What is a Condenser?

What is a Tube and Fin Condenser compared to Flat tube Serpentine? Click here

The air conditioning condenser is a heat exchanger.

Located in front of the vehicle, right in front of the radiator, this part receives high-pressure, hot refrigerant from the compressor. Refrigerant flows through the condenser and cools off from either the wind when driving this is called 'Ram Air", or air blowing from electric cooling fans or the fan clutch at low speeds and idle.

Older cars condensers were built using a serpentine design, they have one long tube that folded back and forth, with just a single path for the refrigerant to flow through.

Newer designs are called parallel flow, and have many tubes stacked horizontally, connected to a vertical tube at each end. Refrigerant can travel many different paths through a parallel flow condenser.

An example of each condenser type is pictured below.


Parallel flow condensers are much more efficient than serpentine condensers. The problem is, when a parallel flow unit gets trash in it, called 'restricted', it is impossible to clean. The passageways through a condenser are very small as small as 6mm in diameter, and debris can really get wedged in there. Flushing has no effect, because the flush simply goes around the restriction.

Remember, the refrigerant entering the condenser is at a very high pressure. A small restriction, inoperative cooling fans, faulty fan clutch, or poor airflow across the condenser can prevent the refrigerant from cooling down as much as it needs to. This will result in at least warmer air, at at most excessive back-pressure to the compressor, which will damage the compressor.

To perform a test to determine if there is a problem in the condenser, the temperature at the inlet and outlet of the condenser can be measured, with the A/C on MAX, all doors and windows open. The difference from inlet to outlet should be 20 to 40 degrees. Less than 20 degrees usually indicates an airflow problem; either the fan(s) is not working, the front of the condenser is blocked with road debris, etc... something like that. If the difference is greater than 40 or 50 degrees, there is a restriction in the condenser.

Auto Air Authority has a great selection of A/C condensers for most vehicles.