Uploaded March 2018 | Updated September 2026, 2 weeks ago
All I ask is that you read the video description before you comment. Please don't make me ask you to do that. Most of you have been here long enough to know how the game is played.
What you're looking at for the first five and half minutes of video is a refrigeration system I put together as one of many "workplace simulation projects". When I first started the program, there were several training units made from refrigeration decks and evaporator coils same as the ones you see in this video. Along with the program itself, these had fallen into a state of disarray. None of them worked properly.
The original "trainer" units these were a part of used a thermostatic expansion valve, or TXV, for their metering device. As far as anyone could tell, the sensing bulbs for these had lost their charge, and they were intended for R-12 rather than the R-134a these had been crudely retrofitted to use. The instructor and another student tried installing a capillary tube metering device at that time, but performance was no better. So all of these were scrapped and replaced with modified window air conditioners.
After they sat around for several months without being hauled away, I rescued all the compressors and a few of the evaporator assemblies from the scrap heap, thinking that I'd use the compressors as vacuum pumps and not really knowing what I'd do with the evaporators. The compressors all ran when I brought them home, though they wouldn't start without help after they'd been sitting open to the elements for a while. I think this had something to do with flash rusting of the cylinder walls. That's why I added the start capacitor, which was all it took.
The system I put together works well. I have yet to build a proper box for it. It'll pull the interior of a cardboard box with lots of air leaks down to about 40°F, which isn't bad at all. Superheat and subcooling are both well within spec.
The dorm fridge is explained in the video. I recovered the contaminated refrigerant charge, pulled and broke a vacuum on it with dry nitrogen several times to clean up the system as best I could (it was the only means I had available), removed the old compressor, installed the "new" one, added the service fitting on the process tube and finished up by pulling the unit into a deep vacuum. (Yes, I know I called it the "suction side" in the video, which for most intents and purposes it is.) I then weighed the correct amount of refrigerant into it. We have charging cylinders in the lab for this job, but they are all broken down and unusable.
Constructive criticism is always welcome. However, bear in mind that all of these are learning exercises and they they *do* work reliably. Don't be a dick, because that's all you will be proving to the world and I won't put up with it.
Oh, and don't complain about the standard definition video either.
The new Youtube "design" is utterly awful, especially on slower computers like netbooks.
All I ask is that you read the video description before you comment. Please don't make me ask you to do that. Most of you have been here long enough to know how the game is played.
What you're looking at for the first five and half minutes of video is a refrigeration system I put together as one of many "workplace simulation projects". When I first started the program, there were several training units made from refrigeration decks and evaporator coils same as the ones you see in this video. Along with the program itself, these had fallen into a state of disarray. None of them worked properly.
The original "trainer" units these were a part of used a thermostatic expansion valve, or TXV, for their metering device. As far as anyone could tell, the sensing bulbs for these had lost their charge, and they were intended for R-12 rather than the R-134a these had been crudely retrofitted to use. The instructor and another student tried installing a capillary tube metering device at that time, but performance was no better. So all of these were scrapped and replaced with modified window air conditioners.
After they sat around for several months without being hauled away, I rescued all the compressors and a few of the evaporator assemblies from the scrap heap, thinking that I'd use the compressors as vacuum pumps and not really knowing what I'd do with the evaporators. The compressors all ran when I brought them home, though they wouldn't start without help after they'd been sitting open to the elements for a while. I think this had something to do with flash rusting of the cylinder walls. That's why I added the start capacitor, which was all it took.
The system I put together works well. I have yet to build a proper box for it. It'll pull the interior of a cardboard box with lots of air leaks down to about 40°F, which isn't bad at all. Superheat and subcooling are both well within spec.
The dorm fridge is explained in the video. I recovered the contaminated refrigerant charge, pulled and broke a vacuum on it with dry nitrogen several times to clean up the system as best I could (it was the only means I had available), removed the old compressor, installed the "new" one, added the service fitting on the process tube and finished up by pulling the unit into a deep vacuum. (Yes, I know I called it the "suction side" in the video, which for most intents and purposes it is.) I then weighed the correct amount of refrigerant into it. We have charging cylinders in the lab for this job, but they are all broken down and unusable.
Constructive criticism is always welcome. However, bear in mind that all of these are learning exercises and they they *do* work reliably. Don't be a dick, because that's all you will be proving to the world and I won't put up with it.
Oh, and don't complain about the standard definition video either.
The new Youtube "design" is utterly awful, especially on slower computers like netbooks.
