Heater Fan Ducts

The inlet shroud and stand manages airflow turbulence and provides a free air path. The outlet shroud improves airflow for the heated air. The inlet and outlet together nearly double the airflow from the bare heater block. This is important to lower the temperature of the exit air and ensure the heater operates at maximum power.

PTC heater block: https://www.aliexpress.com/item/1005001891297046.html
Airflow design reference: https://www.fantech.com.au/Content.aspx?ContentID=L5#1

The inlet stand is made in two parts so that it can be printed without supports. The base and inlet printed parts nest together and should be glued - I used epoxy. I printed the inlet and base in PLA @ 0.2mm 15% infill 4 perimeters. 

The outlet MUST be printed in a high temperature material like ABS to handle the heated air when operating and soak heat when recently turned off. I printed the outlet in ABS @ 0.2mm 15% infill 4 perimeters.

No brims, rafts or supports were needed.