Reader Mail: 06/16/2003
Cutting Through Marketing
Since the production ban of CFC refrigerants, a variety of R-12 replacements have been introduced to the HVACR industry. Many of these replacement refrigerants have a limited temperature range and require various degrees of system conversion and fine-tuning.Countless dollars are lost each year in the service sector in the form of wasted materials, premature equipment failure, and lost man-hours as a direct result of individuals being influenced into buying and using improper or limited- range R-12 replacements.
How can technicians cut through the marketing to get the facts? Let’s examine some of the major aspects in marketing R-12 replacements and other ways to look at the statements.
The promotion: “They have lower pressures than R-22-based blends.” Some considerations: Which R-22 replacements are better for your system — those that provide less pressure than R-12, or those with more pressure than R-12? First of all, R-22-based blends have dominated the industry for well over a decade, primarily due to their ability to cover the widest R-12 temperature range. The additional system pressures that are experienced with R-22-based replacements are relatively insignificant and rarely require any form of system modification or control adjustments. On the other hand, the lower pressure R-134a-based replacements are limited in their temperature range and pull down time, and in far more cases require some form of system prepping or control adjustment to be used.
So it is ironic that “lower pressure” — billed as being a major strength of R-134a-based blends — is more times than not the No. 1 weakness of those products.
The promotion: “They are compatible with all oils.” Some considerations: Producers of both R-134a- and R-22-based replacements use this point, and it is a very important factor in the selection process. Since there are three very unique and commonly used oils in our industry — mineral, alkyl benzene, and POE — you need to be confident that the replacement you are using will not have any adverse chemical reaction with any one particular oil.
But unfortunately the “compatibility” statement is often misperceived and leads some to believe that the replacement can be used with any oil at any temperature. This is where you need to dig deeper into the producers’ charging guidelines. Several replacements require specific oils and varying amounts of charging or mixing to ensure adequate oil return, primarily in low temperature applications, and/or in systems with long line sets.
The promotion: “They do not contain hydrocarbons.” Some considerations: Such a statement can be misleading, implying that any product that contains a hydrocarbon (butane, isobutene, and propane) may create a serious service-related hazard.
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So why have some producers opted to incorporate a flammable hydrocarbon into their refrigerant? And are they really dangerous to use? The first answer is pure science and cannot be disputed. Hydrocarbons do provide significant assistance with oil return in low temperature applications, and with all of the most commonly used oils. Many in our industry believe that only R-414B (marketed as Hot Shot) is the only major refrigerant that incorporates a hydrocarbon (1.5 percent 600a — isobutene), when the fact is that several refrigerants contain hydrocarbons, including two of the most successful R-502 replacement refrigerants, R-402A and R-402B (marketed has HP80 and HP81). They both contain 2 percent of a hydrocarbon known as R-290, which is better known as propane.
The answer to the question of danger can be answered very easily by looking at the refrigerant’s ASHRAE safety classification. If the product has received a classification of A1, it has been independently tested and found to be nontoxic and nonflammable.
R-402A, R-402B, and R-414B are ASHRAE designated and have a safety classification of A1.
It is also interesting to note that several R-12 replacements incorporate nonhydrocarbon refrigerant components that are classified as flammable. For instance, the refrigerant R-142b has been used as a component in a number of replacement refrigerants (such as R-409A, R-414B, and RB-276.) It is not in the hydrocarbon family, yet is nonetheless classified as being a flammable refrigerant.
For refrigerant producers, the key to using a flammable refrigerant as a replacement component has always been quite simple: Only incorporate what is needed and what is safe.
So the message here is: “Look beyond the headlines, and be sure to ask lots of questions.”
Jamey Hale, Technical Support Supervisor, ICOR International Inc., Indianapolis, Ind.
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Publication date: 06/16/2003