Has anyone used the components from Radiantec and do your own install (slab-on-grade), and if so, how did everything go?
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Replies
I did a staple up system from them in my own house 20 years ago from them.I only used them for the pex, aluminum plates, and advice,but the boiler and controls I bought locally. They advised on what and how to do it, ..this was way before any of the locals here had even heard about RFH.
All went well, still have the same system, works quite efficiantly.
A plumber buddy looked at my pex as I was putting it up, said I was out of my mind "wood doesn't transfer heat- your gonna freeze yer arse off". Fast foward 10 years, his card reads "Radiant specialist"-go figger.
Thanks Jay,
If I use them (RT), I'm gonna pick thier brains clean. To me, the advice is worth the cost of admission.
The locals here still haven't caught on, so I've little choice but to do it myself. Forced air is still the standard in these parts, and not too many old dogs willing to learn new trix.Live in the solution, not the problem.
This is what I started with.
Thanks, but my dial-up is so prehistoric that I can't open your attachment. Can you resize? Little help here rez?Live in the solution, not the problem.
David,It's a pdf document, so I can't resize it. But I can cut it down into sections, which are much smaller. See if this is a better filesize to open, and if it's of interest to you. If so I'll run parts 2-11.Best,
Steve
Thanks Roman, but I don't think that stuff is gonna be helpful given the system I'm trying to use.Live in the solution, not the problem.
It will be an advantage to you to get cable or DSL to get information, life is to short to sit and wait for downloads
sorry most of the info I can give is on PDF or Photo
Since WM makes boilers, that's what all their systems are going to utilize. I'm hoping to use a water heater for the rad. and domestic HW.
Thanks anyway.Live in the solution, not the problem.
Since WM makes boilers, that's what all their systems are going to utilize. I'm hoping to use a water heater for the rad. and domestic HW.
How does one plan anything without the simple basic knowledge of the task
Well your mind is made up, but I will say that a properly controlled radiant system is essential for success
OK, OK, I'll do the research. Don't you understand that I want the benefit s of the best system without having to actually do the homework necessary to choose such a system?
Oh yea, and I want it for 1/2 price.
ThanksLive in the solution, not the problem.
If done by ones self there is a chance it will be less than 1/2 price.
Were you able to open the Tekmar essay?
It will help to understand different types of systems for controlling
These are the best, in control for RFH.
don't rush and it's not difficult
ask your local supply houses if they deal in radiant heating supplies, you maybe surprised at the answers
I used RT for my house . I put it under the basement floor on 12" grid . It works but I have installed others on 6inch grid . I have mine on a water heater , make sure you get a good waterheater . I would buy from RT again if the need arises.
Just curious. Why use a wh at 45% when you can get a boiler that is 95% effecient?
rich1
water heaters vary temendously in efficency, but that's not the real reason..
It's because in a well insulated home the water heater is a better fit than a boiler.. the smallest boilers do two things wrong.. they put out water at a temp much higher than is called for by the tubing.. 130 degrees is about maximum. to get water at that temp it must be cooled down. and there goes all your efficency.
That's the prime operating range of water heaters..
second, boilers generate too many BTU's. Keeping all that water at that sort of temp and then cooling it down means there is wasted BTU's. BTU's are expensive no matter what fuel is used.. waste them and you are spending money that doesn't need to be spent with a better fit..
Modcons can modulate down to about 30,000 - the same as a water heater, and they can handle any temp of water. All at 90+
You are talking about cast iron. Two different animals.
Modcon?????????Live in the solution, not the problem.
several mod/cons can modulate down below 20kBTUs/hr actually, and run at 95%+ on a low temperature system, and produce hot water more efficiently than any water heater at any price.assuming gas fuel which, if a water heater is being considered, is usually the choice being made.furthermore they are wall hung, nearly silent, usually sealed combustion and require no chimney.In most heating climates, in most homes, it's a hands down no brainer if gas is the fuel of choice. It will, on any hydronic system, pay for the difference in material cost between it and anything lesser in a reasonable, if not rapid, timeframe.True for all but the lowest of load systems. Here in maine, I'd call the cutoff at 20kBTUs/hr under design conditions... below that, I consider a tank water heater. Of course, you can add a buffer tank to the mod/con and get the cycling down again, but in that case you're basically betting that the cost of fuel is going to keep going up.. payback under current conditions is a bit longer there.Of course, where do you think fuel is going? down?Anyway... cast iron or conventional boilers are dead and obsolete, unless you are burning oil. They make sense nowhere in the gas realm anymore. It's mod/con or tank water heater (WITH A HEAT EXCHANGER) these days, IMHO.-------------------------------------
-=Northeast Radiant Technology=-
Radiant Design, Consultation, Parts Supply
http://www.NRTradiant.com
You do know that you are preaching to the choir, right? LOL
Hi Rich,yeah, I know, you were just the last reply when I got here ;)-------------------------------------
-=Northeast Radiant Technology=-
Radiant Design, Consultation, Parts Supply
http://www.NRTradiant.com
In the real world it ends up a wash . The water heater keeps the water warm enough to use all the time . during the heating season all zones will not be on at once but maybe staggered. You are using heat most of the day . The 45% ( I think it is higer then that)is figured for domestic water use where the water is used early morn after sitting all nite heated then maybe at noon and again in the evening.
The boiler heats the water up to a temp that can not be used in a RFH situation . Then it must be cooled before running it through the system . there goes your effeciency. then the cost of a boiler is a lot more than a water heater. My guess is use what you are comfortable with.
Read NRTrob's reply addressed to me. Modulating/condensing boilers beat water heaters every time.
It is my understanding that high-temp water from a standard boiler is cooled by mixing it with cold water, which is then sent through the RFH tubing. So, the BTU's aren't wasted, they're simply diluted prior to circulation.
That said, the mod/con's are still significantly more efficient.
You need an awfully low heat load for a water heater to make long-term sense, IMO."Listen, strange women lying in ponds distributing swords is no basis for a system of government."Jon
Spent the AM at the local supply houses. Most can't even spell radiant. I was even catching s**t from the contractors at the counter. "Whatcha wanna use that #### for", was the general tone.
Is the Tekmar essay the pdf that Roman resized?
Thanks for the help.Live in the solution, not the problem.
David,
Exactly what I thought, I had the same experience.
I found a supply house owner willing to get me anything I wanted as long as I could supply part numbers.
He did me very good even on the prices. I used the existing boiler,(oil) made up the near boiler piping, ran the pex (alumi pex) and aluminum plates, 1200+ sq. ft ranch with existing joist ties, plumbing and wiring.
Variable speed injection, outdoor reset, indoor sensor and boiler protection using a Tekmar 361.
David,
My BIL has and it's worked well.. they are helpfull people and provide a lot of good advice..
Ask this question on "the wall" at http://www.heatinghelp.com and I'm sure you'll get a lot of answers from good heating professionals.
View Image GO SABRES!!!
Most won't reply about RT because of the risk of a lawsuit.
Thanks Santa, I'm there.Live in the solution, not the problem.
My understanding, gathered from doing much homework,
is that if you are doing new construction, an overfloor
solution is much better than underfloor.
The Cadillac of overfloor is said to be Warmboard.
Other aluminum panels that also get mentioned are
Rau Panel and Roth Panel.
There's also the lesser-known Radiant Max, which is
also a thick, extruded aluminum panel, and you can
purchase DIY kits online dirt cheap.
My situation is a mix of old and new . The existing is 100 yr. old with accessable joists (32' x 40'), and the new slab-on-grade will abut to the wood framing @ the same F.F. level.
What could be simpler right?
Every day I realize more and more that I don't know squat!!!
Live in the solution, not the problem.
Edited 10/29/2007 4:26 pm ET by davidhawks
radiant max doesn't have a heavy aluminum over-floor method that I am seeing, only a lightweight plate "sandwich" system. Got a link?-------------------------------------
-=Northeast Radiant Technology=-
Radiant Design, Consultation, Parts Supply
http://www.NRTradiant.com
You're right, Radiant Max is just a plate. Maybe that's why it's so cheap.I'm getting all these radiant products confused! Do you have any idea how Radiant Max compares to the more expensive ones such as Raupanel? http://www.radiantmax.com/r-overfloor.html
It's a sandwich method. I would call it somewhere around 10 to 15 degree rise in water temperature compared to a more capable plate, maybe 20 or 25 compared to the top dogs.However, it is also a lot less expensive, and can often generate good, condensing water temperatures on a typical heat load and flooring choice. We use a lot of sandwiches in low-cost labor situations.-------------------------------------
-=Northeast Radiant Technology=-
Radiant Design, Consultation, Parts Supply
http://www.NRTradiant.com
Thanks for the info. Even at that rate, it'd be better than
the only stuff my local guys can get, foil panels fed by
tubes that are 3/8 or less (and costing $10 sf!)
Surprised no one mentioned that their advocated practice of using "open" heating systems (combining domestic hot water with heating water) is extremely controversial. I would not do that in my own home.
The "open" system is exactly what I've been interested in. Controversial??? Tell me more.
As far as boilers go, I simply don't want to eat up square footage unnecessarily. Gotta have a WH anyway, so why not combine?
Maybe I'm trying to over-simplify this whole issue too much.Live in the solution, not the problem.
I think Radiantec has their place but you can do better.
Boilers are a lot smaller than you might think, In the attached picture, the unit on the wall is a 175,000 btu boiler, the unit next to it is the heat exchanger for domestic hot water. They are combined as you are hoping but opposite.
The boiler is 95% efficient per the yellow energy label, and is in fact nearly silent when firing.
My system is operating as we speak but I've still got some more plumbing to tie in the domestic water and a condensation drain. FWIW, I would listen to RobNRT on here, he has helped me a lot whether he knows it or not. Thanks Rob!
Aaron
"The "open" system is exactly what I've been interested in. Controversial??? Tell me more."
Oh dear. These discussions often get out of hand, but I will try to stick to the facts.
"Open" systems are not even always allowed by code.
The primary concern is health. Since some zones may not cycle for several months of the year, the potential for building microbe colonies in the "dead legs" of the system exists. Unlike copper, which is a biocide, PEX can support a bio-film. Think legionaires and similar. The jury is out on the probability, but I do not like the risk level.
Second, the idea they promote about "free cooling" from the incoming domestic water is questionable. The minute you cross the dew point, you will get condensation in the summer. Could be tough on a hardwood floor, or fester mold and mildew.
Third, they tend to suggest zones that are much larger and less controlled than prevailing best practices.
I would suggest doing extensive independent research before making such a large commitment. Adding a heat exchanger to seperate heating and domestic water would not be a huge investment relative to the whole system cost.
Also, as others have suggested, it may be worth looking at small boilers instead of water heaters.
Best of luck.
What I initially thought would be an "easy" solution to heating this project sure did get complicated awful fast.
Heat exchangers, dew points, bacteria...geez louise!
Extensive research. Yea!
ThanksLive in the solution, not the problem.
Try this link: http://www.healthyheating.com/tools/<!---->Dave%20Yates%20H20%20vs%20Boiler.pdf
Then you can visit http://www.wattsreg.com and follow the link for a free DVD called "Scalding - Danger Lurks" Lots of rock-solid info on hot water issues - including bacterial amplification in potable hot water systems.
Or you could simply go to Google and type in "Legionella + warm water" or "bacterial amplification + water heaters" or any number of other combinations.
Heating systems are far more complex than most people imagine. It's a big investment, and worth doing right.
If you are serious about designing your own system, this book is the best place to start:
http://www.hydronicpros.com/publications/index.php?id=24
Get the basics down , stay out of the what if stuff. Keeping the domestic and heating water issues separate.
TOO many opinions, balance out put to btu loss means control.
The wheel is already invented.
Personally, while I do think on many systems the risk of bacterial amplification is real, it's not my primary objection to open systems. My own personal objection is that given a choice between running unnecessarily gigantic tubing at on centers far too wide for ideal residential performance, or risking my heating system's smaller ports and pipes gumming up or calcifying from the constant introduction of fresh water day in, day out, I'll choose a heat exchanger every time. At least heat exchangers can be cleaned or replaced a lot easier than the rest of the system..It's just cheap insurance. Not to say it's cheap, but for insurance it is. and if it happens to protect against bacterial amplification as well, great, that's a nice bonus.-------------------------------------
-=Northeast Radiant Technology=-
Radiant Design, Consultation, Parts Supply
http://www.NRTradiant.com
"My own personal objection is that given a choice between running unnecessarily gigantic tubing at on centers far too wide for ideal residential performance, or risking my heating system's smaller ports and pipes gumming up or calcifying from the constant introduction of fresh water day in, day out, I'll choose a heat exchanger every time. At least heat exchangers can be cleaned or replaced a lot easier than the rest of the system."
Well, that's a good point. I had not thought about the calcification potential.
True enough about their odd large format tubing (7/8" as I recall?).
I have read the studies about tube spacing and tubing diameters, but the online versions moved behind a paywall, so I cannot link to them. Basically, increasing the diameter of the tubing made very little difference in net heat transfer, but did increase the return water temp. Much more hot water was sent out, but very little additional heat was transferred.
Based upon these results, some folks have advocated using tubing smaller than the near standard 1/2", though it seems like diminishing returns to me because the loops have to be shorter.
Loops may have to be shorter, but the little secret there is, shortER does not have to mean short.We are designing many loops with 0.2 to 0.3 GPM requirements... even 3/8" can run a respectable length at that flow. In many cases (like basements) we are finding that we can often run 400 ft+ loops with 1/2" pipe at a normal frictional loss (i.e., we are not upsizing the pump). Doing this aggressive flow management requires hardware, but it results in smaller pipes, smaller pumps, less electrical usage and better comfort management as well.Just to make sure a reader doesn't get the wrong idea, there are situations where 250 feet is too long for 1/2" as well. it all depends on overall system flow, pump selection and heat load.For now we stick with the 1/2" standard, but I'm thinking we'll break out of that soon.-------------------------------------
-=Northeast Radiant Technology=-
Radiant Design, Consultation, Parts Supply
http://www.NRTradiant.com
csnow,
You made a clear case against the use of an open system and did so without too much bias.
I would like to point out that there are dead legs in many water systems.. the unused guest batthroom or the second floor shower etc.. Plus people do go away for the summer or come only during the summer etc..
While the potential does exist for stale water issues a good well maintained filter should provide a reasonable assurance of safety..
"I would like to point out that there are dead legs in many water systems.. the unused guest batthroom or the second floor shower etc.. Plus people do go away for the summer or come only during the summer etc.."
True enough, though capped dead legs are generally not allowed by code for health concerns. Also, copper acts as a biocide, and does not support a bio film, where PEX or PVC can.
Another consideration; A radiant heating system may have thousands of feets of dead leg, where a domestic water supply tubing dead leg might be tens of feet. This represents far greater surface area.
"While the potential does exist for stale water issues a good well maintained filter should provide a reasonable assurance of safety.."
The filter would have to be at the point of use.
Shower water coming from the molecular filtration system? I highly doubt it! Showers are where where mists will be breathed deeply into the lungs and the greatest health risks from bacterial amplification lurk. You can safely ingest legionella-contaminated water without any known risks, however, inhaling finely misted water droplets of bacteria-laden water is a whole different matter.
Casual knowledge/advice in these matters is like casual sex - you never know what you'll catch/give!
replying to whole discussion, not just the last post:
i would highly recommend a closed system. in addition to the concerns already raised, it is far easier to identify a leak in a closed system. also, the amount of water you will spill will be much smaller when you do get one. (as water leaks out, the system pressure will decrease, so you will eventually get an air pocket that stops the leak)
i think radiantec does a reasonable job with system design etc... their prices are ok too. if you are already here, asking questions, you might want to consider buying Sieganthaler's book and designing your own system. however, the labor and learning required is not trivial. you can get advice here and at the wall but a lot of us will disagree, ignore you, focus on technical details that will sidetrack you, etc... if you design and build your own, you will need to be or become an expert. since each house is unique, nobody here can tell you what will or what won't work unless you propose something ridiculously over or under built. similarly, nobody can design your system for you, unless you pay them. if this sounds daunting, go with radiantec as they include the design cost. it's a huge deal.
with regard to the heat source, you need to calculate how many btus you will need under a design load, and make sure your sources can supply that load. since a design load is maybe 1-2 weeks a winter, don't upsize that. after all, do you really need your house to stay at 68 when its -25 outside? especially if you have a fireplace. which reminds me. radiant systems work extremely well when combined with woodstoves, fireplaces, even old forced air systems as auxilliary heat sources. /digression
back to heat source. many pros like nrtrob like the mod/con boilers. they are slick, no doubt. but you have to calculate how long that efficiency will take to pay for itself. work the numbers. i went with a tankless takagi that has 95% efficiency, and cost $500, versus $3000 or so for the mod con boilers. i figured it would take decades for the supposed energy savings to make that pay off.
since when does takagi have a 95% efficiency?Last I knew, they were 83%, and that's heating hot water, not running a radiant system. When you run REAL (well, more real at least) numbers, you find in the vast majority of systems, the upcharge pays for itself using mod/cons. Crusing through their site just now I don't see any claims of 95% efficiency which only the best mod/cons claim as a standard rating (though we can push most of them over that with proper control on a low temp system).-------------------------------------
-=Northeast Radiant Technology=-
Radiant Design, Consultation, Parts Supply
http://www.NRTradiant.com
Didn't the bean post some unreal headloss numers for takagi?
csnow,
I looked very closely at an open system with the idea of using the all of the heat of the boiler. I believe that it can be safely used as long as the owner is aware that some water will be "stale" and should be flushed regularly.
Since I live just south of the permafrost <G> I felt that it would be reasonable to flush the whole system regularly. (even during the summer) I also am using a 4 tier filtration system Since I no longer want to buy bottles of drinking water which should go a long way towards preventing bacterial contamination..
In the end I decided not to.. not out of concern about safety or legal issues (It's legal in some communities and not in others) but because it added greatly to the complexity of the system as I desgned mine..