Cap tube sizing rule

[johann]

6 feet is short in comparison to what? a 0.031" cap with r507?

I don't think 8 feet will be able to hold the load anymore. but maybe start with 8 feet and work down from there.

I agree with this, 240cm (8ft) is close to a good length of 0.028" when you use R507a or R402a. R290 likes it a little shorter. I would guess around 200cm of 0.028 would be pretty close to what will be ideal for you but to be safe you can start at around 240cm abd work your way down.

As said before, it also depends on the compressor and evap you use, my guess is based on usage of a NL11F (220v) or NF9FX (110v)

[[XC] 2long4u]

Can I go shorter since I'm running an accumulator?

[Pansuu]

Any idea how long captubes i need, first stage and second? Tube size is 0,79mm.

Cascade with two 1hp rotary`s. First stage maybe r402 or r410a and second etylen.

[tim-]

for first stage you could use a tvx if you want 'cause the load is pretty stabile and big enough.

otherwise I would start with 2,5-2,7meters of captube in both stages, maybe a little longer in second.

[Pansuu]

Hmm.. i have one Danfoss TX2 but it is only -40c and r22

[[XC] 2long4u]

Ok again. Can I go shorter since I'm running an accumulator?

[Ssilencer]

Ok again. Can I go shorter since I'm running an accumulator?

Yes you can
Start making your own field experiences man.

[Unknown_road]

doesn't help efficiency though

[Eightballrj]

Ok, can someone tell me why or if it would be bad to go with a shorter cap tube than needed? Seems like you have more head room the shorter your cap tube is (to a certain extent of course). I am thinking of starting a vap phase system this summer and having one of my buddy's dad charge it for me with whatever refrig is needed for my setup(evap going on either GPU or CPU)... would love to build a dual head until but that might be a bit hard for a first build.

Thanks!!

[Marvin]

i have found a good article about refrigeration, also cap tube measures. Unfortunately it is in portuguese, but altavista can be your friend :
http://www.trocalor.com.br/apostilas/rac_01.zip
page 84.
regards.

[ae804]

First off, Great read, lots of information here. I appreciate it all

secondly...

Ok, can someone tell me why or if it would be bad to go with a shorter cap tube than needed? Seems like you have more head room the shorter your cap tube is (to a certain extent of course). I am thinking of starting a vap phase system this summer and having one of my buddy's dad charge it for me with whatever refrig is needed for my setup(evap going on either GPU or CPU)... would love to build a dual head until but that might be a bit hard for a first build.

Thanks!!

I'm guessing it's because it's easier to make a captube shorter than longer.

Thanks!

[[XC] gomeler]

Yup, trimming is a breeze, splicing.. yuck

[ruffus]

so i was reading this over and if you had 10 foot of 0.028 for a 150 watt load on r404a/r507
and if you are to get a increase of 15 watts for every foot you remove then to get 300 watts would you not have to remove all the cap tube by this rule

[teyber]

so i was reading this over and if you had 10 foot of 0.028 for a 150 watt load on r404a/r507
and if you are to get a increase of 15 watts for every foot you remove then to get 300 watts would you not have to remove all the cap tube by this rule

which means that you shouldn't use .028 for 300 watt load eh?

that is funnyt hough

[n00b 0f l337]

Its not really an accurate rule, the best way is to simply try something from someone else, then tune around that.

[ruffus]

i use 0.031 but i seen this rule and seen this problem and thought i might say something about it

[TheMysticWizard]

So I have 10 feet of .052 cap tube laying around... I am planning on about 150w load. Any way I can make this work?

[Moc]

Nope. Captube is cheap, buy .031 tube

[sdumper]

bump

[Ian[Frozen]]

I'm not sure where I came across this article from Supco but a method is described using a balance gauge to determine if the cap tube length is sufficient of a restriction or not simply running the compressor on filtered air for just a few minutes to test, which can be done prior to charging..

http://www.supco.com/images/pdfs/Man...g%20Manual.pdf


I think there may be a few things wrong with the theory for our needs but what do I know, like we're testing and adjusting the cap tube with air which has very different flow characteristics then a fluid, a cold one at that! But I'm wondering if it's worth a shot?? Any ideas?

[n00b 0f l337]

That was one of the few awesome articles I've read in a while. Quite good and a hand off to supco.

[Ian[Frozen]]

I'm glad it was a worthwhile read, wasn't sure how it applies in our scenario. I'm wondering if we could use a vacuum gauge instead of a flow meter??