Anyone used Rointe heaters?

Cardew

Paulb_2 said:

Which say they use 16 temperature probes in the test room and measure how quickly the whole room is up to temperature. Again, setting electrical efficiency aside, if I'm sitting in a room and one heater switches the thermostat off sooner for the same power rating, yet still makes me feel warm and cosy then it will cost me less, so it is more efficient at heating the room.

• BTU (Btu) - British Thermal Unit - also known as a "heat unit" in United States.
• Calorie.
• Joule.

Let us put it another way. The measurement of heat  is calculated in BTU(British Thermal Unit) or Calorie or Joule.

For a given consumption of electricity, all electrical heaters produce the same amount of heat(BTU/Calorie/Joule) and are all 100% efficient.

If you want just yourself to be warm when sitting in a room, then the most effective method would be an InfraRed heater. That 'beams' heat toward an object and a 400 watt heater would be sufficient. These are sometimes used as a patio heater, or for a person working at a bench in a garage.

It is rather like someone sitting alone in a large room wanting to read. It would be sensible to use a reading lamp rather than having the whole room brightly lit.

As said previously, if you want to get the whole room up to heat quickly, use a fan heater. The heat produced will warm the air quickly, but as soon as the heat stops being produced, the room will cool quickly as the heat in the room will be absorbed by the floor/walls/furniture.

QrizB

Paulb_2 said:

QrizB said:

Paulb_2 said:

Which say they use 16 temperature probes in the test room and measure how quickly the whole room is up to temperature. Again, setting electrical efficiency aside, if I'm sitting in a room and one heater switches the thermostat off sooner for the same power rating, yet still makes me feel warm and cosy then it will cost me less, so it is more efficient at heating the room.

It might be quicker at getting the room to temperature but, unlesss you're in the habit of heating rooms and then immediately leaving them once they're warm, it won't be any more efficient and it won't cost you less.

it will heat back to the thermostat temperature quicker the next time as well so won't be used as much as a comparable heater. 

No, that's still wrong. You have a fundamental misunderstanding of how heating (and heat loss) works. I can't believe I'm about to write the next half of this sentence but there's a graphic on Rointe's website that will help explain. It's wildly inaccurate but will serve for this purpose.

Ignore all the words for now, and the crazy time scale on the X axis. Look at the red curve with humps and bumps. This is something like an oil-filled radiator which has high thermal mass. It's slow to warm up the room but then turns off at the top of the cycle and stays off until the bottom of the curve, when it turns on again. In the graphic it spends half its time on and half its time off.

Now look at the wiggly blue(?) line. This is something like a convector or fan heater, with low thermal mass. This one heats the room quickly then turns off. It then turns on again soon and off again. And it keeps repeating that on-off cycle. The "blue" heater is switched on for just as big a fraction of the time as the "red" one is, but rather than a long "on" and a long "off" it has lots of short "on"s and "off"s.

They will both use the same amount of electricity, on average, over any reasonable period.

(Please note *some* heater manufacturers claim their magic clay gives the heaters high thermal mass, but then at the same time publish marketing material that suggests their heaters have low thermal mass. This is unhelpful and inconsistent, a given heater can't have both.)

Gerry1

Can't help noticing that Paulb_2 has visited just 10 times in 15 years but five of his six posts have been within the last 15 hours.

Must be a massive Rointe fan !

Reed_Richards

Gerry1 said:

Can't help noticing that Paulb_2 has visited just 10 times in 15 years but five of his six posts have been within the last 15 hours.

Must be a massive Rointe fan !

No I don't think so; just somebody trying to make sense of a Which report.  @QrizB makes a sensible comparison between a fan heater and and an oil-filled radiator but I cannot see the sense in comparing one fan heater with another if they really draw the same amount of electrical power.  It's like going to the supermarket with pound coins or 10p pieces and seeing if £10 worth of either coin buys you more groceries.  Then how on earth do you assess the temperature of a room distributed with 16 thermometers?  Do you take the mean reading or the median or wait until every thermometer has reached or exceeded some desired temperature?  Any of those options (and there are others) has some validity but they might not all give the same result.   

Cardew

I am a fan of WHICH, but this must be one of the worst reports they have ever written. I can see why Paulb_2 is confused when you read this extract:

'If you choose a high-powered heater that warms your room up quickly and then switches off, it will use less electricity than a heater that takes longer to warm your room.

The quickest Best Buy heaters we've tested were able to raise the temperature of our test room in less than 10 minutes - the worst took more than 30 minutes. You can use our tests results to see whether it would actually end up costing you less to buy a heater with more power.'

Paulb_2

Cardew said:

I am a fan of WHICH, but this must be one of the worst reports they have ever written. I can see why Paulb_2 is confused when you read this extract:

'If you choose a high-powered heater that warms your room up quickly and then switches off, it will use less electricity than a heater that takes longer to warm your room.

The quickest Best Buy heaters we've tested were able to raise the temperature of our test room in less than 10 minutes - the worst took more than 30 minutes. You can use our tests results to see whether it would actually end up costing you less to buy a heater with more power.'

Cardew has expressed what I'm struggling with, in theory it should take the same Kw to heat and maintain the temperature in the room with 100% efficiency yet the Which tests suggest otherwise.

Reed_Richards, it doesn't matter if you take mean, median or wait for all of them, as long as you use the same parameters for each heater test to assess them on an equal basis?

Gerry1, not sure how you've jumped to that conclusion from my posting history? As I said, I was researching heaters and came across this thread, its suplemental heating for a beach house that currently has storage heaters.

Gerry1

Paulb_2 said:

Gerry1, not sure how you've jumped to that conclusion from my posting history? As I said, I was researching heaters and came across this thread, its suplemental heating for a beach house that currently has storage heaters.

OK, I believe you ! 

The problem is that non-storage 'magic dust heaters generally have a very poor reputation (extremely expensive to run because they use full  price daytime electricity) and manufactureres' claims have often been taken to task by the ASA.  Anyone who suddenly starts claiming that they can be cheaper tends to raise eyebrows a bit...

matelodave

I've been watching this and really cannot understand what all the fuss is about.

1kwh of leccy will produce 1kwh of heat. You can convert it to joules, Bthu etc but it will still produce the same amount of heat so it really doesn't matter what sort of heater you use as you'll get the same amount of heat out of it for the same cost.

The only difference is how the heat gets distributed and how fast it get dissipated into the room. Rointe heaters are just posh oil filled radiators and will take longer to heat the room because they have to get the oil hot before they produce heat and will continue to dissipate heat when they are turned off as the oil cools down. Same with magic dust. They dont produce more heat but just dissipate it in a different way as their dissipation lags their energy input.

Convector heaters should heat up faster because there's no heat storage, fan heaters are even faster because the air is forced through the element but they all produce the same amount of heat and will all cost the same amount to run assuming that they are heating the the same space over the same period of time to the same temperature.

A higher output heater will heat the space faster than a lower rated unit but will still consume the same amount of energy to get it to the same temperature as a smaller heater, it will just do it faster

As Scotty said, "ye canna change the laws of physics".  I havent read the Which? report but if it really does say what Cardew reports (and I've no reason to doubt him) then whoever wrote it should be taken out and shot. 

There really is no advantage in spending hundreds on a pretty radiator when a £10-£20 heater from Argos or similar with the same rating will produce the same amount of heat forthesame running cost.

IMO the only consideration is whether you need a quick blast for ten minutes, in which case a cheap fan heater will do the trick or longer term heating where a convector or oil filled rad maybe more suitable as the heat output is a bit more even than the on/off off blast from a fan heater.

Paulb_2

Gerry1 said:

Paulb_2 said:

Gerry1, not sure how you've jumped to that conclusion from my posting history? As I said, I was researching heaters and came across this thread, its suplemental heating for a beach house that currently has storage heaters.

OK, I believe you ! 

The problem is that non-storage 'magic dust heaters generally have a very poor reputation (extremely expensive to run because they use full  price daytime electricity) and manufactureres' claims have often been taken to task by the ASA.  Anyone who suddenly starts claiming that they can be cheaper tends to raise eyebrows a bit...

Gerry1, I'm not claiming anything, I'm trying to understand the Which report and how the heating rates can be different under the same test parameters and consume more/less power to reach and maintain the given temperature.

Reed_Richards

The problem here is that only @Paulb_2 has a Which subscription so nobody else can comment on what the article says but there are two fundamentals:

1. 1 kwh of electricity will give you 1 kWh of heat.  This heat may go immediately into heating the air in the room or it may take some time (as in the case of an oil-filled radiator) so two heaters with the same input power can differ in the rate at which they raise the air temperature of a room.
2. If a room is held at the same average air temperature for a while then the rate of heat loss from the air in the room is just dependent on the rate at which the room loses heat to its surroundings.  In this steady state all the heat sources in the room just need to match this rate of heat loss and all electrical heaters (that have been in operation for some time) will use the same amount of electricity to do this.  

There is a way a heater could be less efficient in the steady-state scenario which is if it creates a hot spot on an exterior surface (that is why some people put metal foil on the wall behind a radiator).  But hot spots are very unlikely to have a big effect on efficiency because the hot area would be small compared to the total external surface area of the room.  Some thermostatically controlled heaters will be better than others at maintaining a constant room temperature (rather than one that alternates between being a bit too hot and a bit too cold) but they will still use the same amount of power on average.