Onix - jupiterheating.com · Onix is a flexible tubing specifically engineered and manufactured for use in radiant floors or as hydronic supply and return tubing. The unique chemical

Getting Started

As the radiant industry grows and newproducts become available, one ques-tion continues to surface: What tubingdo I use?

The best answer to this question isthis: choose the right tool for the job.Is Onix right for every job? Or shouldPEX be used?

The following charts illustrate a typi-cal frame floor application, using bothUnderFloor and Thin Slab approaches.The values listed are Watts Radiantlist prices. Actual costs may varyfrom area to area

What do these charts show?

Basically, Onix Staple-Up™ can deliverthe necessary heat load, comfort leveland installation requirements at amuch lower price than any otherunderfloor installation technique.

Misconceptions:One misconception with a frame floorapplication is that a frame floor, orunderfloor application, cannot deliverthe same amount of heat as a ThinSlab or Slab-on-Grade.

Fact:Heat output from aradiant floor islimited by thefloor covering,fluid supply tem-perature and theallowable floorsurface tempera-ture. On average,the maximumfloor surface tem-perature allowed is85°F, which corre-sponds to about 45BTU/sqf. This istrue regardless ofthe floor construc-tion.

The only excep-tion to this is witha suspended instal-lation. Since there is no direct contactwith the tubing and the subfloor, themaximum heating output from aSuspended floor is limited to around25 BTU/sqf. This limitation should benoted in the design process, if the sys-tem is a floor warming application orin a low heat demand environment.

Misconceptions:Thin Slabs and PEX plates enhancethe floors ability to heat a room whencompared to a Onix Staple-Up.

Fact:Thin Slabs and plates may allow alower required supply fluid tempera-ture, but no not increase the floorsability to emit heat. The floor’s abilityto transfer heat to a space is limited bythe floor covering material. Moreconductive floor coverings, with ahigh emissive value will emit heat eas-ier and faster than a more insulativefloor covering.

3131 W. Chestnut ExpresswaySpringfield, MO 65802ph: 417.864.6108 800.276.2419fax: 417.864.8161web: www.wattsradiant.com

Onix and get going

get

EPDM Outer Cover

Aramid Reinforcement

EDPM Boding Layer

AlumaShield

EPDM Inner Tube

Item Number of Units Cost per Unit Total 3/8" Onix 4000 $1.55 $6,200.00Staples 8000 $0.018 $140.00Angle Drill (rental) 1 $50.00 $50.00Splice Kit 1 $20.00 $20.00Unwinder 1 $70.39 $70.39Manifold - BVR 4 $249.50 $998.00SelfTite Clamps 4 $12.41 $49.64Staple Gun (rental) 1 $50.00 $50.00Labor* 20 $100.00 $2,000.00Insulation** 2400 $1.00 $2,400.00

$11,978.03$4.99 per sq. ft.

(List Price)

Onix: Staple-Up ™ 200 ft CircuitsM-5 Manifolds8” oc Spacing

Item Number of Units Cost per Unit Total1/2" Pex 4000 $0.75 $3,000.00 Plates 1600 $3.30 $5,280.00 Nails/Screws 1 $20.00 $20.00 Silicone 1 $40.00 $40.00 Angle Drill (Rental) 1 $50.00 $50.00 Splice Kit 1 $2.85 $2.85 Manifolds - BVR 4 $200.40 $801.60 Crimp Rings (100ct) 1 $21.00 $21.00 Crimp Tool 1 $260.00 $260.00 Unwinder 1 $464.89 $464.89 Labor* 40 $100.00 $4,000.00 Insulation** 2400 $1.00 $2,400.00

$16,340.34$6.81 per sq.ft.

(List Price)

Item Number of Units Cost per Unit Total 1/2" Pex 3000 $0.75 $2,250.00 Staple Gun (rented) 1 $50.00 $50.00 Staples 3 $17.50 $52.50 ThinSlab Material*** 2400 $4.00 $9,600.00 Splice Kit 1 $2.85 $2.85 Manifolds - BVR 3 $200.40 $601.20 Crimp Rings (100ct) 1 $21.00 $21.00 Crimp Tool 1 $260.00 $260.00 Unwinder 1 $464.89 $464.89 Labor* 15 $100.00 $1,500.00 Insulation** 2400 $1.00 $2,400.00

$17,202.44$7.17 per sq. ft.

(List Price)

PEX Thin Slab: Crimp Fittings330 ft CircuitsM-2 Manifolds

12” oc Spacing

PEX Underfloor: Plates: Crimp Fittings300 ft CircuitsM-4 Manifolds8” oc Spacing

3131 W. Chestnut ExpresswaySpringfield, MO 65802

ph: 417.864.6108 800.276.2419fax: 417.864.8161

web: www.wattsradiant.com

Comparision Details

House Size: . . . . . . . . . . . . . . . . . 2,400 sqfNo. of Zones: . . . . . . . . . . . . . . . 4Average Zone Size: . . . . . . . . . . . 600 sqf

System options, accessories and dealer discountsmay alter actual system costs.

All prices shown are list prices.

Onix Staple Up ™

*Labor cost is based on $100/hr; 200ft/hr**Insulation cost is the same for all frame floor comparisons

- value estimated to include insulation and installation labor

PEX Underfloor: Plates; Crimp Fittings*Labor cost is based on $100/hr; 100ft/hr**Insulation cost is the same for all frame floor comparisons

- value estimated to include insulation and installation labor.

PEX Thin Slab: Crimp Fittings*Labor is figured based on $100/hr; 100ft/hr**Insulation cost is the same for all frame floor comparisons

- value estimated to include insulation and installation labor.

***Cost excludes double framing of wall and increasedstructural costs 1.5" of thinslab - cost may vary.

Watts Radiant Literature, July 1, 2003 – Not All Radiant Tubing Is The Same ©Watts Radiant 2003 page 1

&FACTDATASHEET presented by

Onix is a flexible tubing specificallyengineered and manufactured for use inradiant floors or as hydronic supply andreturn tubing.

The unique chemical composition andmanufacturing process of Onix make itthe perfect choice for use as long-lasting,high-temperature hydronic tubing.

Most people are familiar with the manydifferent types of plastic (PEX, polyethyl-ene, CPVC, and ABS to name a few) andtheir different characteristics and applica-tions. Just as different plastics have dif-ferent material properties, so do differenttypes of rubber (EPDM, SBR, NBR ornitrile, Neoprene, natural rubber).

Question:What is Onix?

Answer:Onix is a polymer-rich EPDM; compris-ing a five layer, synthetic, flexible tube.

The inner fluid channel is a peroxidecross-linked, high-grade EPDM. Theinner tube is wrapped with a flexible 00grade aluminum oxygen barrier. Next isa peroxide cross-linked middle layer ofEPDM, wrapped by spiral cords ofaramid reinforcing. The cover is a sul-phur cross-linked EPDM.

Question:What is EPDM and why was itchosen for this application?

Answer:EPDM (Ethylene Propylene DieneMonomer) is a flexible cross-linked mol-ecule. The repeating unit is ethylene,propylene, and a diene, which contains adouble bond for crosslinking. The dieneis ENB (norbornene).

There are many different grades ofEPDM. Unlike other grades of EPDM,the EPDM used in Onix is a high quality,polymer-rich formulation, utilizing rela-tively high ethylene grades with highmolecular weights.

EPDM was chosen because it has aproven track record at high temperatureapplications. EPDM has been used inapplications such as steam hose sinceWorld War II. Because of its molecular

makeup, EPDM is an extremely stablepolymer for high temperature applica-tions.

Question:What is vulcanization?

Answer:Vulcanization is the process that cross-links the rubber molecules to form astronger, more durable molecule.Vulcanization involves immersing therubber in a steam bath where the energyfrom the steam and a peroxide catalystcross-link the rubber molecules intolonger polymer chains.

Peroxide vulcanization uses peroxide as acatalyst in the crosslinking process ofEPDM. The peroxide is scavenged in the

EPDM Outer CoverAlumaShield™ Oxygen Barrier

EPDM Inner Tubing

Aramid Fiber ReinforcingEPDM Bonding Layer

Fluid ChannelOnix™ by WattsRadiant

ONIX™:Not All Radiant Tubing Is The Same

ONIX TESTING

Third party testing results “place thismaterial [Onix] among the most stablematerials we have reviewed.” In addi-tion “this compound is among the bestthat we have tested.”

Samples of Onix have been running at180ºF on test panels for over 60,000hours – CONTINUOUSLY.

Who Is Watts Radiant?

Watts Radiant has been involved in the hydronic radiant floor industry since 1980.

Watts Radiant is a wholly-owned subsidiary of Watts Industries. Since 1874, WattsIndustries has been a leading world-wide manufacturer of valves, hydronic heating,and plumbing equipment. Watts is currently traded on the NYSE as WTS.



Question:How is Onix manufactured?

Answer:Onix is made in a continuous, five-stageprocess, using three extruders, an alu-minum applicator, and an aramid braider.It is then cross-linked in a 325ºF steambath.

– Raw materials are mixed together, thenheld until passing Quality Control tests.

– Inner tube is extruded through a die ina screw extruder while being checkedby a laser micrometer. Nitrogen gas isused to expand the tube wall and main-tain a consistent inside diameter.

– Aluminum oxygen barrier is applied.

– Bonding layer of EPDM is extruded.

– Spiral aramid reinforcement iswrapped.

process, leaving a single carbon-carbon(C-C) bond.

Cross-linking forms a three dimensionalmolecular network that makes EPDMextremely stable over a wide range oftemperatures and pressures.

Question:What is aramid fiber reinforcing?

Answer:Aramid is used as a reinforcement toresist pressure. It gives Onix a 800 psiburst pressure at ambient and a 600 psiburst pressure at 180ºF (compared to 325psi burst at 180ºF of Pex).

Aramid offers the best heat resistanceover time of any reinforcing. Pound forpound aramid is stronger than steel.Aramid is used in bulletproof vests underthe trade name Kevlar .

– Outer cover is extruded.

– Entire Onix assembly is vulcanized in alow-pressure steam bath at 325ºF.Vulcanizing in a pan limits the longestcontinuous length but is a more consis-tent/higher quality cure process than acontinuous cure process.

Question:

Ethylene

Diene(ENB)

Propylene

X

Y

Z

Cross Linking SiteA peroxide catalyst breaks the double bondto form C–C (Carbon to Carbon) singlebond with the next EPDM molecule, form-ing a strong, large, three dimensionalchain of molecules.

Chemical Facts

EPDM is cross-linked with carbon-car-bon single bonds.

It takes more imparted energy fromoxygen, sunlight, chlorine, or otherdamaging agents to break a singlebond than a double bond. This isbecause the double bond has a free“leg” available to reconnect to a newmolecule. The result is a very stablelong lived material.



Why is there only one manufactur-er of EPDM tubing for radiantheating?

Answer:Watts Radiant holds the patent for radiantfloor applications using EPDM with anoxygen barrier.

There are only a handful of polymer man-ufacturers who have the capacity and vol-ume to produce EPDM tubing.Manufacturing multi-layer EPDM tubingrequires a very large capital investment,up to eight times greater than required toextrude plastic. This investment resultsin a product with only one application -radiant.

Question:How is Onix tested?

Answer:Onix has been tested by independent thirdparty labs. Components used in the con-struction of Onix have been subjected toaccelerated lifetime prediction tests, suchas differential scanning calorimetry(DSC), and thermogravimetric weightanalysis (TGA). The DSC testing stud-ies the oxidation process of the polymer.The TGA test studies weight loss.

– Third party testing results “place thismaterial [Onix] among the most stablematerials we have reviewed.” In addi-tion “this compound is among the bestthat we have tested.”

Representative samples are periodicallyplaced on Watts Radiant's long term test-ing panels, where they undergo continu-ous exposure at elevated temperatures toboth water and water/glycol mixes.

– Samples of Onix have been running at180°F on test panels for over 60,000hours CONTINUOUSLY.

Quality Control Testing: – As part of each shift's production, hose

samples are pressure tested. Pressuresinclude proof (400 psig) and burst test-ing.

– A Rheometer test is performed on eachbatch of compound (tests crosslinkingover time by measuring torque).

– Tensile, elongation, specific gravity,viscosity, and moony scorch testing isdone on designated batches.

– Tensile and elongation at break ismeasured for each lot of the aramidreinforcing yarn.

Question:What is the difference between

Onix and flexible tubing like auto-motive heater hose or other radi-ant hose?

Answer:The base polymer for Onix is a high-grade EPDM. The base polymer forheater hose is SBR (Styrene-butadienerubber). Other material used as radianthose has been NBR (nitrile-butadienerubber)– EPDM is inherently stable at high tem-

peratures, and is not dependent on theanti-oxidant package for protection. AnEPDM is like using a stainless steelroof - it is inherently corrosion resist-ant.

– All extruded and cured pipes (PEX orCPVC, for example) use an anti-oxi-dant package to extend protection

ONIX: Table of Material Properties

Tensile Strength . . . . . . . . . . . . . . . . . . . .1000 psiPercent Elongation . . . . . . . . . . . . . . . . . .300 %Low Temp Flexibility . . . . . . . . . . . . . . . .10 times ID @ -40ºFOzone resistance . . . . . . . . . . . . . . . . . . . .100 pphm, 50% extension, no cracksElectrical resistance . . . . . . . . . . . . . . . . . Greater than 10 mega ohmsBurst pressures

at ambient . . . . . . . . . . . . . . . . . . . . . .800 psi at 73ºFat 180ºF . . . . . . . . . . . . . . . . . . . . . . . .600 psi at 180ºF

Thermal conductivity . . . . . . . . . . . . . . . .0.17 Btu/hr-ft-Deg F

ONIX Product Dimensions

Bend Fluid CapacityProduct I.D. O.D. Radius per 1000 ft.

3/8” 3/8” 11/16” 3” 6.25 gal.1/2” 1/2” 7/8” 4” 10.25 gal.5/8” 5/8” 1” 5” 16.00 gal.3/4” 3/4” 1-1/8” 6” 25.00 gal.1” 1” 1-3/8” 8” 43.50 gal.

General Properties of EPDM

Abrasion Resistance . . . . . . . . . . . . . . . . .ExcellentOxidation (resistance of) . . . . . . . . . . . . . .ExcellentOzone (resistance of) . . . . . . . . . . . . . . . .ExcellentSunlight Aging . . . . . . . . . . . . . . . . . . . . .ExcellentHeat Aging . . . . . . . . . . . . . . . . . . . . . . . .Excellent

Why should I install Onix?

Long lasting . . . . . . . . . . . . . .Backed by a comprehensive 25 year warranty

Most flexible, durable radiant tube available . . . . . .Installs in less time than any other radiant tube

Flexible to -30ºF . . . . . . . . . . .Easy installations in freezing cold weather

Can't be kinked . . . . . . . . . . .Double it up and push it through a hole in a joist forfaster Staple–Up™ installations

UV resistant . . . . . . . . . . . . . .Up to 5 years. Leave it exposed on a job-site, worry-free

No special tools required . . . .No expensive connection tool or tube unwinder

Crush resistant . . . . . . . . . . . .Large concrete pours are possible – let the concretetruck roll over Onix (see Onix Installation Manual)

Aluminum oxygen barrier . .Flexible oxygen barrier is protected inside the tubing – Can't damage it on the jobsite– Aluminum oxygen barrier is unaffected by tempera-

ture (just as effective at 180°F as 100°F, unlike otheroxygen barriers on the market)

No expansion . . . . . . . . . . . . .No movement when Onix heats up – Never noisy in a Staple–Up application; stays in con-

tact with subfloor for better heat transfer



3131 W. Chestnut ExpresswaySpringfield, MO 65802

ph: 417.864.6108fax: 417.864.8161

www.wattsradiant.com

ONIX Staple-Up™

ONIX Slab–On–Grade

ONIX with SubRay™

ONIX Snowmelt

against premature "aging" of the pipe.Other rubber materials such asSBR/NBR is extremely sensitive tohaving the correct anti-oxidant pack-age. Anti-oxidants retard thermaloxidative hardening by capturing radi-cals and preventing the chemical reac-tion from propagating. This is similarto using a plain steel roof (NBR orSBR) - you have to paint it (add anexact amount of anti-oxidants) to keepit from rusting.

At the molecular level, the major differ-ence between NBR (or SBR, or neo-prene) and EPDM is that NBR containscarbon-carbon double bonds whileEPDM contains very stable carbon-carbon single bonds.– Double bonds are very reactive and are

"unsaturated." This means that the car-bon-carbon double bonds of the NBRare much more likely to be oxidized(age) than the "saturated" carbon-car-bon single bonds of EPDM, thus mak-ing EPDM a much more stable mole-cule at high temperatures.

– Single bonds require more energy tobreak than double bonds.

Because of Onix’s inherent benefits forRadiant Floor Heating pipe and Supplyand Return Piping—its flexibility,longevity and durability (see table)—it isthe best material to use in your nextUnderfloor, Slab, or snowmelting appli-cation.


There seems to be a lot of misinforma-tion regarding performance and efficien-cy of Staple-Up™ systems. Despite thefact that Watts Radiant has experiencewith tens-of-thousands of Staple-Upsystems over the last 22 years in someof the coldest climates in the country,some insist that Staple-Up "doesn'twork" or it has "limited heat capacity"or it is "much more expensive to oper-ate."

The goal of this technical piece is to putthese myths to rest and help explain theadvantages of Staple-Up systems.

Question:Is it true an Onix Staple-Up applicationcosts less than PEX, even though theOnix tubing costs more?

Answer:Yes, Onix Staple-Up applications docost less than PEX Underfloor applica-tions. There are two main reasons. Thefirst has to do with labor. Onix installs2-3 times faster than PEX. This is duein part to the increased flexibility ofOnix over PEX, not to mention theadditional time needed to install the spe-cial fasteners required for PEX, such asclips and/or heat transfer plates.

These additional fas-teners also increasethe cost of a PEX sys-tem. Even thoughOnix tubing may costmore than PEX tub-ing, the cost of Onixwith staples is about40% less than PEXwith metal plates (seetable).

Question:Why can't PEX be stapled directly to theunderside of the subfloor like Onix?

Answer:PEX will expand and contract as it isheated and cooled. How much it willmove is directly proportional to thechange in temperature. PEX tubingexpands 1.1 inch for every 10 degreerise in temperature for every 100 feet oftubing. If a 200 ft. circuit of PEX is

filled with 60°F water and heated to160°F, the PEX expands approximately22 inches.

This movement can cause noise andwear, either against the floor or againstthe staples themselves. A considerableamount of noise can be generated as thePEX expands and rubs against the metalplates or staples. This noise is transmit-ted into the house. Also, there is a ques-tion of heat transfer. As the PEXexpands it has a tendency to pull away

WattsRadiant Literature, May 1, 2003 ©WattsRadiant 2003 page 1

Onix Staple-Up PEX w/Plates PEX Sandwich PEX ThinslabTubing Cost $2.55 $1.24 $1.24 $0.85Staples/Screws $0.02 $0.50 $0.08Metal Plates $4.00SubRay $4.65Light Crete $4.00Structural $1.50

ModificationsTOTALS $2.57/sf $5.74/sf $5.97/sf $6.35/sf

Values shown are based on a list price per square foot basis. Cost considerations are for tubing and attachment materials only.Labor costs are in addition to the totals listed above.

Staple–Up™ With Onix

from the subfloor. Thisseparation decreasesthe tubing's ability totransfer energy to thesubfloor, and reducesits overall heating abil-ity.

Question:Why doesn't Onix havethese problems?

Answer:Onix is comprised of across-linked EPDMcompound that doesnot expand with tem-perature changes. Onixis the same diameterand length at 200°F asit is at 50°F.

No expansion meansno wear on the tubing,no noise and noreduced heat transferdue to tubing movingaway from the floor.

Question:I've heard Staple-Up applications causethermal striping. Is this true?

Answer:No. Onix Staple-Up does not cause ther-mal striping (objectable temperature dif-ferences). All radiant floor applicationswill experience some thermal variancesin floor surface temperature on start up.This is due to the instantaneous load onthe floor at that time. As the floor reach-es steady-state conditions, this varianceevens out, resulting in a very even floortemperature.

The surface temperature for an OnixStaple-Up system will be nearly identi-cal to that of a PEX underfloor systemwith plates.

Most ThinSlab applications will experi-ence a greater sense of thermal stripingon start up than a Staple-Up application.This is because the increased conductiv-ity of the thin concrete above the tubingsends the heat to the surface faster thanthe mid-point between the circuits. Thisresults in a greater initial striping.

Tube spacing has a direct impact onhow much temperature difference afloor can experience. The wider the tubespacing the greater the potential forstriping. Staple-Up applications are 8"on center while Thin Slab applicationsare usually 12" on center.

Phase 1: Initial Start-up Conditions

Radiant Energy Transfer

Foil Faced Insulation

Air tight cavity is important to help maintain a constant,uniform air temperature in the joist cavity.

Onix stapled directly to subfloor.

&FACTDATASHEET


Phase 2: Mid-Point Conditions

Phase 3: Steady-State Conditions

Conductive Energy Transfer

80°F 77°F 80°F 77°F

The two images on to the left show a the temperature of a floor ina standard forced air heated home. The image to the right showsa radiant tile floor.

Notice the color of the radiant floor and the person’s hand. Bothare about the same color, indicating both are about the same tem-perature. The person in this room is losing very little energy tothe floor and is much more comfortable as a result.

Once all properly installed radiant sys-tems reach steady-state conditions, tem-perature differences are insignificant,resulting in a very even floor tempera-ture.

Question:I've been told heat transfer plates arerequired to spread the heat out acrossthe floor. Why doesn't Onix need heattransfer plates?

Answer:Onix does not need heat transfer platesfor two reasons. First, Onix is in directcontact with the subfloor, resulting indirect conductive, efficient heat transfer.

Second, Watts Radiant recommends allOnix Staple-Up installations use foil-faced insulation. The foil on the insula-tion "reflects" the downward energyback up into the subfloor. This reflectedenergy is spread out over the bottom ofthe subfloor, creating an even tempera-ture.

Question:Does Onix Staple-Up take longer torespond than other frame floor applica-tions?

Answer:No. Response times are dictated by thethermal mass of the construction materi-al, not the radiant tubing. All construc-tion materials have a Specific HeatValue; this is the amount of energyrequired to raise the temperature of onepound of material one degreeFahrenheit.

The tables reflect the requirements for a1,000 sf. room with a floor temperaturechange from 50°F to 80°F with a 50,000Btu/hr output boiler. These numbersonly reflect the time and load requiredto change the floor mass temperature,and do not take into account the addi-tional load required to raise the roomtemperature, or to sustain the room'sheat load.

&FACTDATASHEET


Onix Staple-Up Nomograph showing a supply temperature of 125° with a BTU load of 25 BTU/sqft andfloor surface temperature of 81°F.

PEX with Plates Nomograph showing a supply temperature of 120° with a BTU load of 25 BTU/sqft andfloor surface temperature of 81°F.

Question:Why don't hanging PEX applicationswork as well as Onix Staple-Up?

Answer:Hanging PEX applications suspend thetubing in the joist cavity with a series ofplastic clips spaced every 24 - 32" oncenter. This is done to eliminate thenoise as the PEX tubing expands andcontracts with temperature changes.This creates an air gap between thePEX tubing and the subfloor, eliminat-ing conductive heat transfer from thetubing. A major result of this lack ofcontact is a reduction in the total BTUsproduced. Most hanging PEX applica-tions are limited to a maximum of 20BTU/hr per square foot, often requiringthe installation of supplemental heat.

Onix Staple-Up applications can pro-duce up to 45 BTU/hr/sq. ft. of useableheat. This is a result of the Onix havingdirect contact with the subfloor.

Question:Why does Onix require a higher supplywater temperature than PEX when bothare installed the same way?

Answer:Onix requires a slightly higher watertemperature because of the physicalproperties of the material. Onix is com-posed of EPDM rubber with a thickerwall profile (added resistance to jobsiteabuse) than a PEX tubing.

Due to the thicker wall, a slightly higherwater temperature is required to achievethe same outside tubing temperature aswould be seen with PEX. Since bothpipe outer surface temperatures are thesame, then they both have the sameBTU delivery to the floor and sameoverall system response.

On the average, when compared toPEX, Onix will only see around a 5-8°Fvariance on supply fluid temperatures.

Question:Doesn't a higher supply temperaturemean higher operating costs?

Answer:No. Operating costs are determinedsolely by the amount of energy con-sumed (BTUs), not by the supply watertemperature.

One easy way to monitor energy usageis to measure flow rate (gpm) and sys-tem temperature drop (supply watertemp - return water temp). At a flowrate of one gallon of pure water perminute, a temperature drop of 20°F will"deliver" 10,000 BTU/hr. Whether the

HiGuard™ Industrial Cover

AlumaShield™ Oxygen BarrierDurel™ Inner Tubing

Aramid™ Fiber Reinforcing

Contour Extrusion Layer

Fluid ChannelOnix™ by Watts Radiant

Inside Diameter Outside Diameter Thermal Conductance Thermal ResistanceTubing Material (inch) (inch) (Btu/hr.*ft.*°F) (hr.*ft.*°F/Btu)1/2" EPDM 0.5 0.875 0.17 0.52391/2" PEX-AL-PEX 0.472 0.63 0.26 0.17671/2" PEX 0.472 0.63 0.237 0.19391/2" L Copper 0.545 0.625 223 0.9775 x 10-4

Temperature DropTubing Material (tw - td) °F1/2" EPDM Rubber 13.0981/2" PEX-AL-PEX 4.4181/2" PEX 4.8481/2" L Copper practically 0°F

&FACTDATASHEET


The average supply fluid temperature differencebetween Onix and PEX is approximately 8°F.

tw = supply fluid temperaturetd = outside tube surface temperature

Fluid Temperature Variances

Various Piping Thermal Properties

4” Concrete 9.80 BTU/ft3°F1.5” Thin Slab 3.22 BTU/ft3°F0.75” Subfloor (Staple-Up) 1.10 BTU/ft3°F

Heat Capacities

4” Concrete 294 MBH 1.5” Thin Slab 96.6 MBH0.75” Subfloor (Staple-Up) 33.0 MBH

BTU’s Required

4” Concrete 5.88 Hours1.5” Thin Slab 1.93 Hours0.75” Subfloor 0.66 Hours

Time Required to Heat Floor

&FACTDATASHEETtemperature drop is from 150°F to130°F or 110°F to 90°F, one gpm willalways "deliver" 10,000 BTU/hr.

Btu/hr = GPM x 500 x DTGPM = system flow rate in

gallons per minuteDT = Supply water temperature -

return water temperature

Most radiant systems operate with anon-condensing boiler, meaning theboiler needs to operate at 140°F to160°F (supply) or above. So, whether aradiant system operates at 150°F or110°F, the boiler water is "mixed down"to supply the radiant system. Thismeans the flue and stack losses from theboiler will be the same for both radiantsupply temperatures.

Remembering that the energy consumed(BTU/hr.) is determined by flow rateand temperature DROP (not supply tem-perature), a radiant system that requires150°F supply will not use more energythat a system that requires 110°F.

The only time a lower water tempera-ture translates to better efficiency is if acondensing boiler is used. These boilersare designed to operate at very lowreturn temperatures, such as asnowmelting application.

Question:What material is Onix made from?How is it different from other rubberslike automotive radiator hose or otherradiant hose materials?

Answer:Onix is a multi-layer composite product,with EPDM, aramid reinforcing and aductile aluminum oxygen barrier.EPDM stands for Ethylene PropyleneDiene Monomer, which is a cross-linkedsynthetic rubber. The peroxide-curedcarbon-carbon bonds that form thecross-linking in the Onix tubing areextremely stable and give Onix the abil-ity to resist sunlight, oxidative aging,and and long term effects of high tem-perature operation.

Question:What testing has taken place to ensureOnix will last?

Answer:Watts Radiant continuously tests Onixin multiple phases of production. Eachbatch of tubing produced is tested to amin. 100 psig pressure to ensure burstresistance. A Rheometer test is also per-formed on each batch, which tests thecross-linking. During production othermaterial properties are tested, such astensile strength, elongation, specificgravity, and viscosity levels.

Besides being operated for over 60,000continuous hours of testing at 180°F,Watts Radiant sends samples of Onix toindependent labs for further testing.These labs test the components used inthe construction of Onix tubing.

These tests determine the physical andchemical changes the compenentsundergo. Based on the variances frombeginning to end, an estimated life spanis determined.

-

Question:How does Onix compare to PEX?

Answer:Onix outperforms PEX on several lev-els.

1.Onix has a tighter bend radius thanan equivalent PEX size, makinginstallation easier. Onix can beinstalled in tighter areas, allowingfor more effective coverage.


Tensile Strength . . . . . . . . . . . . . . . . . . . .1000 psiPercent Elongation . . . . . . . . . . . . . . . . . .300 %Low Temp Flexibility . . . . . . . . . . . . . . . .10 times ID @ -40 Deg FOzone resistance . . . . . . . . . . . . . . . . . . . .100 pphm, 50% extension, no cracksElectrical resistance . . . . . . . . . . . . . . . . . Greater than 10 mega ohmsBurst pressures

at ambient . . . . . . . . . . . . . . . . . . . . . .800 psi at 73 Deg Fat 180 Deg F . . . . . . . . . . . . . . . . . . . .600 psi at 180 Deg F

Thermal conductivity . . . . . . . . . . . . . . . .0.17 Btu/hr-ft-Deg F

Onix (EPDM) Properties

I.D. Onix Bend PEX Bend Size Radius Radius3/8” . . . . . . .3” . . . . . . . . . . . .41/2” . . . . . . .4” . . . . . . . . . . . .5”5/8” . . . . . . .5” . . . . . . . . . . . .6”3/4” . . . . . . .6” . . . . . . . . . . . .7”1” . . . . . . . .8” . . . . . . . . . . .10”

R4"R3"

8"6"

4"

R3" R4"R3"

8"6"

4"

R3"

Onix Bend Radius PEX Bend Radius

&FACTDATASHEET


2.Onix cannot be permanentlykinked, eliminating wasted jobsitetime spent repairing kinks in PEXtubing.

3.Onix is UV resistant for a minimumof 5 years, so it can be left in thesun on the jobsite without damag-ing the tubing or the oxygen barrier.

4.Onix remains flexible to sub-zerotemperatures, making it easy toinstall in frigid environments.

5.Onix has a burst rating of 600 psigat 180°F, while PEX has a burstrating of 325psig at 180°F, meaningit will hold up to extreme "run-away" boiler conditions.

6.Onix does not require special toolsto make the connection at the mani-fold, saving hundreds of dollars intool costs.

7.Onix's oxygen barrier is inside thetubing, protecting it from job siteabuse.

8.Onix's outer cover is extremelydurable, protecting the inner tubingand oxygen barrier from job siteabuse.

9.Onix is crush-resistant, recoveringits shape after being compressed byvehicles.

The Bottom LineOnix Staple-Up is a very straightfor-ward, simple-to-install system that iseasily understood by the installer andthe owner. The system doesn't requirespecial fasteners, metal plates, propri-etary tools, heavy concrete, or a specialmechanical room design. It's a systemthat works without all the complica-tions.

Onix Staple-Up works, and it workswell. Try it on your next project. Designthe system with our Radiant Works soft-ware and you'll have the experience of22 years of successful radiant systemdesign guaranteeing it will work like achamp!

Onix allows for a faster, easier, cleaner installation.

Documents

Onix - jupiterheating.com · Onix is a flexible tubing specifically engineered and manufactured for use in radiant floors or as hydronic supply and return tubing. The unique chemical