Closeup on a spool of electric radiant floor heating wire and its application in a floor

A radiant floor heating system provides heat directly to the floor and uses that to raise the temperature of the room to a comfortable level.

To a large extent, these systems depend on radiant heat transfer. This is simply the delivery of heat directly from the warm surface to objects and people through infrared radiation.

Radiant floor heating has become more popular over the last several years. It has a lot of benefits, the biggest one being efficiency.

They are typically more efficient than both baseboard heating and generally more efficient than forced-air heating, as energy loss through ductwork is not a concern.

For those who suffer from asthma, allergies, or other respiratory problems, in-floor heating offers a solution that doesn’t require air circulation and the dust distribution that comes with it.

Radiant systems consume little electricity, which is a considerable advantage for off-grid homes or homes located in areas where electricity prices are high.

Utility bills are a pretty big consideration when looking at HVAC solutions. Since these systems often rely on electricity, let’s take a look at what you can expect to spend on operation costs so you can make an informed decision.

How Much Electricity Does Radiant Floor Heat Use?

Most electric radiant floor heating systems consume 12 watts every hour per square foot. This figure amounts to 1,200 watts per hour for a 100-square foot room, or 300 watts less than the average space heater.

In place of PEX tubing to conduct water, an electric radiant floor heat system uses electrical cables that work like the resistive components in electric space heaters, even though they don’t get nearly as hot. 

The mechanisms of an electric radiant floor heating system in a home

The radiant floor heating system’s cables can be powered by a 240 or 120-volt electric circuit—a 120-volt is better for smaller floors. On the other hand, a 240 volts circuit is better suited for larger spaces.

A 240-volt system draws lower current levels than a 120-volt system to attain the same level of power. 

How to Calculate the Electricity Costs of a Radiant Floor Heat System

You can easily determine the power needed to heat a specific area by following the steps listed below.

  1. Determine the square footage of the heated area in your house by multiplying the square footage of the entire room by 0.9
  2. Now multiply the result you got in step one by 12, as most radiant floor heating systems consume 12 watts per square foot. 
  3. Divide the total watts by 1000 to determine the kilowatts the radiant heating system will use every hour. 
  4. Lastly, multiply the number of kilowatts used every hour with how much the electricity provider charges per kilowatt in your area. For reference, the average US residential electricity rate is around 14.47 cents. 

What Factors Impact the Running Costs of Radiant Floor Heating?

Several factors can impact the cost of running a radiant floor heating system.

Some of these variables include:

The Price of Electricity 

A critical aspect you should consider is the price of electricity per kilowatt in the area where you live. A quick call to your electricity provider will answer this question for you.

Size of the Room 

The size of your room plays a vital role in the electricity consumed. The bigger your room, the longer you need to run the heating system to heat the space effectively. This operation leads to increased electricity consumption. 

Some homes will use in-floor heating as a supplemental heat in bathrooms, bedrooms and living areas. You don’t need to use an in-floor system to heat your entire home. This setup can save you some money on utility bills while providing maximum comfort by heating only the areas needed.

A radiant floor heating system installed on a living room floor

Floor Insulation or Underlayment 

Investing in the appropriate insulation for your electric radiant heating system can improve efficiency.

Note that insulation will prevent heat from getting lost in the subfloor underneath. In addition, insulation will push the heat upwards to your floors and then pass them on to the space above.

When you don’t have proper insulation, you’ll have to deal with longer heating times and quicker cooling down times, meaning you will need to run the system for longer, which consumes more electricity. 

A good-quality underlayment with a high R-value can also work as insulation. You don’t need to give up on any of the advantages underlayment can offer while still having an insulating barrier.

We recommend the QuietWalk underlayment as it offers key features like compression support, sound reduction, and moisture protection, all while keeping an R-value of 0.58. 

Flooring Material 

Lastly, the kind of flooring you have in your home will impact the efficiency of your electric radiant floor.

Because of their excellent conductivity, stone and tile make the ideal material to go over radiant floor heating systems. They warm up quickly and cool down slowly. 

On the other hand, carpet is a floor covering that can negatively impact the heating systems. Carpet generally acts as an insulator and traps the heat underneath. It is not recommended to install in-floor heating beneath carpet.

When selecting a wood flooring product for installing a radiant floor heating system, you should limit your options to engineered products because solid hardwood is highly vulnerable to cupping and warping when exposed to heat.

Looking down at a crosssection of and exposed radiant floor heating system at left and a section of the wood flooring covering it to the right

We strongly recommend that any product you pick should come in snap-together planks that make floating floors, or it should come in planks that can be glued down. You cannot hammer nails into the floor without damaging the heating cables. 

How to Make Electric Radiant Floor Heating Systems Energy-Efficient

Energy efficiency is a big deal, not only for the environment but also for your wallet. Most homeowners choose HVAC solutions with operation costs in mind.

There are a few thermostat choices that can improve the efficiency of your in-floor system.

Programmable Thermostats

Programmable thermostats allow you to set particular days and times for the heating system to run as per your schedule. This means you aren’t wasting money on heating costs when you aren’t using the area.

Even simply turning the thermostat down while you are at work can save money on utility bills.

Smart Thermostats 

Smart thermostats have a variety of technologies that help them maximize your energy savings. You can also access these systems from your phone, laptop or tablet while you are away from home and adjust your heating system as needed.

These systems can use programs, just like the programmable thermostats, but they also have geotracking features that will turn the heat down when you leave the house and turn it back up when you get closer to home.

A smart thermostat on the wall in our second net-zero home
A smart thermostat on the wall in our second net-zero home

Adaptive Thermostats 

Many radiant floor heating manufacturers even provide adaptive thermostats that learn the time it takes a particular heating system to reach temperature control so they can account for that in your schedule. 

Last Few Words

Radiant floor heating systems have a few options to save on the electricity they consume. Insulating your floor and using some type of programmable thermostat can help save some money on utility costs.

Alternatively, if the thought of heating an entire home with in-floor heating sounds too expensive, a lot of people choose to heat small areas like bathrooms and bedrooms.

This can take the strain off your main heating system while creating a comfortable indoor environment during the winter season. 

Potential utility costs are a big consideration but make sure to take a look at installation costs and what changes may need to be made to your home.

It is often easier to install an in-floor heating system in a new house than it is for an existing home.

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