Aftermarket May 2022

44 AFTERMARKET MAY 2022 AIR CONDITIONING www.aftermarketonline.net each year. Given that the average age of vehicles in the UK car parc is 8.6 years, the majority will still require ‘old gas’, meaning an availability crunch could be on the horizon. ”One potential solution is the so-called ‘drop-in’ gas R- 456a. Compared to R-134a, its global warming potential (GWP) is around half, and trials have shown it to be compatible with existing R-134a systems. We would recommend technicians keep their ear to the ground – as R-134a reserves dwindle, something will need to fill the gap it leaves behind, and it’s likely R-456a will emerge as the answer.” Bob added: “We would always recommend conducting air con checks as standard whenever a customer brings in their vehicle for a service. Even minor tweaks to the system will deliver noticeable improvements in comfort, as well as enhancing the long-term health and performance of the vehicle.” https://omnipart.eurocarparts.com Condenser focus Focusing on the air conditioning condenser, Nissens Marketing Manager Jan Zieleskiewicz said: “A faulty condenser, even if it is still partially working, can lead to severe A/C problems and sometimes result in damage to, or even seizure of, the compressor. Compressors are costly and replacing one will take the vehicle off the road as the rest of the A/C system will need to be examined and flushed, and the oil/gas refrigerant mixture replaced. “The condenser is typically attached to other heat exchangers in the engine compartment and its role is to ensure that the state of the refrigerant changes from gas to liquid, which happens through condensation. The airflow through the condenser’s fins enables this process by extracting the refrigerant heat and exchanging it with the ambient air.” With regards to what can go wrong, Jan commented: “Mechanical damage is often ruled out as a reason for reduced system performance or compressor failure because leakages and surface perforations are generally considered the most common causes. However, even light mechanical deformation of the condenser tubes and fins can result in severe system performance limitations.” On corrosion, Jan said: “As one of the A/C components placed closest to the elements, the condenser is exposed to harsh conditions, especially in climates subject to heavy rain, snow and humidity, where condensers exposed to salt spray are at increased risk of corrosion. Even if the condenser doesn’t leak and seems tight, as corrosion attaches to the thin aluminium fins, the working surface area is reduced, consequently reducing the condenser’s overall heat exchange capacity. Deterioration of only one fin row from the condenser can reduce its thermal performance by up to 5%.” Then there are blockages: “When impurities develop in the system,” observed Jan, “the thin channels of the condenser will quickly clog. This can restrict the refrigerant flow, eventually reducing the unit’s ability to exchange heat. In most cases, this will subsequently cause overpressure in the system, which is very harmful to the compressor. Condensers with micro and nanotube technology are at significant risk because, while micro tube technology offers outstanding cooling performance, the thin tubes are more prone to blockages. As the flow is restricted to a more confined area, less impurities are needed for a blockage to occur. Among the main causes of blockages are improper system flushing, degraded lubricant and too much additive in the A/C system. Impaired function of the loop’s receiver drier is another common culprit.” High performance requirements Meanwhile. MAHLE Aftermarket is expanding its portfolio to include indirect air conditioning condensers, which are fast becoming standard kit for modern vehicles. “By continuously extending its thermal management product range, MAHLE Aftermarket is making it easier for workshops to generate new business,” said Olaf Henning, Corporate Executive Vice President and General Manager MAHLE Aftermarket. Looking further ahead, thermal management system maintenance on EVs and hybrids is set to supersede the oil change as standard practice for garages. Olaf observed: “In an electric vehicle, the air conditioning system takes care of the cabin, and also cools the battery, electric motor, and power electronics. Accordingly, the system must be designed to meet high performance requirements and needs several circuits at different temperature levels. In the future, the maintenance and repair of such systems will constitute a major part of everyday business for workshops. The company is thus preparing workshops for the future and helping them with the switch to alternative drive systems. We recommend that our customers build up their skills in this area.” Design, function, repair, and maintenance On the different systems technicians now face, Olaf commented: “Indirect condensers, which cool down and thereby liquefy the refrigerant that has become heated during compression in the compressor, are already used in many modern vehicles with combustion engines and also represent the best technical option for hybrid and electric vehicles. They are more efficient, powerful, and compact than directly cooled condensers and can also be placed anywhere in the vehicle. Directly cooled models, on the other hand, must be installed at the front of the vehicle in order to make use of the ambient air.” Olaf continued: “MAHLE Aftermarket provides information on the design, function, repair, and maintenance of thermal management systems in its TechTool online database. This gives detailed insights into automotive air conditioning and engine cooling in passenger cars and commercial vehicles. For workshops requiring specific training for their employees, MAHLE also offers in-depth courses.” Olaf added: “Through MAHLE, workshops have the option of upgrading the air conditioning service units with the Left: Nissens corrosion protection label