Amazon low energy heater costs pennies to run - does it really?

[The Legal Occupier]

Now, I know nothing about energy, so I need your help.

One thing I know is that Amazon reviews are easy to manipulate, but, before discarding it, I'd like the panel's opinion.

[The Natural Philosopher]

Where electric heaters are concerned, they are all 100% efficient. So anyine claiming one is better than another is scamming you

My 2Kw heater I use on very cold days has a thermostat. It cycles on and off. That one would cycle on, more than off.

[mm0fmf]

It's a 500W heater producing 500W of heat. It's no surprise it costs a

1/4 of what a 2000W heater costs to run, it produces a 1/4 of the heat.

[Tim+]

All resistive heaters are 100% efficient. One can not be magically more efficient than another. Any ad that claims their heater is “more efficient” is generally talking bollocks.

That doesn’t mean they’re all the same though. Fan heaters are good for heating a volume of air quickly but are relatively noisy. The way the thermostats work can affect comfort. If you’re relying on warm air been blown directly at you a basic on/off thermostat can be uncomfortable and I believe ceramic plate heaters with digital controls can provide a much more constant output temperature.

A radiant heater works by warming you directly via infra-red radiation and doesn’t significantly heat the air and may be more useful in a workshop say where you may want to be warm but have no need to heat the whole room.

Tim

[David Wade]

I suggest you read the comments on the article. For example:-

"You clearly haven't read the reviews at the link you've provided, sent direct from China, no safety and reports of it melting! "

as all electric heaters are 100% efficient it will cost the same to heat a given room to a given temperature. So a 1Kw heater will heat a room in half the time. Same cost. As for the revue which says not pressing the button on the central heating. If its gas it will almost certainly be cheaper as gas is around 25% the price of electricity..

Dave

[Tim+]

Am I the only one a bit puzzled by someone who wants to build an electro magnetic pulse treatment device but doesn’t understand basic physics? I mean, we all have gaps in our knowledge but it’s a pretty huge gap for someone with electronics knowledge.

Tim

[Harry Bloomfield Esq]

Obvious init? All electric heaters are exactly 100% efficient, no more, no less - all that might vary is the method of delivery of the heat. 1Kw of heat, costs what it costs, and cannot be bettered, except for by a heat-pump.

[Adrian Caspersz]

No, I'm not puzzled. His bar is low.

It is the lack of understanding of science, and non-willing to trust, that causes some to fall victim to alternative therapies, and fall victims to charlatans and device of magic.

I sadly know two people that through going through their own misguided ways in the face of better advice from professionals, basically died of it.

complementary, yes alternative, NO.

[John Rumm]

Well it says all you need at the top of the page:

"This article contains affiliate links, we may receive a commission on any sales we generate from it"

Other than that, it makes no claims that are obviously wrong. The only thing it leaves out is that a 500W heater will take rather a long while to do much in all but the tiniest of rooms.

Efficiency will be as good as any other resistive electric heater.

[zall]

Yes you do.

The fundamental with that sort of heater is that all that matters is the watts it consumes. 500W is f*ck all for a heater and it is a bare faced like that it will only cost pennies to run.

[Robert]

Similar claims like " powerful enough to heat the largest room" may well be scientifically accurate; but Joe Public puts a different meaning on the words used.

I had one of these type of devices donated to the charity shop I volunteer in. I was not happy with having something which got so hot plugged directly into a wall or more likely extension socket, result - recycled !

[The Natural Philosopher]

Not sure that is true today.

Its a fast moving market

[David Wade]

Well I still have a fixed deal, so for me that is still true. But for many yes, the ratio is/has will change, its now between 27% and 32% so still considerably cheaper. However the change does mean high efficiency heat pumps can now be cheaper to run than a gas boiler. Capital costs still higher.....

Dave

[The Natural Philosopher]

I do know that to fill an EV up with electrons costs more for the same miles than to fill it with diesel.

[Max Demian]

Better still, an electrically heated suit. 500W might be enough.

[Paul]

With resistive heaters, there are no tricks. You are getting what you paid for.

Electricity costs a fortune.

It's a bad way to heat an entire dwelling.

If you designed a "thermal suit", such as some of the space suits that keep the occupant warm, that's a better usage of energy. Because it only keeps the human warm, and not the entire house.

But a home could be damaged, if the temperature inside drops too low, which is why we adjust the thermostat to meet at least that level of heating.

The thermostats on portable heaters, vary in accuracy. And may actually do a poor job of regulating room temperature. Such a controller is called a "bang-bang" controller, because it attempts to maintain the temperature, by the long term average of the ON and OFF times. The thermostats on these cheap items, seldom trip at the same temperature each time. You might find the heater, "stays on all the time". And the room is slightly too warm (if it's a small room that is).

The wall thermostats can be a bit better in this regard.

Continuously variable devices, can achieve tighter control on temperature, which is only a boon to the sensitive who are bothered by temperature fluctuation. For example, older refrigerators, used the "bang-bang" controller. Some newer Korean units, the compressor operates at a variable rate, and the compressor never stops turning. The compressor only need turn fast enough, to balance the leakage through the refrigerator walls. It is still a closed loop feedback system, but the response is variable in strength. A processor implements the algorithm, for the continuously variable system, rather than the simple bimetallic element in a bang-bang controller.

*******

A "better" heater, is a heat pump.

If I put 8KW of electricity into a resistive heater, I get 8KW of heat.

If I put 2KW into a heat pump, I get 8KW of heat. This assumes the "hot" end of the heat pump is above -15C and there is energy to be pumped. A heat pump does not create energy, it just moves the heat it finds. Once the source drops low enough in temperature, a heat pump is useless.

So if you want to actually save energy, that's a heat pump, not an Amazon heater. The heat pump costs 3x-4x less to operate. An example of a heat pump, would be a "split unit" heat pump, that fits on either side of a house wall. This would be (presumably) an air-source heat pump. Better heat pumps, use a "field" to provide the heat, and are referred to as "ground source" heat pumps. If a water stream went through the neighbourhood, that might make a good source of heat. Or, you can sink "collectors" into your back yard, and the heat pump can pump a fluid through the loop, to collect the heat energy and pump it into the house. Even if the dirt is only 5C, you can still get heat enough to heat a room to 22C.

Even though a source of heat does not feel "warm", the heat pump fixes that, as the exit temperature can be quite a bit higher. It uses phase change (liquid refrigerant versus gaseous refrigerant) as part of the heat transferring mechanism.

Resistive heating is a great solution... if your real heating solution has died, and you're waiting for a replacement part to arrive. But as a regular solution, you would have to be crazy to use it. Like here, with the resistive heating, I heated the house for 3 days, using 10 or so heaters, and that made a size-able difference to the monthly bill. I know now, that 3 days is all I can afford to wait for a replacement part.

Paul

[Rob Morley]

But stick it under a desk and it will keep your knees warm without having to heat the whole room. I prefer far-infrared panels for that sort of application though.

[Tim Streater]

Unless it doesn't cost a fortune, and is cheap, such as when produced by nuclear power. As the French can tell you.

Unless it's cheaply produced, in which case it's a good way: no emissions at the point of use.

[Animal]

500w is low level heating. 'Packs a punch' has no legal meaning when applied to non-punching products, hence advertisers like it. Plastic & fan heater are not a safe combination, and should never be bought. 500w in a package that size is just scary. And electric heating is the most expensive method available. Other than that, great.