my next phase of construction is radiant flooring has anyone had experiance with radiantec systems?
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Greetings westy-
This post, in response to your question, will bump the thread through the 'recent discussion' listing again which will increase it's viewing.
Perhaps it will catch someone's attention that can help you with advice.
Cheers
Parolee # 53804
Radiantec...
The pros hate them.
I have friends with their systems that love them.
They are probably OK for a simple system - no boiler, outdoor resets, same water temp throughout etc.
Their 7/8 tubing is not particularly strong - 1/2 pex is better in most applications.
The "open" system is often called into question b/c of stagnancy concerns.
The Polaris heater they push has reliability issues, most any powervent heater can come close to their efficiencies.
I would get their estimate/plan utilizing 1/2" tubing, then look on http://www.pexsupply.com for components, and locally for a water heater.
I have had good results with http://www.radiantdirect.com I have one of their Bock systems now.
Good luck!
thanks for the info brian they are about the only co that recomends 7/8 i'm just starting research and intend to be installing the tubing this summer keith
I used them for manifolds and pumps. Nice folks. I used 1/2 inch pex from menards. Works great. The open system has no more chance of 'stagnancy' than a hot water heater or a long run of plumbing. In fact there are many people putting in pumps to circulate hot water in the regular system - not a problem. Make sure you understand how the system works before listening to the 'pros' that hate them.
It's not just the stagnancy, it's also the temperature the water's at (perfect for breeding bacteria). Considering how little extra it costs to set it up as a closed/indirect, why take the chance?
how is this more dangerous than a typical hot water system?
As I understand it (caveat: I'm not a heating pro, I just hang out at heatinghelp.com a lot)... a hot water system keeps the water hot enough to prevent bacterial growth; whereas a radiant floor operates at lower temps, which are pretty much ideal for bacteria. It's also got something to do with oxigen levels of fresh water coming in; as opposed to a closed system where the oxigen gets "cooked out" of the water after awhile, the constant supply of fresh oxigen helps bacterial growth. BTW, it also spells "oxidation" for the pumps, valves, etc.: this is the reason for pex-al-pex instead of straight pex, after all - to seal out the oxigen.I might point out that the dude at radiantec's "fine print" disclaimers about code compliance, liability, etc., makes him less-than-perfectly-trustworthy in my eyes; especially when all the pros (who would be liable if they installed a health hazard) are so unanimous in condemning the practice.The "that settles it" point, though, is that I can't see any possible advantages to an open system. Why gamble where there's nothing to gain? To save a few hundred bucks? For the extra expense of a heat-exanger & a few extra runs of pipe, to set up a closed system... me, personally, I'd rather play it safe.I had a close friend get legionnaire's - it's not worth it, to me, to take that chance - the guy lost 50 lbs by the time he got out of the hospital, it took him 4 months to get back on his feet to where he could work again. Not something I want to take chances on.
The radiantec open system is now allowed by code in many areas. The open systems are part of the hot water system, fresh water from the flows through the system when ever hot water is used. It's interesting to me that hot water recirculation systems are installed in hotels and, increasingly, in homes and has all the same issues and features of a radiant heat system. Lots of fear mongers out there. The advantages are a simpler system, fewer pumps to buy and to break, no loss due to heat exchanger and a few hundred bucks less. The disadvantages are the costlier pump (stainless steel). The oxygen thing isn't a problem for brass valves and SS pumps. Did your friend with legionnaire's get it from a radiantec designed system? Can anyone send an article about an open system (as described by radiantec, properly installed) making the home owner sick? The only way bad bugs can get in the system is if they come from the main, just like the rest of the system.I'm not a rep for the company, I just hate the 'why risk it' argument against good plumbing science. PEX wasn't allowed in NY for years after it was in wide use the pros didn't want it. - sometimes its not the technology that's the problem, its getting the technology accepted.
No, the friend didn't get it from an open system, he got it on a 2-month camping trip where it rained & rained & rained... But that wasn't the point. I brought him up to explain my extreme caution: we're not talking about having the runs for a couple of days (that, I might risk), we're talking about being unable to work for a few months. Over a couple of hundred bucks? Not me, thanks.I don't follow why you "hate the 'why risk it' argument, when it's only a few hundred bucks for peace of mind. If it was a few thousand... I'd probably still disagree, but I could at least see your point.BTW - any heat loss from the exchanger is happening inside the house, so it isn't really a loss.Not sure what you're getting at with wondering how bugs get in: most water from the main does have a certain amount of legionella & etc in it, just not enough to pose a real risk. The concern isn't that an open radiant system is going to make bugs magically appear, it's that the system gives them place/time to breed, untill there is enough to pose a real risk. I've also spent enough time in the trades to see lots of products and concepts come down the pike, cause lots of problems, and dissapear. Even good products need a decade or two before all the bugs get ironed out - it takes awhile for the field data to accumulate, before folks work out what works and what doesn't. So maybe I'm overly cautious; FWIW, I want to see another few years from pex before I'd use it on potable. BTW, Code approval doesn't impress me all that much. Codes set the lowest expectation that you absolutely must meet to be passable; I try to aim a little higher than that.
you're absolutely right. code is suspect, science is suspect, you can't trust anyone.
Oh, come on - I haven't given you cause to get sarcastic! I'm just saying that it's not a chance I'd take, just to save a couple hundred bucks. I never said code was suspect: I said it establishes "acceptable minimum", as opposed to "best practise". I never said science was suspect, I only indicated that for me, there isn't sufficient field data to draw firm conclusions. I never said anything about people, on way or another. Again, I'm not sure where you're coming from with this. Issues, much?
Yeah, sorry. Of course there are always more than one way to skin a cat. If you've been around the trades you know how resistant to change tradesmen can be. Should we all drive an extra nail or double that header just to be safe? Why risk building to code?I haven't heard a well reasoned argument as to the risk. It's no worse than the rest of the potable water systems in the house. Is it okay to have supply lines running in a slab? Is that guest bathroom a risk because the water sits in the line for weeks on end? I don't want to poison my family any more than the next guy. The system, as designed, is really good. Take a close look. You do make a good point about camping in the rain! ;-)The lost heat into the house theory is a good one, but it's not putting the heat where you want it. My son made the same argument about leaving the television on - all the expended energy was released into the house. The second pump doubles the electrical load of the system, granted it is a small amount. But it does use more energy over the life of the system.Sorry to harsh your mellow, Frenchie. I just hate much fear about nothing. Ted
open systems have one benefit, and one benefit only; up front cost. Realistically, the pumps on these systems last for many decades, and you're talking about (in most cases) just one more pump using a relatively small amount of electricity when the system runs.-You provide what.. 20x, 30x, 50x or more pipe than a typical domestic system would have in it?.. for bacteria to potentially grow in. That's expoentially more biofilm per gallon of water than, say, an equal increase in water heater size, because it's all smaller diameter pipe. And it's concentration of the bugs that matter, not absolute quantity but quantity per gallon. Because we fight the stuff off all the time... but it's harder with higher concentrations. THAT'S why it's worse than a potable system. No potable system has thousands of feet of pipe in it. And potable systems rarely go unused for several months a year with only a quickly flow of water through which is supposed to "flush" organisms out of a biofilm? Please.But you know what? Forget the bacteria. It hasn't been studied, some interested parties have managed to get codes changed... whatever. Skip it. I'm sure everyone concerned about it are in the pockets of heat exchanger salesmen.-The fact is, constantly introducing fresh water into your heat system is risky FOR THE SYSTEM, as well as for your house. Spring a leak, ever, and it just keeps leaking, for one, until someone notices. For two, you're constantly bringing in whatever is in your water, to potentially calcify or gum up all of the components in your systems (valves, fitting inserts, pumps, etc).IF that happens, there isn't much to do except start over. I've seen open systems die, open systems that I was a part of the design team for. It's not common... but a heat exchanger and an extra pump are a pretty cheap insurance policy on both counts. I will not help clients risk that again.Take whatever risks you like. But don't act like anyone concerned about this stuff is "old and resistant to change". I'm certainly not old, and I was trained to design those systems. I have learned that they are not as great as some people say they are. And I see no good reason to cheap out the relatively small additional cost now for the pleasure of risking the largest investment most people ever make in their lives... do you?-------------------------------------
-=Northeast Radiant Technology=-
Radiant Design, Consultation, Parts Supply
http://www.NRTradiant.com
NRT Rob said it right, the only benefit is upfront cost. Rob has given me some excellent pointers designing my own system .
Even if it costs a thousand bucks it really is cheep insurance for a system that will last many times longer and does not have any chance of making you sick.
There is no way to deny oxygen oxidizes and the more new oxygen introduced the more oxidization occurs it is proven science.
Also true is the more oxygen introduced the more stuff grows and stuff loves warm water also proven science.
If energy efficeincy running an extra 75-150watt pump is a concern why heat with a DHWH.
I will agree that trades don't like to change but this simply is not the case. This sounds more like the tradsman telling you regular drywall is fine behind the shower to save $20. Sure it will work and well for a period of time but chances are it will fail given time and when it does that $20 will look very cheep.
But don't make up your mind reading one or two posts from wing nuts like me checkout the wall on http://www.heatinghelp.com Also try to talk to as many professionals and people with systems as possible.
Good luck on your heating endevore
Thanks for the support, Rob & Diesel.Ted - this thread kept popping up in my mind all weekend. I have to take issue with your dismissal of tradespeople's conservatism as "fear about nothing". It's not random paranoia, it's the result of repairing houses where someones else, ten or twenty years earlier, tried out the "latest new tech" approach. Consider the following:- galvanized water pipes
- aluminum wiring
- poly vapor barriers in mixed climates
- tyvek under cedar
- fibercement roofing panels
- Since I started out in boat repair, I'll add "ferrocement boats" as a trump card.In each of these cases, someone decided they had a "better" (or cheaper) way of doing things, and the science backed them up. In each case, a decade or so of field use brought out new issues or problems that nobody had considered. Nowadays we know that:- galv pipes aren't worth the trouble they cause;
- aluminum wiring is hazardous unless every sparky who ever works on that house understands the issues involved (is that stuff even allowed anymore?);
- unless you're in Canada, a vapor barrier will cause mold & rot problems, whereas a vapor retarder does the job while avoiding the problems;
- cedar over tyvek ought to be back-primed, or better yet furred out from the tyvek and back-primed;
- fibercement is fine for siding, but not for roofing;
- ferrocement boats are just plain stupid.But all those lessons were learned the hard way: people had their houses get flooded (galv pipe), burn down (aluminum wiring), rot & grow mold (poly vb), leak (cedar on tyvek), had their roofs cave in (fb roofing), or wached their boats crumble apart when the rebar rusted away, before the lessons were learned.So here's the question: would you rather be the guy whose house has the problems, or the guy reading about those problems & drawing the relevant lessons?
no, not all trades people are resistant to change and not all change is good. My whole point in this disscussion was the fear of microbes in an open system is unfounded. You were spreading that fear in self proclaimed ingorance of the subject. "caveat: I'm not a heating pro, I just hang out at heatinghelp.com a lot"I'd been waiting for NRT Rob to chime in, he seems to lower his rant on bugs, adding in a disscussion of surface area while ignoring the surface area of heat exchangers and the fact that you need to run 2 pumps instead of one for the life of the system. It does take more energy. But the heat exchanger system or a dedicated heat source are also wonderful systems that can do a great job. Just more complex and using more energy. Peace, y'all.
Go ahead and compare the internal surface area of a heat exchanger to the surface area of a few thousand feet of pipe. Remember only half of it is on the domestic side of the system while you are at it. And let me know how many plates you want to use. Of course, you can pretty easily remove and clean a heat exchanger. Let me know how cleaning that open radiant system goes.<br><br>I didn't ignore the two pumps. I mentioned it specifically, which you know because of course you read the post. I'm a big fan of less pumps, personally. I make a habit of pushing large square footages on regular $70 cast iron circulators. But, on a decent system, the second pump is run at variable speed anyway.. extremely low power usage, in most cases. I guess if you're just doing 'bang bang' systems, you could just say the run time is less... <br><br>It's pretty hard to say the fear of microbes is "unfounded". Unconfirmed, yes, but unfounded is a fairly strong statement. All the elements for bacterial amplification.. ALL of them.. are there, the CDC openly acknowledges that legionnaires is in all likelihood extremely under-reported even in regular plumbing systems, and the only answer thrown back by proponents of these systems is "show me the bodies", which is not a particularly responsible response, now is it? Unfortunately, no one is sponsoring a study on this. But go ahead and search out discussions on this matter, and you'll see... as you already know, undoubtably, since you knew enough to know I wouldn't let that post go by unanswered, but chose to ignore to make a good post... that microbes are not the only or even the foremost reason I don't like open systems. <br><br>So I'll say it one more time, and maybe you'll hear it this time: it's about risk in general. You have a health risk at some level, you risk the heating system itself, and you risk excessive damage to the home from an uncontrolled leak or burst. A one time insurance policy and an average of, say 30 watts (half power 15-58) for the heating season isn't a real big problem to avoid all of those issues, is it? Heck, some of that turns to heat, no less, to be carried into the system. You lose a little in the HE as well, sure. Insulate it. <br><br>I'm not saying you can't argue for them, though the only real arguement you have is "it's cheaper" as far as I can tell. I mean really.. the two or three dollars of electricity you're using a month during the heating season for the second pump can't be THAT big of a deal, can it?<br><br>
-------------------------------------
-=Northeast Radiant Technology=-
Radiant Design, Consultation, Parts Supply
http://www.NRTradiant.com
Edited 5/7/2007 2:44 pm ET by NRTRob
no, it's not much. The open system designed by radiantec is elegant and simple, especially for a small addition. " Unconfirmed, yes, but unfounded is a fairly strong statement. All the elements for bacterial amplification.. ALL of them.. are there, the CDC openly acknowledges that legionnaires is in all likelihood extremely under-reported even in regular plumbing systems, and the only answer thrown back by proponents of these systems is "show me the bodies", which is not a particularly responsible response, now is it?"Proving a negative is difficult. Is it a possibility, however far fetched? I guess so, just not a realistic problem as shown by experience. There are real concerns to be afraid of. What kind of potable plumbing system would you put in your house? Bio filtration at each spigot? Is it irresponsible not to? after all the CDC has said... What do you think of The GFX Heat exchanger ( http://oikos.com/products/mechanical/gfx/ ). I'm curious because it has the same problems of more pipe in the system, warming up the water, etc. I installed one at my previous residence and dramatically cut my electric water heating bill. A plumber friend was aghast at the thing that would bring grey water and potable water so close despite the double wall. Also, how about the recirculating hot water systems that are getting more mainstream? This is an open in floor/wall heating system in it's own right. I'm surprised we don't hear more about the dangers involved there.I do respect your expertise and guidance you've provided on these pages. Thanks Rob.
heh. "simple and elegant". simple, I agree, it is simple. I see nothing elegant, however, about elevated risk. Elegant is addressing risk issues elegantly, not ignoring them.The gfx (which interests me greatly, and we have a client who bought one and put in some thermometers to check out the temp rise through it.. I can't wait to see what it will do), recirc systems, etc do not have nearly as much pipe in them as most radiant systems. A small addition.. sure, maybe, but for a small enough addition I wouldn't even go hydronic, I'd use an electric mat which would be by far simpler.I don't believe in sterility, personally, though admittedly others who agree with me on open systems do apparently believe in killing all the bugs. I don't.. I think it's important to be exposed a level of bugs in your environment. you didn't even bring up solar hot water systems, which I love... and which cannot be kept at 140 like most people recommend for water heaters. ugh!!!! So the short answer is, I don't know what to do with plumbing systems, which have to be open. I don't believe in constant, elevated temperature recriculation for most people (though in nursing homes, etc, yes...). Then again.. who's to say the next person who owns your house won't be very old, or very young, and susceptible? I really don't know.. it's a conundrum.However, if there is an easy choice... not being an open system... which is an option, I see no reason not to do it. Especially since there is MORE than bacterial issues at work. I didn't stop using this approach because I know a client who died.. I stopped, because I saw a couple of systems stop working, and I saw pictures of what happens when uncontrolled leaks happen in a home. You can drain a DHW system if you ever leave the house for a month in winter. It's not a good idea to turn off the heat.. and it's pretty hard to drain a radiant system.-------------------------------------
-=Northeast Radiant Technology=-
Radiant Design, Consultation, Parts Supply
http://www.NRTradiant.com
I see your points, and they're good. I accept the risks of my open systems (potable water and heating) and hope I don't get a leak, That part does concern me. In any water system leaking is an issue. No more in heating than an upstairs bathroom. Where have you seen leaks in hydronic systems? poorly driven nails or failed pex? Thanks again.
well, if you install a radiant system, it's possible.. not common, but I have personally seen it several times... for a nail to seal its own hole. Holds pressure, everything's great... until a year or so down the road when it rusts out enough to leak.If you have a constant source of pressurized water, you'd never know unless it leaked so bad it caused visible damage. Or, until the mold sets in and it's far too late. In a closed system, you can see pressure drop and you know you have something that needs fixing... and if you don't notice, the system will stop working when it's lost enough pressure, to demand your attention.Other times are during freeze ups.. something bursts. In a closed system, what's in it will drain.. about a gallon per hundred feet of pipe that can drain to the breach. That stinks, but it's recoverable. In an open system, it just keeps pumping water, and pumping water, and pumping water until someone notices or you run out of water. You can have these issues in plumbing systems too, but there are two major differences:
-Plumbing is usually in joists and walls, out of harm's way. Most radiant hits occur during flooring installation. Not all, but most.
-People who leave their houses in winter often drain their plumbing systems. at least, the smart ones do. you can't do that with your heating system.. at least, not easily, and not with guaranteed success.-------------------------------------
-=Northeast Radiant Technology=-
Radiant Design, Consultation, Parts Supply
http://www.NRTradiant.com
Sorry if I misled you. I wasn't proclaiming complete ignorance, only allowing that a heating pro could probably explain it better. How about you? No offense, but you're contrasting my purported ignorance to your own status as... ???... your profile list "other", that doesn't tell me a lot. I'm also not seeing a lot of evidence for your assertion that the risks are unfounded. All you've done is assert it. In contrast, I gave you a bunch of examples of products & approaches that were backed by all the science & testing you could throw at them, and were approved by the code... but turned out to have loads of problems in real-world application. Got anything that'll show me that open systems won't turn out the same? Because so far, all you've offered up is assertions, with the odd bit of sarcasm & subtle digs thrown in for good measure. That's supposed to convince me?
Not a heating pro. I went through the same experience as westy1 and found the same responses. I've done some research and made my decisions based on facts.
Which facts? My whole point is that untill there's a few more years of widespread use, all we have is conjecture. I did the same research, and reached the opposite conclusion...Let's just admit it: we both based our decisions on other people's opinions. The only real variable is our prejudices about new approaches, and which opinions we tend to give credence to. Me? I tend to be overly cautious - I not only owned up to that from the outset, I gave a bunch of good reasons why. And I tend to give disproportionate weight to the opinions of tradesmen, because they work with this stuff every day; they can reasonably be expected to understand the issues involved better than you or me; and they stand to be liable if something goes wrong.So... we already know that you tend to be more adventurous with new tech, not that you've explained why; but whose opinion did you give disproportionate weight to? What's your dismissal of pro opinions based on? The guys at randiantec, with all their disclaimers?BTW, I am open to being convinced, it's just that you haven't given me anything to work with.
Not just opinions. The fact that the systems are engineered to to protect the system from stagnation and corrosion. The fact that there is no recorded incident of Legionnaires's disease attributed to an open system as designed by radiantec. The fact that code allows the system based on review of the design.
As NRT Rob pointed out there are the same risks with domestic hot water systems but I bet you don't think they are too 'risky'. You will not be convinced. No worries. Go on with your life.
1 - you need to re-read Rob's post; he said exactly the opposite of what you're claiming.2 - you really don't do very well with having your point of view questionned, do you? ..."You will not be convinced. No worries. Go on with your life." I mean, sure, it sounds dramatic and all, but I just got done teling you that I'm open to being convinced. Did you even consider anything I've written to you?3 - your facts:a) the fact that it's engineered to prevent stagnation and corrosion... only underlines the fact that it needs to be engineered around those issues, as opposed to a closed sytem, which avoids those issues in the first place. b) as Rob pointed out, the fact that no documented cases of legionnaire's exist to prove it, doesn't disprove anything. We know that legionnaires is under-reported due to misdiagnosis. And does anyone track vectors for those cases of legionnaire's that are properly identified? "There's no documented cases" means nothing, if there's nobody tracking the relevant data.c)the fact that code allows the design... All of the examples I brought up earlier, of systems that failed, were code-approved too. Code approval didn't stop fb roofs from failing to the point of collapse; code approval didn't stop electrical fires caused by aluminum wiring with CU-rated devices or wirenuts; code approval didn't... you get the idea. Tell you what - let's pick this up in 10 years. Either you'll have racked up some hospital bills, or you won't. But right now it seems clear that it's YOU will not be convinced. Until then, I'm not going to sit here and let you say things like "open systems are fine", without a challenge. Not when every reputable pro I know of says that they're dangerous. You don't want to spend a few hundred bucks being safer? That's fine(some people don't want to wear seatbelts); but it's another thing when you encourage others to take the same risks, without presenting both sides of the issue.
I do agree there are the same kinds of risks.. I strongly disagree that the risk is equal in most radiant systems. I believe I've made that pretty clear, so please don't support your statements by misrepresenting mine.-------------------------------------
-=Northeast Radiant Technology=-
Radiant Design, Consultation, Parts Supply
http://www.NRTradiant.com
Sorry Rob, I posted that you agree that there are the same type of risks (microbes) in the DHW systems that are standard in our homes as there are in an open system. I didn't say you thought they were equal, just the same type. You just think that the risk is higher because of the extra pipe, right? How long a run of pipe is safe? 10'? 100'? 500'? This is a good question, is a small house plumbing supply safer than a large house? Anyone know? By the way westy1, Radiantec was very helpful, fast and worked with the local inspector and convinced them that the system was safe. They also will do a heatexchanger design. Or a seperate heat source. So will Rob! (I think so, at least)
Ted
You're missing my entire point. No one knows what is really "safe", for each individual person or owner of a building. Since separation protects against several potential problems, I always do it when possible. It's not possible in potable systems. It is possible in heating systems.. so I do it in heating systems. It's really that simple. You increase risk by not separating... period. It is that simple. How much the risk is increased, whether you can skate through without addressing separation, what's going on in potable systems are all possible arguements and discussions, but none of them address that risk is increased in open systems, to the owner, the house, and the system itself.If someone wants to make an informed choice, and chooses those risks, that's up to them. I won't design their system, because I won't choose those risks and I don't want my name on a system that destroys a house or makes someone sick. but they can go for it another way if they like.But I take very great exception to anyone advocating for these systems without being open and honest about definite (never ending leaks) as well as possible risks (system seizure, bacterial growth). Not being open about those risks shows either great ignorance, or a great disregard for an owner's well-being.-------------------------------------
-=Northeast Radiant Technology=-
Radiant Design, Consultation, Parts Supply
http://www.NRTradiant.com
Sweetlake, thanks for your thoughts. I too, have never seen a compelling argument, and have heard of no cases of any sickness from open heating systems.
My hot water is much cooler than my heating system - well within legionnella range - so that would make it more dangerous than my heating loops, at 150 degrees. Most homes with kids/elderly keep their hot water at these temps, btw...
To me, open systems are straightforward and elegant - but I am open to arguments otherwise...
Treat every person you meet like you will know them the rest of your life - you just might!