Uponor Solutions:
Residential Radiant Floor Heating

Radiant Floor Heating FAQs for Builders

How does radiant floor heating work?
How long has Uponor Radiant Floor Heating been around?
What are the main components in a radiant floor heating system?
What is PEX tubing?
What is the difference between PEX-a, PEX-b and PEX-c tubing?
What installation methods work best for installing radiant floor heating systems?
Is radiant floor heating energy-efficient?
Can the tubing leak?
Is a supplemental ventilation system necessary?
Does the radiant floor heating system have to be hooked up right away?
Does Uponor offer a warranty on its radiant floor heating system?

In a radiant floor heating system, warm water flows through flexible plastic tubing called PEX that is located underneath or within the floors. (PEX is an acronym for crosslinked polyethylene.) The PEX tubing carries the warm water into specific rooms or “zones” to effectively heat people and objects in every corner of the room.

Uponor (formerly Wirsbo) was the first to bring radiant floor heating to North America more than 40 years ago. And the concept of radiant floor heating has been around since ancient Roman times. Radiant floor heating has been, and continues to be, used in many countries around the globe to effectively bring comfort in even the most extremely cold climates of the world.

The main components in a radiant floor heating system include a heat source, pumps, manifolds, PEX tubing and controls.

PEX is an acronym for crosslinked polyethylene. It is a flexible, durable, corrosion-resistant product that possesses distinctive properties that make it ideal for radiant floor heating and plumbing systems. There are three different types of PEX tubing: PEX-a, PEX-b and PEX-c. Uponor manufactures PEX-a tubing, which is considered the superior type of PEX in the industry.

All three PEX manufacturing processes generate tubing that is crosslinked to varying degrees and are acceptable for potable-water and hydronic radiant floor heating applications.

  • PEX-a is manufactured using the  Engel or peroxide method
  • PEX-b is manufactured using the Silane method
  • PEX-c is manufactured using the E-beam (electron beam) or radiation method

Uponor manufactures PEX-a tubing. The PEX tubing industry considers PEX-a 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 PEX-b or PEX-c), resulting in a more uniform, more flexible product with no weak links in the molecular chain.

It depends on the application. For a concrete floor, it’s best to install the tubing before the concrete is poured. You can tie the tubing to wire mesh or staple it down to foam board and then pour the concrete over the tubing to embed the tubing in the slab. For plywood subfloors, you can use Quik Trak® radiant panels or Fast Trak™ knobbed mats. For joist-heating applications, where the tubing is installed between the joists under the floors, you can use clips to “hang” the tubing or use Joist Trak™ heat-emission plates. To learn more about these products, visit www.uponorpro.com.

Yes. Because water has a capacity to transport energy 3,500 times greater than air, a hydronic radiant floor heating system can heat a home using less energy than a traditional forced-air heating system. This amounts to greater comfort at a lower thermostat setting, which provides lower energy bills. In fact, more people are comfortable with radiant floor heating at a lower thermostat setting than with forced-air heating at a higher thermostat setting. Additionally, a radiant heating system works in zones, allowing different areas of a home to heat at different temperatures. This allows typically chilly rooms, such as bathrooms, basements and entryways, to receive more heat when needed. At the same time, rooms with less traffic, such as a den or formal dining room, can be set to a lower thermostat setting, making the system even more energy-efficient. And radiant floor heating systems pair really well with highly energy-efficient solar and geothermal heat sources, making the system even more efficient.

Leaks are not a concern with an Uponor radiant floor heating system 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 more than 40 years. What's more, all Uponor PEX tubing is thoroughly inspected before it leaves our manufacturing plant to ensure a quality product. And, we also offer a 30-year limited warranty on our PEX tubing and ProPEX® fittings when installed by an Uponor-trained professional.

Yes, ventilation is necessary to address the latent load and bring in the required fresh air. However, the ducts can be smaller which saves structural height.

No. Uponor offers what we call Radiant Ready™, where the PEX tubing is installed in the concrete slab during construction and the homeowners can choose to hook up the system at a later time.

Yes. Uponor proudly backs the PEX tubing and ProPEX® fittings in its radiant floor heating systems with a 30-year limited warranty when installed by an Uponor-trained professional.