The fresh air and heating system which is integrated into the side channels of the fuselage have been reported by many owners to be lacking due to the heat loss due to external air temperatures at altitude.
I decided that I would used the side vents in the instrument panel and the rear vents in the aft passenger section only for fresh air.
Heating would be sourced through dedicated vents under the instrument panel and through vents under the front seats directed towards the rear passengers feet.
To complete this work I went though a number designs to determine an optimal way of connected the forward and aft vents with minimal amount of tubing and complexity.
Here are the vent parts that step down the naca scoop from 53mm down to 2" to accommodate the 2" scat tubing.
The NACA parts were a bit trick because when they come out of the mold the circles are not quite round so it was difficult to get an accurate measurement.
The aluminum part and the tee fittings that come from the factory need to be modified to accommodate these parts.
I drilled out the rivets that hold the tube in place and was left with the tabs shown below.
With the cross tube removed I cut the remaining tub back to about 1.75" from the base giving enough room to slide the 3D printed vent over the top of it.
I cut some scat tubing down to connect the NACA vent to the upper fitting and a small section to connect to the back on the instrument panel as shown below.
Here is another view looking down at the assembly.
The upper tube has enough flex to connect to the back of the instrument panel.
Once I was happy with fitment I had someone on Etsy print them out in ABS plastic which is far more stable and will not shrink, deform or breakdown over time due to age or UV exposure.
All parts will be glued in place during assembly of the canopy and fiberglass deck using Sikaflex.
