Dura-Pex vs copper pipe

[Doc_Bob]

Just how hot do you expect the supply water to get? Pex can handle water up to 200 degrees at 80 psi, and even hotter if the pressure is lower. It seems to me that something is wrong if your water is that hot coming from the collector, and you are losing a lot of efficiencies. Generally, you can regulate the supply water temperature by increasing the flow rates so that the water moves faster and has less time to heat up.

In general, for best efficiencies you don't want to have more than a 10-20 degree temp rise through any heat exchanger. Any more than that and your efficiency will suffer.

I just quoted the folks who make the Dura-pex (CPI?). Their email is part of my post. I thought it would be a great idea, but the makers of the product think otherwise.
Bob

 

[LarryRB]

I just completed a considerable amount of Pex in an old house, and guess what? Probably 6 or so fittings are now behind walls,,., No one told me it was illegal , although in honesty, I didn't ask either,, Maybe this is a state law where you live?

 

[randy41]

i think illegal in the plumbing code sense not the cops are at the door sense.

 

[mlinnane]

There has been so much talk about the pex I had to my two cents. I have Wirsbo pex in my floor for radiant heat. I had the tool so I decided to do my new boarding kennel in all Wirsbo pex and this stuff I have found to be great. I have run hot and cold water all over my kennel. The kennel area is 90 feet from one end to the other. I have come out of kennel bathroom with hot and cold run it in PVC conduit attached to the ceiling and run it to all ends of the barn. We have over 6 outside runs which are mostly cold water and then three runs that are hot and cold. I choice to use ¾ inch supply and then ½ to all sinks or facets. We used about 200 feet of ¾ inch for supplies all over the kennel then we went with ½ inch. I have about $1200 in materials but, if you look at we did it would of cost a lot more in copper. I have two kitchen sinks in the kennel, there is tub in the grooming shop, in the bathroom there is toilet, sink, shower, and washing machine.
Going out to my kennel we have water facets in about 4 different spots, water is piped outside in six different runs on the building 6 cold and 3 hot. My carpenter who is putting on some finishing touches for me did all the plumping work and had never touch pex before and he loves it. Most of the $1100 in materials are inline shutoffs. With the kennel I could not afford to shut water off at the manifold. I went a little over board with the shutoffs but that was my choice. What we also did was connected all the hot and cold facets with a Y and now I just turn on what I want hot, cold or both for warm water. I have a hose connected to all the facets so not matter were I am I can wash stuff off with warm or hot water. This makes my life so easy for cleaning stuff in the indoor kennel.
IF there is a leak you just apply a heat gun and no more leak. Also what I did was use connectors so that all I do is slip this over the pex to connect and I can disconnect it the same way.
One application I use the manifolds for is I have run a ¾ inch supply line on the top of a cement block wall that runs thru the center kennel. This also feed the water facets at the end of a building. I used the connectors so can take this down off the wall to work on it. I used manifolds and Ts to supply automatic watering for each kennel. It is really pretty slick. But you are talking to a real Pex fan here. I found the supplies I needed at good prices at Colonial Plumbing Supply in Albany, better then I could find on the internet.
The ¾ inch 100 ft is about I think $70 or $60 I do not remember and the ½ pex is about $30 something for 100 feet. I could of never done what I did if I had to run copper we would still be soldering, fluxing and sanding pipes. Also I could of never afforded the copper tubing or the plumber to do it. So I love the Wirsbo tubing. I also found Colonial Plumbing supply house to be great. Off course I bought a lot of stuff from them, but it has been worth it. I in the process of transferring my web page so once I get that up and done I will get pictures of my kennel out there so you can all see.

 

[kmdigital]

A new clerk says the stuff is great except you can't put the fittings inside walls!!! What good is this system if all the fittings have to be out in the open somewhere? OR, is this guy informed wrong?

That guy is 200% misinformed! All plumbing pipe is rated for use in walls, etc. The only thing you aren't supposed to use in inaccessible areas are things like flex connectors, hoses, etc. Remember, the tech support help at most home centers is only (and that is often highly questionable) slightly more knowledgable then the average home owner when it comes to things like plumbing and electrical. If you can find an older guy that has been in the business they usually know more, but the kids don't know anything other than what someone else has told them

 

[kmdigital]

Ok, the water can get pretty hot, but that hot water isn't going to be in the PEX pipe if there isn't any electricity. It will just set up on the roof inside the collector. And when the power comes back on it may get a brief surge of very hot water, but unless your collector contains several dozen gallons of water it won't stay hot long enough for the pipe to get soft enough to cause any issues. At least that is my opinion.

 

[kmdigital]

If the crimping system is anything like the crimping system used on qest pipe in moblile homes than I would be leary. I never had one come apart but have had dozens seep and cause a big enough leak that I would replace the joint with a compresion fitting. I realize that the pipe itself is different but not sure about the crimp connections.

I assume that the mobile home used the Acetel plastic fittings with the grey polybutelyn (sp?) pipe. These fittings were bad news, especially because the early crimp rings were aluminum, which would sometimes crack after a few years, and then they definitely leaked. They soon switched to copper crimp rings, which worked great, but even then the plastic fittings would sometimes fail if they were under stress , such as an elbow or tee. These plastic fittings cost the industry millions to replace, but then some years later the pipe started failing also, so the industry went bankrupt.

The PEX pipe uses the same crimp tool, but all crimp fittings are either copper or brass, never plastic. And all crimp rings are always copper, and the pipe has a thicker wall, and is superior in every way to the PB pipe.

Why was PB the first choice, even though PEX was also available? Because it is about 1/2 as expensive as PEX, and the $ drives everything

 

[Greenhouseray]

Hi All
Pex solved a problem for us. Our house is approx 40 yrs old.
The copper pipe in our horizontal runs started to get tiny pinholes in it emmitting a fine spray. I plugged some of them with a peice of rubber and a gear clamp. When I got about six of my patches in place I figured I better replace the copper. Our water supply is 6.4 on the acidic side. Thats how the copper got eaten out.
I decided to use pex to replace the copper because acidic water will not hurt it.. When I went to buy a crimping tool, I almost changed my mind. My gosh they are proud of those tools. Bought a 3/4" crimping tool on ebay for 1/3 the price Lowes wanted. Pex is so easy to work with, no mess and fuss as with soldering Copper, especially doing repair work no stuffing bread up the pipe to keep water away from the solder joint!!!!!!!
We have a greenhouse business. The acidic water coming from our well is perfect for our fertilization program. Most growers have to inject acid into their irrigating water to make the fertiliser work properly.Most of the water lines were black PVC with gear clamp joints.Always seeping due to temperature fluctuations, sometimes the joints just come apart and we have flooded plants. NO MORE OF THOSE PROBLEMS. Replacing everything with Pex. No seeps no leaks no floods!!! It is getting around the $135.00 price of the crimping tool that is the difficult part of Pex.
Ray

 

[MikeD74T]

Ok, the water can get pretty hot, but that hot water isn't going to be in the PEX pipe if there isn't any electricity. It will just set up on the roof inside the collector. And when the power comes back on it may get a brief surge of very hot water, but unless your collector contains several dozen gallons of water it won't stay hot long enough for the pipe to get soft enough to cause any issues. At least that is my opinion.

In my case the hot water made it 70' to the basement thru insulated pipe & was still hot enough to lift the relief. I can't imagine that anyone is going solar with uninsulated pipes!!! Fortunately my relief is piped to a 5 gallon jug so I didn't loose any antifreeze but lost system pressure & had to pump it all back in after the collectors cooled down. Don't know if it would affect PEX but it should be considered. MikeD74T

 

[MikeD74T]

That guy is 200% misinformed! All plumbing pipe is rated for use in walls, etc. The only thing you aren't supposed to use in inaccessible areas are things like flex connectors, hoses, etc. Remember, the tech support help at most home centers is only (and that is often highly questionable) slightly more knowledgable then the average home owner when it comes to things like plumbing and electrical. If you can find an older guy that has been in the business they usually know more, but the kids don't know anything other than what someone else has told them

He may be only 100% misinformed. I got this answer from Wirsbo, a leading manufacturer:

The QS20 connection is a mechanical connection, and would not be recommended for placement in wall without an access panel. BOCA would not allow this to be buried for plumbing, but QS20 fittings are a heating product and fall under different standards.

I would strongly recommend using our ProPEX connections for concealed installations. They are a manufactured connection and have an extended warrantee of 25 years.

Do you have an expansion tool?
I have 3 factory reps that cover your area from Urell Inc., as well as 3 or 4 distributors that stock our offering that could help.

Please write back to me, and I will help you with your issue. I do not know if you are using QS20 with our manifold, or with fittings used for baseboard loops ..... pleased advise so I may further assist you if need be.

Respectfully,
PDR

Patrick D. Reed
Northeast Regional Sales Manager
UPONOR Inc. (formerly WIRSBO)
PO Bx 296
Selkirk, NY 12158-0296
Office: 518-767-3370
Fax: 952-997-1712
e-mail: PATRICK.REED@uponor-usa.com