Product history

The concept of Polarized Refrigerant Oil Additive (PROA) technology was developed in the late 1980’s by Dr. C.H. Wilkins, Dean of the Dept. of Metallurgy, University of Alabama and Dr. Charles Thompson, Retired Chemical Engineer, DuPont Chemical and a Professor at the University of Alabama. They also named Mr. Jack Hammack as co-inventor.  Mr. Hammack was in charge of sales of the product.  They patented their air conditioning additive concept under US Patent 4,963,280 which became known as the Wilkins & Thompson patent.


Though awarded their patent, there were numerous complications with the Wilkins & Thompson technology, including the chemical structure itself which caused the manufacturing process to consistently fail and never achieve the desired results. The product damaged compressors.

Due to the failure of the product and lack of sales the partnership between Wilkins & Thompson dissolved in the early 90’s,  Each party was awarded a third of the patent with the Chief Tribologist and lead chemist, Dr. Charles Thompson, moving to Houston, TX to take the technology in a new direction. In Houston he joined forces with Tony Sgarbi, an industry expert with extensive chemical process manufacturing knowledge and expertise. Mr. Sgarbi built a sophisticated chemical separator and reactor and was able to make the end product (PROA). Mr. Sgarbi then formed the PolarShield Corp.


Mr. Sgarbi is credited as the person who finally developed the sophisticated set of processes that allowed chemicals to bond together and perform as described in the Wilkins & Thompson patent. He also owns the trade secrets to the various manufacturing processes.

Tony Sgarbi is the person who first named the PolarShield product a PROA and trademarked it with the U.S. Patent and Trademark Office (trademark serial: 76158191). Any company claiming to sell a PROA is in direct infringement of this Trademark.

Mr. Sgarbi has diligently worked and perfected his technology. While others try to copy his inventions and learn from his success, he has been able to maintain and develop the best product in the market today.

PROA technology was tested by the Department of Energy (DOE) and approved under the Federal Energy Management Program (FEMP). Since then there have been several companies that have tried to duplicate the PROA product without success. Although Wilkins and Thompson are deceased and the PROA patent is now expired and is public domain, it is of little value without the trade secrets critical to the PROA manufacturing process.

The PROA product performed very well until major changes in the HVAC industry were mandated by Congress in the late 90’s. The new laws required the ozone-depleting refrigerants be replaced with more ozone-friendly refrigerants. This series of actions rendered the PolarShield PROA incompatible and ineffective with HVAC systems to the point that using a PROA in today’s equipment is likely to harm the equipment. 

Knowing his PROA was no longer the answer to solving the HVAC flaw; Tony Sgarbi went back into the lab to totally redesign and perfect his refrigeration performance solution. His efforts resulted in four new patents in 2000 relating to processes and products, This technology is compatible with all of the new types of refrigerants.  Mr. Sgarbi also used this new technology to develop new products compatible with the legacy systems and the older refrigerants that remain in service.  The HVAC industry is still in process of transitioning to the newer refrigerants and synthetic oils. One product alone will not solve the chemical compatibility requirements needed to ensure safe usage across the various equipment in the market today.

With years of experience in this field along with several patents, Sgarbi developed the most advanced and most efficient product yet: CRYOGEN-X4. this latest product line with improved chemical compositions and a broad range of additional performance benefits, is the answer for today's high tech HVAC systems