system advice

fixerDIYupper

Long time reader, first time poster...



I'm hoping you guys can give me some feedback on proposed components for a piping conversion of ci rads to pex-al-pex tubing. I know there are a lot of threads here on this conversion, and I think I've read all of them.



I'm thinking of using a Rifeng 8 port radiant heating manifold combined with Rifeng Pex-Al-Pex tubing. I originally wanted to use the MultiCor, but I realized the manifold is an EK20 thread connection, and the Wirsbo PAP compression fitting are QS style, and supposedly will not fit.



Are Rifeng tubing and manifold systems really that bad, and am I going to have to dish out the money for a Wirsbo manifold? I need an 8 outlet for one zone and another 5 outlet for a second zone.



Any advice on the quality of Rifeng products is appreciated! Thanks,,,

Snowmelt

Sizing

Why would you use a wirsbo manifold?



What size piping are you using? What's the heat load of each zone?



Why can't you make a copper manifold?

heatpro02920

Im confused, but that don't take much to accomplish..

For forced hot water cast iron radiators, I wouldn't use a radiant heating manifold, check what your flow rates are going to be and do the math, figure out what size tubing you need, figure out how many of them, get your flow rates and make or buy a header to handle the load...

http://www.ravenproducts.us/hydronics.htm#headers

Eastman

DIYer

People use manifolds for rads all the time. It saves time and I don't think you'll save much cash assembling your own. I'm pretty sure you can get QS adapters for anything (definetly EK20) but the cost adds up when you need a bunch of them.

Ironman

You get what you pay for

I would not use any Chinese manifolds. They're junk. Why would you attempt to construct a Cadilac from Yugo parts?I've had two jobs where the customer supplied the manifolds (both Refeng) and they leaked like sieves. Since then, I insist on using ones that I provide - Rehau, Caleffi or Viega.The same goes for pex-al-pex. I wouldn't consider the Chinese stuff.There are photos somewhere on the site of the Chinese pex delaminating and blistering after a short time.If you're looking for all the features that good manifolds provide (individual circuit purging, flow control, balancing, etc.) then you'll find you're better of purchasing them than trying to construct them.

Harvey Ramer

EP Manifold

I have been using Uponor's EP fittings, including their EP Manifold for a quite a while and never had a lick of trouble. The EP Manifold is very affordable and I like all the goodies that come with it. I use Viega's stainless manifold sometimes too and it is really nice.



Don't put junk in. It will never let you alone and you won't feel good about it.



Harvey

fixerDIYupper

Thanks for the advice guys.

I didn't realize that Rifeng was Chinese, and I haven't been able to find much feedback about the products besides "..wow...great value..." I decided to go with MultiCor and Uponor manifold. I can;t get around using their QS compression fittings, can I? they're like $11 a piece, and I need 80!

Eastman

Uponor

You can buy Uponor manifolds that come with matching QS fittings at basically no additional cost. Why do you need 80 of them?

Ironman

Doesn't Add Up

He posted earlier that he needed one 8 station manifold and one 5 station. That's 13 loops and 13 sets of connectors.

fixerDIYupper

80 not yet

So I have 8 radiators on the second floor, and there are going to be 4 or 5 on the third floor. Each radiator needs two connections at the rad, in/out, and the same for the respective rad at the manifold, so 4 fittings per rad, so 52 connections for 13 rads. My fault on the 80, that was including the first floor rads which I'm not going to be converting just yet. But... the first floor is also 8 rads, so down the road, another 32 fittings (this is a duplex where first floor is one unit, and floors 2 & 3 are the other unit).

fixerDIYupper

matching QS fittings

Thanks Eastman... could you send me a link to a manifold that includes the fittings. I'm looking at the manifolds on pexsupply, ands they all say something like:



"This manifold requires (##) Loop Fitting Assemblies:"



And then it lists the compatible fittings for respective tubing type.

Ironman

Manifold connectors vs Male adapters

The fittings needed at the rads will be male adapters, not manifold connectors.

fixerDIYupper

MultiCor or hePex

is there a substantial advantage for PAP over hePex. I know the max's are a bit higher, @ 180F up to 200PSI for PAP. This factor probably would impact a hydronic heating system as the temps will be run a bit higher than an in-floor radiant heat... right??

Eastman

too good to be true

Either they removed those kits or I am going crazy and my memory is failing me. I can't find it anywhere on that site. I recall there being manifolds with adapters included for specific pex sizes/types, but maybe it was all a dream.



sorry to get your hopes up, fixerDIYupper

Eastman

difference

hePex, even with its o2 barrier is not truly oxygen tight. PAP is 100% tight. PAP also moves less than regular pex due to its stiffness and substantially less coefficient of thermal expansion. Less movement generally translates to less noise, and perhaps less wear and tear if the tubing is rubbing on something sharp.



The max temperatures aren't really important here, even with a radiator system.