maintain the cleanliness of microchannel coils

  • A clean air conditioning or refrigeration coil is essential for proper heat exchange in any type of air conditioning or refrigeration system, and microchannel coils are no different. As a result, multi port tube are becoming more and more popular in the industrial sector. In some cases, the cleaning procedures for microchannel coils are different from the cleaning procedures for standard fin and tube coils. Technicians should be aware of this when performing cleaning procedures for microchannel coils. They should be aware of and prepared for these variations.

    Microchannel condenser coils, as opposed to conventional condenser coils, are made of aluminum or stainless steel. In contrast to conventional condenser coils, they are composed of a series of flat tubes with small channels (aluminium micro channel tube) through which the refrigerant flows. It is possible to achieve the most efficient heat transfer possible by incorporating angled and louvered fins between the flat tubes of the radiator. It is hoped that the new tube-and-fin coils will be lighter and more durable than conventional tube-and-fin coils, as well as provide better heat transfer while using less refrigerant than their predecessors. The new coils will also be smaller and lighter than their predecessors. They also use less refrigerant, which results in cost savings.

    Mike Heidenreich, vice president of product engineering for the Luvata HTS (Heat Transfer Solutions Division), explains that when compared to conventional plate fin-and-tube heat exchangers (PFTU), micro channel tube accumulate more dirt on the coil's face and less dirt inside the fin pack, which results in an overall more sanitary environment. Unlike conventional plate fin-and-tube heat exchangers, multi port tube are typically thinner in depth than their counterparts. As a result, they can operate at higher temperatures. It is necessary to take into consideration the differences in their construction in order to properly clean them.

    Before any work can be done on an electrical piece of equipment that needs to be serviced, the power supply must be disconnected from the equipment. Personal protective equipment (such as safety glasses, gloves, and other similar items) must also be worn when working with chemicals because of the potential for chemical burns.

    Use a vacuum cleaner to remove any surface debris from the carpet (preferably one that has a brush or other soft attachment rather than a metal tube) in order to prevent further damage from occurring to the carpet. Third, thoroughly vacuum the carpeting to remove any remaining debris. Remove heavier particles from the machine's interior by blowing them out with compressed air. For the removal of heavier particles from the surface of the water, it is preferable to use a nonmetallic soft-bristle brush rather than a metal brush whenever possible. It is not permitted to use the vacuum tube or the air nozzle to impact or scrape the coil under any circumstances.

    As a result of the potential for corrosion in microchannel heat exchangers caused by chemicals (including those marketed as coil cleaners), it is not recommended that these chemicals be used for cleaning purposes. Wash your hands thoroughly with soap and water after the third step. There should be no motion other than a rinsing motion when washing your hands. The heat exchanger should be taken out of service and gently rinsed with water, preferably from the inside out and from top to bottom, with water passing through each fin passage several times until the water is completely clear of contaminants.

    Although microchannel fins are more durable than traditional tube-and-fin coil fins, Heidenreich cautions that, due to their small size, they should still be handled with care due to their fragility. Please make certain that the hose does not come into direct contact with the coil! It is also recommended to use your thumb to cover the hose end rather than the nozzle end when using a hose. There is less impact damage caused by this method because it produces a softer spray. It is also more convenient than the previous method. The use of a pressure washer to clean a microchannel heat exchanger, according to Heidenreich, is possible; however, as with any coil-finned surface, extra caution should be exercised because it is possible to irreparably damage the coil. Other suggestions from the author include using a wide-angle spray nozzle rather than a pencil nozzle and spraying the coil only at 90 degrees to the coil face. It is recommended that you use the nozzle at a distance of at least 24 inches from the face of the coil. By gently sweeping your hand back and forth, you can ensure that the 90-degree angle is maintained at all times.

    When it comes to microchannel heat exchangers, blow drying is an optional step. This is because the fin geometry of the exchangers encourages water to accumulate within the channels. According to the design and installation of the coil in question, blowing or vacuuming out the rinse water from the unit to accelerate drying may be advantageous.

    In the manual, it is stated that any type of chemical cleaner or detergent should only be used on  in the most extreme of circumstances. A cleaner with a pH of eight or lower on the pH scale and one that does not contain any hydrofluoric acid should be specified, as water alone has been shown to be ineffective at cleaning the coils. After a thorough cleaning of the coil with water alone has failed, it is recommended that a cleaner with an acidity of eight or lower on the pH scale and that does not contain any hydrofluoric acid be specified.

    When using any cleaner, consumers are advised to always read and follow the manufacturer's instructions before getting started, according to the bulletin. Even if the cleaner's instruction manual specifies that the coils do not need to be rinsed, it is necessary to thoroughly rinse the coils after they have been treated with the cleaner to ensure that the cleaner does not leave any residue. When cleaners or detergents are incorrectly rinsed and remain on the coil, they greatly increase the likelihood of corrosion damage to the microchannel coil.