Drying PET-CF / PAHT-CF

Yup, I’ve since realized that’s exactly what they mean. Heating air will drop its relative humidity, but it has no effect on the dew point. For reference sake, air which has a dew point of -40c would have a relative humidity of 0.80% at 20C room temperature. So, almost certainly the make-up air that you’re feeding into your filament dryer is already too moist compared to spec. Even a refrigeration type dehumidifier won’t get the air dry enough. What you need is a desiccant enhanced compressor based air dryer to generate the air that gets blasted onto the filament at its specified temperature. Maybe with a mountain of desiccant you could do it with desiccant alone, but the dwell times for desiccants are long, so most likely that’s going to require an impractical amount of desiccant. You need the full package, like is being discussed on this other thread by @IslandBill and others: How are people keeping their filament dry? - #172 by NeverDie