Infrared blanket energy use: per session, per week and per month

The energy use of an infrared blanket for a 30 minute session is between roughly 0.13 and 0.20 kilowatt hours, and including the preheating a complete session comes to roughly 0.21 to 0.29 kilowatt hours. That applies to the usual power ratings of 500 to 560 watts. Two sessions a week means about 2.1 kilowatt hours a month and about 25 kilowatt hours a year.

Below you'll find the calculations: kWh per session per model at 20, 30 and 40 minutes, the consumption per week, month and year, the comparison with an electric blanket, heated throw, cabin and Finnish sauna, and the formula to work it out yourself. The power on the rating plate is the maximum, not the average, so you'll see two figures everywhere: the upper limit and the realistic middle.

The short answer in kilowatt hours

Electrically speaking, an infrared blanket is simple. It contains a heating element with a power rating in watts, and your energy supplier charges in kilowatt hours, in other words kilowatts times hours.

The Luxyor models are close together. The Slimline 100 is 500 watts nominal with a peak of 600 watts, the Comfort 150 is also 500 watts and the Deluxe 310 is 560 watts. The difference between the models is small compared with the effect of the temperature you set.

kWh per infrared blanket session, per model and per duration

The "full duty cycle" column assumes the element runs flat out for the whole session. That doesn't happen, but it's the hard upper limit. The right hand column is realistic: the element is actually on 50 to 70 percent of the time.

There's a factor of four between the lowest and the highest figure, and that difference comes almost entirely from session length and duty cycle, not from the model. If you want to manage your consumption, look at the setting and the timer. Which model suits you depends on size and finish: see Slimline 100, Comfort 150 and Deluxe 310.

Preheating calculated separately

The table above only counts the session itself. On top of that comes the preheating, and that's exactly when the element is on almost continuously. A sauna blanket generally needs 10 to 15 minutes to reach temperature. The element itself is quicker: with the Slimline 100 you feel warmth within about a minute.

Preheating for 15 minutes instead of 10 costs about 0.05 kilowatt hours extra per session, a good 5 kilowatt hours a year spent waiting. What the warm up time depends on is explained in the warm up time of a sauna blanket.

Why the rating plate isn't your consumption

This is where most calculation guides go wrong. They take the power, multiply it by the time and call that the consumption. That's only correct for appliances without a thermostat, such as a kettle.

An infrared blanket does have a thermostat, just like an iron: the element switches on until the set temperature is reached, switches off, lets the heat drop a few degrees and switches on again. The ratio between on and off is called the duty cycle. Over 30 minutes it's usually between 50 and 70 percent.

The figure on the rating plate is the maximum the appliance can draw, not the average it does draw.

That's why there are two columns everywhere. You'll never reach the upper limit, and the realistic range is closer to your annual energy bill.

Energy use per month and per year

A single session says little, it's the pattern that counts. This table assumes 10 minutes of preheating plus 30 minutes of use at 500 watts: realistically 0.24 kilowatt hours, upper limit 0.33. A month counts as 4.3 weeks, a year as 52.

For the Deluxe 310, add about 12 percent: two sessions a week then becomes 2.3 kilowatt hours a month and 28 a year. Sessions of 40 minutes add 30 percent.

How to work out the energy use yourself

Different brand, different power or different duration? Check it in seven steps. All you need is the rating plate and your own rate.

About step seven: we don't give amounts, because rates differ per contract and change every year. A rate of 0.30 euros per kilowatt hour is often used as a working assumption, but fill in the rate from your own annual bill. The same method for a cabin is explained in working out the energy use of an infrared sauna yourself.

1. Note the powerOn the label on the blanket or in the manual, in watts. If it gives a range, take the highest figure.
2. Work out the upper limitWatts divided by 1000, times the time in hours. You'll never go above this figure.
3. Estimate your duty cycleWarm room and low setting: 0.5. Cold room and high setting: 0.8 or higher. If in doubt, take 0.7.
4. Add the preheating10 to 15 minutes on almost continuously. At 500 watts that's 0.08 to 0.13 kilowatt hours.
5. Scale up to week, month and yearSessions per week times 4.3 gives your monthly consumption, times 52 your annual consumption. Only then apply your own rate.

Energy use of an electric blanket compared with an infrared blanket

This is the most frequently asked comparison, and the answer is more nuanced than a single kWh figure. An electric underblanket is usually between 60 and 150 watts, three to eight times less. But it's often on for an hour or longer, sometimes all night, while an infrared blanket switches off after 20 to 40 minutes. How to work that out per type, with the duty cycle included, is explained in the energy use of an electric blanket.

The figures for cabins and Finnish saunas are indicative and vary widely per model. The direction is clear: an infrared blanket is closer to a heated throw than to a cabin, and a Finnish sauna is in a different order of magnitude. A cabin heats a whole space with air and wood, a blanket only the surface around you. See sauna blanket versus infrared cabin.

Keep in mind that an electric blanket and an infrared blanket don't do the same thing. One preheats your bedding, the other works with far infrared heat during a defined session at 50 to 70 degrees. See sauna blanket versus a regular electric blanket and heated blanket or infrared sauna blanket.

Luxyor Comfort 150

• 500 watts nominal, so you can work it out in advance
• Adjustable from 35 to 80 degrees, timer 30 to 60 minutes
• A lower setting means a lower duty cycle and lower consumption
• 60 days to change your mind and a 2 year warranty

View the Comfort 150

What pushes consumption up or down

The maximum power is fixed, but how often the blanket needs that maximum is up to you. These six factors make the biggest difference, with the effect per session at 500 watts.

The top two together make the biggest difference. If you go from 65 to 52 degrees and from 40 to 30 minutes, you bring consumption per session down from about 0.32 to 0.18 kilowatt hours: almost half, without a different appliance. Which setting suits which moment is explained in the complete temperature guide.

Sauna blanket in a cold house or a poorly insulated room

In a cold or draughty room the blanket loses more heat, so the element switches on more often. The maximum doesn't change, but the duty cycle shifts from 0.5 to 0.8 or higher. That's 20 to 40 percent more consumption per session in a room at 15 degrees than in one at 21 degrees.

Four things help and cost no electricity. Put an insulating layer under the blanket, because a cold floor draws heat away from the underside. Choose a spot out of the draught. Close the blanket up to chest height. And don't preheat for longer than needed, because that's the phase with the highest duty cycle.

What doesn't help is turning the setting up because the room is cold. You feel warmth sooner, but you pay the full duty cycle. A lower setting with insulation underneath is often more pleasant and more economical.

Honestly: an infrared blanket doesn't lower your heating costs

The most important objection deserves a straight answer. An infrared blanket isn't a heating solution and doesn't lower your heating costs. It warms you during a defined moment of 20 to 40 minutes, not your living space. As soon as you step out, you're standing in the same room at the same temperature.

Nor does it replace insulation. A poorly insulated wall, single glazing or a draughty door stay as bad as they were. If you buy a blanket so you can turn the thermostat down, you're buying it for the wrong reason. It comes on top of your normal consumption, not instead of it.

Two things belong in this honest list. The stated power on the rating plate is the maximum, not the average, and any guide that mixes the two up gives a figure that's too high. And all the ranges here remain estimates: the only truly reliable measurement is an energy meter in the socket.

Measuring it yourself with an energy meter

An energy meter between the plug and the socket gives you a figure with no assumptions in it. Reset the counter, measure a complete session from preheating until the timer switches off, do that three times on the same setting and take the average.

The result almost always comes out lower than power times time. If the blanket keeps drawing full power continuously without switching back, something is wrong with the thermostat.

Frequently asked questions

What's the energy use of an infrared blanket per session?

At 500 watts and 30 minutes the upper limit is 0.25 kilowatt hours and the realistic range is 0.13 to 0.18. Including 10 minutes of preheating, a complete session comes to 0.21 to 0.26 kilowatt hours, or 0.23 to 0.29 at 560 watts.

How much does an electric underblanket use?

An electric underblanket is usually between 60 and 150 watts. Preheating a bed for 30 to 60 minutes uses 0.03 to 0.15 kilowatt hours. If it stays on low all night, that rises to 0.20 to 0.60 kilowatt hours per night.

What's the energy use of an electric blanket compared with an infrared blanket?

Per hour an electric blanket uses three to eight times less, because its power is lower. Per use they're closer together, because an infrared blanket is on for 20 to 40 minutes and an electric blanket often for a whole night.

What's the energy use of a heated throw?

A heated throw for the sofa is usually between 100 and 180 watts. With one to two hours of use that's 0.10 to 0.36 kilowatt hours, close to a session in an infrared blanket but over three times as long.

What does an infrared sauna use compared with a blanket?

A cabin for one or two people is typically between 1,500 and 2,500 watts and comes to 0.80 to 1.90 kilowatt hours per session: four to eight times a session in a blanket, because a cabin heats a whole space.

What does a sauna blanket cost in electricity per month?

With two 30 minute sessions a week, about 2.1 kilowatt hours at 500 watts and 2.3 at 560 watts. Multiply that by your own rate. We don't give amounts, because rates differ per contract and change every year.

Does a higher setting use more electricity?

Yes, but not because the maximum power goes up. That stays 500 or 560 watts. On a higher setting the element has to switch on more often, so the duty cycle goes up. Between 50 and 65 degrees that easily makes a difference of 0.08 kilowatt hours per session.

In short

At 500 watts, count on 0.13 to 0.18 kilowatt hours for 30 minutes, plus 0.08 for preheating. Two sessions a week is about 2.1 kilowatt hours a month and 25 a year. The upper limit is a third higher, and the Deluxe 310 about 12 percent higher.

The formula stays simple: watts divided by 1000, times the time in hours, times the duty cycle, equals kilowatt hours. The biggest lever is the temperature you set, then the session length, and only after that the model. Also read the energy consumption of an infrared sauna blanket or view the collection of infrared sauna blankets.