Phase Change

[bigben2k]

I agree with your assesment: replace the dryer, and get the right cap tube.

Someone double check what I just wrote here, please? (Bowman?)

[|PuNiSh3R|]

The refrigerant I have been talking about.. R-404B.. That's a typo.. It's R-406A..

it can be purchased here
http://www.autofrost.com/frmain.html

provided you have a green card.

[ssjwizard]

yea pun i belive that adding a bit of freon into your system will help stabalist the temps. i think that you should try to get some new cap tubing and add a little length to it if your still using the cap from that 1/20 compressor of yours its probably to wide.

[SonixOS]

NONONONO. When i said direct phase change cooling. I ment is still keep the water and everything, just take out the peltier and pump water through the water pump. THe water will still be cooled by the evaporator.

BTW Pun- Compressors do turn off after a certain period and they turn back on again. I think its because of built in Thermal Protection.

[bigben2k]

Originally posted by SonixOS
BTW Pun- Compressors do turn off after a certain period and they turn back on again. I think its because of built in Thermal Protection.

Uh oh... here we go again...:shrug:

[bowman1964]

|PuNiSh3R| i am not positive but your problem with the up and down temps is proberly the condensor.a dd cube as you are using if my memory serves me right doent have the tubes properly running to use in refridgeration system.you see if the freon when cooled at the the first part of the condensor starts to liqiidfiy it will collect in the low spots in the tube bends.and i have found that is shows signs of the pressure running erractic up and down and temp movement.now this is caused by say your system is running fine and is cooling lets say at -20.now after a few minutes the freon starts to make it all the way around the system evenly.but it starts to puddle in a low spot in the condensor.which after a while will run the evaporator out of freon or stops the steady flow of liqiud to the calpillary tube.now when this happens all of a sudden there is no freon boiling off in the evap.this causes the low pressure to drop because now the compressor is sucking harder and there is no boil off to offset the hard vaccum.so temps go up suddenly.now after a short time enough freon makes it back to the condensor to push the rest out of the low spot in the condensor and the cooling starts again.

now you can check this by moving the condensor while the system is running and watch the temps.and see if i am right.
now you can add more freon to offset the low spot in the condersor but it will raise the low side pressure causing your temps to rise.
so i hope this helps..i might me wrong about the dd cube if so i am sorry but been a while since i saw one.in my hands

[|PuNiSh3R|]

Sonix.. that's because it over heats... if you have the proper amount of oil in the compressor that won't happen so fast. Although you are putting quite a bit of load on the compressor.. so it's wise to put a fan blowing on it.. this will keep it cool enough to stop that thermal protection shut down. My compressor was over 150F last night.. so it's not uncommon to have a really hot compressor.. nothing in their but metal anyway..

Thanks, bowman.. someone else I know is saying that it's the DD cube as well.. It worked fine though in my 1/20hp compressor system.. which is what I find odd that it doesn't work now..

Adding more freon last night didn't do a thing.. The psi on the high side just kept going up and up.. same on the low side..

I have a feeling I know how to help the condensor issue..

I figure if it's cooling the vapor and it is changing over to a liquid to fast.. I could replace the 120mm fan with a smaller fan.. less CFM.. less cooling.. maybe.. I don't think that's the problem though.. even my dryer is about 10F above ambient.. which isn't right.. My friend think I am getting vapor in the evap because the DD cube isn't changing the vapor over to liquid properly.. this is a possibility.. I am going to try a few things today.. possibly vac the system out.. I have a good feeling I got air in the system .. Last night after I put oil in I didn't vac the system out.. I know I got some air in it..

If I vac it.. it still doesn't work.. I'll change the condensor.. if that still doesn't do it.. I'll change the dryer/cap tube.. if that doesn't do it.. then this is just a crap compressor.. which would explain why the refrigerator i got it out of was in the garbage

[SonixOS]

I can touch the compressor. Hence, the temperature is not beyond 100C. It sez on the label it can get as hot as 150C. But i doubt it really went that high.

[|PuNiSh3R|]

ARGH! I am having such a bitch time trying to fill from my tank of propane..

My compressor won't suck it in or something.. I mean.. I hear gas going from the tank to the system.. but the PSI's dont' go up and the temp don't fall.. I tried several times.. trying to get a vacuum etc etc.. to pull the gas in.. nothing.. at first it goes in good.. then it doesn't

I have a regulator valve on my tank.. cuz it's really for our BBQ grill.. I think it would work better with out that regulator valve.. But now I have to try and .. uh.. "jerry" rig some fittings..

[bigben2k]

Yeah, that regulator is stopping you. It prevents the output pressure from getting up there. It's probably set very low.

You're going to have to pump that propane in your rig, if you can't remove the pressure regulator. Not a pretty prospect!

[|PuNiSh3R|]

The propane regulator is something my pops put on the tank.. I just unscrewed it.. it's like a little round disc ..

Anyway the reason why I didn't take it off before is because I was having trouble finding fittings to go on the piece that the regulator screwed into.. well I got a reducer that fit.. and now things are good.. I am blasting propane out at super high PSI's

I vac'd my system.. filled it with straight propane.. HOT DAMN! THIS SHIT WORKS!!

So far I've seen -13F.. that didn't last long though.. temp rose.. I ain't getting that crap like before.. where the temp would drop.. then rise.. then drop.. it's staying well below 20F this time.. It seems that the propane likes a high highside pressure.. of around 200 to 210PSI.. and the low side around 5PSI to 10PSI.. although if your compressor was strong enough to put the system in a vacuum with that high of a highside.. then the propane would work even better.. cuz vacuum is good

I filled that sucker up good.. letting it sit now for like 10 minutes.. so the temps will even out and what not... Then I will add more or release some.. whatever needs to be done.. this is a 25gallon tank I am using.. I think.. costs 10 dollars to fill it up.. I used 3 cans of 134a last night.. each can is 12oz.. cost me 3.50 a can! WHAT A WASTE! PROPANE OWNZ J00!

I was really afraid at first.. to screw around with propane.. hot temps.. etc.. but I got over it.. and did it..

My whole condensor is hot now.. even the very last pipes are warm.. The dryer is around 90-100F.. I believe that the dryer should be cool.. but.. the system seems to be working fine even though..

Time to roll

Oh, the only down-fall to using propane is there is a chance of having a small amount of air in the tank.. As far as I know they don't vacuum your regular residential tanks before filling them.. but oh well.. still works fine.. as long as you don't have moisture in your system it's all good.. plus.. the propane smells like ASS..

[bigben2k]

Originally posted by |PuNiSh3R|
I was really afraid at first.. to screw around with propane..

Well if you suddenly quit posting one day, we'll know what happened to you!

Nice work!

[|PuNiSh3R|]

MUWAHAH! trust me.. you'll hear the bang.. see the smoke.. and hear it on the news lol

[bowman1964]

FUNNY GUY JUST BOOM AND WE ALL KNEW YOU WELL LOL.YOU ARE SAFE UNLESS YOU GET A SHORT INSIDE THE COMPERSSOR.HIGHLY UNLIKELY.HEY TRY A LITTLE 134A TO THE PROPANE I HAVE HEARD IT WILL REALLY BRING DOWN THE TEMPS.JUST A SMALL AMOUNT.
KEEP US POSTED

[|PuNiSh3R|]

Bowman.. I've heard that as well..

I plan to do it .. just to make the propane molecules a bit heavier (which is probably why the temp goes down) and also to help cure some of propanes insane flammability

My PSI was at 225 ish on the high side and jumping aroune 12PSI and 8PSI on the low side.. The temp was around 5F.. that is to high.. my compressor on the top is 180F.. the condensor is equally hot.. just the high side line going to the condensor.. it is seriously hot.. i accidently brushed it with my finger,.. i got burned!
I let some of the propane out.. the high side PSi went down to around 200.. 210.. the temps started to fall.. last I saw I was at -12F.. and around 5-10PSI on the low side..

[|PuNiSh3R|]

I dropped out some more propane.. got the PSI's down around 160 on the high.. Temps really started to go up so I put in a tiny tiny bit of propane.. Then the temps went down again.. now they were creeping up a bit again so I put in a really really small amount again.. and back down they went.. the PSI didn't change..

[ssjwizard]

hey punisher how much did your guages cost you??? just wondering ive seen them online and the price was rather high but i found a pretty nice deal on a set here im getting the tomarrow.

[|PuNiSh3R|]

check ebay and what not.. I have no clue.. my dad had them from when he was going through basic HVAC classes.. He also had the pump... he got it like.. 20 years ago I think.. cost him 250.00.. it's a Robinaire.. It's a very nice.. powerful pump.

[ssjwizard]

i c... yea the set im getting were alot like the 200 dollar set on that website you linked me to im geting them for 30 dollars.

[|PuNiSh3R|]

yea you can pick the gauges up at auto zone for 30 bux

[bowman1964]

ok guy maybe i should tell everyone not all ac gauges are the same.now there are two different types basic ...alll you guy will see...r134 and r12/22.never buy the r134 set unless you are prepared to buy adapers and all.the r12/22 gauges have the proper markings for what we are doing and have std 1/4" jic flare fitting on the hoses to connect to the scrarder core.the r134 set will have quick connect fitting on the hoses for automobles.

and please read the instuctions carefully guys if you hock them up wrong one time you have runed them completly.
|PuNiSh3R i know you have allready been shown by your dad so you know how, but alot of these guy know nothing about ac gauges.we can help them out. now your dad has in my opinion one of the best brands you can have so feel glad he let you use them.
so everyone beware not all gauges are the same.

[|PuNiSh3R|]

Actually bowman.. you are wrong.. my dad hardly knew anything about it.. It has been a good 20 years since he's did refrigeration.. And he mainly did cars.. like his own car AC and stuff.. took it apart.. rebuilt it.. etc.. So he has pretty much forgot everything.. We are talking about doing the AC in our ford taurus wagon.. which we nick named The Boat.. it's a POS.. ANyway the R-12 leaked out.. so he wants to work with me on getting the system filled with 134a or maybe R-406B if I get my green card..

He even set the hoses up wrong.. like putting the little needle valve push that is in the one end of the hose on the gauge instead of on the shrader valve.. etc.. heh.. He showed me the very basics.. I learned all of it by myself.. I haven't even read 1 refrigeration book heh..

But you are right about the gauges.. I should of clarified that.. THe ones you will buy at auto zone .. etc.. will all be 134a gauges.. Just stay away from 134a completely.. it's horrible... You all remember the problems I was having last night?

Since I have filled with propane today I have had NO problems at all.. I am seeing temps below -34F.. and they fall.. and they stay there.. not like last night.. bobbling back and forth.. propane is a really good refrigerant.. it's a mans refrigerant.. R-134a is for girls...

Be aware though.. PROPANE IS FLAMMABLE AND VERY MUCH SO EXPLOSIVE!

My compressor has been running all day at a good 180F+ with no problems.. same with my high side line.. Propane is perfectly stable at those temps as long as there are no leaks in your system.

When you fill with propane.. do it slowly at first.. You never know what "might" pop up.. R-134a IS PROPANE.. with a ton of shitty additives to make it heavier.. non-flammable.. etc.. but adding all of these other chemicals makes the boiling point of 134a only -15F .. Pure propane isn't an issue when it comes to filling your system.. just use common sense..

Plus propane has a HUGE price to quantity advantage over 134a.. I used a LOT of 134a.. atleast 10 12oz cans.. I've put out well over 25 dollars on that shit.. I took the propane tank off of our grill.. 20lb tank I believe.. Been using it all day.. filled my system now 3 times.. blow a bunch of the propane out.. still got plenty left.. Cost to fill that tank - 10 dollars..

If you are afraid of the propane going bang .. then slip a bit of 134a in your system once you fill it with propane.. The 134a will make the propane less flammable.. You might even get colder temps.. I doubt it though.. You will most likely go up a few degree's F.

Anyway.. I hope I helped some of you along.. I was scared of using propane today for the obvious reason.. But after F'in with it all day long.. I found that it's not so scary after all.. Oh, when you are filling your system.. don't be smoking a cig.. or a joint

[8-Ball]

How much noise do these compressors make?

Is it generally the case that more powerful compressors make more noise?

Ultimately, I'm after a quiet system, but would love to get involved with phase change.

[|PuNiSh3R|]

Yes, larger compressors make more noise.. BUT.. if you have a good brand of compressor.. it will be quiet..

I mean.. you can't hear my 1/20HP compressor.. My 1/4HP compressor.. Well I got that out of the garbage.. It makes a few odd noises.. but when the thing is running right.. it just makes a very low humming sound.

If you really want to shell the dollars out.. get a Danfoss or Tecumseh compressor.. You'll be happy with it.. just be careful.. if this is your first time with refrigeration I'd suggest just getting compressors from refrigerators or AC's that are out in the garbage.. most of the time the compressor works.. Atleast if you kill them.. it won't matter.. It'll give you something to practice with.

You might just find a compressor in the garbage that you really like.. and decide not to buy one.. Just my opinion.. Get a couple of them.. run them.. decide which ones you like from a noise stand point.. and which ones actually work.. and then build a system with them.. or build several systems.. heh

*there is a little set of electrical stuff that plugs into the 3 pins on the side of the compressor.. YOU NEED THAT.. it's the over load relay starter.. If you don't get nothing but the compressor.. You'll need to get an overload relay starter .. one that is for your HP compressor.. I got mine at a local "chop shop" appliance repair/sale place.. 5 bucks.. That is good cuz it's a nice one.. and anywhere else they would want 20-50 dollars for it..*

[SonixOS]

interesting. My problem could be with the gas. I am thinking I might not have enough gas in the system. Plus my compressor is VERY LOUD. As in I can hear it over my central A/C and its definitely louder than my fridge. I am thinking mebbe its trying to compress liquid so that will break it and might cause all the noise.