I've made a modification to my curing cabinet to keep the air moving in a more sustainable and reliable way. The fan that I was using previously was a cheap USB fan, shown orange in the picture. These fans are designed for occasional use and the motors burn out very quickly. I got through three of them in a couple of weeks even though I was only using them in 30 minute bursts.
Now I have switched to using PC cooling fans, shown black in the picture. They are also very cheap and come with USB connectors. I have bought two sizes at 40mm and 60mm. These fans are designed for continuous use so I am hoping to get longer than a few days use out of them. I've started with using the 40mm fan. I notice that it is quieter and that it makes a much smaller air movement than the previous fan. I think will be a good thing as I want a gentle circulation around my curing sausages rather than keeping them in a wind tunnel.