R410a not a good choice?

[supercoolin]

I am new to this site and have been looking at all the great threads and ended up a little puzzled. There is very little use of R410a refrigerants in the small single stage systems. I modified a Vapochill LS to use HC-502a to get a little bit better temps and in all my playing around I ended up using R410a as my final refrigerant because of it’s capacity and lower temps.

The LS is basically stock other than added a small receiver (1” x 4”), changing the expansion bulb and line (3/8” line with a 2”x 6” tank) and adding a little TEC block inline to pull a few more watts during benching. The final charge was 3.5oz with 1.5psig low side, 255psig high side under 125W load with evap temps of –45C and Phenom II core temps of –16.5C during Wprime1024 @4.1Ghz and 1.5875V.

I have tried R404a, R22, HC22a, HC502a, and R410a with the R410a being the clear winner, what am I doing wrong or is there a better coolant that I am missing?

http://members.cox.net/gorillasnawt/410_1.jpg
http://members.cox.net/gorillasnawt/410_2.jpg
http://members.cox.net/gorillasnawt/410_3.jpg

[teyber]

wow nice results and clean build!

are those soldered joints though? -_-

[Buckeye]

There is a lot of stuff packed in that case :up:

[n00b 0f l337]

Is that a receiver, before the condenser?

[supercoolin]

wow nice results and clean build!

are those soldered joints though? -_-

yes, I used silver solder on all the joints since it was used prior, hard to braze over solder.

[supercoolin]

Is that a receiver, before the condenser?

In order to increase the amount of R410a in the charge, I added a little 1" x 4" homemade receiver, it added 3/4 oz and stablized the load temps. It also cut down the start-up time by almost 30 sec. I was really surprized how well it worked for something so crude and simple.

[sjg0]

yes, I used silver solder on all the joints since it was used prior, hard to braze over solder.

uhhhh..... you dont mean solder like, with a soldering iron do you?

[teyber]

yes, I used silver solder on all the joints since it was used prior, hard to braze over solder.

wow... very nice looking brazes you have there :eek: its so clean it looks almost like you soldered it with like electrical solder :shrug: but nope you just have mad patience :up:

[supercoolin]

uhhhh..... you dont mean solder like, with a soldering iron do you?

No, no, SAFE FLO lead free silver solder that you need to use at least a MAPP gas torch to use. For HP plumbing joints.

[sjg0]

No, no, SAFE FLO lead free silver solder that you need to use at least a MAPP gas torch to use. For HP plumbing joints.

lol k. Beautiful work btw. Good idea with the receiver. :up:

[sdumper]

Nice job1

Whats your static and start up PSI?

[n00b 0f l337]

What is the receiver supposed to do though?
If the output is through the bottom, you really don't accomplish anything; it's not feeding liquid to the condenser for sure. Doubt its stifling vibration...

[Moc]

A reciever BEFORE the condensor is totally useless and will only produce problems.

[sjg0]

A reciever BEFORE the condensor is totally useless and will only produce problems.

oh wow lol. yea I didn't even notice it was before condenser. I don't see how it would produce problems though, seems to me to be just a bit of a waste :S

[[XC] gomeler]

It could potentially collect oil, not good.

[Ozzfest05]

it looks pretty tight fit in that case

[supercoolin]

Nice job1

Whats your static and start up PSI?

Static is 68psi @ 21c
3 sec 325psi 48psi 21c evap
10sec 305psi 22psi 21c evap
20sec 285psi 5psi 16c evap
30sec 270psi 4psi 10c evap
45sec 265psi 3psi 2c evap
60sec 260psi 2psi -10c evap boot
75sec 258psi 1.5psi -23c evap 1c BIOS Core
90sec 256psi 1.0psi -37c evap -12c BIOS Core
105sec 254psi .8psi -46c evap -18c BIOS Core
120sec 255psi .5psi -58c evap -23c BIOS Core

I am using the AOS Silicone Heat Compound and have ordered some Artic Cooling MX-2 to see if the core temps go down a little further. At the same time I change the thermal grease I will relap the evaporator hoping that will improve the core temps a ltille more also.

[supercoolin]

A reciever BEFORE the condensor is totally useless and will only produce problems.

What is quite strange in this little mod was that when I added the homemade receiver after the condenser it was useless, I didn't increase the charge volume at all. It was just playing around and trying to get it to fit better that I connected it to the system before the condenser. It wasn't until after I had recharged the system and had it running that I noticed the error. Much to my surprize on this little system, I added 3/4oz of charge volume and it reaches low temp almost 30sec faster. Fluke? I don't know, but it has actually improved performance and capacity, so I don't want to mess up this Mod by relocating it. As for oil retention, it could only capture a couple cc's in the bottom before it is pushed up the liquid tube.

Anyway the unconventional location helped, not hurt this little SS Mod.

[aenigma]

It is possible the improvement might actually be from it acting as an oil separator, so you're getting less oil in your evaporator which is helping performance.

[tiborrr]

It is possible the improvement might actually be from it acting as an oil separator, so you're getting less oil in your evaporator which is helping performance.

My thoughts exactly. Anyway, very nice mod! :yepp:

[DetroitAC]

Back on topic, R410a is not terrible, just not the best choice.

R507 will do better

[sdumper]

It is possible the improvement might actually be from it acting as an oil separator, so you're getting less oil in your evaporator which is helping performance.


So whats to keep it from collecting oil until the compressor runs low and starts to generate friction? Or if it fills up with oil then it becomes useless right because then any new oil just floats over the top and back through the lines again.

Sorry if this is a stupid question but trying to figure this out...

[DetroitAC]

So whats to keep it from collecting oil until the compressor runs low and starts to generate friction? Or if it fills up with oil then it becomes useless right because then any new oil just floats over the top and back through the lines again.

Sorry if this is a stupid question but trying to figure this out...
Not a stupid question at all Scott, If it has a dip tube for the outlet it stores a little bit of oil (not enough to harm the compressor) and then does nothing. It's what I would call a discharge line muffler.

This sort of thing actually happens all the time. Somebody will run a "test" on something without really having control over the variables, and something will appear to be better. I do believe that the OP got better performance after adding this muffler, but I don't think it's because of the muffler. Something else changed...

[sjg0]

Something else changed...


The TEC after the condenser maybe? lol
Although i dont see how that would get better temps, i was thinking it would just be able to hold more load. :shrug:

Oooohhhhhh..... Maybe because of that TEC it is reducing the delta between load/idle to near 0 so thats why he gats better temps. I get it.

[Moc]

When you get good results with R410A, then I guess your captube is too long for R507, R404A. If you would short it, you'll get the same power but lower pressures.
Lower pressure make the unit more efficent and silent.

[supercoolin]

When you get good results with R410A, then I guess your captube is too long for R507, R404A. If you would short it, you'll get the same power but lower pressures.
Lower pressure make the unit more efficent and silent.

Thanx for that info. The system was originally set up for R404a and I had converted it to HC-502a for a little better load handling. To get the -54c temps with the HC-502a I had cut off about 10" from the cap tube on that MOD, so it carried through to the R410a MOD. I think the shorter cap tube has contributed to the great performance of the R410a and the low head pressure of 255PSI. The unit is surprizingly quite and with the R404a, a Phenom 9950 @1.5v, 3.85Ghz, it ran -2C at full load, with HC-502a 1.55v, 3.92Ghz it ran -9C at full load. With the HC-502a and a Phenom II 940 @ 1.585V and 4.16Ghz it ran -13C and with the R410a it is running -16-17c at full load. I should have some MX-2 grease tomorrow and I will start measuring again, I am hoping for some better core temps with a hand lap and better thermal grease.

BTW i am going to go off on the deep end and build a cascade with a target of -70c, could someone post a link to a website that has casacde controllers (2-3 stage) for sale. I have had no luck in all my searches for a site that sells and will stand behind the product they sell. I have had multiple burns on private sales over the years, so I want to make sure we have PayPal or a credit card involved in any purchase. I am not looking for cheap, I am looking for function and quality. I have learned that any cascade is only as good as it's controls.

[supercoolin]

The TEC after the condenser maybe? lol
Although i dont see how that would get better temps, i was thinking it would just be able to hold more load. :shrug:

Oooohhhhhh..... Maybe because of that TEC it is reducing the delta between load/idle to near 0 so thats why he gats better temps. I get it.

It doesn't lower the evap temp any, it gives me 5-6c better core temps under plus 2hr torture tests (improved load as you sumized, makeshift intercooler/subcooler). It keeps the high side a couple of degress under ambient under full load conditions.