Building my chiller, a few questions

[ben333]

Well last night on ebay I found a new five thousand something BTU compressor for $20 with free shipping, never been used so I bought it. I figure it should make a nice chiller but I have a few questions. So I'm guessing that this thing has two gas out fittings and two returns. One pair hot and one pair for what you are chilling. So I would just solder copper pipe into or over these and the cold one goes inside my insulated water tank and the hot one goes to a condenser (which i'll probobly pull from an old AC unit) I am also guessing I'll need a capicitor (or whatever that silver box is) Sorry for being such a noob and thanks for your help,
Ben
EDIT: And I plan to pay someone to fill it with r22 unless it can be done myself for under the cost of a professional

[ben333]

*bump* and also where is a good place to find a cheap condenser? (because the ones in old AC units are usually damaged a lot.

[ben333]

any chiller experts awake now?

[Xeon th MG Pony]

Oh boy, where to start correcting?

Better yet lets start you off here: http://www.refrigerationbasics.com/1024x768/rb1.htm

By the sounds of it you have lots of fundimentals you need to learn for your own safety. This stuff can and will kill you if botched bad enough, or burn your house down.

there are for parts that make up a refrigeration cycle untill you can understand them put the compressor to the side and learn, more you learn the better your first project will be.

[Xeon th MG Pony]

A Hermetic Recipicating Compressor will have 1 discharge line, One suction line with a suction pressure acces line, some times it will have an inbuilt oil cooler that will have 2 access lines.

So a standerd recip will have a total of 3 ports on its shell, A recip with a oil cooler will have up to 5.

A Rotory will have only two connections, Suction and Discharge!

As to the Capacitor, it depends do you need a run cap or a start cap? Do you need one at all? do you need both? is it an RSIR, CSIR, CSCR Motor? Thats what you have to find out befor you know if you need a capacitor.

What expansion device? Cappilery tube, Thermal static expansion Valve. this too will determin if a starting capaciter is needed or not.


You see what I mean? More you learn, the better you can focus down your questions and the more procise answers we can offer No need to apoligising for being a noob, we all started there after all! But now lets turn you from a newb to a beginner hobbiest!

Read over the web site untill you under stand it, right there, that will get you out of the Tera-newb class into the novic class

[ben333]

Thanks man I'll post the model of my compressor...
http://cgi.ebay.com/ws/eBayISAPI.dll...m=140195360150
BTW: I am pretty good at soldering and I am going to pay someone to fill this for me. I know that the gases used are deadly or harmful if ingested so I will be careful when dealing with them. I don't know if I need the capacitor yet...

[[XC] gomeler]

Those are the little 1/2hp Rechi rotaries, decent compressors for the price but a bit on the loud side along with vibrations. Just make sure to isolate it from the rest of your system with some coiled copper otherwise it'll shake everything to death, or atleast mine did. Don't solder, braze it all as solder will just crack and leak. That does need a capacitor to run, believe it was a 25uF run capacitor but don't quote me on that, memory is fuzzy. Read the stickies and fill your head with delicious knowledge

[Xeon th MG Pony]

Well if you managed to eat them that'd be bloody impressive! Inhalation is the most dangerous at certain levels. Read the site over it will help you allot.

That is a Rotory you'll need a Perminant split phase capaciter "PSC" for the starting of it. As the above post says, 20 - 25Uf (MFD on some) Should suffice.

The top middle is the discharge, and the side port on the round thing is the suction accumulator.

[ben333]

Image taken from overclockers.com

From this image, phase change looks simple... Do I pretty much do this?

[Movieman]

any chiller experts awake now?

You've hear the old line" He knows just enough to get him into trouble"?
I've been reading about this and phase for 2 years and what I've learned is that as the gentleman above said "It can and will kill you" if you don't know what your doing. The gasses in some cases are highly explosive and the pressures in the lines on parts are very high.
Read and learn and ask lots of questions.
Jumping into this cold( bad pun) is like taking a 16 year old kid the day he gets his drivers lisence and sticking him in a F1 car..
Very short lifespan..

[ben333]

I understand all of that (and meant to say inhaled) and I will have a professional fill and leak test the unit. I am really just wanting to know what parts I need and how to assemble them. Dose the pic I showed work for that?

[Xeon th MG Pony]

Crudely it does, but it is much more complicated to properly size them. For example, the cappilery tube must be sized to match the flow rate of refrigerant to the load produced by the processor. For a chiller it is better to use the TXV (Thermal static valve) Which again has its own special needs, in system design and charge.

You need to use the right gas that will keep the compression ratios correct, for your compressor it is 5:1, The evap must be designed to be able to take in the heat with out freezing up, yet to allow for low pressur drop accross it.

It is like trying to explain nuclear physics to a cave man, with out a good base understanding it is hard to even start explaining the why and how's.

Just like how it is hard to even ask the right question, Again if you read through that web site it will assist you in asking the right questions and help you understand why they are connected the way they are and the things needed to do so.

[bassie]

I understand all of that (and meant to say inhaled) and I will have a professional fill and leak test the unit. I am really just wanting to know what parts I need and how to assemble them. Dose the pic I showed work for that?

The pic is just to show how it works(phase change). You need to change the captube with a tvx. The flex with a solid line, the evap with a heat exchanger, a hot-gas-bypass. You need the right oil for the refrigerant and lots more. Its not as simple as that picture makes it look.

But do your self a favor and get a book like Modern Refigeration and AC, if you want to save some money get a 1996 edition as long as its the hardcover . Take some time to read and understand it. Then comeback here with the questions that you still have.

[ben333]

well I might just end up buying an AC unit. I mean for $70 its all done for me... I'd like to get into DIY but I think I might just save that for a summer project. If I just wing it, make it look like the pic I listed and then pay someone to fill it will it come out as a totally non working piece of junk or will it just be a bit off and otherwise do a pretty OK job?

[Xeon th MG Pony]

it would just blow out/up and/or burn, at best it simply will burn the compressor out. Either way I prommis it won't be nice.

This is NOT some thing you can just "wing"

Read the site I posted its the most dead simple explination of every thing you could ask for and it'll get you up to speed!

Things need to be matched and calculated for it to work and work good.

[bassie]

well I might just end up buying an AC unit. I mean for $70 its all done for me... I'd like to get into DIY but I think I might just save that for a summer project. If I just wing it, make it look like the pic I listed and then pay someone to fill it will it come out as a totally non working piece of junk or will it just be a bit off and otherwise do a pretty OK job?

If you make it look like the pic it wont work! The pic is for a dd unit not for a waterchiller. You have to change so many thinks to turn it in to a waterchiller.

Just get that book (modern refrigeration and ac), and old edition (1996) wont cost you much ($20). The knowlage is the cheapest and most important part of the whole build. Without it you cant start your build

[ben333]

I am saying buy an air conditioner, take off the case, seal the evap in a box with a radiator, fill the box with anti freeze and then insulate the box. I still want to get into custom phase cooling but I think I might save it for a summer project so I can take the time to learn more about it.

[Fujimitsu]

I am saying buy an air conditioner, take off the case, seal the evap in a box with a radiator, fill the box with anti freeze and then insulate the box. I still want to get into custom phase cooling but I think I might save it for a summer project so I can take the time to learn more about it.

AC mods aren't a bad place to start, what you're talking about has been done a lot. You'll get good temps for cheap, but it's bulky and inefficient.

It's a good place to "get your feet wet" for cheap, although far from an ideal system.

[ben333]

looks like I'll visit that road. Then like I said over the summer when I have more free time I can do the research and maybe replace the compressor. I just right now need to milk a little more out of my quad

[Xeon th MG Pony]

have you read the link I gave you yet?

[ben333]

yeah I have been looking a lot of the stuff over but probably won't have the time till next weekend or the summer to really start learning this stuff.

[Athanatos]

read the literature here too

http://www.sporlan.com

a lot of good info once you understand some of the technology

[Xeon th MG Pony]

it would literaly take two days at most reading that site for only 30 minutes or less a shot!

[Akula]

I was in the same boat as you this summer Ben333, I discovered this forum and immediately wanted to jump into something elaborate, but my budget prevented me from buying the necessary tools to charge my own systems, so I took the route of modding a window A/C unit. I think, I came up with a design that will allow me to upgrade when I feel I have a level of competency to start brazing my own loops. From my experience with my project, I am glad I decided to use an existing A/C loop, it would have been too much for a first project.