First SS build

First off let me thank all of the long time contributors here for the wealth of information.
I have been reading up and I think I have figured enough of this out to get started with my first build. I have acquired some parts and still have some more to get, but I wanted to get some input from the experienced guys before I get the last of the needed parts.

I acquired this Sharp 10,000 BTU portable a/c unit:
Attachment 130257

Here it is with the covers off:
Attachment 130255

Here is the compressor:
Attachment 130258
Attachment 130256

I also got this:
Attachment 130260

Here is a picture with a couple notes outlining the basic setup:
Attachment 130259

(My apologies for the cell phone pictures, it is the best camera that I have.)

Do I have this figured out correctly? Is there any reason to change any of the other existing lines?

Evaporator construction
I saw a guide or two for evap construction, but they were old and missing pictures. It seems pretty straightforward. I assume that I insert the cap tube (red) and put it flush to the inside of that top surface, then braze in place (and make sure to use sheilding gas.) Then simply insert 3/8" tube (blue) in the center hole and braze in place, careful not to insert too far? Finish off by brazing the outer shell in place at top and bottom. Is it that simple?

Attachment 130261


I am still working on captube sizing, it seems this is the largest obstacle. There is so many variables, so, I am still figuring this out. It seems that I should be able to get most of what I still need at grainger. filter/dryer, scraders and capilary tube. I am not sure if they have flex line, I may order that from "Under the Ice."

If it matters, the main purpose of this will be benching.

I haven't decided on what refrigerant to use, but I am leaning towards r290.
I do have gauges and vacuum pump, torches (propane and oxy/acetylene), and tubing cutters and flaring stuff.

One last thought while I am having it... :D

I have a whole pile of Berz-o-matic ns-3 brazing rod. It is the blue, flux covered stuff. It is my understanding that this is not what I want to use. Could someone confirm that for me? I want a 15% silver rod without the flux?

Well. You do the evap all at once.
Drill the cap tube hole at an angle for your cap tube, make it go away from the spiral so the top layer gets flow. Then plant the 3/8" suction tube. Then put on the outside pipe.
Now braze it while pumping shielding gas through the capillary line. Keep the heat off the capillary (I have a jig and point the torch at the base of the evap until its red). I like to braze the bottom ring, then the top ring, then the suction tube, then the capillary line last. Try not to burn the cap tube.

Quote:

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Originally Posted by n00b 0f l337

Well. You do the evap all at once.
Drill the cap tube hole at an angle for your cap tube, make it go away from the spiral so the top layer gets flow. Then plant the 3/8" suction tube. Then put on the outside pipe.
Now braze it while pumping shielding gas through the capillary line. Keep the heat off the capillary (I have a jig and point the torch at the base of the evap until its red). I like to braze the bottom ring, then the top ring, then the suction tube, then the capillary line last. Try not to burn the cap tube.

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Thanks!

Am I looking ok for the basic plumbing and where to hook everything else?

Looks good man.
That is a huge AC unit ! :)

Thanks for the input. I found .031 cap tube and everything else I need at grainger, except the flex line. So I should be able to start assembly as soon as I can order a flex line.

What about that brazing rod? Is it worth trying?

Quote:

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Originally Posted by Buckeye

Looks good man.
That is a huge AC unit ! :)

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It is even better because I got it for free. :D
I found someone in the local classies giving it away! I was going to have to settle for a 7000 or 8000 btu unit.

I am thinking that the evaporator could be reworked as an condenser for another project, if I have a need.

I am working on this and have been sorting out the wiring and getting rid of all of the unneeded stuff. This motor for the fan is an ac motor with circuitry to control the speed of the motor. Is the fan with a variable speed useful? I was thinking that by lowering the speed of the fan that i could effectively lower the wattage requirement of the load,~ so I can run lower wattage cpus by running the condenser fan slower. Maybe this is unecessary since I have an accumulator already in the system. Any thoughts?

Quote:

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Originally Posted by xsuperbgx

I am working on this and have been sorting out the wiring and getting rid of all of the unneeded stuff. This motor for the fan is an ac motor with circuitry to control the speed of the motor. Is the fan with a variable speed useful? I was thinking that by lowering the speed of the fan that i could effectively lower the wattage requirement of the load,~ so I can run lower wattage cpus by running the condenser fan slower. Maybe this is unecessary since I have an accumulator already in the system. Any thoughts?

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It certainly would help with preventing flood back under low load conditions. As for necessary or not, I'll leave that to the SS experts to answer.

I would leave the fan controller active. I have flex if you need some. I can also throw you some brazing rods. I like dynaflow myself. Send me a pm if your interested.

You could lower the fan speed when you don't have the big load to make the cooler a bit quieter.

Thanks, it seems that it will be a good idea to keep the variable speed. I will have to see if I can figure out how to control it, as it is all automated now. It has been a long time since I studied electronics, other than the occasional voltmod. I was studying the circuits and the wiring schematic and I think I should be able to put a switch or knob to control the speed. I will sort it out later.

Quote:

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Originally Posted by runmc

I would leave the fan controller active. I have flex if you need some. I can also throw you some brazing rods. I like dynaflow myself. Send me a pm if your interested.

You could lower the fan speed when you don't have the big load to make the cooler a bit quieter.

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Thanks. Pm sent. I may as well get everything that I need from you, if you have it.

for the fan just use a rheostat and do it manually . ( like to keep things easy )

Nice project you have on the go plan on starting one my self in the next few months .

Well, having looked over the circuit boards that control it originally, there is no way I can easily control the fan speed. It has a microprocessor and sensors and all kinds of stuff that make it a bit over my head. I may try something in the future, after the rest of the build is finished. I have all of the wiring figured out except switches for turning on and off. I can either use a household light switch or get a couple smaller rocker switches and then use a relay or two.

If you cut the wires going to the fan to the controller then feed it from a source that matches the fan voltage a rheo would would with out using the controler and the temp profiles they have setup

I have been working on this a bit. I got the wiring figured out , I just put two switches for now.


http://i201.photobucket.com/albums/a...x/IMAG1427.jpg



I also got my evaporator and suction line brazed up today. I used nitrogen to purge while brazing.

http://i201.photobucket.com/albums/a...x/IMAG1422.jpg
http://i201.photobucket.com/albums/a...x/IMAG1423.jpg

Testing for leaks in water, plus I will let it set until tomorrow to make sure that I lose no pressure. Then I will clean it up.

http://i201.photobucket.com/albums/a...x/IMAG1424.jpg

Good job for a first shot at it. Little tips for that kind of flex. Get sum braid on it if you can. Also, how deep are the pipes in? The joint there can be very weak.

The lines are not very far into the flex. Perhaps 1/4 inch. I tried to get them in futher, but it was too tight. I tried sanding a bit off of the stubs, but it wasn't helping.
You think I should use some braid under the insulation? I was going to get some pipe insulation to cover it all. I assume that is what most people use. Also, where does everyone get that large size of the plastic braided stuff.

Oh not the plastic. The metal braid that goes below the insulation itself. If done properly it greatly reduces risk of ripping the flex. Or just be careful and don't bend it while cold :)

Is this the common flex that most use, or do some people use other types of hose?

So, put the stainless braid over the flex line, then insulation, then the plastic braid with heatshrink at the ends to hold it?

Where would I get the plastic braid?

Yeah you pull the stainless tight over the tube, then using some 45% silver rod and flux braze it in position or clamp it with a piece of pipe over it and braze that in.
Then insulate.
Then the plastic braid you see is "expandable wire sleeving" oftenly. Heatshrink or tape armaflex insulation works to hold that well.

Ebay is your friend.

Thanks for all of your help.

Mesh braid to cover insulation - Wirecare.com At least 1 1/2" size

looks good man

I had the R22 recovered and vacuumed by a guy at work that used to do a/c work.
Today, I almost got the brazing all done, but it got too dark outside before I could do the last connection. I will try to get the rest done tomorrow. I will put a few pics up after I am done.
What is better propane for charging and testing this? The kind in the little green bottles like for lanterns etc. or the big bottle for my bbq grill?

I finished up the brazing and pressure checked over the last couple days. Last night and today, I vacuumed and put a charge in. I have to figure out a load to use to charge it properly, but I did make some frost!
I also need to figure out the shrouds, and covers. Also I need to get the insulation figured out.

http://i201.photobucket.com/albums/a...x/IMAG1469.jpg
http://i201.photobucket.com/albums/a...x/IMAG1468.jpg

Thanks again to everyone for all of your assistance and guidance!!