# di minimis



## Mr. ReardonHVAC (Aug 17, 2011)

Last night a student of mine, while failing to pay close attention to instruction, opened and began purging his low side hose, which was filled with liquid. Besides speaking to him about doing something he was not asked to do, I asked him if he was familiar with the term di minimis to which he responded, "Yes, and I was told that what I did was the definition of di minimis." Tonites lecture includes talk about di minimis, as well as a repeat lesson in gauge procedure, including weighing in a charge and ensuring the complete weight, including liquid in the low side hose, makes its way into the circuit. Your thoughts or perhaps even legal definitions related to the industry re: di minimis are welcomed & appreciated.


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## Vaporx (Jun 29, 2011)

I got this off the EPA site...
*
The Prohibition on Venting*

Effective July 1, 1992, Section 608 of the Act prohibits individuals from intentionally venting ozone-depleting substances used as refrigerants (generally CFCs and HCFCs) into the atmosphere while maintaining, servicing, repairing, or disposing of air-conditioning or refrigeration equipment (appliances). Only four types of releases are permitted under the prohibition:



"De minimis" quantities of refrigerant released in the course of making good faith attempts to recapture and recycle or safely dispose of refrigerant.
Refrigerants emitted in the course of normal operation of air-conditioning and refrigeration equipment (as opposed to during the maintenance, servicing, repair, or disposal of this equipment) such as from mechanical purging and leaks. However, EPA requires the repair of leaks above a certain size in large equipment (see Refrigerant Leaks).
Releases of CFCs or HCFCs _that are not used as refrigerants_. For instance, mixtures of nitrogen and R-22 that are used as holding charges or as leak test gases may be released.
Small releases of refrigerant that result from purging hoses or from connecting or disconnecting hoses to charge or service appliances will not be considered violations of the prohibition on venting. However, recovery and recycling equipment manufactured after November 15, 1993, must be equipped with low-loss fittings.
I personally feel the intent of the EPA regs was to establish recovery procedures, to eliminate the practice of simply dumping system charges. As long as we're making good faith efforts to comply with the _spirit_ of the regulations, I think we're OK.


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## DuMass (Jul 7, 2009)

As far as I know, normal purging of hoses is okay as far as the EPA is concerned, but with the cost of refrigerant now, many techs use low loss fittings on their hoses and will also purge the high side hose into the low side hose through the manifold and then back into the equipment on the low side service valve.
It’s quick, clean, environmentally friendly and doesn’t fill the area up with a cloud of refrigerant and oil mist, which is nasty to breathe if you’re working on something like a refrigeration condenser unit in an enclosed area, such as a basement or utility room.


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