Goliath Triple Cooling System

[Sweeper]

Looks like it's undercharged to me, or the txv is undersized. You said -32C evap inlet, and I see an uninsulated and sweating suction line where the bulb is attached, so that line is lower than dew point, higher than 0C. Superheat must be between 32C and 52C, in any case way too much!

If the txv is sized correctly for the load, add charge until you get a reasonable superheat in the range of 3C to 10C.

I added more liquid refrigerant on the high side until it would not take anymore, the superheat only got to 16.9C. and the suction line stop sweating. The TXV is a Sporlan FSE-1/2-ZP and my compressor 1/2HP, so I think the TXV is sized correctly.

Wait, is your low and high side pressures different when system is off?

Yes, the pressures are different...this is what I have this morning with the system off.

Yep agreed on undercharged, also what sorta load is that pump providing? Insulate up first since your system will see different loads that way, add more refrigerant, and make sure your TXV is sized right.

I'm not sure what the load is for the pump....I'll do a test to find out.

By the way guys, I appreciate your advice and help.

[DetroitAC]

You added to the high side? You must mean with the system not running ?

The proper way to charge is to add to the low side with the system running until you 1st get the superheat under control, 2nd get the subcool that you want.

Pressures when the system is off are not important with a system like this. The system will be what I would consider "normal" with enough charge to be saturated when off. Thus the high and low side readings are the saturation pressures for the temperatures present. They will eventually come to equilibrium at the saturation pressure of the coldest point (unless your txv is really sealing off well). So you take a look at the gauges somewhere in that process...it tells you nothing except how cold the evap is at that moment.

I looked through the thread, and can't find the model Tecumseh you are using, but I agree that your txv isn't undersized (can't tell if it's sized right).

[Sweeper]

You added to the high side? You must mean with the system not running ?

The proper way to charge is to add to the low side with the system running until you 1st get the superheat under control, 2nd get the subcool that you want.

Pressures when the system is off are not important with a system like this. The system will be what I would consider "normal" with enough charge to be saturated when off. Thus the high and low side readings are the saturation pressures for the temperatures present. They will eventually come to equilibrium at the saturation pressure of the coldest point (unless your txv is really sealing off well). So you take a look at the gauges somewhere in that process...it tells you nothing except how cold the evap is at that moment.

I looked through the thread, and can't find the model Tecumseh you are using, but I agree that your txv isn't undersized (can't tell if it's sized right).

Yes, I added liquid charge on high side when the compressor was off. and added vapor charge to low side when the system is running. The suction pressure continues to raise to about 20 PSI and the high side starts to drop. When the system is off, the suction pressure continues to rise to about 90 PSI and the compressor is hard to start.

The compressor model is AJA2419YXA.

[Sweeper]

Good News! Thanks DetroitAC and noob for the advice. I was way undercharged on the system. I'm starting to see good results with the cooling now. I need to insulate and apply heat load to fine tune the system. Also, think I will start on completing the cooling chamber system, so I can tune both systems in the normal operating stage.

Superheat temp 4.1C and liquid block temp -15.8


Running pressures


Think its time to insulate


I like to see frost

[n00b 0f l337]

Where ya measuring superheat at?

[CL3P20]

Single-handed..the most amazing build I have ever witnessed. This thing is EPIC. Cant wait to see more!!

*now off to linky a few folks here*

[Sweeper]

Where ya measuring superheat at?

I measured the superheat after the bulb...see the third picture.

[AllAgainstPaul]

For a second there I thought the frost pic had the window on. Until I saw the wires leading out.

Have you check what the base ambient air temperature is inside the chill-box?

[CyberDruid]

FROST! That's a great sign!

[DetroitAC]

correct me if I'm wrong sweeper, but you've got a temperature of 4.1C after the bulb? That's not the same as a superheat, unless you're using a T1-T2 function on the TC reader (doesn't look like it based on the LCD). Based on your gauge reading, I'd say you still have 20~30C superheat. You should keep adding charge until you get subcooling (got a sight glass?)

Your compressor will be hard to start with R507 because it's an R134a compressor AJA2419YXA. Y=R134a code, Z=R507 code

R134a uses a lot more compressor displacement per motor power than R507 does. In the case of that compressor, Tecumseh makes the same compressor for R507 AJA2419ZXA, and my guess is it has the same compressor parts with a (more powerful) motor more suited to R507.

[Sweeper]

correct me if I'm wrong sweeper, but you've got a temperature of 4.1C after the bulb? That's not the same as a superheat, unless you're using a T1-T2 function on the TC reader (doesn't look like it based on the LCD). Based on your gauge reading, I'd say you still have 20~30C superheat. You should keep adding charge until you get subcooling (got a sight glass?)

Your compressor will be hard to start with R507 because it's an R134a compressor AJA2419YXA. Y=R134a code, Z=R507 code

R134a uses a lot more compressor displacement per motor power than R507 does. In the case of that compressor, Tecumseh makes the same compressor for R507 AJA2419ZXA, and my guess is it has the same compressor parts with a (more powerful) motor more suited to R507.

Yes, 4.1C was after the bulb and I was using T1 function. I also have a sight glass and its almost filled solid, except for a little circulation. I agree it could use more refrigerant, but I think I should wait to add more refrigerant once I get the cooling chamber system operation with heat load to tune both systems without overcharging. The gauges are within 10 psi of being even pressure and the compressor starts fine now. I'm in the process of insulating and its real pain, because I didn't allow enough clearance between the lines.

If this compressor fails to do the job....I have a back up plan to use a low temp 1 HP compressor made for R507. I also have a low temp 2 HP compressor, but I'm sure this monster would be overkill.

Thanks again guys for your comments and I will keep you up to date with progress.

[Polizei]

If this compressor fails to do the job....I have a back up plan to use a low temp 1 HP compressor made for R507. I also have a low temp 2 HP compressor, but I'm sure this monster would be overkill.

*looks back at rest of thread and all the pictures*

[THRASHER2]

That System is

[Sam__]

that thing is freaking awesome!!!!!

[Fusion2002]

wow.... amazing

subscribing

[MuffinFlavored]

Amazing.

[n00b 0f l337]

Any updates Sweep? On any projects
Hoping for some load temps here this really is quite nice

[Sweeper]

Any updates Sweep? On any projects
Hoping for some load temps here this really is quite nice

I have a little update on two of my projects and the last pics are for you noob I've almost completed the insulation on the liquid chiller and the cooling chamber system should be complete by the weekend. I will update more pics once I get both systems running.

Both systems almost complete


What do you guys think of the insulation job....


noob, this is your muff prototype....what do you think. I can make this for you within the budget we discuss. Let me know if you still want them.

[n00b 0f l337]

Very nice, really need a lip or something though around the outside though for a mounting plate to sit on. Would that be possible? Probably 3/4" lip area height wise, maybe half the thickness there? I gotta figure out a holesaw size or something though to make a matching hole for the mounting plates.

[Sweeper]

Very nice, really need a lip or something though around the outside though for a mounting plate to sit on. Would that be possible? Probably 3/4" lip area height wise, maybe half the thickness there? I gotta figure out a holesaw size or something though to make a matching hole for the mounting plates.

I thought the 1 1/2" evaporator would insert through the hole and have a lock ring at the base. Then, insulation between the evaporator and the inside of the muff. PM me on the total length of the evaporator and I will make you mounting plate and a muff to fit.

[n00b 0f l337]

Hey PM feature wont pull up under your name.
The 1.5" evap goes in the hole and lock rings, so then Muff sits on the ring around the evap, insulation between evap and muff, heights not a matter on the Muff really. Then a mounting plate needs to sit onto the Muff and be able to freely spin basically, mounting plate will be universal and I have a cheap material thats plastic picked out that I can get cut into any rectangle/square and rounded off rather cheaply, then just have to do the mounting hole to fit around the lip there

[coo-coo-clocker]

What do you guys think of the insulation job....

Like everything else on this project...
TOTALLY PRO!
*sob* its beautiful man!

[[XC] gomeler]

Just use a lathe to trim a small quantity of material from the outside of that muff like the old Chilly1 mount. God that mount kicked ass, melted my last one a few months back

Great unit there Sweeper, it looks industrial

[CyberDruid]

I feel like I got a touch of double vision

Beautiful work

[[XC] riptide]

Xtreme in its Finest Tradition.