromethane) in a Refrigerant R-12 (dichlorodifluoromethane)-based refrigeration system. 
     The method and apparatus in the preferred embodiment further entails providing the above described mix of chlorodifluoroethane/1,1,1,2-tetrafluoroethane and lubricant in 25 lb cylinders, where the cylinders are pressure sealed and fitted with an outlet compatible for existing Refrigerant 12-type refrigeration manifolds typically ¼ inch male flare. 
     Further, it was noted that the systems tested ran more smoothly and the compressor showed less vibration during the test period, as the mixture was added. It is theorized that the lubricating oil, being soluble in the refrigerant gasses, was better able to lubricate the compressor and reciprocating parts than the existing Refrigerant R-12 (dichlorodifluoromethane) lubricant used by itself. In some applications, depending on the charge, a reduction in power consumption maybe also noted. The optimum percentage charge for this invention is at a 92% charge of the called for charge of the R-12 system being retrofitted. 
     Pure refrigerant 1,1,1,2-tetrafluoroethane is not miscible with naphthenic oil or mineral oil (both of which could be used as the lubricants of the present disclosure). Chlorodifluoroethane is miscible with most naphthenic oils such as alkylbenzene and also mineral oils. The presence of the chlorodifluoroethane allows the use of naphthenic oil alone or mixed with mineral oils in the refrigerant blend and system of the present invention (a translucent, partially miscible blend is formed). Alkylbenzene, when added to mineral oil, is accepted to provide improved lubricating qualities to those of mineral oil alone. The lubricant can advantageously be partially polymerized into longer chain molecules to allow it to function at very low percentage levels. The lubricant can be hydrotreated or polymerized for stability and wear resistance. 
     The lubricant of the present disclosure is miscible with R-12, R-22, and the blend of the refrigerant gases described herein. 
     Although exemplary embodiments have been shown and described, it will be clear to those of ordinary skill in the art that variations and modifications may be made of the refrigerant taught herein, and that those are within the scope and spirit of the invention as taught above and claimed here below.