Efficient Small Heating Solutions for Low-Temperature Projects | Expert Advice

[beshpin]

Basically, what we're looking to construct is a very small heating apparatus.

We need to find an appropriate material to heat 28.26 cm sq., to roughly 150C or 423 K. We would prefer to use a battery mounted system but are equally ok with making some sort of plug-in system.

We're not quite sure where to start and figured you guys might have some solid advice.

 

[mgb_phys]

What are you heating, how well insulated is it and how fast do you have to heat it?
That determines how much power you have to put in.

The simplest/cheapest solution would be a heater pad as used for engine blocks in cold countries, they should supply upto 500W. Google for, silicone or rubber heater pads.

 

[berkeman]

I googled nichrome wire heater, and got lots of good hits. Nichrome wire is often used for making heating elements. Check out these two hits, and google the same terms to see what other info pops up. 150C is pretty hot, but very do-able with nicrhome wire.

http://www.heatersplus.com/nichrome.htm

http://www.dewbuster.com/heaters/nichrome.html

 

[beshpin]

thanks, basically what we're trying to do is create a coal-free hookah. We're looking at ways of creating a simple heating system for our tobacco. To see what we're talking about go to www.hookah-shisha.com and you'll see what kind of set up we're looking to build.

 

[mgb_phys]

You were rather precise in the area needing to be heated so I assumed it was a flat surface, for just heating a bowl of tobacco then a wire heater element soemthign like the one in a hair dryer or slow cooker would be ideal.

Does the tobacco need to burn or just be heated?
For a prototype I would probably use parts out of an old hair dryer.

 

[berkeman]

Does the tobacco need to burn or just be heated?
For a prototype I would probably use parts out of an old hair dryer.

One thought, though. Since this is for heating tobacco, the heater element and bowl would need to be of food grade materials. I'm not sure the coil out of a hair dryer or other general air heating device would be food grade (which I know very little about). The OP should combine the words food grade with the google search that I did, to see if there is special nichrome wire that needs to be used for this type of application. And the bowl materials would need to be food grade as well -- can't just use any old stuff, I wouldn't think.

 

[mgb_phys]

I'm not sure the OP is looking for FDA certification for the world's first SafetyBong (tm) !
But if you were worried you could put the tobbaco in a removeable stainless steel cup with a heater element wrapped around it.
Cleaning burnt tobacco out of a heater wire would be a pain anyway.

 

[beshpin]

One thought, though. Since this is for heating tobacco, the heater element and bowl would need to be of food grade materials. I'm not sure the coil out of a hair dryer or other general air heating device would be food grade (which I know very little about). The OP should combine the words food grade with the google search that I did, to see if there is special nichrome wire that needs to be used for this type of application. And the bowl materials would need to be food grade as well -- can't just use any old stuff, I wouldn't think.

Well the clay bowl's are already acceptable for use, as well they have the coal currently directly placed onto a metal grate on top of the bowl, so heat transmission is not an issue.

Although you're right about the food grade info for the wire, the wire itself isn't going into the bowl, it's probably going to be set up in a coil or other formation on top of the bowl with air being drawn down into the tobacco. I assume that any sort of heat produced wouldn't be any worse than the smoke from the tobacco so different grades most likely wouldn't be an issue. I'll pick up some stuff tonight and see what we can get going.

 

[mgb_phys]

If it ever gets to a product consider a tilt switch that turns off the heater when it is knocked over, there have been a few fatalities in Canada with students knocking over hookah pipes. An electrical one would be a lot safer.