
Acid Indigestion
Everything you have been told is all wrong!
After-market additives used to neutralize acid from a compressor burnout
or to prevent a future burnout are some of the worst chemical mixtures
we have encountered.
These are not high tech remedies or advanced systems treatments. They
are, in fact, very crude antidotes which can be more harmful than the
actual ailment they intend to cure.
Breakdown
We have analyzed three different varieties of the neutralizers.
Product
1. A mixture of Isopropyl Alcohol and Potassium Hydroxide (KOH) in
mineral oil.
2. Alcohol/solvent blend having an alkaline signature.
3. Industrial grade Ethanol 95%, with 5% water.
Solvents and Alcohols are some of the most damaging compounds you could
ever introduce into a working Refrigeration System.
Your compressor oil does not tolerate being mixed with aggressive
chemicals. Addition of any one of the above products will reduce your
oils’ viscosity and the oils’ ability to impart proper lubrication on
the main bearing journals. Notwithstanding, well documented chemical
incompatibilities and notable side effects.
Special Effects
Whenever an acid molecule is neutralized, one molecule of water plus one
molecule of salt will be produced as the byproducts. This is a basic
chemical fact, it is not some hypothesis or theory, it is as real as 1 +
1 = 2. The resultant water and salt become the main culprits which will
eventually eat your system from the inside out.
The incorporation of alcohol in the above mixtures serve to further
complicate matters. Alcohol drives all water out of the drier desiccant.
Your drier will become completely disabled to perform the function for
which it is intended. Overtime, the driers’ desiccant begins to adsorb
the free alcohol circulating in the system. This is because your drier
prefers alcohol over water. (Refer to our article "Kiss of Death").
Sealed tube tests have shown that small quantities of alcohol will react
with metal, cause insulation to become brittle and deposit solid gray
aluminum masses into the oil.
The Neutral Zone
Being a longtime bench chemist, I have lots of skill and experience when
it comes to adjusting or neutralizing the pH of a solution. I can tell
you it cannot be done without a good pH meter. Just one drop too much
neutralizer and the batch is blown. I can’t imagine any Tech in the
field being able to blindly slug feed a system with a neutralizer and
assume ‘it is right on the money’.
More than likely, the neutral point(7.0) will be overshot and the oil
will become alkaline.
Dangers of Alkalinity
Believe it or not, the optimum fluid condition of an Air Conditioning or
Refrigeration system must stay mildly acidic.
1.0 5.5 6.5 7.0 14.0
acidic neutral basic
The circulating Refrigerant-Oil stream will have a nominal pH value
between 5.5 to 6.5, depending on the Refrigerant type and Oil. This
holds true for a CFC, HCFC, or HFC system.
I shall quote form an official source:
It is especially important not to use alkaline or basic material such as
these or any other alkaline agents with R-22. This refrigerant is
sensitive to alkaline conditions and tends to be decomposed by basic
materials. Pg. 177
Compounds [refrigerants] containing hydrogen are especially sensitive to
pH, being relatively stable in neutral or acidic solutions but rapidly
hydrolyzed under alkaline conditions. Pg. 183
Source, "Fluorocarbon Refrigerants Handbook", By Ralph C. Downing, 1988
Prentice Hall, ISBN 0-13-322504-6. Get a copy !
The Additive Gang
The oils, refrigerants, gaskets, seals and metals used in the sealed
system today have been carefully tested for chemical stability and
longevity.
The use of additives may be tempting under certain conditions.
The professional service tech will work to remove the cause of trouble
rather than resort to the latest scatterbrained cure. Adding anything
foreign to the system often leads to trouble down the line. The least
contaminated system will be the best performing system.