Hi Captain,
I do batches regularly, but as Santaman2000 suggested, I don't use any heat source whatsoever, just natural airflow. These days I have a plastic framework set up with a bug-proof net stretched over it, but the first time I tried it I just improvised the set-up and the results were just as good, (except for 1 aspect, which I'll come to later.)
My very first set up was 4 wine bottles - same height would be good, but if you haven't got 4 the same, just stack up the shorter ones to match the height of the tallest. (This is actually a V. good excuse to go and buy 4 bottles of your favourite plonk.) Next you need a grill of some sort to place on top: I used a cake rack thingy that I found in the kitchen. Once you know the size of the rack, you can see where to position the bottles - one at each corner. This is your basic 'structure,' but reinforce it by sticking it all in place with sellotape - you don't want the wind blowing the whole lot over.
Next, you need something to hang the strips of meat from. I used paperclips, each bent into S shaped hooks. These are the traditional type of hooks used to make biltong - at least that's what my Saffa mate told me! The more 'modern' method is to use the coloured plastic coated paperclips - less chance of the meat getting tainted by contact with metal. The final piece of 'specialist' equipment is a bug-net of some sort. I used an old mossie net cut to shape, but you could use a portion of plain net curtains - you might want to wash them first. With this set up I was able to process about 40 to 50 strips at a time, but of course it depends on the size of rack. Oh, and you'll also want a tray underneath to catch the drips.
That's the equipment. Next, a very brief description of the method: First, remember that there are 100's of variations of how to do this and each 'expert' will have their own preferences. Don't be intimidated - at the end of the day, all you're trying to do is hang some marinated meat up in an airflow. So here goes:
Cut the meat in strips about 3mm thick: Good quality meat, as lean as possible, cut across the grain (to reduce the toughness of the finished product), use a plastic chopping board - wooden ones are more prone to storing germs.
Stick it all in a bowl overnight in the fridge with your marinade of choice - I'll come back to this.
Next day, quickly dab each strip on a piece of kitchen towel, just to remove the bulk of the marinade. Pierce it with a paperclip and hang it underneath the rack. Repeat until rack is full or meat is used up.
Cover whole structure with net and make sure no bugs can get to it. Weigh the edges down if necessary - remember, a fly would like nothing more than to lay eggs on all that juicy meat. Don't hang any pieces too near the edges, you don't want the breeze blowing the net onto the meat.
Position the structure on a table next to the best airflow that your house will allow: Near a back door, or in a corner with 2 windows creating a cross-flow. It will be OK to close the door/windows at night, but leave them open for as long as possible during the day. This is why I usually process mine during the weekends when I know I'm not going anywhere.
Now leave it for about 2 and half to 3 and a half days. After about 2 days, test it to see if it's ready: Bend a piece and it should fracture but not snap, you'll see fibres breaking away from the main part. You can't really over-dry it, it just won't be as nice to eat, but if it doesn't fracture it isn't dry enough and will go off quickly. Once done, store it in the fridge in a paper bag, not plastic. This will still breath and will help avoid any build up of moisture. It should store like this for at least 6 weeks, but generally I eat it before this time.
Marinade: Salt is traditionally the main preservative for jerky, but acids e.g. vinegar or citrus juice in marinades can also help to kill bacteria. Soy sauce & apple cider vineger both work. Experiment. But one thing I would say to do - that I initially didn't do and I could have saved myself a lot of trial and error - keep a record of your contents and quantities that you use. That way it's much easier to modify and rectify a marinade that ends up too sickly or too salty, etc, etc. This was the one aspect that I refered to at the top of this post. I got the process sussed very quickly, but it took me several attempts to produce a truely good tasting batch, because I couldn't remember what ingredients I'd used & so I couldn't modify the taste with any accuracy.
The set up above is good for buying about 1kg of meat at a time. This won't all end up as nice strips of jerky, there will be a lot of inferior offcuts, but you can just stick them in a stew!
Have fun.