FAQ (FREQUENTLY ASKED QUESTIONS)

Uponor Radiant floor heating is a comfortable and efficient form of heating where warm water circulates through flexible, specially designed PEX tubing installed under the floor. The heat radiates evenly up through the floor warming people and objects in the room and providing more comfort for less money.

Unlike traditional heating systems that just warm the air, radiant heating warms the floor and the objects in contact with the floor. The entire floor distributes a consistent, even and quiet heating. There are no drafts and radiant floor heating takes the chill out of cold tile, marble and wood floors.

Yes, however the ducts can be smaller which saves structural height. Ventilation is necessary to address the latent load and bring in the required refresh air.

Uponor Radiant Floor Heating has existed for more than three decades. We've been making the PEX tubing used in our radiant floor heating systems since 1970, longer than any other PEX tubing manufacturer.

PEX (crosslinked polyethylene) tubing is a specially designed plastic tubing with distinctive properties that make it ideal for radiant floor heating and plumbing systems. Uponor produces PEX-a tubing, which is considered the superior type of PEX.

Currently, three methods for producing crosslinked polyethylene (PEX) tubing exist: (1) Engel or peroxide method (PEX-a); (2) Silane method (PEX-b); (3) E-beam (electron beam) or radiation method (PEX-c). All three processes generate tubing that is crosslinked to varying degrees, and are acceptable for potable water distribution applications according to ASTM F876 and F877 standards. Uponor manufactures Engel-method PEX-a tubing. The PEX tubing industry considers this tubing superior because the crosslinking is done during the manufacturing process when polyethylene is in it amorphic state (above the crystalline melting point). Because of this, the degree of crosslinking reaches around 85% (higher than the other methods), resulting in a more uniform product with no weak links in the molecular chain.

No. A properly designed radiant floor heating system will deliver comfortable warmth that's a pleasure to walk on - especially in bare feet! If additional heat is needed to satisfy the heat load, additional warmth can easily be added by installing radiant walls and/or ceilings. Uponor offers technical design support as well as design software.

Not at all. Our Quik Trak™ system is perfect for remodeling or retrofit projects. Quik Trak™ is installed over a plywood subfloor. It's great for putting radiant comfort in a basement or anywhere in your home.

Absolutely. Uponor radiant floor heating systems are flexible, meaning you can heat the entire home or only those rooms you want to heat. The bathroom is a popular area of the home to heat.

Uponor offers two types of PEX tubing — Wirsbo AQUAPEX® tubing and Wirsbo hePEX™ plus tubing. Wirsbo AQUAPEX® is used in plumbing and under certain circumstances in radiant floor heating systems. Typically, Wirsbo hePEX plus is used for radiant floor heating as it contains an additional layer on the tubing which acts as a barrier and reduces the amount of oxygen entering into the heating system.

We offer Radiant Ready™, in which the PEX tubing is installed in the slab during construction and you can complete the system later. This adds relatively little to the cost of a poured floor, but can add a great deal to the value of your home later.

Sure you can. In fact, separate heating and cooling systems really make the most sense. Radiant floor heating keeps the heat near the floor where it does the most good; and air conditioning ductwork is placed only where it is needed to cool your home. The result is optimal comfort and efficiency all year.

Yes, our radiant heat system has no drafts, fans or blowers to circulate dust, dirt and other allergens throughout your home. Warm radiant floors can eliminate the need for carpeting which is a breeding ground for dust mites, a very common cause of allergic respiratory disease. The result is a clean, healthy environment —a must for people with allergies.

Radiant cooling has gained recent popularity in Europe and North America because it offers the potential to reduce cooling energy consumption and to reduce peak cooling loads when coupled with building thermal mass.

Radiant cooling refers to any system where surrounding surface temperatures are lowered as means of removing sensible heat gain and thus contributing to thermal comfort.

A hydronic radiant cooling system is an installation of embedded tubes or surface mounted panels that are designed to absorb and remove energy from a space, 50% to 80% of which is radiant energy. Just as in heating, a radiant cooling system uses the structure and surfaces of an area to transfer energy.
In radiant heating systems, the energy moves away from the heated surface towards the cooler area. In radiant cooling systems, the energy moves towards the cooled surface from the warmer area.

No. A phase change is required to address this load. This is accomplished by the ventilation system of the building. The ventilation system will also control the balance of the sensible load throughout the occupied time of the day.

No, one system can both heat and cool and in some climates in North America, the system may do both throughout the day as well as be design to transport heat from one side of the building or the other!

Yes. Specifically there are Low Mass and High Mass radiant cooling systems. Low mass radiant systems circulate cool water in specialized panels or beams and typically operate during the occupied time; high mass systems cool the building structure (slab, walls, ceilings) during unoccupied time and provide the additional advantage of off-peak cooling and further reduction in energy costs.

Because radiant surfaces are often cooled only 2-4°C below the desired indoor air temperature, there are many opportunities for innovative cooling sources such as night fluid cooling, ground-coupled hydronic loops, and indirect evaporative cooling.

• Museums • Institutional + Educational facilities • Office buildings + Atrium areas • Manufacturing + Retail spaces • Hospitals + Health Care facilities • Dormitories, Barracks + Prisons • Churches • Airports

Yes, there are very considerable LEED advantages with radiant cooling systems. Including, but not limited to peak loads that are reduced as a result of thermal energy storage in the panel structure, exposed walls, and partitions. Radiant cooling systems operate at a higher supply chilled water temperature, and therefore ground and bay water could be utilized.

The cooling capacity of a floor system depends on the heat exchange between the floor surface and the space (convective and radiant heat exchange coefficient), the heat conduction between the floor surface and the tubes (floor surface material, type of concrete, slab thickness, spacing between tubes) and the heat transport by water (water flow rate, temperature difference between supply and return). Dew point, floor coverings, AUST(average uncontrolled surface temperature) and average water temperature.

Leaks are not a concern with Uponor PEX when the system is properly installed. With a life expectancy of more than 100 years, Uponor PEX tubing has withstood the most extensive tests in the industry for over 30 years. What's more, all our PEX tubing is thoroughly inspected before it leaves our manufacturing plant. We also offer a 25-year limited warranty when installed by an Uponor-trained plumbing professional.

Yes. We are so confident of the quality of an Uponor radiant floor heating system that we offer a 25-year warranty on the tubing when installed by a member of our Home Comfort Team (HCT).

Uponor PEX carries the following hydrostatic temperature and pressure ratings:

• 200°F at 80 psi
• 180°F at 100 psi
• 120°F at 130 psi (1/2" Wirsbo AQUAPEX tubing only)
• 73.4°F at 160 psi

Uponor PEX and associated fittings are manufactured to the following standards:

• ASTM F876 "Standard Specification for Cross-linked Polyethylene (PEX) Tubing"
• ASTM F877 "Standard Specification for Cross-linked Polyethylene (PEX) Plastic Hot and Cold Water Distribution Systems"
• ASTM F1960 "Standard Specifications for Cold Expansion Fittings with PEX Reinforcing Rings for use with Cross-linked Polyethylene (PEX) Tubing"
• ASTM F2080 "Standard Specifications for Cold Expansion Fittings with Metal Compression Sleeves for Cross-linked Polyethylene (PEX) Tubing"

Additional standards for Wirsbo AQUAPEX tubing and associated fittings include:

• ANSI/NSF Standard 14 "Plastics Piping System Components and Related Materials"
• ANSI/NSF Standard 61 "Drinking Water System Components — Health Effects"

UL 1821 "Standard for Safety for Thermoplastic Sprinkler Pipe and Fittings for Fire Protection Service" (1/2" Wirsbo AQUAPEX only)

Radiant cooling works best where wet bulb gain in the building can be controlled by the air handling system. Most often this is found in commercial building, however, in some climates where relative humidity is lower and in larger residences, where relative humidity can be controlled; radiant cooling is a additional strategy to lower cooling costs.

Yes, a floor cooling system should primarily be used where the system also will be used for heating in winter. Design a radiant heating/cooling system to maximize the cooling capacity.

Yes, however the ducts can be smaller which saves structural height. Ventilation is necessary to address the latent load and bring in the required refresh air.

Uponor PEX plumbing systems for residential and commercial applications use crosslinked polyethylene (PEX) tubing instead of metal piping to distribute the water. PEX tubing is clean, non-toxic and extremely durable. The flexible nature of this tubing is gaining popularity with plumbers for both new construction and retrofit applications.

An Uponor PEX plumbing system is a clean, healthy, quiet and reliable alternative to other systems, such as copper. Our innovative system is also corrosion and freeze resistant providing you with peace of mind.

First of all, it's a clean and quiet water distribution system. Additionally, Uponor's plumbing system features Wirsbo AQUAPEX® tubing, which is corrosion resistant. Aggressive water and soil, common across the United States, is not kind to copper plumbing and pinhole leaks can occur in copper as a result of these aggressive conditions. Additionally, An Uponor PEX plumbing system is quiet. No more singing pipes and water hammer typically heard with metal plumbing systems.

Uponor PEX tubing has been used worldwide in plumbing and radiant heating systems for more than 30 years, longer than any other flexible system on the market.

Yes, Uponor PEX has undergone 35 years of rigorous testing. In 1973, Uponor (then Wirsbo), submitted PEX tubing samples to an independent laboratory. For three decades, these samples underwent continuous hydrostatic tests at extreme temperatures and pressures — up to 203åF and 239 pounds per square inch. When the 30-year life cycle tests were concluded recently, not a single piece of Uponor PEX had experienced any breakdown or failure.

An Uponor PEX plumbing system is a very cost-competitive plumbing system when compared with other systems.

Uponor offers two types of PEX tubing — Wirsbo AQUAPEX® tubing and Wirsbo hePEX™ plus tubing. Wirsbo AQUAPEX® is used in plumbing and under certain circumstances in radiant floor heating systems. Typically, Wirsbo hePEX plus is used for radiant floor heating as it contains an additional layer on the tubing which acts as a barrier and reduces the amount of oxygen entering into the heating system.

Uponor PEX and associated fittings are manufactured to the following standards:

• ASTM F876 "Standard Specification for Cross-linked Polyethylene (PEX) Tubing"
• ASTM F877 "Standard Specification for Cross-linked Polyethylene (PEX) Plastic Hot and Cold Water Distribution Systems"
• ASTM F1960 "Standard Specifications for Cold Expansion Fittings with PEX Reinforcing Rings for use with Cross-linked Polyethylene (PEX) Tubing"
• ASTM F2080 "Standard Specifications for Cold Expansion Fittings with Metal Compression Sleeves for Cross-linked Polyethylene (PEX) Tubing"

Additional standards for Wirsbo AQUAPEX tubing and associated fittings include:

• ANSI/NSF Standard 14 "Plastics Piping System Components and Related Materials"
• ANSI/NSF Standard 61 "Drinking Water System Components — Health Effects"
• UL 1821 "Standard for Safety for Thermoplastic Sprinkler Pipe and Fittings for Fire Protection Service" (1/2" Wirsbo AQUAPEX only)