Fan heater technology

[sarabande]

I have come across PTC fans for the first time. Positive Temperature Coefficient.

They claim lower internal operating temps. Which might be a good thing, but begs the question - do you need a larger footprint to achieve the same output ?

Snake oil, or not ?

 

[johnalison]

I can get a perfectly good fan heater, 2 or 3 Kw for about £15 from B&Q, so I don't see the virtue of complicating things, given that the efficiency of all of them will be the same, ie 100%.

 

[maby]

I can get a perfectly good fan heater, 2 or 3 Kw for about £15 from B&Q, so I don't see the virtue of complicating things, given that the efficiency of all of them will be the same, ie 100%.

There is nothing particularly complicated about a ceramic fan heater - which is what most "PTC" heaters are. It's just a different composition of heating element from the traditional resistance wire - the element runs at a lower temperature which provides a theoretical safety improvement.

 

[pvb]

Snake oil, or not ?

As johnalison has correctly said, the efficiency will still be 100%. So paying double for minimal benefit isn't a great idea.

 

[anoccasionalyachtsman]

Definitely snake oil. Most metals have a positive temperature coefficient wrt electrical resistance. So a pct fan will be much like your Mum's and your Gran's bar fires were. Their resistance rises as they get hotter.

 

[maby]

Definitely snake oil. Most metals have a positive temperature coefficient wrt electrical resistance. So a pct fan will be much like your Mum's and your Gran's bar fires were. Their resistance rises as they get hotter.

While it is true that most metals have a positive temperature coefficient, the coefficient is relatively low and heaters with conventional resistance wire elements run at quite high temperatures - often close to red hot. The temperature coefficient of the ceramics used in the elements is higher and they are self-regulating at lower temperatures.

That said, I would not claim that conventional fan heaters are in any way dangerous - there are not hundreds of people killed each year in fires triggered by overheating fan heaters! I think you'll find that it is increasingly difficult to purchase metal element fan heaters - the world seems to be switching to ceramic. They are small, light weight and seem to be reliable - at a price that is similar to the conventional design.