Dyson Hot Review – A Scientific Approach
- November 6th, 2011
- Posted in Blog
- By Paul Anthony Wilson
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Abstract
The Dyson Hot is a commercial air heater that became available during autumn 2011. Dyson claims that it is a very efficient heater which excels beyond the more conventional heater by quickly and evenly heating a room. Being many times more expensive than most of the other heaters on the market it was of interest to scientifically quantify the claims by Dyson. The aim of this experiment has been to assess the performance of the Dyson Hot by comparing it to a standard heating oven. Although this has not done in a professional test lab, great care has been given to make sure the measurements were as accurate as possible.
Instrumental Setup
The two heaters, the Dyson hot and the conventional heater, were placed at a distance of 3.04 meters (10 ft) away from a temperature module based on the DS18B20 (info). The temperature module was suspended in the air so that it was not affected by the material it would have otherwise been lying on. The power consumption was measured using a energy meter. The relative humidity in the room was controlled by a Duracraft Dehumidifier. The uncertainty of the power consumption is only an estimate from watching the readings change with time.
| Heater | Power consumption |
| Conventional Heater | 2125 ± 12 W |
| Dyson Hot | 1951 ± 3 W |
Data Acquisition
The data was sampled at a frequency of once per minute. Prior to recording the data the room temperature was measured to be stable within 0.5 °C. The error of the temperature module is given to be ± 0.5 °C by the manufacturer. The measurements were both started at 15.0 ± 0.5 °C and stopped after 90 minutes.
Results

Temperature curves between the conventional heater and the Dyson Hot, both rotating and non-rotating. The Dyson Hot, regardless of mode, is more efficient at heating a room.
The conventional heater
The conventional heater started heating the room at 15.0 ± 0.5 °C with a relative humidity of 73 ± 5 % as measured by the TFA humidty meter. 90 minutes later the room had reached 19.63 ± 0.5 °C with a relative humidity of 66 ± 5 %.
The Dyson Hot (without rotation)
The Dyson Hot started heating the room at 14.75 ± 0.5 °C with a relative humidity of 73 ± 5 % as measured by the WH2080 Weather Station. 90 minutes later the room had reached 21.50 ± 0.5 °C with a relative humidity similar to the conventional heater.
The Dyson Hot (with rotation)
The Dyson Hot started heating the room at 14.88 ± 0.5 °C with a relative humidity of 72 ± 5 % as measured by the WH2080 Weather Station. 90 minutes later the room had reached 20.56 ± 0.5 °C with a relative humidity similar to the conventional heater.
Discussion
It is clear from the results that the Dyson Hot is indeed more efficient at heating a room. Not only was the room warmer after 90 minutes, but the Dyson Hot had also used less electricity. After 90 minutes the conventional heater had used 3.188 kWh whilst the Dyson Hot used in the same time 2.927 kWh, a difference of 0.262 kWh. Initial tests showed that a similar relative humidity was required for an accurate comparison. The Dyson Hot also seemed to push the hot air around more efficiently as shown in the figure below. We are not able to quantify just how much more efficient the Dyson Hot is at distributing heat as the heaters were placed at a fixed distance during all the measurements. Neither the Dyson Hot or the conventional heater gave off a burnt dust smell. The major downside of the Dyson Hot is the price. Assuming a conventional heater costs about £ 12 the Dyson Hot currently priced at £ 269.99 is then 22.5 times more expensive. One might thus argue that it is more convenient to use two or more conventional heaters to warm several rooms instead of having to move the Dyson Hot around from room to room.

A figure from the Dyson website showing the distribution of heat between a conventional heater and the Dyson Hot.
Conclusion
The Dyson Hot is without doubt more energy efficient and thus more cost effective. It is also better at heating a room, both in terms of speed and heat distribution. The major setback is the price. If you decide to get the Dyson Hot and you liked this scientific review please buy from the link below:
I demand more reviews of household products. Cars? Kettles? Phones?
Haha.. Yes Sir!
As an engineer, I have to comment that it sounds like you use kW as a unit of energy (whereas it is a unit of power)… Do you mean kWh? If that is so, it still sounds low, because it would give an average power of only 200 W, or three old-fashioned light bulbs.
Well spotted Johan! I have now done the corrections. Thank you.
Still 2 “kW” hanging there….
I have left it there as I mention “After 90 minutes” earlier in the sentence. I am here talking about the consumption over 90 minutes and not over an hour.
But you cannot say that “in 90 minutes it used xx kW”, it’s like saying “after three hours I had travelled 90 km/h”. Was the power (energy per time) at the time exactly 90 minutes after start 3.188 kW, or did you have the average power of 3.188 kW during the first 90 minutes? And I am confused how a subtraction of two values in kW can result in a value in kWh.
Haha…yes. Ok fully corrected now.
Wow, more than I could have asked for. Thanks for the analysis.
The space heater I currently use at home from time to time cost $50 and lacks some of the features and all of the style of the Hot.
When the Hot drops in price as much as the Dyson fans have I’ll likely pick one up. At a price around $150 I think it becomes compelling.
Good basic review overall… better in general than others out there. I do wish there was a slightly better analysis done with at least one summary table. On that table should be consumption data, percent efficiency compared to control, and standardized to cost per degree maintained (at least one home-use scenario of maintaining an ambient temp of say 25 from a baseline of 15-20 external temp. for X hours, standardized for total power consumption.)
Not sure I fully understand what you mean by “percent efficiency compared to control” and “standardized to cost per degree maintained”. Investigating the cost of maintaining a constant temperature sounds interesting though. I will keep it in mind if I in the future do a similar review.
You give values of 2125 and 1950 in a table, however at a glance these values are not as useful as it being 9% more efficient, however at 9% increased efficiency at 20x the cost, there will be an equilibrium point at which the Dyson will ACTUALLY have a monetary value over the competitor = dP-(E1/E2)*cost where dP is difference in price E1/E2 is relative efficiency and cost is the current cost of energy. That was off the top of my head so it could be wrong, but that should give you the amount of time you’d have to run it until you broke even.
I’d also liked to have seen in your discussion explanation as per why the rotating fan was less efficient. I assume this was because the fan was no longer pointing at the thermometer, although I would expect the whole room heating efficiency of the rotating fan to be higher than that of the others… unless some weird air currents are happening that optimize for statitionary.
Ultimately, I’d like to know a couple things at a glance: price difference, percent efficiency difference (for those that care about being greener), and finally how long it’d have to run to break even as compared to the control (the cheapo heater)