Comparing Floor Heating Energy Use to Common Appliances

Did you know that an electric floor heating system for a small bathroom uses nearly three times less energy than a portable heater? Or that it uses less than half the energy of a single window air conditioning unit? Even when heating an oversized master bathroom, it will still cost you more to run your water heater than your floor heating system.

Floor heating electricity usage is remarkably efficient and cost saving in addition to being very comfortable.

If you’ve ever wondered, “Do heated floors use a lot of electricity?”, the answer is: less than you would think. In reality, a radiant heating system for a small bathroom uses about the same amount of energy as a freezer.

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In this article, we’ll evaluate how the energy use for electric floor heating compares to the power consumption of other common household appliances.

Electric Radiant Floor Heating Cost to Operate

A typical electric floor heating element produces 15 watts per square foot. When installed in a small 35 square foot bathroom running a total of 8 hours a day, the system would only use 4.2 kWh per day. That’s 128.1 kWh per month.

The national average kWh rate is $0.12. As a result, the cost to operate an electric radiant floor heating system in a bathroom this size would be $0.22 a day or $6.60 a month. 

By comparison, it costs about $34.10 a month to run a window air conditioner and $36.50 a month to run a portable heater. You may notice that the calculation for 4.2 kWh at a cost of $0.12 per kWh didn't equal $0.504. (After all, 4.2 x 0.12 = 0.504.) But that's because an electric heating system isn't "on" during it's entire run time. 

Typically, the control (usually a thermostat) for an electric floor heating system will cycle on and off to get the temperature in the correct range. This means that you'll be charged less for electrical use than if the system was "on" the entire time. (See "Duty Cycling for Electric Floor Heating" section below for more information.)  

Granted, a 35 square foot bathroom is a small space to heat. What would it cost to heat a large master bathroom with radiant floor heat? Assuming the average master bathroom is about 160 square feet in size, a floor heating system running 8 hours a day would use 19.2 kWh per day. That’s 585.6 kWh per month.

Although the energy consumption for such a large room is higher than a single air conditioner or portable heater in this case, you would still spend less in operating costs.

According to WarmlyYours’s Operating Cost Calculator, a floor heating system running 8 total hours a day in a 160 square foot room would only cost $1 a day. That’s $30 a month.. That’s still $6.50 in savings each month when compared to a portable heater.

Duty Cycling for Electric Floor Heating

One important factor that helps to determine the energy efficiency of a radiant heat flooring system is the thermostat that is used to control the system. Electric radiant heating elements, like TempZone Floor Heating Cables, are “constant wattage”, which means that they always use the same level of energy or electricity when they are on.

This also means that the heat output of the cables is always the same when they’re on. This is why we never recommend running a floor heating system using a simple switch as the control. Because you would use far more energy than necessary and controlling the ambient or floor temperature would be next to impossible.

The way that a radiant floor system is able to achieve different floor or ambient temperatures is by using a specifically designed floor heating thermostat. For example, the nSpiration Series from WarmlyYours, that employs a functionality called a duty cycle. This essentially means that the thermostat will turn the system on until it reaches the desired temperature and then it will turn the system off. The system will then kick back on once the temperature drops below the desired level.

The duty cycle functionality ensures that your floor heating system doesn’t use unnecessary energy and it gives you a high degree of control over your system. This increases your ability to control your comfort.

Energy Efficiency of Various Appliances

Among your household appliances, some of the biggest energy consumers are your water heater, kitchen range, refrigerator and freezer. And if you have a hot tub or pool, you know those energy offenders are at the top of the list for household energy consumption. Here’s how they rank by monthly electricity consumption, per Warren Rural Electric Cooperative Corporation.

• Pool pump: 1,240 kWh per month
• Pool heater: 670 kWh per month
• Water heater: 411 kWh per month
• Portable heater: 365 kWh per month
• Air conditioner: 341 kWh per month
• Hot tub: 304 kWh per month
• Kitchen range: 186 kWh per month
• Refrigerator: 180 kWh per month
• Bathroom floor heating: 128.1 kWh per month
• Freezer: 124 kWh per month
• Clothes dryer: 90  kWh per month

The above figures are estimates based on average consumption rates but, of course, there are other variables to consider. One variable that will have a definite impact is how long you run your appliance for and how often you operate it. In the examples we used for floor heating so far, we’ve used 8 hours of use per day because this is the typical usage reported by our customers. 

However, by making use of a programmable thermostat like the nSpire Touch, you can set up a schedule that only turns on the system when you need it on. This is typically most useful in rooms like the bathroom where the majority of use is in the morning and before bed. By setting up your own schedule, your energy use/cost will be significantly lower.

Electricity Usage in the US

Your home heating bill will tell you exactly how much electricity you’re using each month. It is a good starting resource for evaluating your next steps towards energy conservation. Your utility provider might even tell you where you stand among your neighbors in terms of energy usage.

But how much electricity do all U.S. homeowners typically use, and how much of that comes from heating sources? U.S. residences consumed an average of 10,399 kWh of electricity in the year 2017, according to the U.S. Energy Information Administration. Only 8.5 percent of that total came from heating sources. The majority of electrical usage (31.3 percent) comes from miscellaneous items like household appliances, and a sizable portion(15.4 percent) comes from cooling and air conditioning.

So, with all of that in mind, how much electricity does a house use per day? On average, the U.S. home uses about 28.5 kWh per day.

Another factor relating to heating systems that must be considered, beyond just energy use, are the additional costs. For forced air, this can sometimes mean a steep natural gas bill.

According to Move.org, the average monthly bill for natural gas in the US is $82. Of course this will vary based on the temperature, time of year, and location. But by supplementing your heating needs with electric floor heating, you can help significantly lower this monthly cost.

How to Use Radiant Heated Floors

If you want to heat spaces larger than a typical bathroom, such as a basement or living area, your energy consumption will go up correspondingly. In this case, you’ll probably ask yourself, “Are heated floors worth it?” It all comes down to comfort vs. cost. Most times, comfort wins because, without radiant heat, certain rooms — like the basement — are simply unusable because they’re so cold most of the year.

Wondering what is the most energy efficient way to heat your home? Electric floor heating is a great way to add supplemental heat in the rooms that need it. Most likely, it wouldn’t be cost effective to use throughout an entire home, but when used strategically, it’s likely to save money and energy over alternative heating options.

That’s because it’s energy efficient, but also because it has the flexibility of “zone heating.” This means you’re not tied to heating the entire house to the same temperature at the same time.

By using radiant heat in specific rooms like the bedroom and master bathroom, you are provided the opportunity to turn down your primary heat source at night. You rely on your heated floors for warmth instead. That’s just one way that radiant heating can save energy and money.

If you’re constantly turning up the thermostat to accommodate an especially cold area of the home, radiant floor heating was made for you! To get a quick and free quote, check out the Radiant Floor Heating Quote Builder (you might be surprised to find out how affordable the in-floor heating cost really is).

To calculate the operating cost for your potential room, you can also use the free Operating Cost Calculator. You can also call us anytime at 847-603-2906 to discuss the benefits and opportunities of installing heated floors in your home with one of our experienced professionals.