How Radiant Floor Heating Works

Radiant floor heating takes a different approach to heating a room than a traditional forced-air system. Instead of heating the air and moving it around the room with a blower, warm fluid circulates through PEX tubing installed beneath or within the floor. The floor then radiates heat upward into the space.

For concrete floors, the tubing is typically installed before the slab is poured. That makes the insulation and tubing layout important parts of the installation. The Crete-Heat system combines insulated floor panels, a built-in vapor barrier, and a grid for securing the PEX tubing, making those steps easier to manage.

Barn World carries the major components used with these systems, including Crete-Heat insulated floor panels, radiant heat PEX, and electric boilers.

 

What Are Crete-Heat Floor Panels?

Crete-Heat panels are insulated floor panels designed for radiant floor heating installations. The panels provide insulation below the heated floor while also providing a pattern for securing the PEX tubing in place.

The panels are made from EPS foam and include a vapor barrier. Their interlocking design helps keep the panels aligned during installation, while the raised knobs hold the PEX tubing in position.

That combination is useful because installing radiant tubing directly on an unfinished floor can involve considerably more measuring, fastening, and handling. With the Crete-Heat system, the tubing is pressed into the panel's grid rather than being individually stapled to the floor.

Crete-Heat Panel Thickness and R-Values

Barn World currently offers Crete-Heat insulated floor panels in 1-inch, 2-inch, and 3-inch thicknesses. The insulation value increases with panel thickness.

Panel Thickness	Insulation Rating	Typical Application
1 inch	R-6	Projects where a lower-profile panel is preferred
2 inches	R-10	Common slab-on-grade and insulated floor applications
3 inches	R-15	Projects where additional insulation is desired

The current Barn World collection lists R-6 for the 1-inch panels, R-10 for the 2-inch panels, and R-15 for the 3-inch panels.

The best thickness depends on the construction of the building, the floor assembly, and how much insulation is appropriate for the project. The panel should be selected as part of the overall floor design rather than based on thickness alone.

 

Why Insulation Matters With Radiant Floor Heating

Putting heat into a concrete slab does not accomplish much if a significant amount of that heat can escape downward. Insulation below the heated slab helps direct more of the heat toward the space above it.

This is one of the main reasons the Crete-Heat panels are more than simply a way to hold PEX tubing. They provide insulation between the heated slab and the surface below while incorporating the tubing support and vapor barrier into the panel system.

The current 2-inch Crete-Heat panel provides 2 inches of EPS insulation with an R-10 rating. Barn World's product information also notes that the knobs add approximately 7/8 inch to the overall panel height, making the overall assembly approximately 2-7/8 inches before the concrete covering is considered.

Installing PEX Tubing in Crete-Heat Panels

The PEX tubing is the part of the system that carries the heated fluid through the floor. The tubing is laid out in loops across the insulated panels and pressed into the raised grid.

The panel design helps keep the tubing in position while the concrete is being placed. It also eliminates much of the individual fastening that can be required with other radiant tubing installation methods.

Barn World carries oxygen-barrier PEX tubing specifically for radiant floor heating systems. Available tubing includes 300-foot and 500-foot lengths, along with custom lengths for larger or unusual installations.

How Much PEX Tubing Do You Need?

Radiant floor tubing requirements depend on the design of the heating system, tubing spacing, heat loss, and the layout of the area being heated. As a general planning reference, Barn World's older system information used approximately 1 linear foot of tubing per square foot of heated area and a 300-foot loop for approximately 300 square feet.

That should be treated as a planning guideline rather than a universal rule. A properly designed radiant heating system should account for the building's heat loss and the requirements of the boiler and manifold system before the final tubing layout is determined.

Electric Boilers for Radiant Floor Heating

The boiler provides the heat that circulates through the PEX tubing. Barn World's current radiant heating collection includes electric boilers designed to work with radiant floor systems in applications such as homes, garages, workshops, and other buildings.

The boilers are supplied as preassembled units with components including an expansion tank, electric boiler, and circulation pump. Current Barn World information lists electrical service options from 20 amps through 60 amps, depending on the boiler configuration.

The appropriate boiler depends on the size of the heated area, the building's heat-loss requirements, and the available electrical service. This is an area where sizing the system correctly matters more than simply choosing the largest heater available.

Radiant Floor Heating System Components

A complete hydronic radiant floor heating system consists of several components that need to work together. The exact configuration depends on the project, but the basic components include:

• Insulated radiant floor panels
• PEX oxygen-barrier tubing
• An electric boiler or other appropriate heat source
• Manifold and tubing connections
• Circulation equipment
• Expansion tank and related controls
• Appropriate heating fluid

Barn World currently carries these products individually, allowing customers to build a system around the requirements of their particular project. The radiant floor heating collection is the best place to see the current product selection.

Where Radiant Floor Heating Can Be Used

Radiant floor heating is particularly well suited to concrete floors. Depending on the system design and construction, it can be used in a variety of spaces, including:

• Basements
• Garages
• Workshops and shops
• Home additions
• Barns and agricultural buildings
• Greenhouses
• Other concrete slab applications

The floor construction and insulation need to be appropriate for radiant heating. New construction is often straightforward because the tubing and insulation can be incorporated into the slab design. Retrofit projects require more attention to available floor height, insulation, and the finished floor assembly.

New Construction vs. Retrofit Radiant Heat

Radiant floor heating is often easiest to plan during new construction because the insulation, tubing, and concrete slab can be designed as one system. The tubing can be installed after the insulated panels are placed and before the concrete is poured.

Retrofitting radiant heat into an existing building requires more planning. Available floor height, existing insulation, the finished flooring, and the method of installing the tubing all need to be considered.

Crete-Heat also offers panel configurations intended for retrofit applications. The current Barn World information identifies a 1-inch EPS retrofit panel with an R-6 insulation value and an overall thickness of approximately 2-1/8 inches.

Advantages of Radiant Floor Heating

There are several reasons people choose radiant floor heating instead of conventional forced-air heating.

• Even heat: The floor provides a large surface area for transferring heat into the room.
• Quiet operation: There is no furnace blower continually moving heated air through the room.
• Comfortable floors: The floor itself becomes part of the heating system.
• Flexible installation: PEX tubing can be laid out in different patterns to suit the space.
• Insulated installation: Crete-Heat panels help reduce heat loss through the bottom of the slab.

Actual heating performance and operating cost depend on the building, insulation, climate, floor design, heat source, and controls. Radiant heating is not automatically the least expensive heating method for every building, so the entire system should be considered when planning a project.

Planning a Radiant Floor Heating System

The most important step is sizing the system before ordering the components. Start with the area to be heated and determine the building's heat-loss requirements. From there, the tubing layout, number of loops, boiler capacity, and electrical requirements can be established.

It is also important to account for areas that should not be heated, such as locations underneath permanent cabinets or fixtures, depending on the project. Tubing spacing can also vary based on the heat requirements of the space.

If you're building a new slab, radiant heating should be planned before the concrete work begins. That allows you to coordinate insulation, tubing, manifolds, electrical service, and the final slab thickness as part of the same project.

Radiant Floor Heating at Barn World

We've been selling radiant heating components for years, and the most important thing we've learned is that these systems work best when the individual components are treated as parts of one heating system rather than separate products.

Crete-Heat panels provide the insulated base and tubing grid. PEX carries the heated fluid through the slab, and the boiler supplies the heat. Getting the sizing and layout right is just as important as selecting the individual products.

Browse Radiant Floor Heating Products at Barn World.

If you're planning a radiant floor project and need help determining which components are appropriate, contact Barn World before ordering. For larger projects, having the floor area, insulation details, tubing requirements, and available electrical service information will make it much easier to determine what you need.

Radiant Floor Heating FAQ

What is radiant floor heating?

Radiant floor heating warms a floor by circulating heated fluid through tubing installed beneath or within the floor. The heated floor then transfers warmth into the surrounding space.

What are Crete-Heat panels used for?

Crete-Heat panels provide insulation, a vapor barrier, and a grid for securing PEX tubing in a radiant floor heating installation. The interlocking panels help simplify tubing installation before the concrete slab is poured.

What thickness Crete-Heat panel should I use?

Crete-Heat panels are available in 1-inch, 2-inch, and 3-inch thicknesses, with R-6, R-10, and R-15 insulation ratings, respectively. The appropriate thickness depends on the floor assembly and insulation requirements of the project.

Can radiant floor heating be installed in an existing building?

Yes, but retrofit installations require more planning than new construction. Available floor height, insulation, tubing installation, and the finished floor all need to be considered. Crete-Heat offers panel configurations designed for retrofit applications.

How much PEX tubing is needed for radiant floor heating?

The amount depends on the size and design of the system, tubing spacing, and the heat requirements of the building. A common planning guideline is approximately 1 foot of tubing per square foot of heated area, but the final layout should be based on the system design rather than this rule alone.

What size electric boiler do I need for radiant floor heating?

Boiler size depends on the heat-loss requirements of the building, the area being heated, and the electrical service available. It is important to size the boiler as part of the complete radiant heating system rather than selecting one based only on square footage.