water chiller from portable a/c

[cooling storm]

hey im planning of using my 12k btu portable ac to cool water/glykol mix but the minimum temp is only -25C and im not happy with it i want louer temps can i pinch the captube to louer the temps or will it FUUUU up everything specs is under


220v-230v~
50hz
cooling capacity 12000btu/h
7.5amps
r407c/600grams
suction pressure 1.2mpa
discharge pressure 2.8 mpa


and how the hell am i going to get a cool box in that?????




help will be aprisiated

[cooling storm]

Help!!!! Please????

[Stewie007]

In order to modify this unit you absolutely have to recover the refrigerant. Pinching the cap tube will not give you the desired results and you would risk compromising a charged system.

What units are you meaning to show? MegaPascal (MPa) is the only thing I can figure and that would convert to a 174 PSI suction pressure. That wouldn't make for very cold temperatures at all...

[cooling storm]

im not aming insane low just the -30C range so i dont ned to have the pc in a vacum chamber and it gets -27C only evap in air i tested it for 5 mins in water and it cooled 15 liters of water to 1C before the evap got totaly iced up 1.5 cm thick in 5 min and it took 6 houors to get back to water from a ice block it gets cold egnought and im planning on having the radiator outside in whinter it gets COLD here -26C here in norway so not so mutsh energy usage only need it in summer time to save energi sorry for stupid bad english D:

[Stewie007]

Well, first off you need to test it in the coolant mixture that you will be using. For 15 liters of coolant, you want at least 9 of those liters to be your glycol. A 60/40 mix of glycol to water respectively is a good target for your coolant. That way you can more effectively test your system. Also, you will find that you wont be able to sustain the ultra low temp under loaded conditions, and you will want to test your unit with some sort of heat load applied to see what kind of loaded temps your system is capable of reaching.

[cooling storm]

its insane i had a 1000watt heater on a variac i had it on full and it stayed within 5C of set point so it has uber controll its a comp with a lra of 40 amps

but also we have super cheap power here in norway so wont be a huge power bill

[Stewie007]

The LRA isn't really that important in load conditions as it repersents the current draw during locked rotor conditions, which basically means start-up. FLA, which represents full load current draw is a more important indicator of how much power you will be drawing. It doesn't really indicate much capacity wise.

You want to look at the RLA which represents the current draw at the rated load. Basically, that is just the measurement taken during testing when the system was running according to its specified load. If you look at compressor's specifications you will note that the power draw decreases as the temperatures, and thus capacity drops. As you increase the temps, capacity increases and your power draw increases (All of this assumes normal operating conditions without defect). If you want to know the maximum current draw take a look at the MCC rating, which is Maximum Continuous Current. That is the upper limit of the motor.

What compressor is inside that unit? Brand and model number?

[cooling storm]

umm the comp is unknown brand is matsu.s.h.i.t.t.a yes i know stupid name XD its a supid design so i cant see the comp specks good D: sorry man

[Stewie007]

Well, maybe the brand and model number of the actual A/C unit?

[cooling storm]

tha brand is wilfa and the unit was made in 2005 an the model is wac12000a and thers nothing on the internett about it D:

[Stewie007]

http://www.wilfa.no/katalog/product....195&imageid=90

There seems to be something there, but for the life of me I cannot read your language.

[cooling storm]

thats the new version of it mine is square pice of chinece built

[cooling storm]

it looks like this http://www.finn.no/finn/torget/tilsa...nkode=29869720

[Stewie007]

So what coolant mixture are you using?

[cooling storm]

dont know yet what do you recomend as a pump and coolant?

[Stewie007]

Well, like I said earlier, a good mixture is a 60/40 mixture of glycol and water. I like antifreeze made with propylene glycol the best; as it is non-toxic in the event that pets might get their paws on it. 9 liters of glycol to 6 liters of water. That should be able to keep your evaporator from freezing up.

As far as a pump, well I would look for something with a bit more flow than a typical water cooling system. I would say 1500 - 2000 Liters per hour. I've got some Little Giant pumps (Iwaki competitor) that put out ~3000 for one and ~4500 for the other. You don't really have to go that far, though. LOL.

Of course, it is acceptable to use something like an MCP655 which puts out 1200 Liters/hour. Its probably less costly, too.

[cooling storm]

ok thanx for the tip i have a 3000l/h pump shold i use it? or is it OVERKILL?

[Stewie007]

It depends on how many lines you are using. That is quiet a lot for a single line and more restrictive blocks might cause some pressure behind the restriction. Although, it shouldn't be enough to cause you leaks. Its something that I would monitor carefully.

For reference, the pump I am using pushes 1200GPH (approx. 4500 L/h). In my case it will be split four ways and with every split flow will decrease per new line. While the cumulative will remain somewhat constant, each line will only have a percentage of the whole thus keeping my pump from overwhelming the blocks with ridiculously high flow. It will also keep the flow high enough through the blocks while maintaining the much higher cumulative flow over the evaporator which will be just after the pump.

So what are you going to be chilling here? How many blocks?

[cooling storm]

im making it for a frend he is planning on using 3 blocks 1 for cpu and 2 for vga we are making it for the gathering 2012 norway

[Stewie007]

There are two ways you can do it. I would recommend splitting the lines before your blocks. This way you are getting about 17l/h through each line instead of 50l/h using one line. In American units that is 13GPM which is quite high for a typical water block. This way the equivalent of 4.4GPM is running through each block and that will equate to less pressure drop.

Don't forget to insulate everything.

Also, what kind of pump is that 3000L/h pump? I don't want to recommend that you use it without knowing. Some pumps are made from materials that aren't too friendly to these cold temperatures.

[cooling storm]

its a submersable pond pump 85 watt one

[cooling storm]

heres the pc

Dvd-reader : SONY DVD Recorder 24x SATA Dual Layer
Harddisk 1 : OCZ SSD 120GB Vertex 2 RW:285/275 MB/sec
Harddisk 2 : Western Digital Caviar Green 2TB 7200rpm
Kabinett : Antec Super Midi Tower P183
mtherboard : Asus Rampage 3 Extreme socket-1366
CPU : Intel Core i7-960 3.2ghz 8mb cac, s-1366
screencard 1: Gigabyte Radeon HD 6970 2GB GDDR5
screencard 2: Sapphire Radeon HD 6970 2GB GDDR5
PSU: ANTEC High Current Gamer HCG-900-PSU

[Stewie007]

So that's something like 750 Watts of modestly overclocked TDW.

Just see if you can find a minimum operating temp for that pump. It may not be a problem, but its one of those "nice to know" kind of things.

You might consider up sizing the PSU to give yourself some breathing room.