Hi my friends,
I hope if any one Know about (VRV REFNET Joint) minimum distance between two pcs.
also what is the recommended distance for bends after the REFNET Joint.
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Hi my friends,
I hope if any one Know about (VRV REFNET Joint) minimum distance between two pcs.
also what is the recommended distance for bends after the REFNET Joint.
I can't see any 'specifics' in the Daikin manual but perhaps you would like to check yourself - here.
http://www.daikinac.com/commercial/d...stallation.pdf
Thank you Brian, I did. and also I didn,t find any specific informations.
A refnet is in fact a simple junction, so I don't think there's a minimum distance to be respected. But that's only loud thinking.
I even don't see why you should must a Refnet in the suction.
If you install the liens properly, then you can do a whole VRV/VRf without those but most manufacturers then comes with warranty.
I suspect them more willing to sell additional expensive Refnet/Headers.
Well, I've been on a few VRV/VRF training courses and the only mention about Refnet joints has been concerning the maximum distance between the first refnet and the last fan coil, or about not fitting refnets after distributors etc.
No mention has ever been made by any manufacturer about the distance between refnets or the distance for bends after refnets.
In fact, I don't know any manufacturer who has mentioned/published data about distance for bends in pipework.
Where does this question come from? - what installation problem are you considering?
As general rule we have always fitted ref nets no closer than a metre, Also you should use the ref nets supplied never mix in or just use tees its bad.
I bet if you ask the Fridge guys what they use on multiple evap systems they do not use Refnet joints,just tees probably and it makes no difference.I was actually sent a video from Daikin showing the importance of the Refnet joint using water and open end pipes,what this showed was that if you fit the Refnet outwith the parameters on a horizontal plane then more water flows out the bottom pipe.My take on this was that if you have open ends then obviously this will happen, however when connected on the refrigeration system the electronic valves creating the restriction would not cause this to happen, but to prove a point I would have to become very elaborate maybe using glass pipes! Its my opinion that they want to sell a very expensive peice of copper!! And cover their backsides over problems.
Ok guys the story as following: Two DAIKIN service engineers eas visit our site about 2 monthes ago and sent to us the follwing comment : (Avoid direct bends after Refnet joints).
I asked them what is the recommended distance? They said we will send you the ansower by email. I am still waiting thit ansower, the last news they will send it at 2 Aug.
And also I am tring to find some ansowers here.
Generaly there is no any informations about this isue in DAIKIN manuals and I told them this.
The reason for the bend not to be after the refnet is due to expansion and contraction of the pipes on the refnets, this is why it is also important when supporting your pipes to make sure they are not secured down too tight so that they can expand and contract as the pipes can go from a temp of 70 degrees to minus temperatures in the space of minutes so you can just imagine the expansion going on there.
Also make sure that you do not support the pipes too close to the refnet for the same reason..
hmm... interesting
Iv done a few installs where i put 2-3 refnets directly one after the other with no ajoining pipe between, all the systems worked well.
daikin techs came out to commission and saw the pipework, and didnt mention anything, so i assume there are no issues with this.
The way the system performed says the same thing!
Do you mean the direct bends after the refnet make a reduction for the pressure and according to this some of liquid refrigerant will be gas?Quote:
Originally Posted by brunstar