>What size heating element should I use on a 15L
>boiler?? I hear using the fire is more danger than
>its worth. and How effective are hot plates are they
>dangerous or safe. I want to know what is best.
The heating element does two jobs
1) bring all the wash etc up to distilling temperature, then
2) create the vapour during distilling
Its for step (2) that you need to size the element to the column diameter.
In most cases this works out to around 750W to 1500W for diameters between 1
and 1.5 inch.
There is some help to do this at
These calculations are a little optimistic - make the diameters a little
larger than what it suggests (e.g. it predicts a 21mm diameter to suit 1380W
- too narrow - I've had to go up to a 36mm diameter). Check out the
size/heat combination with the other distillers here to see if they're doing
similar, or have had to go larger/smaller.
What size diameter is your column ?
The trouble with having these smaller sized elements is that then it takes
ages to heat up the pot during (1). Some people don't mind this wait (e.g.
it takes my 1380W element 1 hour to heat up 20L of wash - I just find
something else to do). Others will put in a second element just to help
boost it during the heatup, then turn it off once up to temperature. Others
use a really big element (say 3kW) and a variable power control (triac) to
turn it down once at temperature.
This is where you can get into some difficulty if using a stove hotplate to
do the heating. If set to "simmer" they will turn on & off to maintain the
lower temperature. This is fine for a pot of carrots, but not too good for
the still, as you'll get vapour surging up the column when its "on", then
nothing when its "off". You'll get low purity out of it. This is why the
"triacs" are used - they turn off & on, but very rapidly, so that the
flowrate of vapour, although less, doesn't follow it on/off in sympathy. If
you're going to use the stovetop, you may have to use it only on "high" heat
to avoid this switching.
If you're going to use gas as a heating, see David's comments about it at :