Underfloor heating has a long history dating as far back as 5,000 BC. Archaeological findings in Asia and the Aleutian Islands of Alaska reveal that people in these places drafted smoke from fires through stone covered trenches excavated on the floors of their dwellings.
The hot smoke helped to heat the floor and then radiated into the living spaces, keeping the inhabitants warm and cozy. In those days, they called them “baked floors” or “warm stones.”
Fast forward today, and floor heating is still a necessity for many. Without proper heat, floors become freezing-cold, creating a risk of respiratory illnesses. It has also been shown that walking barefoot on icy floors increases liver and kidney diseases.
Fortunately, you no longer have to use underground smoke channels to heat your floors. Instead, all you have to do is purchase a floor heating system, lay it wherever it’s needed, or install it throughout the home. One such floor heating solution, and perhaps the most popular option at the moment, is radiant floor heating (RFH).
We’re going to show you how radiant floor heaters work, the many radiant floor heaters, and how to pick the right one for your home. First, though, a look at some high RFH systems to consider.
How Radiant Floor Heating Works
There are three broad categories of radiant floor heaters; electric, hydronic, and radiant air heaters (though radiant air floor heating systems are no longer very popular). The three work very differently.
Electric Radiant Floor Heaters
Electric radiant heaters use electrical resistance cables to produce heat. There are two broad options here as follows;
The most popular type of electric radiant heaters is the electric mat. An electric mat features cables embedded in thin mats installed under tile, stone, laminate, or engineered wood floors. They’re an excellent choice for retrofits.
During installation, the mat is connected to a thermostat where you can select your desired temperature settings. Some even feature timers that allow you to program your heating.
For instance, you can set the heating to start perhaps 30 minutes before you wake up. Some electric mats are certified for whole-house use, including in the bathroom.
It’s crucial to note that electric mats are ordered to size. You can’t order a larger one and cut it to fit a smaller space or go around vanities and drains.
If you need to get the mat around unnatural shapes, you need to order the piece from a manufacturer and your specifications so that the final piece fits like a jigsaw. Alternatively, only install the mat in high traffic areas.
Electric mats almost always require professional installation. The cost of installation can also be relatively high. In most cases, the mat is installed before the flooring material is laid.
However, you have two other installation options;
- Buy mats designed to be stapled between floor joists: This way, you can add radiant floor heating without removing the existing flooring. You can then install insulation under the mats.
- Do It on Your Own: Many manufacturers advise against DIY-installing electric mats. But, some experienced DIY enthusiasts have shown that you can do it if you know.
Cost: The cost of electric mats (including the connectors and controllers) range from around $5 to $7 per square foot. Professional installation, meanwhile, will cost you between $3 and $5 per square foot.
Electric Single Wire Installations
Single wire installations comprise a single, continuous wire snaked around metal clips attached to the subfloor.
It’s a great alternative to electric mats for two reasons. First, single wire installations offer more room for customization. You can lay the wires exactly where you want to heat. Secondly, they are less expensive compared to electric mats.
The wires can be bare or insulated. The wire is fed through small plastic supports nailed to the floor and then encased in a thin layer of mortar where the bare cable is used. Insulated electric wires, meanwhile, are laid directly onto the floor and cast in thin-set concrete.
Hydronic Radiant Floor Heaters
As the name suggests, a hydronic heater uses water to heat your home. It draws water from the home’s hot water supply or may use a separate boiler.
The hot water is then directed through a series of PEX tubes embedded beneath the floor in either a dry or wet installation. The tubing system is completely closed.
A key advantage of hydronic radiant heating is that the system can be installed in any floor system. Even better, hydronic radiant heaters are the most efficient form of floor heating. It’s been shown that they can save you up to 30% in costs than electrical heating.
Here too, there are two options to consider;
- Open-loop hydronic heaters
In open-loop hydronic heaters, also known as direct systems, water is continuously pulled from a source that can be a well or a large tank. The water is then heated and pumped through the piping system before being discarded.
- Closed-loop hydronic heaters
Closed-loop (indirect) hydronic systems are slightly different. Here, a heat exchanger constantly heats water, pumped through a loop, and back into the boiler system. So water isn’t discarded.
Closed-loop hydronic heaters are advantageous for two reasons. First, they protect you and your family more from things like bacteria. Secondly, they can operate on liquids other than water, such as glycol or a mixture of water and antifreeze.
Cost: Hydronic heating is the cheapest to install among the three primary forms of radiant floor heating. Costs start at around $10 for dry installation and $14 for wet installation.
Air Heated Radiant Underfloor Heating
Finally, you can also opt for air heated RFH systems. These are some of the oldest forms of floor heating and the closest to the “baked floors” we mentioned initially. It’s almost similar to how hydronic heaters work except that instead of pushing water (liquids), you’ll be pushing air.
The biggest drawback to air heating, however, is efficiency. Air heated RFH systems aren’t very efficient. Why? Because air loses heat very easily. As such, the majority of air heaters are rarely more than 70% efficient.
You can improve your air heater’s efficiency by ensuring that the system is closed and completely sealed. It’s also advisable to use wet installation to seal off any air paths.
The great news is that radiant air heaters can be used in all buildings and with all floors, from hardwood to tile, engineered wood, vinyl, laminate, concrete, stone, and even linoleum.
Cost: Air heating is also not as expensive as electric heating. Installation costs start at around $14 per square foot, excluding the flooring cost over the ducts.
Pros and Cons of Radiant Floor Heating
As you can already tell, radiant floor heaters can be an invaluable addition to your home. At the same time, though, they come with a few drawbacks.
The following are a few pros and cons of these units to help you make an informed decision.
Radiant Floor Heater Pros
- Enjoy quiet, discreet heating
This is perhaps the most apparent advantage of radiant floor heaters. They heat your rooms discreetly without anyone noticing. Even you (the house owner) may not realize that there’s a radiant heater operating under the floor with the right temperature settings.
- Excellent heat retention
Radiant heaters have an exceptional ability to store heat. Since the heating systems are buried deep within thermal masses (such as between cement and ceramic tile), the units can retain heat for a long time, which allows them to continue warming your home even after power is turned off.
- Takes some load off the furnace
It’s great to have a central furnace. But, quite often, the furnace is overworked. In most homes, the furnace runs around the clock, but the same unit is expected to warm every room in the house. This often leads to faster wear and tear. Radiant floor heating takes some load off the central furnace, extending the central heater’s life.
- Reduce overall heating costs
There’s a great chance you’ll notice a drop in your heating costs. Why? Because, first, your central heater won’t have to work as hard as previously. Secondly, you may not need to use too many space heaters when the radiant floor heating is on. Lastly, radiant floor heating is more efficient than space heating.
- Helps in homes with naturally-cold floors
Some flooring materials are naturally cold. Stone, for example, can be icy even during fairly warm weather. Two other materials that tend to get very cold are ceramic and concrete. Unfortunately, space heating alone may not help when the floor gets too cold. That’s where radiant heating comes in.
- No more uneven room heating
A common challenge in home heating is cold spots. If you only run the central heater and perhaps a few space heaters, you’ll notice that some room parts are never heater, probably because of obstructions. Radiant floor heating fully solves that problem because the heat rises from the floor to every corner of the home.
- Low maintenance
Electric floor heaters don’t need much maintenance. Once the system is installed and the flooring is laid, you may not need to worry about the heating process underneath for several years.
Compared to central furnaces and space heaters that require constant monitoring and regular maintenance, it’s a huge relief.
Radiant Floor Heater Cons
- Difficult to install
This is, without a doubt, the biggest drawback for radiant floor heating. All three options take a lot of effort to install. You must remove the floor, install the heating system, and then install a new floor. It’s a process that could take a lot of time and almost always requires professional installation.
- Heating effectiveness depends on floor type
The truth is that not all radiant floor heating systems will work effectively with any floor type. Save for hot air systems (very inefficient) can be used on pretty much any floor type; the others work better with just a few floor types. For instance, electric mats don’t work well under carpeting or vinyl since the heat can be trapped between the subfloor and the insulating surface layer.
- Costs can be an impediment
Radiant floor heating costs a lot of money upfront. First off, you need to buy the electric mat or hydronic/air heating and tuning system. These products aren’t cheap. As we saw earlier, the mats go for as much as $7 per square foot. Considering that the standard room size is about 500 square feet, that’s already $3,500. When you add $5/sq. ft. for installation, it comes to $6,000 for a small room.
- Repairs are a major headache
Although underfloor heating systems don’t break down often, the repair process can be one hell of a job when they do break down. You may need to remove a large portion of the floor to locate the problem in some cases. Not only is this labor-intensive, but it could also be very costly. A professional is often needed.
Things to Consider When Shopping for a Radiant Floor Heating System
Despite the challenges and drawbacks, though, with some forethought and a bit of research, it’s possible to find the perfect radiant floor heating system for your home. The following are some of the key factors to consider;
- Initial costs: The cost of buying and installing a radiant floor heating system can be relatively high. As we’ve already shown, it costs up to (or even over) $6,000 for a small room. You’ll easily come across figures up to $20,000 for an average-sized, 1,500 square-foot home. Are you in a position to shell out that kind of money?
- Warranties in your home: There are two things to keep in mind here. First, installing radiant floor heating can void your flooring warranty. So, make sure to check with your flooring contractor. Secondly, does the radiant heating system itself come with a warranty? It should. If the one you’re considering doesn’t, ask the contractor about it or look elsewhere.
- DIY or hire a specialist: Installing radiant heat flooring is expensive. You’ll need to pay up to $2,500 per average-sized room and $7,500 for a typical home. You can save money through DIY installation, fine. Just remember that the work is incredibly complex, and even small mistakes can cost you big. You may even void the manufacturer’s warranty.
- Whole-house vs. targeted heating: Since installing radiant heat flooring is an expensive and worthwhile alternative would be to install it only where it’s necessary and rely on other forms of heating, such as space heaters, for supplementary heating. Which option would work better for your situation?
- Your climate is important too: Radiant heating can be invaluable in the right conditions. But, it can also be ineffective in specific environments. If you live in an area with humid winters, radiant floor heaters won’t dry your surfaces. In this case, blowing is necessary, which makes fan-forced heaters a better choice.
- Think about thermal mass: Thermal mass is the measure of how well a material can store and radiate heat. For radiant heating, you need building materials, especially flooring, with high thermal mass. Some great options include concrete, tile, and special paneling made specifically for radiant heating.
Best Hydronic Radiant Floor Heating Systems
1. HeatTech 50 sqft Mat Kit, 120V Electric Radiant Floor Heat Heating System
Another tremendous electric mat, the HTMAT-KIT-120-50 from Heat Tech, is a 50 square-foot under-tile heating mat with adhesive backing. It lays flat, thus doesn’t need stapling. The carpet is 30 inches wide and 20 feet wide and is rated at 120 volts, 5.0 amps, and 600 watts.
The unit comes with a Honeywell/Aube TH115-Af-120s digital programmable thermostat for easy temperature monitoring and control.
The thermostat is floor-sensing, but a dedicated floor sensor is also included in the package. The 20-foot long heating cable is only 1/8-inch thick. On the mat, the cables are spaced three inches apart.
It’s worth noting that the mats can be combined to warm up to 150 square feet, which means up to three such cables being stapled together. The combined mats use a single thermostat. Cutting of the mats, however, is prohibited.
This heater generates Zero Electromagnetic Field (EMF), UL Listed, and a 25-year limited manufacturer warranty.
- Supports a wide variety of flooring materials
- Adhesive backing allows the mat to lay flat
- Digital programmable thermostat included
- A sensor is also included
- The product comes with a 25-year warranty
- No remote control
- No timer
2. Heatizon’s Heatwave 30 Sqft Electric Floor Heating 120 Volt System
Heatizon makes some excellent home heating products. The M429 HeatWave System is another fantastic unit from their line of electric mats. The 30 square foot mat (20 inches wide x 18 feet long) is a high-quality mat made in the USA and listed as safe for wet conditions.
The first thing you need to know about the M429 is that it comes with a programmable thermostat for easy and convenient temperature control.
The unit also comes pre-programmed, but you can later change the settings as you wish. There are up to four settings. You also get to choose from Automatic, Manual, and Comfort programming options. The user interface is very easy to operate.
The unit is equipped with two sensors. The first is a built-in air sensor that feels the air conditions and returns feedback to the heating system. The second, meanwhile, is a floor sensor thermistor. The unit comes with a 10-foot long floor sensor strand.
- It’s a thin-profile, 1/8 –inch thick mat
- Two sensors (air and floor) included
- A built-in 7-day programmable thermostat
- ETL Listed
- Features three heat modes
- Comes with a lifetime warranty
- Requires professional installation
- Manual display
3. SunTouch WarmWire (120V) Floor Heat Kit
The Warm Wire by SunTouch is an energy-efficient, inexpensive to operate dual-wire heating cable designed with a technology that reduces electromagnetic fields (EMF) to ultra-low levels.
Included with the Warm Wire is everything you need to install a 70-square-foot electric heating system on your floor. You’ll also find coil straps in the package, so you don’t need to worry about buying them separately.
An installation manual is in the product package. But, so that you know, the system requires that the wires are placed at least three inches apart.
This makes the Warm Wire easier to install compared to models that require a 2.5-inch gap. A single point power connection further makes the layout and wiring process a breeze.
The Warm Wire is approved for shower application (most radiant floor heaters aren’t) and arrives with a touch-screen thermostat that features a thermostatic wire to monitor floor temperatures for perfect heating. It’s backed by a 25-year limited manufacturer warranty.
- Ideal for up to 70 square feet
- Uses programmable thermostat (included)
- Installation manual included
- Single-point power connection
- Costs over $600
- Combining the heaters is a challenge
4. WarmlyYours TCT120-KIT-OT-040 Tempzone Electric Floor Heating Cable Kit
Another great insulated wire floor heating option, the WarmlyYours TempZone Heating Cable is a cULus Listed radiant floor heating wire designed for application under ceramic tile, nailed hardwood, natural stone, wood floors, and several other flooring types.
The 40-foot free-form cotton cable provides an alternative for installers who prefer the flexibility of working with loose cables over pre-designed mats. The best part is that this cable installs at 3, 4, or 5 inches apart (spacing). It’s also available in two voltage options (120 or 240).
Some of the standout features of the cable wire include an nSPIRE touch programmable thermostat with an energy log for tracking power use.
The thermostat also features a built-in self-testing GFCI with a child-lock function and a 3.3-inch color touch screen. A complimentary floor sensor ensures efficient energy utilization.
The required cable fixing strips are supplied. You’ll find 20 such cable strips. At 3-inch spacing, the cable covers about 10 square feet, while at 5-inch spacing, it covers up to 16.6 square feet. The system is backed by a 25-year warranty.
- Delivers 9-15 watts per square foot
- 120-volt or 240-volt choices
- Easily goes around bends
- Programmable thermostat (included)
- 25-year warranty
- Installation is a challenge
- The 40-foot cable covers only 10 square-feet
5. SEAL 70 sqft 120V Electric Radiant Floor Heat Heating System
Finally, for homeowners looking for an electric mat they can install on their own, the SEAL is arguably the most DIY-friendly option. It’s designed specifically for residential use and works particularly well in the kitchen and bathroom, though it can also be used in living areas.
The installation process shouldn’t take a lot of time or effort. The user guide will tell you, step-by-step, what to do. You’re advised to observe all the safety guidelines during and after installation. Also, you cannot cut the mats. So, you’re advised to choose one that will cover at least 90% of the area you intend to heat.
This particular mat is 15 inches wide and 45.93 feet long, thus ideal for spaces up to 70 square feet. The heating cable is only 1/8-inch thick thus won’t raise an unfinished floor significantly. The cables are spaced at 3-inches apart for optimal heat distribution.
This mat is UL listed and complies with electrical safety standards. Every purchase comes with a 100% Quality and Efficient Service Guarantee.
- Comes in multiple configurations
- User-friendly adhesive design
- UL Listed for safe heating
- Covers up to 70 square feet
- Joining the mats can be a problem
- Ideal for only a small number of floor types
6. Prodeso Heating Membrane Sheet
For those interested in an electric mat but shopping on a budget, the Membrane Roll from Prodeso makes perfect sense. It’s an uncoupling membrane designed to be used with TempZone electric heating cable (sold separately) and recommended for small rooms such as guest bathrooms.
The installation is easy and straightforward. The polypropylene membrane features integrated channels that are shaped to easily and securely hold the TempZone heating cable.
The design of the mat also ensures proper spacing of the cables throughout the entire project. Most people can complete the installation in a day.
Something else worth mentioning about this mat is that it provides uncoupling and crack isolation benefits. This can significantly extend the heating system’s life and your flooring (marble, stone, tile, etc.).
It’s worth noting that the membrane can be waterproofed for high-moisture-applications such as kitchen or bathroom use.
If you need to cover a larger space, several of the 3.3 Ft. x 16.4 Ft. membranes can be joined to form a larger mat.
- Energy-efficient radiant floor heating
- Easy, quick installation (completed in a day)
- Flexibility allows adjustment to fit larger spaces
- The membrane is backed by a 10-year warranty
- The required heating wire is sold separately
7. QuietWarmth QWARM3X10F120 30 Sqft Electric Floor System
Electric mats tend to consume a bit of electricity, which can push heating costs up. The QWARM3X10F120 by QuietWarmth is one of the more efficient options, drawing just 12 watts per square foot. It uses the highly-efficient conductive heat technology to ensure that very little heat is lost.
The mat works well on several floor types but is most effective under floating laminate, engineered wood, and floating tile floors. The heat from the mat disperses evenly and consistently throughout the entire floor. The heat also cycles faster, resulting in less energy consumption.
Installing the QWARM3X10F120 is a pretty straightforward process completed in just four steps. First, install the floor underlayment. Then, roll out the radiant heat film (this mat), hook up the electrical wiring, and install the final floor covering. That’s it.
For purposes of convenience, the mat comes in four rollout sizes that accommodate most floor layouts. The heating wires are pre-attached for ease of installation.
- Approved for all floating floors
- Easy 4-step installation
- Provides uniform heating with no gaps
- Conductive ink technology guarantees efficiency
- Backed by a 25-year warranty
- Thermostat sold separately (at close to $200)
8. Nuheat 120 V, 118″x30″ Standard Mat
The Nuheat F3008 is a standard-size pre-built heat mat that comes ready to fit the room. It keeps everything on the floor warm and comfortable and uses a special Nuheat thermostat for easy temperature control.
It gets better; you can combine multiple F3008 mats to fit a larger room size or to cover irregular shapes. For safety reasons, the mats connect to the thermostat, not to each other. The thermostat will guide you on the maximum amperage limit when combining several rugs.
The mats, however, cannot be cut or altered. So, be sure to choose the right size and if you have any questions, ask an expert for advice
The mats are easy to install. All you have to do is set them in a thin spread of mortar. Once the subfloor is prepared, and the mat(s) are laid, apply another layer of thin-set or mortar, and lay your flooring (tiles work the best). Then connect the mats to the thermostat.
- Easy to install and energy-efficient
- Controlled by programmable/non-programmable thermostats
- Comes in 60 different standard sizes
- Available in both 120-volt and 240-volt formats
- You need to buy thermostats separately
- Temperature sensors also sold separately
Radiant floor heating involves installing electric heating coils or water-heated tubing under your home’s floors. When the heating system is switched on, it heats everything it comes in contact with and radiates some heat from the ground up and throughout the room.
Here’s what you need to know when shopping for such heating systems.
Radiant floor heating (RFH) systems can be a useful addition to your home. The heaters generate gentle, soothing warmth that radiates from the floor upward, thus solving the common problem where heat concentrates at the ceiling leaving the feet cold.
Radiant heat is also healthy and safe, and the radiant heaters easy to use and essentially maintenance-free.
However, keep in mind that the cost (purchase + installation) can be a bit high. Other than that, radiant floor heaters are an investment worth every penny.