I am in the midst of trying to decipher the Radiant thing. I am in n. vermont and am building on a slab with staple up second story. Wirsbro says boiler and 1/2 tube, and radiantec and radiant floor say 7/8. 7/8 makes sense to me. The wirsbro plan also has a lot more parts and complication. Anybody think the 1/2 has the advantage, and why? I appreciate any info in advance.
Replies
Listen to wirsbo, they make the stuff.
Better yet go to heatinghelp.com and do a search on radiantec.
Wasn't aware of any 7/8 tubing.
Radiantec and wirshbo are owned by the same company . Radiantec is directed at diy . But I use 1/2" tube because I can bend it tighter than 7/8 . 7/8 will deliver more heat but not turn as tight of radius . 1/2 will do the same with more tube but with the closer spaceing it will have less of a heat striping effect. .
Radientec pushes waterheater less controlls
Wirsbo likes boilers and tempering valves and lots of other compications to an otherwise simple system.
Wirsbo and radientec owned by the same company?
you got any info to back that up?
Again, wirsbo does not make 7/8.
Larger pipe will not deliver more heat on a staple up system.
Water heaters are generally a poor choice, especially an open system.
Controls do not complicate a system, they make it work as designed .
When an infloor job is percieved as simple, it tends to go bad in a hurry.
Radiantec and Wirsbro are owned by the same Company? I thought Radiantec was in Lynnville, Vermont, out by the airport. Wirsbro is in the Northern Great Lakes. I dealt with Radiantec 10 years ago. They had three or four different brands of tubing and parts. Wirsbro is a manufacturer. I like the 1/2", much easier to bend and put fittings on.
Oh geesh.
Without getting too specific or stepping on too many peoples thumbs...rules of thumbs, that is...
How long are these loops designed to be? A larger diameter tube allows for a longer loop off the manifold, as there is less resistance to flow (head pressure, etc).
Longer loops mean more of a delta-T through the loop. Meaning that potentially the first part of the floor will be warmer than the part of the floor heated towards the end of the loop. Delta-T can be compensated for when running loops on top of a subfloor (gypcrete, etc) or in a slab, but not really when limited to the joist runs in a staple-up.
Longer loops mean fewer loops. Fewer loops mean a smaller manifold. And less zoning.
I guess it depends on what you want from your radiant floor heat.
As to getting more heat out of the larger tube, that's difficult to quantify and explain, at least at this hour.
Both designs include an outdoor rest, right? You will NOT have a system without one.
Wirsbo designs include systems run off water heaters as well. Somewhat simpler in design.
Now, if soneone gave me a staple-up design based off of 7/8ths inch tubing...I'd laugh in their general direction. Ludicrous.
How long are the loops????????
Well, they sell the pipe in 1000 foot rolls, therefore........
And if larger is better, they do make 1 1/2" LOL
Edited 9/6/2005 1:09 am ET by rich1
The loops are 250', They are saying about 50 btu per foot in slab, and 30 in staple up with aluminum fins 2/3s of the length.
The truth:
A homeowner here in CT did a DIY radiant floor heat in a slab. Used 1" black pipe bought at HD.
First heating season, they were asleep at night when the "house exploded" (their words).
They were running 180-degree water through the pipe straight off the boiler, the expansion caused the slab to crack which in turn sent shards of tile flying throughout the room.
Saw some pretty impressive pics of a couple of tile shards embedded in the drywall walls and ceilings. Ouch!
Deep breath...calmly …where to begin... whoodle and others (sorry Mongo forgot to change the reply to 'ALL'...) anyways...<!----><!----><!---->
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First download and read the 22 Myths About Radiant Heating at this link.http://www.healthyheating.com/Radiant_Mythology/Radiant_Mythology.htm<!----><!---->
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Make note of:Myth #4 - Radiant Floor Heating Causes Varicose Veins ( it can't unless you crank up the surface temp...see below)Myth # 15 - The Bigger the Radiant Pipe The More Heat You Will Get. <!----><!---->
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If you ever encounter a radiant supplier claiming, they can deliver anything more than 28 to 30 Btu/hr/sf...run as fast and as hard as you can. Btu/hr/sf output is based on the difference between floor surface temperature and ambient (operative) temperature. At 50 Btu/hr/sf a floor would be operating at 95 deg F which is totally unhealthy and way beyond what is recommended in ANSI/ASHRAE Standard 55, Thermal Environmental Conditions for Human Occupancy which limits floor temperatures to 84 deg F. At 84 deg F surface temperatures, you can comfortably deliver 28 Btu/hr/sf for a 70 deg room temp…REGARDLESS OF THE FLOOR ASSEMBLY...did I say regardless of the assembly...I meant to say R-E-G-A-R-D-L-E-S-S O-F T-H-E A-S-S-E-M-B-L-Y!<!----><!---->
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Floor R-Value, spacing and fluid temperature are attached at the hip. Widen the spacing and you have to increase the fluid temperature. Increase the R Value or reduce the conductivity and you have to increase the fluid temperatures and or increase the tube density. The wider the spacing the less consistent the surface temperature...I have an article coming out in the Radiant Panel Report that is called The 12 Steps of Radiant Design, Heat Loss to Hydraulics...would suggest you pre order the issue.<!----><!---->
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Marketing systems based on how much heat you can get from the surface is unprofessional… its possible to get 200 Btu/hr/sf from a snow melt system so output is not the issue - for space heating it’s not about output - it is however: First - about your safety, Second - your health and Third - your comfort. Anyone who does not get this - should be avoided…period!<!----><!---->
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Radiantec and Wirsbo are not owned by the same company...Wirsbo is part of Uponor, the Finnish Conglomerate. RTI (Radiant Technology Inc) was owned by Uponor Wirsbo but the operations were closed last year with some of the staff moving over to Wirsbo. RTI is not, was not, and never was the same company as Radiantec.<!----><!---->
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Long loops (unless unaccounted for in the design) do not translate to greater delta t’s. Slower flow translates to larger delta t’s. The circulator is selected to overcome the hydraulic resistance at a calculated flow rate, which is based on a designer specified delta t. At design, conditions if the delta T is greater than what was used in the flow calculation then either the wrong circulator was installed or the actually hydraulic resistance is greater than calculated or the boiler is underpowered or it is in a start up mode. The selection of delta t is dependant on application and floor assembly. A small delta t increase flow but delivers a more constant surface temperature. More flow means more money for a circulator. A large delta t means less flow, less consistent surface temperature and less money for circulators. You can play around with tube depth, tube distribution patterns to find the optimum design. Flow in a tube influences velocity and resistance. The bigger the tube at a fixed flow the less velocity and less resistance…but a bigger pipe means more money and a greater chance for air locks and sediment build up. A smaller diameter means higher velocity and more resistance but better heat transfer, less chance of air locks and of course, it keeps sediment in solution. Understanding all of these issues (and more) differentiate the pro’s…which is why you pay more for a Wirsbo then others. <!----><!---->
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Please forgive the abrupt tone of this post…am rushing to get ready for the Canadian Hydronics Council Forum - where we will be discussing the perpetual fog(smog) that hangs over the radiant industry created by the likes of 50 Btu/hr/sf outputs and 7/8” is better than ½” …it doesn’t have to be this way…radiant is not a science experiment…its time to stop the practicing - there are codes (CSA B214), standards (ANSI/ASHRAE 55) and guidelines (RPA)…governing radiant systems - it is high time people started using them.<!----><!---->
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Radiant based HVAC systems can be threatening or therapeutic to you health, wellness and comfort. If you want them to contribute in a positive way – use the documents developed by industry for industry...You’ll be so glad you did.<!----><!---->
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Exhale….deep breath…toss back a dram of sms. Ah…sweet dreams.<!----><!---->
RBean<!----><!---->
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Edited 9/6/2005 9:35 pm ET by RBean
Edited 9/6/2005 9:36 pm ET by RBean
Good points, however...in residential it's quite uncommon to see long loops. When I have seen them (twice) they were both problematic. Design flaws. Long loops on small "standard sized" Taco circulators.
Both houses had cold spots, cold spots were due to long loops, too much head pressure due to the long loop for the tubing size, which all resulted in an excessive delta-T across those loops.
You're correct in that most everything can be compensated for with good design. the problem is that not everyone is as conscientious as you are.
Best, Mongo
Thankyou Robert.
I happen to be an irrigation designer, so I have experience in velocities, flows, and friction loss. However, wee deal with much larger diameters and flows, and velocity we avoid. I have always used wirsbro pex for water, and it has always appeared to be a higher quality product than the others.
Hi - I had a very positive experience with Radiantec, so what follows is my personal experience, not a claim to knowing what is the best radiant heat.
My last house used Radiantec, and we loved it. The company designed a system for our house and we did the staple up w/aluminum plates thing, locally acquired gas water heater. Simple, easy, fast, and it was great heat. I found the company easy to deal with. We had no problems (7 years) with their 7/8" tubing.
I will be using Radiantec in the house I am currently building. My total materials are under $5K (3800 s.f., 2 zones, half in slab, half staple up) plus the heat source, which will certainly be under $1K. I have a friend who had radiant heat installed (complex system) for 5 times the cost.
So for me, the simplicity of a low temperature heat source and the low cost of materials has me back at Radiantec. I have never used or installed the boiler/mixing valve/etc system or the smaller tubing. 1/2" pex is certainly plentiful, and easy to find locally.
Edited 9/7/2005 10:17 pm ET by Brian
Since you are in Md, try Energy Reduction in Pittsburgh, Pa. They will do complete design as well as ship the material to you. Great guys to deal with and the $ is good.
I was missinformed then , I thought that I had read some place that they were owned by the same company.
I have used Radiantec before with good results also. I do like their KISS principal of design.
Robert Bean has NO chip on his shoulder. In fact, he is one of the smartest guys in the biz. Look at his site, NO equipment sales. That in itself says a lot.
BTW, you heating costs are 2x what they could be.
"BTW, you heating costs are 2x what they could be."
please explain.
If my assumption is wrong, i apologize.
You are using a standard water heater. The afue is 45% or less.
Using a condensing modulating boiler with outdoor reset, you can have an afue of over 90%.
Pay now or pay later.
The issue of loooong looooops has plagued the industry for decades which is infuriating since their have been guidelines in place for well over a decade.<!----><!----><!---->
If one runs across a project with such a dilemma the best solution is to use a forward /reverse flow control system...it's based on sending the flow in one direction for a period of time then reversing the flow and send it back through the other end...email me if a schematic is required… <!----><!---->
When systems are installed without doing the math...one ends up with problems and though I am a fan of the KISS principle...its dangerous when one does not understand the limitations(which comes from the science)…it goes back to the saying:
When all you have in your tool pouch is a hammer…everything looks like a nail…and there seems to be no shortage of hammers and nails trying to create healthy, safe and comfortable environments.<!----><!---->
We just concluded our Canadian Hydronics Council Forum where industries representatives met to discuss the challenges facing us in the upcoming years...guess what repeatedly came up as a coast to coast issue which manufacturers, engineers, distributors and contractors have to face and resolve everyday? Homeowners choked over unprofessional designs and amateur installations created by those who disregard industry codes, standards and guidelines.<!----><!---->
The good news…at least for some consumers in <!----><!----><!---->Canada<!----><!---->…is the hammer is coming down.<!----><!---->
There is legislation in place requiring certification in the <!----><!---->Province<!----> of <!---->Ontario<!----><!---->, in <!----><!---->Alberta<!----><!---->, one has to have the involvement of a Professional Engineer for hydronics systems and in several municipalities of <!----><!---->British Columbia<!----><!---->, and one can’t obtain a hydronic system without a certified design and a certified installer. Several of the other provinces are following suit with several enforcing CSA B214, Installation Codes for Hydronic Systems.<!----><!---->
All of this legislations and certification is a direct result from consumer complaints and insurance claims.<!----><!---->
Not sure what the long term outlook is for the <!----><!---->U.S.<!----><!----> There are so many jurisdictions and codes it would seem to be a daunting task to get the entire country to adopt a single code like other countries have.<!----><!---->
In the meantime there will be many that end up owing experiments (liability) that others won’t value when it comes time to sell the asset…<!----><!---->
RBean
web: http://www.healthyheating.com
blog: http://wonderfulwombs.typepad.com
Greetings. My first post at this forum. I'm not sure whether it is directly on point or not. Thanks for indulging me.
Can anyone share experience using an engineered wood product (such as Trex), not laminated wood, over a staple up radiant heat system? Or, any thoughts from those of you who known them how such products might fare? Also, any thoughts about how linoleum or cork would do over radiant? Looking for softer alternative flooring for an arthritic homeowner.
Whether or not any of this will work has everything to do with an accurate, comprehensive, room-by-room heat loss calculation...one that takes into account the heat loss through the foundation, windows and doors; the R-value and type of insulation in the walls and ceilings; the average room temperature desired by the occupants; solar gain; number of heating degree days in the climate; the temperature on a "design day"; etc.
The calculation will provide a btu per hour number to start with. After that, tube size and spacing, technique (staple up, light weight sandwich, in-slab), boiler and control strategy, floor coverings, etc can be designed to that btu/hr number.
If you're looking for rule of thumb, be careful. With a well designed, sealed, and insulated building envelope, you should be in the 10 - 20 btu/hr/sq foot range, but with an extremely cold climate, leaky envelope, inadequete insulation, etc, you may see that requirement go up to 30+ btu/hr/sq ft.
Also the term "staple up" can be misleading as there are lots of different ways to do this. Using aluminum plates as conductors makes a positive difference in how many btu's you can deliver to the floor. But if your heat loss is on the bottom end of the holy 10-20 btu/hr/sq ft, you may be able to just hang the tubes in the joist space, insulate underneath and be done with it.
Choosing the type of finished floor is important and needs to be taken into consideration, but is much more complicated than, say, choosing the type of shingle for your roof. IF you can meet the calculated heat loss for your structure on a design day with your chosen heat source, controls, tubing and construction, without the floor temperature going over 85* F, then cork, solid or engineered wood, carpet, linoleum, tile...whatever, will work fine.
Just some information I picked up while DIY'ing the radiant floor heat for my 1600 sq ft cabin/farmhouse in the woods of SE Minnesota.
Cork, by the way, worked fine for me.