I'm sorry greg, you are mistaken on several points here.
The compressor builds pressure, but the load on the system will massively affect the compressor.
If you don't start with a clean condenser, cleaning JUST the evaporator will fry the compressor. It will impart more perssure, and heat into the system.
Sure, if the same heat is extracted from a closed system over a long period versus a short period it can stress via excess runtime... but that doesn't happen in a car refrigeration system. Load is constantly incoming. So, a clean evap will put more load on the compressor. More heat, and more pressure. That's stress. With a weak condenser the heat and pressures rise, and equipment fails. Start with a clean and straight condenser. Finish with a clean evaporator and enjoy a well working ac system.
Feel free to ask for clarification on any point here... but it's simple physics and thermodynamics. ..
Quote:
Originally Posted by leathermang
""Concentrating first on the condensor fins needing cleaning and straightening is a low percentage approach on these old cars.... they do need to be clean.... but what gets neglected is the EVaporator fins.... a miserable job to accomplish....and hidden from view so that it gets neglected completely for DECADES.....
The evaporator fins being blocked also works the compressor harder""-leathermang
I objected to the impression given by your use of the word 'stress' ... you have since changed to the word ' load' ...
The idea that cleaning the evaporator fins causes more stress on the system is wrong on several levels.... the LOAD when the evaporator is clean IS the load the system is DESIGNED FOR....
Our compressors basically put out a certain amount of pressure when they are running... the amount of pressure in the system is Controlled by turning the compressor on and off. Our systems are ' cycling compressors' ...
So if you look at a set temperature inside the car (constant heat load )... and you do what is necessary to the blower fan to keep that temperature.....
Then what happens with a factor such as impaired air flow across the evaporator is that the Compressor works longer per unit of time compared to the system fins being clean. Running the compressor relatively longer over the long haul is STRESS.....
So cleaning the evaporator does not cause STRESS....it only allows the compressor to work at its designed load and for the designed percentage of time to produce the desired results..
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