Extremely high temps for a phase-change system

[LoudHoward]

Right now Abit EQ is giving me +20 degrees for my 2.4A prescoot not under load. Now this is extremely odd as I have just put a Danfoss SC10CLX condensing unit on it as my home-built phase change.

I have no idea what the problem is, I can't press my block any harder onto the CPU and there is ice all over my evaporator.

Am I going mad? ANy suggestions?


EDIT: Whoops, forgot to say that my capillary tube is less than a metre in length. This is the one I got with the condensing unit. SOunds awfully short to me, could this be causing it?

[JimmyDean]

A meter? That seems really short.. Maybe it cant handle the load? What is the gas the system is using

[LoudHoward]

It is running R404A and yeah, it can handle the heat load. The SC10CLX is rated for -35 @223W. I understand that his is not 100% accurate and not what to expect but come on. How innacurate are the AI7 readings?

[Pandrone]

Try to overclock your machine, if it overclocks higher, then your temps are lower than before. Motherboards are famous for showing wrong...

[LoudHoward]

I get 4.0ghz @ 1.613 volts. My evap temp is roughly -5.

Something is seriously wrong. Capillary tube?

[EmineM]

check your bios. ( PC Health Status )
Abit EQ is not able to report minus temperatures, that was the case with my last 3 Abit ic7 motherboards.

[=w=]

It might just be, because the Pressies run so damned hot...and partially a wrong mobo reading.

[RaVeN155]

Tell us more about this system:
pressures, what condenser etc.

I think that cap tube is too short, try replace it with 1,5m 0,7mm or longer.

Did you tried to add more gas?

[LoudHoward]

Let me give you some background.

I have never tweaked the amount of gas in it, me and the engineer just put some gas in and hoped or the best. The capillary tube is also a tad shorter than what I originally got.

Please please please, can some someone help me.

The compressor is a Danfoss SC10CLX. The condensor is the one that came with it, bout 20 cm's by 20cm's.

Contact was a bit of a problem, I am sorting it out now

[Gary Lloyd]

The cap tube needs to be sized for the heat load and the refrigerant. The length of the cap tube is meaningless if we don't know it's inside diameter.

[LoudHoward]

The cap tube needs to be sized for the heat load and the refrigerant. The length of the cap tube is meaningless if we don't know it's inside diameter.

RIGHT! My cap tube internal diameter is: #110 Cap Tube - .031" ID

I have a prescott 2.4A. I imagine that it would put out about 200W of heat. Lets try tune it for about 220W of heat.

Is it possible to join two lengths of cap tube together? My original cap tube has been soldered into my evaporator.

[Gary Lloyd]

You need about 2.5-3 meters of .031

Use a short piece of 1/8 tubing to join them. You may have to drill it out a little to make it fit. The idea is to make a snug fitting sleeve.

[LoudHoward]

You need about 2.5-3 meters of .031
Thats insanely long!

I am sure tht I can organise everything though.

Out of interest, how about using capillary tube with a different ID/OD? How will that affect temps?

[BuLkHy]

its long bcoz ur using 0.031" ...
better go wit 0.028" ....

[Gary Lloyd]

Originally posted by LoudHoward
Thats insanely long!

I am sure tht I can organise everything though.

Out of interest, how about using capillary tube with a different ID/OD? How will that affect temps?

No, 1 meter is insanely short. Cap tubes less than 1.5 meters long are unstable.

Using .028 cap tube, you would need about 1.5 meters.

[LoudHoward]

Eh he he, I made a boo boo on the internal diameter. its not 0.31. Its 0.61" internal diameter.

How long should it be now? 6m?

[Gary Lloyd]

Rough guess: About 10 kilometers... LOL

[LoudHoward]

Be serious gary, I spent quite a bit of cash on that evaporator block, should I just put about 10m there and hope for the best?

[Z3RO_0]

I would not do that if I were you, it would handle very little heat load. There is a capillary sizing chart over at phase-change.com forums.

[Gary Lloyd]

.061 cap tube is used for the 1000-1500W heat load range. It is not even close to being suitable for these systems.

[LoudHoward]

.061 cap tube is used for the 1000-1500W heat load range. It is not even close to being suitable for these systems.

Ah :banana: :banana: :banana: :banana:. What crappy luck. I told the people here that I didn't intend to work with anything greater than a 200W heat load. So they give me this.

WELL its another $70 for me to get another block and try again.

[Gary Lloyd]

Just cut the cap tube off near the block and splice in some .031 or .028.

[LoudHoward]

Just cut the cap tube off near the block and splice in some .031 or .028.

I had that idea. I just hope against all hope that the refrigeration stores will be open tomorrow.

Will the 0.28" slide right into the 0.61"? Also, what will the expansion from the one capillary tube into the next be like, will it have any hugely negative affect on temps?

[Gary Lloyd]

Originally posted by LoudHoward
I had that idea. I just hope against all hope that the refrigeration stores will be open tomorrow.

Will the 0.28" slide right into the 0.61"? Also, what will the expansion from the one capillary tube into the next be like, will it have any hugely negative affect on temps?

You might be able to drill it out, or better yet tap a small nail into the end to stretch it, so that you can slip the .028 inside the .061. That would be the best way to splice it together. The negative effect, if any, should be very minimal.