I've been working on Biltong dryers for the past couple of years. I love Biltong, just hate paying for it, $10 for 100grams, and most is pretty average for what you pay.
First effort involved a glass door bar fridge, a couple of computer fans, a light and a controller unit.
Wired the light to come on until the box got up to temp, for biltong you need air to be pushed past the meat to cure it over time, and a consistent temp between 22-24 degrees is the go, once it reached the 24 degrees it shut the light off. Fans run all the time.
This unit was great, although I couldn’t get enough in it to do a batch big enough to cater for my mates and me