A/C Basics?

[XeonStrikeForce]

You indeed can teach your self, I tought my self blasting chem and all that stuff but it takes along time to do it care fully though I know you can do THIS! but take your time to care fully learn about it

 

[greenmaji]

I don't totaly disagree with reading up all the information you can find online..
and XtreemSystems Teampuss XtreemResorces and were ever you can find good info, read it.. and ask good questions, you'll get the best answers I can muster up and Im sure some of the other guys here will outdo me on occation

so were were we?

Ahhh a chiller.. there is a very good thread that Ive read a couple of times myself over at XS in the sticky section of the liquid chiller section that would definatly answer some questions in that department..

If your going to break it down to put a diffent evap on it some other modifications would help get it performing better I think..
A TXV (or TEV depending were you look) valve would be an asset IMHO.. what size.. ^^^ these guys would probilbly be better at giveing you a proper answer to that, I would just be educated on my reading guessing.

basic issues like reclaming the original refigerant and vacuming down the system havnt even been touched in your thread yet, what kind of reading have you done on the basics yet?

ps.. Mark Ive seen some of those cool CAD ideas of yours over at reefcentral.. nice work

 

[Pf.Farnsworth]

i agree, but here we are. i think too many people get too technical, this isn't an exact science. yes you can slap something together and i'll work I think that's more important that taking thermodynamics classes and reading up on refrigerants.

I don't. I think proper education in safety and proper and legal conduct is very important. We had people get hurt, and we had people brake the EPA laws and damage the environment by venting refrigerant.

On the performance side also, yes you can slap something together and it will hold your load at -10C but that's not what most people want. And when they spend a lot of money and time and get -10C they get upset, and right as they should be because they were encouraged to proseed with false expectations. This is a pretty exact science, maybe not as exact as making semiconductor products but exact enough that proper education and knowledge makes a world of difference in the finished product.

I don't know crimedog, so I cannot comment on his information. However, most of the "industry professionals" that I have met typically are arrogent. Sure, they know a lot, but why should they freely share the knowledge that they paid for? In my experience, the most knowledgable people in any field are the hobbiests. They have to learn hands on with what resources they can find. Most have not been to a school to learn the details of their hobby. These people typically are willing to share their knowledge so that others do not have such a hard time of it. That is what these forums are for. They are not just to show pics of your rigs and give you bragging rights. If people are not willing to help here then this site is basically useless.



I've always taught myself. I taught myself Pascal programming with a little help from my dad when I was 8. I taught myself BASIC programming by 10 (OK, not real impressive) and was self taught to a college level in C/C++ by 15.

When I started in the aquarium hobby, I learned plumbing, acrylic and general plastic fabrication as well as lighting, heating, cooling, fluid dynamics and chemistry fundamentals with what I found online.

I have never taken a single course on any of these subjects. The programming aspects I learned from books. The rest was learned by asking questions on aquarium boards and learning from the replies of members that have been there before. I can plumb a house to code and I am not a certified and licensed plumber. I can write a complex program and have never been to college. I can build you an aquarium or watercooling reservoir out of acrylic, PVC or glass plate.

Show me the details and any tips and tricks. Point me to websites with detailed info. Answer my questions. I promise you that I will have professional level A/C skills in less than 6 months. However, I cannot do that alone.

Now, can we get this thread back on topic?

I have to agree with that, a lot of people in the industry have little respect for kids that come in their shops and ask for "that thingie that makes something cold to cool my pc". In a way sometimes they take it to far, but from another perspective they have a right to feel that way, they didn't get where they were today by taking a short cut and reading up about "that thingie that makes stuff cold" on line. And when people come in with stupid expectations and attempt to get help to do something they have no business doing I would treat them the same way.

If you want to take this as far as making a system yourself you don't come to a professional and ask about "that thingie that makes things cold". Any professional in any industry will send you home. If you want to dabble in it then you better understand the basics pretty damn well. The basics although are a lot more then what a lot of people think, that's why they get no help and rightly so. Like I said if you want to attempt something serious then you have to be well educated, then people will be willing to help. Otherwise its like helping a 10 year old kid who wants to make a nuclear reactor in his garage, don't give me fuss about the analogy, you know what I mean.

For the record the professionals at XtreemSystems, Teampuss, and XtreemResorces are willing a glad to help out anyone who is taking this seriously. And I think you know what I mean by that,

Learing to type on your keyboard and glue plastic together is not the same thing. This can kill you. There is a difference in learning to program and learning to make a bomb. A mistake in programming will cause you frustration and maybe a broken keyboard - out of frustration, a mistake in refrigeration can cause explosive decompression, flying shrap metal, fires and combustive explosions, as well as damage to the environment. Comments like this are proof of the lack of respect and understanding to a foreign skillset and technology. Proving some people have no business doing this since they obviously overestimate their abilities, or are ceaseless of their own or the safety of others and the environment around them.

 

[XeonStrikeForce]

I collected who knows how much Americium 234 (Can't recall the spelling or isotope, and I don't have a periodic table handy, but it is a Neutron emitter) To make my own reactor even had the graphite rods stainless chambers. Ah well projects since buried never to be revived (Unless they start selling plutonium at the grocery store)

 

[Pf.Farnsworth]

seriously

 

[greenmaji]

seriously

do you expect any less from Xenon really well.. considering this resoponce I take it you have read what he writes over at XS ROFL

Pf. has some points about this being dangerious to you and the enviroment that are valid.. and Xenon made a point of posting that this takes some reaserch and to be care full (carefull with a pause for infussssussssss.. LOL)

learning about static charge, how expansive the gasses your going to be working with are (and calculating needed system capasity to compensate for that), how to properly perge without causing a fire ball explosion (we had a member have a small issue with that not too long ago ) not to mention other things I cant just rattle off the top of my head. (I think some of the magnitude of danger that Pf. is refering to is amplified quite a bit in his mind from reaserch/experince in more complex systems then your currently considering but I may be just guessing here)

this is engenering.. if you have an anilitcal mind it will come pretty natural to you.. If Math and Science were hated subjects in school and you didn't learn to enjoy and become profecent in these subjects as you got older then your going to need to be asking alot of questions to people that know what there doing and not sound like you have done your homework.. this is were you will get responces like Pf. is giving you..

I realize this thread started out with a general question about phase-change but we did get a stickler to come in and "let us know how it is" Pf. I'm not the type of person to do what you have done (I don't like to think others dont have the capasity to learn this subject well enough to do it without giving them the benifit of the doubt) but I must admit your way is safer. at least to bring things that need to be brought to peoples attention - to there attention.

And I havn't picked up a project from lack of room myself, and I know its more then that.. I would still need to do fact checking to get the job done.. even with what I know now. (so hands on experince.. I have none) so Pf.. your more then welcome to cut me down to size if you feel the need.

 

[XeonStrikeForce]

Ya befor I learnt Americium wasn fissionable but rather just a mid range neutron emmiter. They use it in Ionizing smoke alarms (It's the Ion source. By passing the neutron through the air it generates ionization between the two plats, when smoke enters it shorts out this ion field and the alarm detects the voltage drop and triggers) and at like 2microCuries and need insane amounts and reduce it to just get to a slightly use full range.

 

[Burdman27911]

I agree that being "care full" is very important, personally I am a mechanical engineering major and I'm starting to get into the thermodynamics and soon the refrigeration technical electives. I'm interested in Phase change, but in reality I know that I don't have enough hands on experience so I'm taking my time and reading up and will some day (2-3yrs from now) actually build something for my PC. But this is not a field that should be rushed into by any means.

All that said, to say that I can see it from both sides... be careful, read your stuff, ask questions, and take your time, and hopefully you won't die.

 

[greenmaji]

btw.. alot of this can be avoided if you just use the original evap that came with the AC unit.. bend some tubes into a cooler.. get a break in shrader vavle (and cut it in in the right place) and blead the system of some of the exess charge (into a container for greef sake).. and get a switch wired in for this application..
some members know wich swich to swap to.. hopefully they will post.

once you start breaking into the system and changing its design you start needing to be more cautious (because you have more things to do and consider)

btw.. did anyone see the results from Gary Loyd's air con converted liquid chillers? linkage would be killer, Ive never been able to find them

 

[Pf.Farnsworth]

And I havn't picked up a project from lack of room myself, and I know its more then that.. I would still need to do fact checking to get the job done.. even with what I know now. (so hands on experince.. I have none) so Pf.. your more then welcome to cut me down to size if you feel the need.

There it is gentelmen, a mindset like this will get you help from a proffesional anyday. This is what people with knowledge look for in people. The opposite of this guy for example:

http://www.xtremesystems.org/forums/showthread.php?t=97538

Yes me and Xeon are partners in crime at XS he is a baastard alright.

 

[XeonStrikeForce]

lol I'm insane and proud of it, now only if I didn't have so much stollen I could actualy DO some thing But at the rate my lucks going I just may yet get to play

 

[greenmaji]

There it is gentelmen, a mindset like this will get you help from a proffesional anyday. This is what people with knowledge look for in people. The opposite of this guy for example:

http://www.xtremesystems.org/forums/showthread.php?t=97538

Yes me and Xeon are partners in crime at XS he is a baastard alright.

TY Pf..
and BUHAHAHAHAHA!! (I am secretly wanting to be the founding member of the -200C club AUTO-CASCADE, or 8 stages of rotary powered goodness, Ill get started tommorw ROFL!!!!!)

I keed.. that guy needed knocked around some.. greef

Or freind Mark here wanted to do a Air Con. conversion though.. come on, thats far from the worst Ive seen (I WANA BULDA CASCADE RIGHT NOW garbage is for the birds.. )

 

[MarkS]

OK, I've dropped this idea. Actually, I dropped this idea about 10 replies ago...

Anyway, I am going to do a 100% water cooled system using the evaporator of an old A/C as a radiator. In the mean time, I would like to learn the basics of phase change.

I've read post after post about how dangerous this is and why I should not do it, but no one to date has explained how they learned. Am I to assume that all of you are licensed HVAC professionals? I seriously doubt that.

The link that XeonStrikeForce provided in his original reply helped a lot. However, the site was not complete and there was some information missing. It did clarify quite a few questions I had, but also raised some others. For instance...

I must have been misinformed, but I have always read that the refridgerant has a small amount of oil in it for the compressor. Everything I've read on these boards states otherwise. However, NO ONE ever states what kind of oil to use (I've read blurbs about mineral oil...), how much to use, and considering the design of the typical A/C system, how the heck to get it into the system. Can someone please go into detail here? Or, at the very least, can you point me to some threads where this is explained?

How would I know when the system is fully charged? This is something that is taught, so no "it just feels right" comments. The system has to be pressurized to a certain PSI on the high side or a certain amount of refridgerant must be used. I can safely assume that this will be different depending on the size of the system, but how do I find out for a certain system? Where is this information posted?

Where can I get detailed information about the various different refridgerants available? The link that XeonStrikeForce gave was not complete in this regard. How do I know which is best for my purposes? I'd like to stay away from propane and similuar refridgerants for safety purposes, at least at first.

When recovering refridgerant from an old system, what do I recover it in? What if the system is sealed with no ports to charge/discharge the refridgerant? I could add ports, but I'd first need to cut the tubing, which would release the refridgerant...

If you guys are not licensed, how and where do you obtain your refridgerants legally? DO you obtain them legally?

Are there any online courses that would get me licensed?



I could go on and on. All I am seeking is information. Just a push in the right direction. EVERYONE here got that at some point, in some fashion. I do understand the expenses and dangers involved. I would like to work on something in my spare time.

 

[crimedog]

Anyway, I am going to do a 100% water cooled system using the evaporator of an old A/C as a radiator.

condensors aren't good for that application because they are much more restrictive than radiators (long, long runs of copper tubing).

I've read post after post about how dangerous this is and why I should not do it, but no one to date has explained how they learned. Am I to assume that all of you are licensed HVAC professionals? I seriously doubt that.

i still disagree that this is a dangerous hobby. with a little bit of common sense the most dangerous thing you'll come in contact with is hot copper [for single stages].

I must have been misinformed, but I have always read that the refridgerant has a small amount of oil in it for the compressor. Everything I've read on these boards states otherwise. However, NO ONE ever states what kind of oil to use (I've read blurbs about mineral oil...), how much to use, and considering the design of the typical A/C system, how the heck to get it into the system. Can someone please go into detail here? Or, at the very least, can you point me to some threads where this is explained?

i've never seen it explained either, so i don't know how the oil performs in a phase change loop. i do know that you have to use oil compatible with your refrigerant, so it can 'carry' the oil. the most common types of oil i see used are POE oil and mineral oil. to change the oil you turn your compressor upsidedown and drain it all out, and replace it with the same volume of new oil.

How would I know when the system is fully charged? This is something that is taught, so no "it just feels right" comments. The system has to be pressurized to a certain PSI on the high side or a certain amount of refridgerant must be used. I can safely assume that this will be different depending on the size of the system, but how do I find out for a certain system? Where is this information posted?

unfortuantly this is done by feel, you don't calculate how much refrigerant you are going to use. generally what i'll do is put a few shots of refrigerant into a vacuumed system, then when it's on give it a few more into the service port. then you just apply load and keep adding/removing refrigerant until you get your best temps.

Where can I get detailed information about the various different refridgerants available? The link that XeonStrikeForce gave was not complete in this regard. How do I know which is best for my purposes? I'd like to stay away from propane and similuar refridgerants for safety purposes, at least at first.

generally, people use the following refrigerants: r402a, r507, r404a, r290, r22, r134a, in single stages. there is nothing wrong with using propane (r290) in your system, it is perfectly safe. there was one thread at XS where they discussed this because a kid was worried that a r290 system could blow up his house. you need an epa certification to purchase HCFC and CFC refrigerants. it's very easy and cheap to get @ http://www.epatest.com/.

When recovering refridgerant from an old system, what do I recover it in? What if the system is sealed with no ports to charge/discharge the refridgerant? I could add ports, but I'd first need to cut the tubing, which would release the refridgerant...

i've never seen any of the phasers recover refrigerant. i'm sure the big boys have recovery machines and tanks but we do not.

I could go on and on. All I am seeking is information. Just a push in the right direction. EVERYONE here got that at some point, in some fashion. I do understand the expenses and dangers involved. I would like to work on something in my spare time.

go for it man. first step is getting your tools. second is your parts, then your gas and your practice. it's going to cost you a good bit of coin, i recommend you look around and price out everything you'd need before buying anything though.

 

[XeonStrikeForce]

did you read both links?

How'd I learn? I grew up in heavy industry there I learnt a whole ton about gases and such then I took that knowledge and talked to a bunch of HVAC guys, and read up stuff on the net then care fully studied running systems took them apart and then reassembled them.

How do you go about it? Keep reading and have a chat with a local HVAC guy once you got the lingo down.

 

[greenmaji]

@crimedog.. If you are charging a system with a HCFC or CFC gass (R507, R402, R22 ect ect ect) and you have to let out some of the charge to get your best temps, you havn't seen any phasers recover this gas.. or is R290 used prodominatley IYE.
What about the R12, R22 or whatever gas that was origanaly in the system??? (like with air cons or old machs)

and I guess I have read more... oil handling is out there to read :? and knowing about it is one thing but how importaint it is to consider in a single stage system is rather minimal IMHO.

 

[Pf.Farnsworth]

How I learned?

-I read xtremesystems.org/forums for 2 years
-I live with an HVAC engineer

By the way a recovery machine and a tank are not very expensive, most people who are serious have them, other don't want to bother, which is wrong since they are breaking the law and hurting the environment.

 

[XeonStrikeForce]

I'm building a recovery unit that will get at least 80% minimum of the refrigerant recoverd (Probly more, low temp compressors are the trick of this)

 

[greenmaji]

@XeonStrikeForce.. I thought I read you posted a few more details then that elsewere
dont you change the oil? and run a couple of compressors and have criteria for those
details

 

[XeonStrikeForce]

thats for a vacuuming system
The target specs for the recovery unit is 1-2amp compressor, Intake oil seperator, filter dryer, discharge oil seperator, Condencer + 12V fan, check Valve, Tank