CDX825
filtration nut
Glad to hear its working for you! I was going to dry and experiment with different orifice sizes on my truck but you answered that question.
What are your high and low side pressures running at?
So I have been running a mix of R290 & R600a in my A/C system
- Thread starter FoolhardyIDI
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Glad to hear its working for you! I was going to dry and experiment with different orifice sizes on my truck but you answered that question.
What are your high and low side pressures running at?
FoolhardyIDI
Full Access Member
My high side is at 230-235. Low side at idle 50 and driving around must hit 20 . That is where I adjusted my low pressure clutch cut off switch at. I can feel it turn on and off while driving at freeway speed. This was on a 110 degree day when I tested.
Which recycling machine are you using? I wish I had one, I would have done the same thing too! For my setup, I'm using a Red orifice tube. I did try a variable orifice tube but it didn't work so well, those are made for R-134A which is a heavier refrigerant.
The propane blend is too light for proper VOV action.
On another note, I insulated my 'junk' with that frost king stuff and it does bring the temp down at first, but after a while it gets heat soak.
I'm going to add a second layer and see what happens...
BTW, my blend door actuator (vacuum motor) doesn't work. The motor is fine and I can apply vacuum to the white tube and it holds the vacuum. When the A/C is on recirculation, the hose holds a vacuum but it's not supposed to do that. So I think the white tube got pinched somewhere between the climate control and the actuator... Just what I needed, another trip through the dash...
I'm glad to see other guys experimenting with alternative refrigerants, it is possible to obtain better performance, but the most important thing is to make sure the refrigerant and oil is compatible with each other for long compressor life.
R-12, for instance, is not compatible with PAG oil... Instead Mineral oil is used. Ester oil is compatible with Mineral oil and is recommended for use in retrofits from R-12 to R-134A... Finally, there are two kinds of PAG oil used in today's R-134A systems.
The Pag oil that OEMs use is the cheaper kind and is very hydroscopic, meaning that it goes out of it's way to draw moisture to itself. Double Capped PAG is a better type of PAG. It does not draw moisture into the system. SuperCool sells it and you can also find it at Car Quest.
FoolhardyIDI
Full Access Member
I use only ester oil in my system. RG3000 with a 30lb tank is what I use for recovery. I have 5 30lb recovery tanks. So as not to cross contaminate each refrigerant I clean out the machine and the line after each test.
BR3
Full Access Member
Bill, I'm curious as to what led you to The conclusion that your insulation was heat soaking. That would mean the manufactures rating of r3 I think per layer was false. (Not that i would ever argue against false advertising haha), but for that value to be assigned even in a perfect world, there would need to be a continual insulation factor, at very minumium preventing heat soak of components, much less the insulation itself. Was it just that vent temps rose after an initial cool down? Like I said, I did my conversion all at once, so I can't say the exact amount it helped if any at all, thats why I am curious. I do know that most of these trucks came factory with a form of good old fiberglass insulation on them, as every time I go to the salvage yard I see several with it in tact still. So surely it had some benifit. On a side note, I haven't been able to find direct info on the lack of oil fog capability of propane or the acidification of the sulfur scent. Do you have a reference for that or is it just experiance? I love empirical test data like that for some reason, maybe its the hope that some where someone is actually smarter than me and developed a closed test to come up with this information. Or maybe I'm just too broke to keep testing hahaha
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Cool beans! I just looked at the machine on Amazon. It seems that it's been superseded by the RG3.
Will it work on HC refrigerants? I might get me one and a scale with a 30lb bottle... That's gotta be way easier than venting to atmosphere and then having to go through the arduous procedure of purging the gauge lines each time I screw a can on and keeping track of the amount charged by weight with a gram scale...
I too, want to test the different orifice tubes to find the best one for my application.
My vision is to drive a meat truck, super cold during the hottest part of the summer...
Does your recovery machine also recover the oil and put it back? I don't see how that would work???
BR3, When I drive with the system in vent, it gets 10 to 15 degrees hotter than the ambient temp. That tells me that heat is getting in somewhere. Since the vent gets it's air from the top of the cowl, I suspect that heated air in the engine compartment is blasting against the insulation and saturating the insulation to the point that it also is the same (or close to) as the hot engine compartment air.
It is only R-3, that's really very minimal resistance to the spread of thermal energy. R-3 merely just slows the heat transfer down, but heat transfer is still occurring, know what I mean?
I can tell the difference in homes that are insulated with R-19 vs R-13 and both do a great job with the heat, but now Go in a house with R-30, wow, what a difference! With that stuff, you can open all of the windows at night, let it get down to 75 degrees and shut them just before the sun comes up and it'll stay around 75 degrees all day long. That is, as long as the sun doesn't shine into the house proper...
So, R-3 is not really much of a barrier to heat. It does work, I do get a 10 degree reduction from the usual 35 degree drop (45) that I normally experience. But it did inch back up to the normal drop within a 1/2 hour interstate drive...
So anyway, I will try a double layer and see what happens... If that isn't good enough, then triple layer...
Info on the lack of oil fog capability? I found that somewhere on the internet and saved it but that hard drive died and took it to the grave...
The acidification of the sulfur scent? That I found on the ES website and others. Click this linky to go there.
FoolhardyIDI
Full Access Member
No I have never had any oil recovered by the machine. I know that there are machines that say they can recover the oil in the ac system but I find it hard to believe. When I was younger and did not care, and I would vent R12 and R134a into the air. I would only see a very small amount of oil come out of the system onto the concrete with the R134a but The R12 systems would puke out oil.
BR3
Full Access Member
Right, i can see where on the vent setting it would do that. Guess its just not enough to keep the minimal temperature difference from the outside air staying cool as it cools off the first contact surface of the insulation on puny old r3. And boy do I know the importance of more r's. Did ductwork for a long time and a low r value fails inspection lol. Two layers is definitely a great idea! I think I'm more worried about getting my refrigerant mix right first, but it will come haha.
By the way thanks for the link, I didn't see that in my searches. I'll have to take an in depth look and see how dumb I really am haha. Thanks again!
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By the way thanks for the link, I didn't see that in my searches. I'll have to take an in depth look and see how dumb I really am haha. Thanks again!
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