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Old 04-29-09, 02:07 PM   #39
AC_Hacker
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Default We look under the hood to see what's going on... (continue #2)

Lets take a closer look at the flow of refrigerant...


compressor-to-condenser

...here we see the discharge tube coming from the top of the compressor and down through a 'U-shaped' tube, then splitting into two paths and entering into the condenser coil. I have drawn the directional arrow in RED to indicate that the refrigerant is hot at this point, both because it has been compressed, and because it has picked up heat from the compressor. The U-shaped tube is there partly to help spread out the vibrational stress over a longer distance, to prevent pre-mature failure of the copper tube. The splitting of the refrigerant paths is to raise the efficiency of the condenser coil to expose more high-pressure gas to more air-cooled copper tubing.

At the bottom of the condenser coil, the two refrigerant paths converge into one path and enter the cap tube. I have drawn the directional arrow in MAGENTA to indicate that the trip through the condenser has removed heat from the refrigerant.

Then the refrigerant flows through the cap-tube and then enters the 'suction side' (AKA: low-side) of the refrigeration cycle.


cap-tube-to-evaporator

I have shown the path of the refrigerant through the cap-tube in MAGENTA. I have drawn the circle and arrow in BLUE because this is the point of expansion of the refrigerant, this is where the refrigerant flashes from warmish liquid to very cold gas. When we run the AC unit, we can expect to find frost forming at this point first, and then spread along the tube tward the evaporator tube.

here's another detail of the tubing near the condenser:


to_&_from-condenser

I have drawn the flow arrow to the condenser in BLUE to indicate that it is really cold, and the flow arrow from the condenser in LIGHT BLUE to indicate that some of the cold has been lost, actually heat has been gained.

Also note in the background of this picture, the silver cylinder. This is the starting cap for both the fan and the compressor.

Next is a full shot of the condenser.


condenser_&_temp-sensor

Note the temperature sensor at the bottom of the evaporator coil. It is there to sense the temperature of the exiting room-air and also to sense if the evaporator gets really frosty. It will shut down the AC unit to allow the frost to melt. Then after a few minutes (about 5 minutes) the unit will start up again. If we are clever, we might be able to reuse this sensor for our newly re-purposed machine.

Next photo is looking down next to the top of the compressor and shows the return of the refrigerant to the compressor.


back-to-the-compressor

The refrigerant has lost some of it's cold to (gained some heat from) the room air during it's trip through the evaporator coil, but after it passes through the filter (which also contains desiccant to remove any water that may have been inside at the time of manufacture), and enters the compressor, it is definitely cooler than the compressor. The designers count on this to help keep the compressor cool.

(* to be continued *)
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Last edited by AC_Hacker; 06-07-09 at 03:31 PM..
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