Decoding the intricacies of vehicle A/C systems & services
where blizzards are common, having a reliable vehicle air conditioning (A/C) system is
essential. The A/C system can either cool the air in the vehicle cabin or generate heat
during the winter months to keep occupants warm and prevent the windows from fogging
for ease of visibility.
As the transportation industry shifts towards e-mobility, and hybrid and electric vehicles
(EVs) become more prevalent, this critical thermal management system will remain a
staple of vehicle engineering. In fact, according to a report from Mordor Intelligence, a
global market intelligence and advisory firm, experts estimate that the automotive A/C
system market landscape is expected to grow from $69.15 billion in 2025 to $94.56 billion
by 2030.
Every part matters
A vehicle’s A/C system operates by alternating the state of the refrigerant between a liquid
and a gas to absorb heat and humidity from the vehicle and deliver cool, dry air.
Alternatively, to produce heat within the car cabin, the refrigerant flow within the A/C unit is reversed.
The system itself is comprised of a multitude of parts to ensure optimal performance and
to regulate the refrigerant composition to evenly distribute hot or cold air into the vehicle.
This includes the compressor, condenser, dryer, metering device and evaporator. Each A/C
system component needs to be working properly to keep the engine cool and remove any
excess moisture from inside the cabin. Here are the respective roles of each A/C system
component:
When the AC system is on “cool” mode:
• Compressor – Mounted to the front of the engine, the compressor pressurizes the
refrigerant into a high-temperature state and circulates it through the system,
starting with the condenser.
• Condenser – Positioned behind the grill of the vehicle, the condenser releases heat
from the refrigerant into the outside air and converts it into a high-pressure liquid.
The cooled liquid refrigerant then moves to the dryer.
• Dryer – Located between the condenser and metering device, the dryer removes
any moisture or contaminants from the refrigerant.
• Metering Device – Also referred to as the expansion valve or orifice tube, the
metering device lowers the refrigerant pressure and temperature significantly, but
the refrigerant is still in a liquid form as it exits the device into the evaporator.
• Evaporator – The blower motor then pushes the cooled air into the cabin,
completing the cycle.
When the A/C system is on “heat” mode:
When the heat is on, the components work together to circulate hot coolant from the
engine through the heater core, which then warms the air blown into the cabin.
• Heater Core – This is the main heat exchanger, where hot coolant from the engine
transfers heat to the air flowing through the core, warming it up.
• Compressor – The compressor is usually not engaged when in heat mode as the
system doesn’t need to actively cool the refrigerant.
• Condenser/Evaporator – While not actively cooling when heating, both the
condenser and evaporator still play a role in dehumidifying the air passing through
it, removing moisture that could fog up the windows.
• Blower Motor – In this final stage, the blower motor pushes air through the system,
including over the heater core, to distribute warm air throughout the cabin.
As with any other component in the vehicle, regular maintenance is key to ensuring long-lasting A/C system productivity. A leak or malfunction due to a clogged drain or dirty air filter can cost vehicle owners hundreds of dollars to replace, and days of vehicle downtime in the shop to repair or install a new system.
Moisture intrusion is the number one cause of premature component failure (especially for the compressor) along with low refrigerant charge. A vehicle’s A/C charge can decrease 8 grams year over year through service ports or rubber hoses. With vehicle ownership exceeding an all-time high average of 12.6 years*, maintaining proper A/C capacity charge is critical, as refrigerant is responsible for circulating the system’s oil to aid in compressor cooling.
Performing a regular A/C system service check with a skilled technician is imperative to identifying and diagnosing any potential issues and keeping the unit in peak operation. This service includes everything from checking for refrigerant leaks and inspecting pivotal components, to cleaning filters, recharging refrigerant levels, and fixing faulty parts.
Today, technicians have the software and equipment to fully automate a comprehensive A/C service repair of recovery, leak test, vacuum and charge with virtually no support needed from the technician. But this wasn’t always the case. Before industrialized machinery came to market, technicians needed to conduct a thorough, time-consuming and often labor-intensive evaluation to perform a successful A/C system repair.
How it all began
Before the advent of recover, recycle, and recharge (RRR) equipment, technicians were required to understand the characteristics of the refrigerant and the dynamics behind the vehicle’s A/C system. This detailed, independently performed analysis involved taking the time to comprehend and verify a customer’s problem, then finding concrete evidence for the prognosis to not only perform the correct repair, but to prevent a comeback due to a servicing misdiagnosis. This tedious process could often take days to complete versus hours.
Thankfully, A/C system services have become much more automated in nature, making the need to understand refrigerant theory and the role of each component within the system nearly obsolete. The introduction of sophisticated A/C service machines enables technicians to recover, recycle, and recharge the refrigerant with minimal effort or underlying investigation, making diagnosis and repairs faster and more reliable.
Industry trends
As a result of new policies put forth by the Environmental Protection Agency (EPA), the industry is witnessing a transition from conventional automotive refrigerants like R134a to more sustainable alternatives such as R1234yf, which have a lower global warming potential.
One such policy is SAE J2843, established to ensure that R1234yf systems are leak-free prior to recharging, both for environmental benefit and to avoid wasting the refrigerant, which isn’t cheap. SAE J2843 also applies to the safety of flammable refrigerants. The other two standards for servicing R1234yf A/C systems are SAE 2851 and SAE J3030; both principles relate to repair methods that ensure the refrigerant isn’t tampered with during a routine service change.
However, due to these EPA standards, any RRR equipment that uses R1234yf must follow a defined process during a service change. As noted above, a key part of the new requirements includes fixing the leak on the vehicle before a recharge to help minimize refrigerant loss to the atmosphere. The downside to this new mandate is that automatic oil injection is no longer an option for any SAE-certified R1234yf machine to reduce the risk of cross-contamination between PAG and POE oils. Additionally, an EPA-compliant R1234yf machine must be able to identify the gas purity, which adds additional cost to the unit and service time. While some see this as an annoyance, it helps to protect the shop’s internal tank of costly refrigerant from contamination. It also ensures that the customer is getting the quality of the R1234yf they are paying for.
Despite frustrations about changes to automotive refrigerants, it’s wise for technicians and shop owners to reassess their offerings to ensure they have the products, equipment and training necessary to properly service vehicles that use R1234yf – now widely recognized as the “future of automotive refrigerants.”
Latest innovations
With the MAHLE ArcticPRO A/C handling systems, technicians no longer have to “babysit” an A/C service. Engineered to recover, recycle and recharge vehicles that are equipped with any R134a or R1234yf refrigerant, every machine is equipped with a clear, bright color touchscreen that offers step-by-step process instructions for the technician. The ArcticPRO A/C units operate fully automatically, allowing the machine to run virtually unattended so technicians have extra time to perform other service duties. An easily visible LED indicator light at the top of the unit comes on during use to indicate status of operation and when the service has been completed. The technician also has the option to view alerts on their cell phone for added convenience via a downloadable app. Each system supports WiFi/Bluetooth capabilities for automatic programming updates and MAHLE technical troubleshooting and support, network printing, and vehicle communication interface connections.
ArcticPRO A/C units are designed with an ergonomic hinged service door in the front of the machine to simplify equipment service and provide easy access to all internal components. The unit’s cabinet door is gas-strut-assisted and can be opened single-handedly, with no bolts or disassembly required, making the time to maintain the unit a fraction over other units on the market.
Select models of the ArcticPRO refrigerant handling systems enable automatic oil injection, UV leak detection, and feature an integrated refrigerant identifier to eliminate the risk of cross-contamination between different compressor oils.
MAHLE also offers customers onsite technical setup and training as well as free lifetime MAHLE technical service support. If a technician experiences a concern with their equipment, tech support can mirror the customer’s machine for “hands off” diagnostics.
Efficient thermal management technology is key to the mobility of today and tomorrow. In addition to state-of-the-art A/C handling systems, MAHLE Lifecycle and Mobility also offers a complete range of A/C thermal management products including compressors, condensers, evaporators and interior blowers.
Customer-driven Mindset
Vehicle manufacturers are also changing the way they engineer their applications, introducing novel automotive air conditioning solutions to enhance passenger comfort and safety while optimizing space utilization and reducing environmental impact.
For example, in January 2024, Ford secured a patent for an innovative “Vehicle Air Vent System” that enables directed airflow towards specific targets, such as overheated drivers requiring thermal comfort. With sustainability becoming a central focus for manufacturers, the integration of sophisticated smart technologies and connectivity features also enables remote monitoring and control of vehicle climate systems, contributing to optimal energy usage. Advanced A/C systems are also being engineered with recycled materials and environmentally friendly refrigerants to align with an eco-focused, customer-driven mindset. To address the unique designs of modern vehicle interiors, particularly EVs, the weight and size of automotive A/C systems are also being significantly reduced to save more space without comprising efficiency.
Training for Today and the Future
It’s evident that the automotive A/C systems landscape is advancing and will continue to play a fundamental role in the way manufacturers design their vehicles. To adapt to the rapid changes occurring within the transportation industry, it’s important for technicians to keep on top of the latest industry trends, products, and repair standards. One way to do this is by attending a training program, such as an EPA609 training and certification, either in-person or online for added convenience. Following the latest service processes and prompts outlined by the A/C service equipment manufacturer will also help technicians improve their service capabilities and increase productivity.
*2025 Auto Care Factbook. AutoCare® Association. https://digital.autocare.org/2025lang/1.
About the Author
Brian Messenger
Head of Product Management, Engineering & Technical Support, MAHLE Service Solutions
Brian Messenger is the Head of Product Management, Engineering & Technical Support for MAHLE Service Solutions.