Question? Just ask us!
Free Encyclopedia of Building & Environmental Inspection, Testing, Diagnosis, Repair
InspectAPedia ® Home
AFUE DEFINITION, RATINGS
AIRBOUND HEAT SYSTEM REPAIR by WATER FEED VALVE
ANTIFREEZE for BOILERS
BACKDRAFTING HEATING EQUIPMENT
BACKFLOW PREVENTER VALVE
BOOKSTORE - InspectAPedia
BTU USAGE MONITORS
CARBON MONOXIDE - CO
CIRCULATOR PUMPS & RELAYS
DEFINITION of HEATING & COOLING TERMS
DIAGNOSTIC GUIDES A/C / HEAT PUMP
DIAGNOSE & FIX HEATING PROBLEMS-BOILER
DIAGNOSE & FIX HEATING PROBLEMS-FURNACE
DIRECT VENTS / SIDE WALL VENTS
DRAFT HOODS - gas fired
DRAFT REGULATORS, DAMPERS, BOOSTERS
ELECTRIC MOTOR DIAGNOSTIC GUIDE
FLOODED HEATING EQUIPMENT REPAIR
FLUE SIZE SPECIFICATIONS
FREEZE-PROOF A BUILDING
FUEL OIL TYPES & CHARACTERISTICS
GAS BURNER Flame & Noise Defects
GAS PIPING, VALVES, CONTROLS
GAUGES ON HEATING EQUIPMENT
GEOTHERMAL HEATING SYSTEMS
HEAT PUMPS, DIAGNOSIS, REPAIR
HEATING COST SAVINGS METHODS
HEATING OIL PIPING TROUBLES
HEATING OIL TANKS
HEATING OIL TYPES & PROPERTIES
HEATING SYSTEM INSPECT DIAGNOSE REPAIR
HEATING SYSTEM NOISES
HEATING SYSTEM SERVICE FAQs
HEATING SYSTEM TYPES
HIGH EFFICIENCY BOILERS/FURNACES
GAS LP & NATURAL GAS SAFETY HAZARDS
MANUALS & PARTS GUIDES - HVAC
MIXING / ANTI-SCALD VALVES
MOTOR OVERLOAD RESET SWITCH
Natural Gas Combustion
NOISE, HEATING SYSTEMS
ODORS FROM HEATING SYSTEMS
OIL FILTERS on HEATING EQUIPMENT
OIL FILL PIPE LEAKS
OIL PUMP FUEL UNIT
OIL TANK PIPING & PIPING DEFECTS
PLASTIC Plexvent / Ultravent RECALL
PULSE COMBUSTION HEATERS
PUFFBACKS, OIL BURNER
RELIEF VALVES - TP Valves on Boilers
Reset Switch - Heater Primary Control
RESET SWITCH - ELECTRIC MOTOR
SAFETY, HEATING INSPECTION
SAFETY RECALLS CHIMNEYS VENTS HEATERS
SOLAR HEATING SYSTEM DESIGNS
SOOT on OIL FIRED HEATING EQUIPMENT
SPILL SWITCHES - Flue Gas Detection
STACK RELAY SWITCHES
THERMOSTATS, HEATING / COOLING
VIDEO GUIDES: Heating System Videos
WATER HEATERS for HOME HEATING USE?
WINTERIZE A BUILDING
ZONE VALVES, HEATING
Radiant heat tubing & heating fluid choices, advice: This article discusses the suitability of various tubing materials for radiant heated concrete floor slabs, and choices of heat conducting fluids for radiant floors. Our page top photograph shows polyethylene tubing being installed in a new concrete floor slab for radiant heat in a Two Harbors Minnesota building.
Green links show where you are. © Copyright 2014 InspectApedia.com, All Rights Reserved.
Our page top photo shows polyethylene tubing emerging from a radiant-heated floor slab under construction in Two Harbors, MN in 2007. Note the nice detail, use of a larger diameter tubing around the heating distribution plastic tubes, protecting the heating tubing from bending damage where it emerges from the slab.
"Radiant Slab Fluids"
Questions about radiant slab floors:
What is your opinion about the relative suitability of various plastics (e.g. polybutylene, EPDM, etc.) for carrying heat transfer fluids in concrete radiant slab floors?
Which radiant floor slab tubings are acceptable for use with water, propylene glycol, Syltherm 444? -- C.R. MC, East Lansing, MI
Answers about radiant floor tubing and fluids:
Both copper tubing and plastic poly or PEX tubing are used in radiant heat systems. Our photo (left) shows brass or copper connectors used at the transition from an electric boiler to in-slab radiant tubing. These fittings should have not been used in the concrete itself.
Plastic piping or tubing used for radiant heating systems varies in wall thickness, density, and chemical composition.
Consequently, each grade of plastic tubing that might be considered for radiant heated floors has its own temperature, pressure, and chemical compatibility limitations.
High-temperature polybutylene pipe is rated for 200 degF continuous use at 80 psi with water and/or glycols used as heat transfer fluids.
This makes polybutylene piping applicable to many radiant floor designs including the radiant floor design shown in the photograph at the top of this page.
The two radiant heat ubing sizes used most often in radiant heat floor designs are 7/8" Poly tubing or 1/2" PEX tubing. Compared with traditional copper radiant heat tubing, use of these newer materials often reduces the number of connectors and thus the risk of leakage, and easy-radius bends in tubing also improve fluid flows thorugh the system.
Radiant Floor Tubing Choices: diameters, BTUs per foot, temperature & pressure ratings
However when installing radiant heat tubing beneath a wood-framed floor the spacing of the floor joists and other obstacles becomes a consideration when planning for tubing bends, turns, and routing.
Our photo illustrates the radiant floor heating zone manifold for a multi-zone system installed during reconstruction of a home in Tivoli, NY. Copper piping feeds heating water to the zone manifold which in turn distributes heating fluid to four individual heating zones.
7/8-inch Polyethylene Tubing Radiant Floor Heat Tubing
Larger-diameter 7/8" Poly radiant floor tubing spaced 16" on center provides about 50 BTU's per linear foot (depending on heating fluid temperature and flow rate through the tubing.
Using this larger diameter radiant heat floor tubing will reduce the bending radius available for turns at the ends of tubing runs but it can usually be fit successfully in conventional wood-framed 16-inch on center floor joists.
1/2-inch PEX Radiant Floor Heat Tubing
However 1/2-inch PEXC tubing generates about 25 BTU's per foot, so to obtain the desired radiant floor heat capacity you should space the tubing runs closer than with larger tubing - thus you will increase the total linear feet of tubing used and the project installation cost increases a bit for this material. Use spacing of 8" on center.
Photo at left shows PEX tubing used in a water supply installation.
For radiant heat applications operating at higher temperatures or pressures (such as snow melt installations) 1/2-inch PEX tubing may withstand these conditions better than larger-diameter poly tubing but in all installations you should be sure to compare the temperature rating for your tubing with the intended use and operating system temperatures and pressures.
Watch out: in some wood-framed floor radiant heat installations where radiant heat tubing odors were a complaint, in new installations the installer may recommend running the system continuously at higher than normal temperatures for several days in a hope to "cook out" odors. But operating the system at temperatures above those for which the tubing is rated may cause damage or leaks.
Details about PEX tubing and other plastic tubing choices are at
EPDM Tubing Used for Radiant Heat Installations
EPDM tubing, the type used in SolaRoll™, will handle up to 300 degF. for water and glycols.
Neither EPDM tubing nor polybutylene tubing is recommended for use with silicone oils or hydrocarbons [so watch out when choosing the antifreeze product to be used in radiant heat floor systems when this tubing is selected].
Our photo (left) illustrantes Entran 3 radiant heat tubing. See Entran-II leak discussion in the FAQs section below.
High density polyethylene tubing, not the type commonly found in retail building outlets, can also handle water temperatures typical of radiant heat floor systems, but with glycols and silicone oils, temperature limitations apply.
For a given radiant floor heating application, it would be wise to consult with the manufacturer of the specific tubing material and its connectors before making your purchase. Some manufacturers do not recommend the use of brass fittings embedded in concrete. If possible, buried tubing joints should be avoided altogether.
Here we include solar energy, solar heating, solar hot water, and related building energy efficiency improvement articles reprinted/adapted/excerpted with permission from Solar Age Magazine - editor Steven Bliss.
A link to the original article in PDF form is immediately below
Reader Question: what can you tell me about Entran II leak-risk radiant heat tubing and how can I recognize it in a home?
Early Entran™ Tubing marked Entran or Entran II is at risk of leakage and failure where it is installed, particularly if the tubing was subjected to high temperatures. Entran-3 tubing does not have the same leak complaint history.
Our photo (left) illustrates Entran-3 radiant heat tubing - not the leak-prone product discussed here.
Entran radiant heat tubing, produced by Goodyear Tire & Rubber and was distributed by Heatway Systems between 1989 and 1994 and has been estimated to have been installed in abouit 10,000 homes in the U.S. and possibly in Canada. Specifically Entran-II was a rubber tubing product installed for radiant heat floors. It was also installed in driveway or sidewalk snow and ice melting systems.
The defect of concern with Entran-II tubing is that a plasticizer added for flexibility was found to leach out of the rubber if it was exposed to high temperatures. The loss of the plasticizer was associated with odor and smell complaints and ultimately with leaks in the tubing as with loss of plasticizer the tubing will crack.
We encountered this product first as part of an investigation into an odor complaint in a new home with radiant heat tubing stapled under hardwood floors. The installer, hoping to "drive out" the odor, ran the heating system at higher-than-recommended operating temperatures, leading to a double fault: the flooring was damaged (gapping) from the excessive temperature and ultimately the tubing leaked.
You may identify Heatway Entran II tubing by noting its orange color and imprinted markings where you see radiant heat tubing at the supply and return radiant tubing manifolds that are usually close to the heating boiler.
Our photo (left) illustrates Entran-3 tubing.
If the tubing was stapled-up beneath a wood floor and subfloor, by moving insulation (you may have to also remove ceiling coverings) you can also inspect the tubing and its condition.
In our OPINION unless you already see visible leaks, cracks, or damage, it is not easy to determine the remaining life of the Heatway Entran-II tubing. If the tubing was never subjected to high temperatures (which should have been the case with a properly installed and operated radiant heat floor system) the remaining life could be good.
If you suspect that the tubing is already leaking (leaks may not be visible if tubing is embedded in a concrete slab) a pressure test or infra-red scanning and thermography can not only detect the leak but can detect where it is occurring. Of course if the tubing has leaked in a finished ceiling you'll probably see water stains.
Class Action Settlement May Offer Financial Relief to Homeowners where Entran II Tubing Was Installed
Only for homeowners who filed a claim prior to 19 November 2009, a financial settlement offered limited damage payments for homeowners in two categories, depending on the actual extent of leak damages that occured due to Entran-II tubing. The product names involved included Twintran, Nytrace, Entran II Trace, Entran II Wire, Entran 2, Entran 2 Trace, and Entran 2 Wire. Details were at www.entraniisettlement.com or could be obtained by calling 800/254-9222. A follow-up check of these contacts in 2012 lead nowhere.
Green link shows where you are in this article series.
Frequently Asked Questions (FAQs)
No FAQs have been posted for this page. Try the search box below or CONTACT US by email if you cannot find the answer you need at InspectApedia.
Try the search box just below or if you prefer, post a question or a comment in the Comments box below and we will respond promptly.
Search the InspectApedia website
HTML Comment Box is loading comments...
Technical Reviewers & References
Related Topics, found near the top of this page suggest articles closely related to this one.