Eliminating oil fouling that occurs in air conditioning and refrigeration systems should be a priority in maintenance.
by ACR Latin America
In different editions of ACR, we have talked a lot about innovative air conditioning and refrigeration systems and their main characteristics, but now we consider it appropriate to highlight that this class of equipment requires different maintenance so that its operation is always efficient.
Therefore, one of the problems suffered by this class of equipment is known as oil fouling, because the compressors work with this type of lubricant to work properly. However, oil is a compound that accumulates and generates problems in the efficiency of the equipment, so there are alternatives to eliminate these accumulations and allow the systems to continue working correctly.
In this case we will talk about a technology developed by the American brothers Dale & Larrel Willis, who through their company Solid Start, specialized in products for the automotive sector, work on the patent process of a solution for the air conditioning and refrigeration industry which, they say, eliminates the problem of oil fouling.
ACR Latin America: What is oil fouling and what are the reasons for it to occur in HVAC/R systems?
Willis Brothers: Most HVAC/R systems have a mechanical compressor that relies on lubricating oil for operation. During the normal course of the refrigeration process, between 1/2% and 8% of the compressor lubricating oil circulates throughout the system, accompanying the refrigerant. ASHRAE recognizes that oil fouling arises because compressor oil accumulates on the metal walls of the cooling pipe reducing heat transfer between the refrigerant and the pipe walls.
ACR: What kind of inconvenience does oil fouling generate in the equipment?
Willis Brothers: Oil fouling on heat transfer surfaces will result in a loss of efficiency in the air conditioning or refrigeration system. This loss is about 7% in the first width, 5% additional in the Second and 2% additional for each subsequent width. This loss will continue to accumulate until a balance is reached between flow force and adhesion (surface tension). At this point, the oil layer has reached its maximum thickness, producing the maximum loss of efficiency. Usually, efficiency degradation will peak somewhere between 20% and 30%. The information published by ASHRAE confirms these observations. The yield is degraded by up to 30% due to the accumulation of oil on the internal surfaces. Higher percentages have been observed reaching up to 40% in systems with 20 years of age or older.
ACR: What kind of solutions exist to prevent the phenomenon of oil fouling from occurring?
Willis Brothers: The loss of efficiency in heat transfer can be solved by a synthetic additive compound for refrigerants that is non-invasive, which can release overcome and release surface tension forces. It is the Van Der Waals forces that cause the oil globules to adhere to each other and subsequently to the walls of the tubes through which the coolant passes creating oil fouling. Cold Plus is an additive that can overcome surface tension by adhering firmly to metal surfaces creating a layer of PTFE (Teflon) to prevent the recurrence of oil fouling on surfaces for heat transfer.
ACR: What is Cold Plus technology? How is it made?
Willis Brothers: Cold Plus is a product called second generation since it not only cleans the inner part of the pipes to peel off the layer of oil that has been created but also creates a PTFE (Teflon) film that permanently eliminates the problem of oil fouling, as the oil particles will now slip over the Teflon and will not be able to re-adhere to the pipe walls. The Cold Plus is manufactured in Lakeland Florida, in very modern facilities along with the portfolio of products used in the automotive part. In the manufacturing process a strict quality control is maintained to ensure that the product meets all its specifications.
ACR: What proven results has this technology had in the projects where you have participated?
Willis Brothers: The Cold Plus has been tested in the United States, Canada, Chile and other parts of the world in all kinds of applications. From data centers, supermarkets, hotels, industries, residences, refrigerated transport, shopping centers and residences. We have case studies that prove the effectiveness of the solution. In some installations energy savings between 10% and 30% have been achieved, it depends on the installation time of the equipment and the maintenance that has been given to it. Using Cold Plus decreases the starting current of the compressor and even the normal working current which leads to prolong the life of the compressors and the corresponding energy savings.
ACR: What kind of knowledge must the specialist technician have to be able to use this technology correctly?
Willis Brothers: The application of the Cold Plus is very simple since it is injected through the suction port of the system. The recommendation is to do it with a certified HVAC/R technician. We also have demo videos that teach step by step the correct way to make the injection.
Outstanding
Solid Start Quick Story
The Willis brothers (Dale & Larrel) began developing products for the automotive industry in 1976, mainly for competition cars, automobiles and heavy industry. Numerous supplements and additives for engines have been developed. Annual sales exceed US$80 million, with a strategic R&D department and a large number of patents owned by the company. Solid Start products have been used in more than 100 countries around the world. Cold Plus was invented in solid star's laboratories and is awaiting patent approval.
