I stumbled across an article about the production of formaldehyde in e cigs. Basically it said at low voltages there wasn’t an issue, but at high voltages there was alot of it produced. But an expert pointed out that at the voltages they were testing (5volts), it was so high it would basically be ‘uninhalable’.

All good I thought..but my very basic vape device is about 20 watts (about 12 volts)..which is double that, and I know that many are far more powerful than mine.

Linky

My mouth to throat device is set on 4 volts, 19 watts. I think the higher voltage devices are for the more potent mouth to lung devices, the kind that chuck loads of smoke out. I haven’t read the article but are you saying above 5 volts is dangerous?

I should image it depends on the flavouring of liquid too.

That’s what the research suggests yes. But those that dispute it say if you are running 5 volts then you’ll be burning the coil and basically the taste would be awful. I struggle to see how that’s the case as some of the batteries on sale put out over 100 watts..which I assume is more than 5 volts!

That’s said I’m no electrician..so maybe you can’t just equate volts to watts. Indeed mine puts out about 20 watts and is one of the fairly basic all in one units..

The use of electrical units like volts amps and watts is misleading. The author should have used thermal units similar to BTUs or heat flux but that can get complex this page calculates heating coils for vaping
The electrical units play a part along with the size of wire and its resistance to how much heat is produced.
I’m not surprised that burnt vape juice is carconegenic because so is burnt toast amongst a host of other burnt things.

remember the voltages and watts are changed by adding different coils. I am not sure what type of ratings mouth to lung devices use. I probably would not pay much attention to the study.

I’ve no idea about vaping but if you put a high load on a battery the voltage will drop due to the internal resistance.

So Say you start off with a freshly charged 8.4V battery, and connect that to a 1ohm coil. You would get 8.4/1=8.4 amps, and therefore 70.5W. But in reality the voltage of the battery will drop to say 5V when trying to produce that much current, so only 25W (i.e. a massive difference). Hence why you can probably buy a battery that claims to deliver so many watts, because what it’s really saying is it can deliver so much current before the voltage drops.

I guess in an effort to standardize this for the experiment they’ve hooked the coil upto a power supply so can say that “at 5V the coil produces formaldehyde”. Which is a different statement to “connected to a 5V battery the coil produces formaldehyde”.

Maybe time to put my 80W using a 0.15 öhm coil down ?

Dunno, I guess the temperature will depend on the surface area of the coil.

Heat exchange power = k A dT, assuming k is constant (it wont be, especially if stuff is burning) then halve A then dT doubles, so one coil might operate at 150C and the other at 300, and both produce the same amount of power/vapor. Obviously that has an impact if the smoke point of the oil is somewhere between those numbers.