#6. Chiller. First Launch

November 29, 2019 • ☕️ 5 min read

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First launch of the chiller.

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  • As one man which I really respect says: “Thousands want, hundreds can, and only a few people do”
  • So, let’s do it!
  • Greetings ladies and gents!
  • In this video, we’ll talk about the cooling machine, or the chiller.
  • Initially, I wanted to install a compressor with an electric power of 2.5 kW
  • But then when it came to soldering the chiller, I got serious doubts
  • I have, or rather had, 2 air conditioners
  • So, I decided to make some experiments first
  • On one of the conditioners
  • with the electric power of 750 W
  • For starters and general understanding how it works this should be enough
  • To get some conclusions, on the one hand,
  • on the other hand, we’ll clean the system after soldering
  • Anyway if changing the compressor on the chiller
  • we’ll have to get the freon out of the system
  • You’ll see what we’ve got from the air conditioner
  • Of course, this power won’t be enough for heating the whole house
  • I also had this idea that the next step
  • should be to install two compressors in parallel
  • and see what we’ll get from this
  • It’d be very interesting to do
  • I disassembled the conditioner that hung on my wall
  • the compressor was already “dead” there
  • I used some part from it
  • Here are the remnants of that conditioner, the patient, so to speak
  • And here’s what we’ve got from it
  • I’ll need to fasten the heat exchanger
  • I made some holes for this thing.
  • A couple of words about how it works
  • If we go from the evaporator
  • The steam will go through this pipe
  • It enters the tubular heat exchanger, goes around in a circle
  • then it goes into the filter and compressor
  • Out of the compressor, it goes into the condenser
  • Out of the condenser, the pipe goes through the inspection glass into the heat exchanger
  • Here, the condensed freon cools down and the gaseous freon heats up
  • The evaporator will work at +8 degrees
  • 25 - 8 = 17
  • So, we’ll need to somehow take away 17 degrees
  • They’ll be taken away exactly in this tubular heat exchanger
  • So the compressor will be receiving not +8, but +25 degrees for the input. In the ideal case.
  • Out of this heat exchanger comes already condensed liquid phase of freon through a capillary tube
  • Which remained from original air conditioner
  • And here it’ll be connected to the evaporator. I’ll show you that later
  • Cats are really helpful here
  • Here they are, two pipes
  • The gas will go in through the upper pipe
  • The liquid phase will return along the thin bottom one
  • Everything is ready for the evacuation
  • Now I understand why the vacuum was weak last time
  • The oil level was low
  • And that’s why it didn’t pump so good
  • Yesterday it was evacuating for 20-25 minutes. Today it’s 25 minutes
  • We can see the result on the left pressure gauge
  • I did a freon blowing several times, the same as with heat pipes
  • I was closing the low pressure, let out some freon and then pumped it out
  • In that way I replaced the air leftovers with freon and then pumped out
  • Why do we need such a long evacuation?
  • In order to evaporate moisture. The same process happens that I talked about
  • Water begins to boil at low temperatures
  • The task of evacuation is to get rid of moisture in the system
  • I think it’s time to stop and refuel.
  • I use the original condenser
  • It’s connected directly, without any blocks to the compressor
  • The compressor is “spinning” right now
  • Theoretically, it should evacuate the gas phase from this cylinder
  • Now it’s open
  • The red valve is open, the blue one - closed
  • We’ll see. Maybe I’m doing something wrong…
  • To speed up the process, I put R22 in a cup of warm water, so that it evaporates better
  • I see that the pressure has risen
  • We also see a liquid phase in a control window
  • The condenser has warmed up. I can barely hold it. I think it’s time to connect the heating system.
  • Next, I’ll need to refuel it. Otherwise, I’m afraid that the compressor will overheat.
  • Then I heard a strange hissing. Everything seemed fine before.
  • Looks like leakage from under the thread
  • Looks like it’s this part
  • of the capillary tube was cooled to a negative temperature
  • We’ve seen frost right here
  • So, it cooled down
  • I turned off the system
  • And when it heated up again - it started to leak
  • Or I didn’t tight the nut enough
  • Now I’ve made a bigger flange for the nut and tighten it better
  • What should I do in this situation? Should I let out the freon completely
  • and evacuate the system again
  • But I want to try something different
  • It depressurized at the exit, and there is a back valve in the compressor
  • and if we’ll evacuate here
  • then this part of the system will not evacuate until we open both valves
  • I closed both valves for now. The lower and the upper one.
  • I don’t want to completely let out all the freon. Quite a lot of it was * pumped in already
  • About 300 grams.
  • I want to try the following:
  • I’ll slightly open up the top valve,
  • And it’ll start to push out the gas
  • It couldn’t let in much through the capillary
  • Then I’ll pump the system with freon
  • Slightly open this valve to let out
  • the remaining air
  • So, that’s my plan of actions
  • Of course I can freak something up
  • It’s only an experiment after all
  • So what have we got here. The system in its current state doesn’t work right.
  • Because the outlet pipe freezes after the capillary tube
  • The temperature reaches somewhere about -14, -15 degrees. It’s not good
  • Why is this happening? This is due to the fact that the throughput is * not regulated
  • Operating conditions have changed
  • The amount of freon, the volume of evaporators, condensers has changed
  • The system has changed completely
  • In stationary conditions, the capillary tube is selected for a specific air conditioner and everything works quite well
  • If no freon leak occurred or some other failure
  • In my case, I need to adjust it to the system
  • Or pick up a suitable capillary tube
  • Which is a real headache. Each time it needs to be changed, lengthened, shortened
  • It probably can be solved somehow
  • The second option is to install a thermostatic valve.
  • Which is what I’m actually leaning towards