View Full Version : Small 2 Stage Cascade
_HL4E_HalfLife_
07-15-2006, 11:13 PM
Here's another 2 stage cascade i've been working on for the past week. Its smaller than my first 2 stage cascade i did about a year ago. This cascade isn't really for a computer but i know alot of you like to follow the progress of cascades being built so i decided to post it anyway.
1st stage:
Compressor - 1/3hp 4100Btu's High Temp Tecumseh Recip
Gas - 290
HX - 7feet 3/16 inside 3/8
Suction pressure - 0psi
2nd Stage:
Compressor - 1/2hp 6000Btu's Samsung Rotary
Gas - 402A&Co2
Cap tube - Starting at 12feet
1st stage is already complete and running and am currently working on 2nd stage.
Heres some pics.
http://img221.imageshack.us/img221/1264/leftsideie6.th.jpg (http://img221.imageshack.us/my.php?image=leftsideie6.jpg)
http://img221.imageshack.us/img221/1718/rightsideqm3.th.jpg (http://img221.imageshack.us/my.php?image=rightsideqm3.jpg)
http://img221.imageshack.us/img221/3314/beforeah0.th.jpg (http://img221.imageshack.us/my.php?image=beforeah0.jpg)
MORE TO COME
R402a and R290 ? Why that ?
_HL4E_HalfLife_
07-15-2006, 11:57 PM
R402a and R290 ? Why that ?
Because 402A can maintain a more stable temp when its being used in a deep vacuum unlike Co2 which can form dryice and clog up the cap tube and other things.
I've had 402A at -70c before.
In the future i might add Co2 to the 2nd stage to gain a few more C.
And you can't use Ethylen (R1150) ?
_HL4E_HalfLife_
07-16-2006, 12:00 AM
And you can't use Ethylen (R1150) ?
Can't afford it.:(
i used 402a and some co2 in my last cascade and managed to hit -90 so it works real good
co2 can be found and is cheap as chips
the static charge was 40 psi 402a and 20 psi co2
good luck
the_new_guy
07-16-2006, 02:14 AM
what kind of mixture do co2 and 402a form?
404Power
07-16-2006, 05:19 AM
Nice cascade! :)
But wouldn't it be smarter to use the rotary in the first stage and the tecumseh in the 2nd? o.O :) ^^
[XC] Lead Head
07-16-2006, 08:56 AM
Nice cascade! :)
But wouldn't it be smarter to use the rotary in the first stage and the tecumseh in the 2nd? o.O :) ^^
Deeper vacume=Lower temps, So the rotary is best in the seconed stage:)
sl4ck
07-16-2006, 09:05 AM
Deeper vacume=Lower temps, So the rotary is best in the seconed stage:)
I Don´t think so.....
think about holding load, condensing r1150 is such a quiet big load for I stage, plus heatload from evap. You should use most powerfull compressor on I stage, to hold loaded II stage well.
Yeah, you could use most powerfull com on 2 stage, but what you will do when I stage comp will have problems with holding load ? :)
[XC] MarioMaster
07-16-2006, 12:06 PM
and make sure you flip your condensor
_HL4E_HalfLife_
07-16-2006, 12:27 PM
and make sure you flip your condensor
Why? The condensor is in the right position already wouldn't flipping it make the condensed gas have to climb the condensor?
Also if this smaller 1st stage compressor can't handle the load i've got another 6000Btu Rotary i can replace it with.
Carlz0r
07-16-2006, 12:28 PM
Why? The condensor is in the right position already wouldn't flipping it make the condensed gas have to climb the condensor?
You have the cap tube coming out the top right now.
_HL4E_HalfLife_
07-16-2006, 12:35 PM
You have the cap tube coming out the top right now.
LoL that cap tube is the original cap tube from the dehumidifier its been long since removed.You'll see updated pics this evening:toast:
[XC] MarioMaster
07-16-2006, 12:38 PM
ok, i just thought you were gonna use it as is from the picture
Carlz0r
07-16-2006, 02:14 PM
LoL that cap tube is the original cap tube from the dehumidifier its been long since removed.You'll see updated pics this evening:toast:
Ah, so you're using an evaporator.
_HL4E_HalfLife_
07-16-2006, 02:15 PM
Here's some more pics:
http://img375.imageshack.us/img375/1815/hxmw9.th.jpg (http://img375.imageshack.us/my.php?image=hxmw9.jpg)
http://img365.imageshack.us/img365/8443/hxboxod8.th.jpg (http://img365.imageshack.us/my.php?image=hxboxod8.jpg)
http://img365.imageshack.us/img365/9873/frosty1ststageny4.th.jpg (http://img365.imageshack.us/my.php?image=frosty1ststageny4.jpg)
http://img518.imageshack.us/img518/3346/frosty1ststage1eg8.th.jpg (http://img518.imageshack.us/my.php?image=frosty1ststage1eg8.jpg)
Here's a video clip i made a few days ago of 1st stage running. The recip's got a nice hum sound to it.
<object width="425" height="350"><param name="movie" value="http://www.youtube.com/v/1qITrwCk-5A"></param><embed src="http://www.youtube.com/v/1qITrwCk-5A" type="application/x-shockwave-flash" width="600" height="350"></embed></object>
Brettbeck
07-16-2006, 02:31 PM
EDIT: Working now.
_HL4E_HalfLife_
07-16-2006, 03:09 PM
cool vid love the sound
Yea i know that sound could put me to sleep at night lol:p: ;)
_HL4E_HalfLife_
07-16-2006, 07:16 PM
Some more pics!!
http://img122.imageshack.us/img122/8586/desuperheatersi5.th.jpg (http://img122.imageshack.us/my.php?image=desuperheatersi5.jpg)
http://img386.imageshack.us/img386/2867/unit1hb4.th.jpg (http://img386.imageshack.us/my.php?image=unit1hb4.jpg)
http://img149.imageshack.us/img149/6255/unit2ac9.th.jpg (http://img149.imageshack.us/my.php?image=unit2ac9.jpg)
[XC] MarioMaster
07-16-2006, 09:56 PM
looking good
_HL4E_HalfLife_
07-17-2006, 07:32 PM
Ok now that were caught up on the pics i can post the latest ones from yesterday and today.
Most of 2nd stage is done the only thing left to do is braze up the evap. Over the past 2 days i've been working on the wooden frame of this cascade and i think its coming along nicely and will eventually be painted.What do you guys think so far?
http://img74.imageshack.us/img74/236/evapbw9.th.jpg (http://img74.imageshack.us/my.php?image=evapbw9.jpg)
http://img398.imageshack.us/img398/8443/backly5.th.jpg (http://img398.imageshack.us/my.php?image=backly5.jpg)
http://img124.imageshack.us/img124/9143/coverla0.th.jpg (http://img124.imageshack.us/my.php?image=coverla0.jpg)
_HL4E_HalfLife_
07-18-2006, 09:50 PM
2nd Stage is now complete vacuumed and charged and the wiring is also finished and just needs to be tieded up. Lots of pics this time.
12FEET OF CAPTUBING
http://img137.imageshack.us/img137/8595/captubegs7.jpg (http://imageshack.us)
2ND STAGE EVAP
http://img137.imageshack.us/img137/8373/evap1kk8.jpg (http://imageshack.us)
2ND STAGE IS COMPLETE
http://img137.imageshack.us/img137/5082/2ndcompletezk5.jpg (http://imageshack.us)
2 SWITCHES WITH BUILT-IN LIGHTS
http://img137.imageshack.us/img137/4426/lightswitchesph4.jpg (http://imageshack.us)
THE LIGHTS AT WORK:D
http://img231.imageshack.us/img231/3856/switchlightsqf9.jpg (http://imageshack.us)
COOLING HAS BEGUN
http://img110.imageshack.us/img110/499/evapfrostdv5.jpg (http://imageshack.us)
WITH SOME FROST ART IN THE PROCESS
http://img110.imageshack.us/img110/6568/coolfrostpf8.jpg (http://imageshack.us)
O YEA NOW ITS GETTIN COLD
http://img231.imageshack.us/img231/7454/morefrostau3.jpg (http://imageshack.us)
http://img110.imageshack.us/img110/1322/pressuretempvq4.jpg (http://imageshack.us)
Can anyone explain why my temps arn't relating to the suction pressure im getting? With about 19"Hg shouldn't i be seeing temps around -65c?
O and BTW T2 is 2nd stage evap and T1 is at top of HX (u can see it in some of the pics).
do you have enough refrigerant in there
whats the pressure in the second stage?
n00b 0f l337
07-18-2006, 10:56 PM
Nice ghetto cascade! :)
I dunno why your temps are off, maybe your gauges are off?
_HL4E_HalfLife_
07-18-2006, 11:35 PM
do you have enough refrigerant in there
whats the pressure in the second stage?
The pics answer both of those questions mate.
_HL4E_HalfLife_
07-18-2006, 11:38 PM
Nice ghetto cascade! :)
I dunno why your temps are off, maybe your gauges are off?
No the gauges are right on the mark, what else could it be? and i've tried the probe in several places i get about the same temp.
The pics answer both of those questions mate.
the pic is what made me say that
the suction return has little frost on it
this made me think there was not enough refrigerant
also how long did it take the evap to frost right away or 20mins?
_HL4E_HalfLife_
07-19-2006, 12:00 AM
the pic is what made me say that
the suction return has little frost on it
this made me think there was not enough refrigerant
But if the evap is totaly frosted up than there has to be enough in the system doesn't it? Also theres warm air being blown on the suction line from the condensor fan i think thats why there isn't much frost on it.
EDIT:Are we talking about 1st stage suction line or 2nd stage?
But if the evap is totaly frosted up than there has to be enough in the system doesn't it? Also theres warm air being blown on the suction line from the condensor fan i think thats why there isn't much frost on it.
EDIT:Are we talking about 1st stage suction line or 2nd stage?
second the evap
also how long did it take the evap to frost right away or 20mins?
_HL4E_HalfLife_
07-19-2006, 12:08 AM
also how long did it take the evap to frost right away or 20mins?
From the moment i turned on the 2nd compressor it took about 1 to 3 min i really wasn't timing it.
well thats good so there are not any blockages in the cap i would go back and put more refrigerant in so suction frosts upto 1 inch from the comp
_HL4E_HalfLife_
07-19-2006, 12:19 AM
well thats good so there are not any blockages in the cap i would go back and put more refrigerant in so suction frosts upto 1 inch from the comp
Wouldn't that increase the suction pressure which in turn would make my temps worse?
well i can only talk from my personal experience im not saying flood the comp
but if the suction return is not frosting right after the evap it would make me wonder why
and the first thing that jumps to my mind is lack of refrigerant
also what is the high side pressure of the second stage
and is the bottle full of refrigerant as i have had this problem when a bottle is running out
you get high pressure reading but little refrigerant has gone in
_HL4E_HalfLife_
07-19-2006, 11:22 AM
also what is the high side pressure of the second stage
and is the bottle full of refrigerant as i have had this problem when a bottle is running out
you get high pressure reading but little refrigerant has gone in
I don't have a port to check the high side at the moment.
I added some more gas to 2nd stage to get more frost on the suction line and the temps didn't improve.
Im surprised noone else has any suggestions on this matter considering how many people hang around these threads.:stick: :stick:
LukeXE
07-19-2006, 01:43 PM
You must insulate the 2 stage evap. Warm air is :banana::banana::banana::banana:ing big load for it (really)
Check the temp at the out of evap
And insulate the thermocouple ;)
sl4ck
07-19-2006, 03:15 PM
either you don´t have subcooling on 2nd stage cap tube, you should try to subcool 1st stage cap tube too, it improves a lot.
Why did you use a condenser for evap? homemade a/c?
_HL4E_HalfLife_
07-19-2006, 03:54 PM
either you don´t have subcooling on 2nd stage cap tube, you should try to subcool 1st stage cap tube too, it improves a lot.
Why did you use a condenser for evap? homemade a/c?
What would i further cool the 2nd stage cap tube with? If i wrap it around anything it might be warmer than the captube because its already cold enough to build frost and if its not it might worsen temps or increase the pressure on what i wrap it around. Right now i just finished insulating it and the suction lines. Also how would i subcool the 1st stage captube without adding more heat to the 1st stage?
Its an evap i used for an evap not a condensor lol it was part of a window shaker. I still gotta build a removable insulated box that will mount to the top of the case.
sl4ck
07-19-2006, 03:59 PM
wrap it to your 2nd stage succion line to the evap, it's little, but it's a succion line :D
_HL4E_HalfLife_
07-19-2006, 04:10 PM
wrap it to your 2nd stage succion line to the evap, it's little, but it's a succion line :D
Wouldn't that just add more heat to 2nd stage which would raise the suction pressure. I want as low a temp as possibile in the evap.
_HL4E_HalfLife_
07-19-2006, 08:34 PM
Ok i did quite a bit of work on it tonight i changed out the 1st stage compressor it just wasn't keeping the temps as low as i would have liked. I replaced the 4100Btu Recip with 6000Btu Rotary. This Rotary is out of an 18 year old window A/C yes 18 years old!!! The A/C developed a leak and was scraped.
I also tieded up all the wiring,straped the run cap down and insulated most of the lines.
Heres some more pics of what it looks like now.
http://img93.imageshack.us/img93/9500/1ststagecomplm5.jpg (http://imageshack.us)
http://img69.imageshack.us/img69/849/switchesqg6.jpg (http://imageshack.us)
http://img69.imageshack.us/img69/5915/side1zj3.jpg (http://imageshack.us)
http://img69.imageshack.us/img69/462/back2iw1.jpg (http://imageshack.us)
In the 3rd pic does anyone know what that big copper thing is coming off the discharge line from the compressor??
LukeXE
07-20-2006, 02:16 AM
Hm, If I see good, you have an accumulator on discharge ? :confused:
_HL4E_HalfLife_
07-20-2006, 03:50 AM
Hm, If I see good, you have an accumulator on discharge ? :confused:
I dono what it is i didn't put it on there it was on it when i ripped the compressor out of the old A/C.
Seems kinda small for an accumulator doesn't it?
it is a muffler;)
Wouldn't that just add more heat to 2nd stage which would raise the suction pressure. I want as low a temp as possibile in the evap.
you need subcooling and superheat for a good system.
wrap the captube around the suction for better capacity, and with that you get superheat too :)
_HL4E_HalfLife_
07-22-2006, 09:50 AM
it is a muffler;)
you need subcooling and superheat for a good system.
wrap the captube around the suction for better capacity, and with that you get superheat too :)
So ur saying i should do this?
http://img135.imageshack.us/img135/1410/captube1tb1.jpg (http://imageshack.us)
LukeXE
07-22-2006, 02:56 PM
It`s very important to insulate/cool the captube :) So just wrap your captube on rotary`s suction line and it should work well...don`t forget to insulate it ! :)
_HL4E_HalfLife_
07-23-2006, 09:22 PM
Well i did as u guys said and wraped the captube around the suction line, however doing this didn't improve my temps. Any ideas why?
Ps. The suction line has also been insulated!!
Ill have 1st and 2nd suction pressures and 2nd high side pressures later.
_HL4E_HalfLife_
07-31-2006, 09:44 PM
Here's some updates on this project.
I added 3.5 more feet of captube to 1st stage hoping to get the HX a bit colder and i moved all the service ports to a more easy to access place.
In the last pic the gauges are both on 2nd stage and on the thermometer T1 is 2nd stage evap and T2 is temp on 1st stage suction at about 3" from compressor receiver.
_HL4E_HalfLife_
08-02-2006, 03:31 PM
Comon i wanna see some replys guys or ill hunt u all down with a cascade evap and give u all freezer burns :frag: :flame: LOL
Anyway i did some more tweaking and improved my temps bigtime and i still think it can do better with some more adjustments.
Comp-Freak
08-04-2006, 12:11 PM
Nice temps, did you already test with load?
_HL4E_HalfLife_
08-04-2006, 04:54 PM
Nice temps, did you already test with load?
Nah there was nothing in the box but the fan.