The concept of drying the air with coldness instead of a desiccant is great. It's supposed to be the plug-in-and-forget-solution.
Unfortunately the Black Max is a immature product and totally unreliable. It lacks on self monitoring systems.
1. Two times the evaporator felt has simply fallen off. I assume, ice built up and the expanding ice pushed it hard enough.
2. The thermal elements (Peltier) failed frequently. Probably because moisture penetrates. I sealed one additionally, which works since.
3. After just three and a half years the membranes of the cheap aquarian air pump were perforated. Everything looked and sounded normal, but no more air was pumped into the engine.
4. The case got rusty and the paint is peeling off.
According to the manufacturer, the unit monitors that its working by measuring the cooler block temperature against the outside air temperature. That means, if it's very cold outside the unit will assume to be ok, even if it's not.
I found out about those issues only because I led the air through a small box with a hygrometer. Otherwise I'd still think, the device would "save" my angine. And I assume a lot of people still think that.
The manufacturer Ben Omlor was always very helpful and did send me spare parts. But I spent a lot of time to fix it ans also shipping costs. It was always a 50/50 chance if the Black Max was still working, when returning to the hangar. Not a big problem in the summer time, as corrosion, as the engine is protected by the oil for at least a month. But very annoying in winter, when I did not fly for several month.
My neighbour in the hangar built a dryer with cold air by himself, controlled by a Arduino. Works for a fraction of the costs.
