dyson heater energy efficiency

Are Dyson Heaters Energy-Efficient? (A Critical Review)

Dyson heaters are up to 30% more energy efficient than regular space heaters. At least that’s what Dyson claims. Today, I’m going to check whether Dyson heaters are as energy-efficient as they promise to be and whether getting one is worth your money.

I’m an electrical engineer and together with you, I want to cut through the jungle of myths and claims. In this article, you’ll learn everything about how efficient Dyson heaters really are and whether Dyson is overselling their product, or whether it’s worth buying (I surprised myself with my findings).

This is going to be a totally neutral review. But soon, you’ll see that even with neutral words, some of the claims look ridiculous when you look at them from another perspective.

Here’s the short answer: Yes, Dyson heaters are energy-efficient. A Dyson heater does its best at optimizing electricity consumption. However, they are not any more efficient than any other regular space heater. Especially compared to oil heaters, Dyson heaters have no advantage at all. Let’s take a closer look at what I mean.

Let’s take a look at the electricity consumption of the Dyson Hot + Cool.

Power Consumption of a Dyson Heater

The Dyson Hot + Cool is rated at 2kW (or 2000W), which is unusually high. Normally, most space heaters run on 1500W, which is a safer rating. I guess that it draws 2000W in order to be able to heat quicker. By using more power, it can, of course, blast more hot air in a shorter time. Which possibly makes the Dyson heater faster.

But that’s just one option. You could also say that the Dyson Hot + Cool heats using 1500W and powers the fan using the additional watts.

We can’t really know, because we don’t have access to internal data.

But at first, we can see, that a Dyson heater runs on 33% higher power levels than a regular space heater. This implies that it also uses 33% more energy.

So, how does Dyson claim to use 30% less energy than regular space heaters? The truth is that the Dyson Hot + Cool has a built-in thermostat that controls the temperature settings. Using this thermostat it doesn’t always run on full heat. We’ll cover the thermostat in more detail later on.

So far we can say:

On maximum heat settings, a Dyson heater uses 33% more electricity than a regular space heater. That makes it very expensive to run in uninsulated rooms, where it continuously runs on full heat to compensate for the heat loss.

Because of that, Dyson heaters are not good for heating garages, attics, workshops, etc.

But where do these efficiency claims come from? The next sections cover these topics.

Energy-Efficiency Benefits of Dyson Heaters

Dyson advertises many different aspects of their heaters. Let’s take a look at some of them and tell, whether they play into the efficiency’s hands or not.

Air Multiplier Technology

At first, Dyson heaters have a built-in fan. It’s just concealed as “Air Multiplier Technology”. Using this technology, Dyson heaters are 75% quieter than previous models. Of course, they still make noise, because blowing air is never silent.

Here’s something another reviewer said:

“While we don’t have experience with the previous model, the Hot + Cool was far from unnoticeable when in higher speed settings.”

doityourself.com

Dyson heaters are not as quiet as they advertise to be. But there’s a cool info video about the air multiplier technology. I liked it a lot.

As you can see in the video, Dyson’s favorite aspect of the air multiplier technology is that it has no blades. So, you can’t cut your fingers and it’s absolutely pet safe.

Still, the airstream has to be produced somewhere, so what Dyson did is that they just changed the design of regular fan blades and turned them into more of a jet engine look-alike.

Let’s still call it fan. In fact, it is a fan, it just looks different. This fan is hidden in the bottom part of the plastic body, together with the motor that powers it.

And yes, I have to admit that Dyson does not expose any blades, but which fan in the 21st century (except for ceiling fans) exposes its blades? They are always encased in some kind of protective grid.

Dyson is just selling a regular fan with a different layout. Many reviews even suggest that it is in no way better than a regular ventilator.

Energy-efficiency of Dyson’s Air Multiplier Technology

So, let’s finally take a look at the energy-efficiency aspect of Dyson’s air multiplier technology.

To produce a stream of air, you need energy. It doesn’t matter how exactly you create the airstream. And there’s nothing that is convincing me that the air multiplier technology is better than any regular fan.

Here’s why:

According to Bernoulli’s equation, the velocity of a gas increases when it moves through a thinner and thinner pipe. That’s also called the Venturi effect. This is what Dyson’s air multiplier technology does. The air stream is created with a bulky fan and as it reaches the top, it gets pushed out through a thin slit with high velocity.

That’s basic physics and doesn’t save you any energy. The air multiplier doesn’t help with efficiency. It just changes the pressure and velocity of the air. While the pressure decreases, the velocity increases. Which leaves you with a total of zero.

Intelligent Thermostat

The Dyson Hot + Cool comes with an “intelligent” thermostat. As an electrical engineer, I just have to find out what they mean.

Here’s what they say:

“AM09’s intelligent thermostat constantly monitors the room temperature – automatically switching on warm airflow to achieve your target temperature, and off when it’s reached.”

Dyson advertisement page

Now, where is the intelligence?

That’s the BASIC functionality of every thermostat. There’s no intelligence involved. Just a controller that uses the environmental temperature and the set temperature to find the optimum power settings.

Even though when Dyson sells its heaters, it makes them sound like they are disruptive technologies. But it’s far from that. Every control engineering student learns how to build such a control system in his first semester.

You can find equivalent “intelligent” controls in so many other devices around you: In your oven, in a phone charger and especially in other space heaters.

What Dyson sells as intelligent is nowhere near intelligent. There are dozens of other space heaters you can buy that make use of the same technology but cost just a sixth of the price.

You can view these space heaters on my Recommended Products page (click here to view it).

dyson heater thermostat

How every thermostat works

Thermostats are actually very simple (if you ignore the math behind them). The thermostat senses the current temperature in your room and compares it to the set temperature you want to reach.

Based on the difference, it calculates the optimum heat output in order to reach the desired heat without overheating.

When the set temperature is reached, the temperature difference (set temperature minus measured room temperature) is zero, which causes the heater to stop heating.

Are Dyson thermostats more efficient?

I didn’t find any reliable source stating that Dyson heater thermostats are more efficient than others. The only information I found is that once the set temperature is reached, the thermostat decreases the power to around 1000W.

This makes sure the heater runs with reduced energy usage.

Of course, thermostats are GREAT for saving energy. And I truly believe that the thermostat that Dyson uses is a good one that works just right. I also believe that the engineers did a good job at balancing the control parameters to maximize efficiency while still retaining heating speed.

Still, that does not separate Dyson heaters from other, regular space heaters. A thermostat is a good selling point. But you can also get solid thermostat technology with space heaters that cost less than $150. The thermostat doesn’t explain the price of over $500.

Safety

The surface of a Dyson Hot and Cool heater doesn’t really heat up. It’s perfectly safe to touch and therefore a perfectly safe product for families with children.

Also, in my opinion, a surface that doesn’t heat up is a sign of quality. It tells you that the manufacturer has control over the heat distribution on the surface.

But also a cool surface means that Dyson heaters don’t waste any energy for heating the surface. Some other space heaters get so hot, that their plastic surface melts.

I can’t imagine that this will ever happen with a Dyson Hot and Cool.

So that’s definitely a good sign. The energy you put in the heater is what goes out of it. No energy is wasted on the side.

How long does it take to see savings?

With everything we now know about Dyson heaters, it gets pretty easy to estimate how long it takes to see the savings. I want to answer the question “For how many months or years will you need to use your Dyson heater so its savings make up for the $500 price tag?”.

Let’s assume that 30% savings compared to regular space heaters is true (which I don’t really believe). How long will it take to earn (or save) your money back?

To start, we first need to know how much electricity a regular space heater uses. I have already written an article about that and here’s what I found:

“Average 1500W space heaters will cost around $40 per month to run 8 hours a day.”

heatertips.com – Space Heater Cost guide

Assuming that you use your heater only in the winter months (the cold 6 months from October to March), that would leave you with $240 per year of electricity costs for a regular heater.

How much would a Dyson heater use? If we believe the claims of 30% savings, a Dyson heater costs you $28 per month, which is $168 per month. In total, that would be $72 of savings per year.

Now, most Dyson heaters cost around $500.

This means that it takes you 7 YEARS to earn your expenses back. And who knows whether your heater will even last for that long?

A Dyson heater is not worth it in terms of savings if you use it for less than 7 years.

How to Maximize Dyson Heater Efficiency

There’s one concept I love to share on this website and you’ll find it over and over again if you browse through other articles here.

It’s something that nearly everyone misses while talking about the efficiency of heaters.

Here’s everything in one sentence:

Each space heater has characteristics that outperform any other heater if you use it correctly.

me

With “using it correctly” I mean “using it in the right places.

For example:

An infrared heater is able to heat outdoors by heating objects it radiates at. Infrared radiation can’t be carried away with the wind. This is exactly, where an infrared heater outperforms any other heater type. Its special characteristic is that it uses radiation. That’s why it is the best type of heater for heating outdoor locations or uninsulated rooms.

1. Use your Dyson Heater in the right spot

The special characteristic of a Dyson heater is that it distributes the heat using a strong airstream.

Where is this special characteristic useful? You can immediately see, that a Dyson heater is totally inefficient for outdoor heating. Because it heats by blowing hot air, all you do is heating the environment.

With their air multiplier technology, Dyson Heaters are an excellent choice for heating large rooms indoors. Because of the forced air, the heat reaches every corner of the room.

That’s where it outperforms any other heater.

Usually, the best heaters for heating rooms are oil-filled heaters. They are very safe and efficient. However, Dyson heaters are even better than the oil heaters, because their airstream can carry the air wherever you want.

And on top of that, the head of a Dyson heater rotates. Meaning that it automatically and evenly heats the whole room. It doesn’t leave any cold spot.

If you have a living room to heat, that’s where I would suggest using a Dyson Hot and Cool heater. For smaller rooms, smaller, regular heaters are fine as well.

2. Set the thermostat

Dyson has developed solid thermostat technology that is able to save 30% compared to other heaters.

You might already think, that’s awesome, but you can do even better. What if you could save another 4%, 8% or 10%?

It’s actually pretty easy. According to studies, lowering the temperature of a thermostat by just a single degree will save you 4% in heating costs.

Lowering it by 2 degrees will save you about 8%.

Just by lowering the setpoint of your thermostat you can easily save $20-$40 each month. And it’s really easy to do it. I mean, all you have to do to compensate for the lowered temperature is to wear warmer clothes.

You can, for example, just put on a hoodie in the evening. Wearing warm clothes will reduce the need for heating and thus also save you money.

You can use the money you saved to buy even more hoodies (just joking).

Even with an efficient thermostat, there’s always room for improvement. So, lower it and decrease your electricity costs each month.

3. Set the right direction of the airstream

The last step to maximize the heating efficiency of your Dyson heater, another thing you should do is to set the right airstream direction.

The benefit of Dyson heaters (as we already covered) is that they can use the stream of air to carry the heat through your room. If you, however, misplace your Dyson heater, the airstream will face a wall and not live to its full potential.
I suggest to always place the heater in such a way that its airstream goes from one corner of your room to the opposite corner (diagonal).

Diagonal heating means that the resistance of air decreases. Also, make sure that your heater doesn’t face any obstacles. You don’t want to heat up a closet. You want to heat your room.

Optimizing the direction of the airstream causes higher efficiency. Definitely remember this point when you set up your heater.

Comparison: Dyson Hot and Cool vs Regular Oil Heater

To make this whole guide complete, there’s one section that I just HAVE to include. This chapter is very important to understand that not all advertisement claims are as good as you think at first. You’ll see why in just a minute.

Here’s what Dyson advertises:

“No fast-spinning blades, no visible heating elements. Automatically shuts off when tipped over.”

Official Dyson page

Let’s investigate whether these 3 points separate a Dyson heater from a regular oil heater.

No fast-spinning blades

  • Dyson heater: Has no fast-spinning blades.
  • Regular oil heater: Has no fast-spinning blades either.

When you research Dyson heaters, this is one of the most common advertisement statements they use. And it’s absolutely true. Dyson heaters have no fast-spinning blades.

By the way: With fast-spinning blades, Dyson is talking about simple fans to increase the heat transfer. But fast-spinning blades sounds a lot more dangerous. So, that’s the reason they choose to use this phrase.

The truth is: Dyson heaters hide their “fast-spinning blades” inside their bodies.

Now guess what: Regular oil heaters don’t have any fast-spinning blades. Not even ones they hide inside their body. That implies, that at this point, a regular oil heater is even better than a Dyson product.

And the very same is true for infrared heaters or gas heaters, which have no moving parts as well. in fact, many heaters don’t have fast-spinning blades.

The only type of heater that usually has a built-in fan is a ceramic heater, which produces heat using a ceramic heating element. The hot air is then blown out by the fan. But ceramic heaters also encase their fans in some kind of protective grid, so it’s impossible to touch them and hurt yourself.

Dyson heaters have absolutely no advantage in this point.

No visible heating elements

  • Dyson heater: Has no visible heating elements.
  • Regular oil heater: Has no visible heating elements either.

Dyson heaters hide their heating element within their bodies.

The heating element of an oil heater is encased in the metal body as well. Now, oil heaters have an even bigger advantage at this point:

The heating element of an oil heater is permanently sealed in a metal body. It’s absolutely impossible to touch it unless you have a tank to destroy the heater.

Still, having no visible heating elements can be an advantage, especially if you have safety concerns. Heating elements are dangerous when you have kids or pets at home. That’s why a Dyson heater is definitely a better choice than an infrared heater for example.

I have an infrared heater at home and even though there’s a protective grid covering the heating elements, the grid heats up and gets dangerously hot. You can definitely burn your fingers.

Dyson heaters and oil heaters don’t have exposed heating elements, which makes them a very safe choice.

Automatically shuts off when tipped over

  • Dyson heater: Comes with automatic tip-over protection.
  • Regular oil heater: Comes with automatic tip-over protection as well.

The automatic tip-over shut off protection is something that nearly every space heater these days has. It’s nothing special at all.

But that’s positive: Tip-over protection makes space heaters much safer. Dyson has a big impact on the heating industry. If they didn’t include tip-over protection, possibly other brands would copy them and cause a decrease in safety standards.

Well done. Automatic tip-over protection is a must-have.

the dyson heater logo

Conclusion

Dyson heaters are not really better than other heaters. At least not in terms of functionality. Still, they have everything you wish for in a space heater. A good and reliable thermostat, safety features and a very safe design.

What I like about Dyson heaters, is that they just look so much better than regular heaters. You shouldn’t view them as just a heater (or a fan). Dyson heaters are designer products. Having one will make a visual impact on the appearance of your home and definitely make a change.

One guy on a forum said this:

“Come on guys. It’s not just hot air, it’s Dyson hot air…”

macman on moneysavingexpert.com

In terms of efficiency, Dyson heaters are definitely worth considering. Especially if you look for a heater to use long term.

Even though this review was very critical at first, I became a fan of the Dyson Hot and Cool. It’s a new concept, a new design and finally something that revives the heater industry.

I hope that other companies follow along and make their heaters look as good as Dyson heaters. That futuristic style really grabbed my attention.

Attributions: images by TAKA@P.P.R.S (license: CC BY 2.0)

About the Author

Daniel Hirsch

Daniel is an electrical engineer, blogger, and author. He studied electrical engineering and information technology and decided to blog about heaters after working in the temperature sensing industry.