Hybrid Hair Dryer/Propane Torch Heater

[MadScientist267]

Here it is... A hybrid hair dryer/propane torch heater.

Very primitive, but clean and effective. The power factor is a little whack (~0.75, depending on dryer setting and dimmer level) but that can be cleaned up later.





Steve

Edit - Apologies for the cockeyed pic, phone has orientation detection/implementation issues, and at the time, had no way to compensate for it.
Edit - fixed orientation

Also, I don't necessarily recommend this thing as any kind of regular fixture of any kind. I came up with it in an effort to reduce heating costs in the van as winter approaches, but in a way, I'm kinda "cheating" a little bit - At ~150W and a moderate to low flame, it is very efficient, but of course cannot be completely powered by battery for the electric side of it due to my very limited production/storage capabilities currently. Thinking up a MK2 version that may use propane as the sole fuel source, with a 12V fan to make things move. But that wouldn't be "hybrid" now, would it... 

Either way, this contraption is NOT safe to use unattended, and you're risking your property/wellbeing/life by using it at all. You know, open flame, carbon monoxide, hair dryer, particularly in a bathtub

In other words, don't come running to me if you decide to build one and it kills you in the process.

[WooferHound]

You may also suggest that it should not be used to dry your hair . . .

It seems to me that the airflow over the flame would cause it to not burn properly and may cause incomplete combustion.

[MadScientist267]

Thanks Woof for the orientation thing - that was irritating me to no end haha

It can be used to dry hair - once. If you want to dry it repeatedly, you have to wait for it to grow back to dry it again.

I had actually considered the issue with airflow interfering with complete combustion, but even with their gigantor counterparts, they never ran long enough to reach any level I could detect (symptom-wise). Turns out the CO detector I had was a busted POS, but that's another story.

Likewise, this little gem doesn't need to run long either to warm up the space, albeit a little longer than the above mentioned propane hogs. Add that to the fact that the flame is so small (CO production being proportional to the propane burned) and it probably doesn't produce much more toxin than the typical candle (or maybe two). With the other methods (actual bonifide catalytic heater, and a gas cooking apparatus), I would be lucky to get a couple nights worth of heat out of them, and at that, the thermal cycling was ridiculous. I would wake up every couple hours (if that) from an impending chill, and have to light them off again for a few minutes and then kill them, and try to go back to sleep. With all that propane being burned so quickly, there's no telling how much CO was being produced. That said, I'm still working on the cylinder in the pic above, and while from time to time the other methods would use the gas fast enough to cause frost on the cylinder, this typically gets barely a chill to the touch.

With this, I can run it boosted up for about 5 minutes to get the air up to temperature, then pull it back to barely on, and cook it for another 15 minutes. Doing it this way, for whatever reason, ends up in a long lasting heating after I cut it off, and then I can go to sleep without having to light it back up again (at least for now, until the temps really drop).

Of course, CO *IS* still a concern, and I will be mitigating 2 issues at once when I install the vent fan this weekend. Its primary purpose originally was to bring in fresh air to displace smoky air (without causing a draft), but the air change will be more notable for the removal of any CO that might be present. It will be a 4" fan mounted on a partition between the cabin and cargo areas, to pull in fresh air via the front windows, thermally buffered by the cabin. There are a few ways for the "dirty" air to leave the back of the van from there. There will even be a light trap to help thwart those irritating wally world managers.

I have a LOT of upgrades that have been done, and pics all along the way, so when the process is finished, you guys will have quite the transformation to see.

Steve

[rossw]

Of course, CO *IS* still a concern, and I will be mitigating 2 issues at once when I install the vent fan this weekend. Its primary purpose originally was to bring in fresh air to displace smoky air (without causing a draft), but the air change will be more notable for the removal of any CO that might be present.

Not saying it's a good idea, or that it will work, but just a thought.....

If you could get yourself a modest length of (say) Copper pipe (other materials would work fine too) - and contain the flame entirely WITHIN the tube, you could expel ALL the combustion products OUTSIDE. With a venturi, or some clever work, you could probably get the inlet air to come from outside too. There would be a loss in efficiency - but that will depend on how much of the heat you can extract from the (flameproof) exhaust tube before it gets outside. Either way, containing the combustion products entirely outside would improve your chances of survival.

[MadScientist267]

I'll be giving that some thought Ross... I've come up with a few ideas as far as that goes. Biggest problem is breaching the body of the van to do so. Not that I can't, but trying to minimize doing so. It's bad enough I am going to end up putting at least one hole in the side for the AC supply.

The vent fan is installed and does an exceptional job once I figured out the ideal method of steering the air where I needed it to go. I've been using smoke as a guide to tell me what works best in terms of fan speed, direction, and where to let the air out to provide the biggest gain.

With the light trap in place, it also quiets the fan down to the point where at all but the highest speeds, it is virtually undetectable in terms of noise. The air flow is slow, smooth, and has a decent positive pressure from the discharge. There's minimal draft if any, although it does offset the efficiency of the heater to a small degree, but that is to be expected.

It has no problem clearing smoke in short order, and so I am sure the minimal amount of CO produced is equally trivial for it to remove as well.

I got it installed not a moment too soon either - not sure what the temps are going to drop down to tonight, but its rare (so far this year) for me to feel the need to start heat as early as 10PM. We will see how this goes.

Steve