20 plate versus 30 to 35 HX

sdumper · 10-20-2009, 08:26 AM

What do I gain by going to a 30 or 35 plate HX from a 20 plate?

In reference to cascades...

MeltedDuron · 10-20-2009, 08:34 AM

More heat exchanging as there is a bigger area i would of though. Same for using a bigger condesner, bigger so more cooling!

Buckeye · 10-20-2009, 08:58 AM

Don't you reach a point tho where bigger buys you nothing more and has possible negative effects ?

What are the draw backs to simply putting in larger componets ?

So bigger condensor sounds great, but i am sure there is a balance to things, what the design is, what loads its desigened for, cooling capacity etc.

With a larger condensor you would need more refrigerant, how does that effect tunning and load handling and capacity ?

How does a 35 plate heat exchanger effect the loads, does it become sluggish in responce to loads ?

Simply saying bigger is better is not always true and can have other side effects that may or may not be wanted.

sdumper · 10-20-2009, 09:30 AM

Quote:

Originally Posted by Buckeye

Don't you reach a point tho where bigger buys you nothing more and has possible negative effects ?

How does a 35 plate heat exchanger effect the loads, does it become sluggish in responce to loads ?

Simply saying bigger is better is not always true and can have other side effects that may or may not be wanted.

Good points and the reason for this thread...

I have used 10 plate and 20 plate HX's successfully before. the 20 plate seems to work better but I noticed Kayl using a 30 plate so it got me wondering...

tiborrr · 10-20-2009, 10:31 AM

No use, 10 plate is well enough for a two stage cascade & 300W CPU load. I'd go for 20 plate just to be sure in a three stager, but that's just me.

sdumper · 10-20-2009, 11:06 AM

Thats good to know because 10plate is a lot cheaper

teyber · 10-20-2009, 02:21 PM

Quote:

Originally Posted by Buckeye

Don't you reach a point tho where bigger buys you nothing more and has possible negative effects ?

What are the draw backs to simply putting in larger componets ?

So bigger condensor sounds great, but i am sure there is a balance to things, what the design is, what loads its desigened for, cooling capacity etc.

With a larger condensor you would need more refrigerant, how does that effect tunning and load handling and capacity ?

How does a 35 plate heat exchanger effect the loads, does it become sluggish in responce to loads ?

Simply saying bigger is better is not always true and can have other side effects that may or may not be wanted.

jinu illustrated some important notes about having too big of a HX, just as having too big of a condenser on the second stage will require MORE ethylene to condense to static/startup and a high high side pressures.

sorry if that doesn't make sense

sdumper · 10-20-2009, 02:54 PM

Quote:

Originally Posted by teyber

jinu illustrated some important notes about having too big of a HX, just as having too big of a condenser on the second stage will require MORE ethylene to condense to static/startup and a high high side pressures.

sorry if that doesn't make sense

I could use those notes because the desuper im about to use is a lot larger than i normally use:

http://cgi.ebay.com/ws/eBayISAPI.dll...tab%3DWatching

[XC] gomeler · 10-20-2009, 02:57 PM

^ this. Your high-side pressures won't be bad on a 3 stager so long as the 1st stage can handle the load but your static pressure will be through the roof. The 2nd stage shouldn't include anything flexible so you can run a little bit high on the static pressure, just keep in mind the maximum rated pressure on the components, especially the oil separator. This is also taking into consideration that the 2nd stage will NEVER be powered on without being chilled. That oil separator starts to think about becoming a hand grenade very quickly with a 300psi static and the compressor spinning up.

Quote:

Originally Posted by sdumper

I could use those notes because the desuper im about to use is a lot larger than i normally use:

http://cgi.ebay.com/ws/eBayISAPI.dll...tab%3DWatching

Desuperheater size doesn't matter, you cannot condense R1150 at ambient temperatures with the pressures you are using. Your R1150 will be gaseous until it hits the HX. Condenser/DSH sizing only matters when you are condensing refrigerant within it as you start to collect excessive amounts of refrigerant in the coils.

sdumper · 10-20-2009, 03:47 PM

Quote:

Originally Posted by [XC] gomeler

Desuperheater size doesn't matter, you cannot condense R1150 at ambient temperatures with the pressures you are using. Your R1150 will be gaseous until it hits the HX. Condenser/DSH sizing only matters when you are condensing refrigerant within it as you start to collect excessive amounts of refrigerant in the coils.

Cool thanks Chris.

Quote:

Originally Posted by [XC] gomeler

^ this. Your high-side pressures won't be bad on a 3 stager so long as the 1st stage can handle the load but your static pressure will be through the roof. The 2nd stage shouldn't include anything flexible so you can run a little bit high on the static pressure, just keep in mind the maximum rated pressure on the components, especially the oil separator. This is also taking into consideration that the 2nd stage will NEVER be powered on without being chilled. That oil separator starts to think about becoming a hand grenade very quickly with a 300psi static and the compressor spinning up.

Were you talking to me with ^this or Tiborrr ? My build im starting right now is a 2 stage and I dont rebuild the 3 stage until late November.

[XC] gomeler · 10-20-2009, 04:32 PM

Quote:

Originally Posted by sdumper

Were you talking to me with ^this or Tiborrr ? My build im starting right now is a 2 stage and I dont rebuild the 3 stage until late November.

Was indicating teyber's post, your post wasn't up when I was composing mine.

yngndrw · 10-20-2009, 04:38 PM

Quote:

Originally Posted by [XC] gomeler

Desuperheater size doesn't matter, you cannot condense R1150 at ambient temperatures with the pressures you are using. Your R1150 will be gaseous until it hits the HX. Condenser/DSH sizing only matters when you are condensing refrigerant within it as you start to collect excessive amounts of refrigerant in the coils.

Question, does the compression not heat the gas to a higher temperature than the ambient regardless of if it is condensing at that point or not ?

teyber · 10-20-2009, 05:11 PM

Quote:

Originally Posted by sdumper

Cool thanks Chris.

Were you talking to me with ^this or Tiborrr ? My build im starting right now is a 2 stage and I dont rebuild the 3 stage until late November.

ill try to find it for ya mate. And by condenser i mean the hx not dsh..

Ozzfest05 · 10-20-2009, 05:15 PM

Quote:

Originally Posted by yngndrw

Question, does the compression not heat the gas to a higher temperature than the ambient regardless of if it is condensing at that point or not ?

Yes but that heat is removed or transfered into the copper piping in the condenser then the fans removed the heat from the piping/fins, rifled condensers transfer more heat.

sdumper · 10-20-2009, 05:57 PM

Quote:

Originally Posted by [XC] gomeler

Was indicating teyber's post, your post wasn't up when I was composing mine.

Gotcha ... I was dazed and confused for a few minutes

yngndrw · 10-21-2009, 04:24 AM

Quote:

Originally Posted by Ozzfest05

Yes but that heat is removed or transfered into the copper piping in the condenser then the fans removed the heat from the piping/fins, rifled condensers transfer more heat.

Now I'm confused.

They were saying that desuperheater size doesn't matter at all, I.e. It doesn't make a difference. The condenser in the second and third stages is the same as the desuperheater.

The point that I was making is that the compression generates heat regardless of if the gas is condensing or not. This means that the gas leaving the compressor is above ambient and can be cooled to (... close to ...) ambient by the condenser / desuperheater, hence it does make a difference and the size does matter.

Or am I getting something wrong here ?

sdumper · 10-21-2009, 04:48 AM

Quote:

Originally Posted by yngndrw

Now I'm confused.

They were saying that desuperheater size doesn't matter at all, I.e. It doesn't make a difference. The condenser in the second and third stages is the same as the desuperheater.

The point that I was making is that the compression generates heat regardless of if the gas is condensing or not. This means that the gas leaving the compressor is above ambient and can be cooled to (... close to ...) ambient by the condenser / desuperheater, hence it does make a difference and the size does matter.

Or am I getting something wrong here ?

No your not getting anything wrong. A Desuper is needed but it does not need to be very large so long as the gas leaving the condenser is close to room temp so that it doesnt enter the HX excessively warm/hot.

yngndrw · 10-21-2009, 04:52 AM

Okay that makes more sense thanks for clearing that up.

Ozzfest05 · 10-21-2009, 09:50 AM

Quote:

Originally Posted by yngndrw

Now I'm confused.

They were saying that desuperheater size doesn't matter at all, I.e. It doesn't make a difference. The condenser in the second and third stages is the same as the desuperheater.

The point that I was making is that the compression generates heat regardless of if the gas is condensing or not. This means that the gas leaving the compressor is above ambient and can be cooled to (... close to ...) ambient by the condenser / desuperheater, hence it does make a difference and the size does matter.

Or am I getting something wrong here ?

The main thing here is were talking about cascade so yes the condenser is used as a desuperheater and it does not need to be very large
The main purpose is by lowering the heat of the gas which enters the HX
Your putting less load on your first stage less load equals lower pressures and better temps on your final stage.

DonNiger · 10-21-2009, 02:18 PM

20 plate HX should be able to handle 2 - 5kw of heat (a lot of inflected factors), 35 plate up to 8kw - thats a lot I think.

EvoCarlos · 10-21-2009, 04:03 PM

jsut thro a spanner in the works

i have a 24plate on outdoorcade and found it to be no diffrent form the 12plate just larger in size the diffrence in running porformance is minimal

but with more gas in the system = more capasty so larger hx more liquid -more capasity -to that sort of effect

i do think that a dsh is not needed on the 2nd stage but can take 5-10c off the gas temp (as alrady said) making it less load for the 1st satge