Air Leaks

[rodsmith]

I have a huge amount of air entering the cockpit in front of the front door posts on both sides. I can not figure out where it is coming from. I know that I need to add some weatherstripping to the doors. There is a small amount of air entering behind the front door posts that will be fixed with weatherstripping. On cold days the air leaks overwhelm my heater vents which put out a fair amount of hot air.

[AKKen07]

My biggest air leaks came from the aft lower corner of each front window (the ones that open above the door). It blasted my back seaters and froze them on cool days. I put weatherstripping all around the windows which helped quite a bit.
Also, still, despite massive improvements a-la weather stripping I still need to dress for cold weather on cold days. I think of it as insurance for unplanned “layovers.” The interior wind factor is pretty good now though.

[Steve W]

https://www.aircraftspruce.ca/catalog/cspages/epdm.php?srsltid=AfmBOoq3Jw07fqsDgC3VStO6MSm92wN7WqAIEJ0lAfgENmROlRRXa0OT

This stuff is available in P, D and E profiles. It is the best stuff I’ve used over the years. You can find it at most building suppliers too. If it is too thick for a lap joint, just move it back enough to seal the edge as the joint comes together.
Steve P203

[Battson]

This is normal, you will need weather strips to make the cabin air and water tight. Otherwise the heater will not cope, and it is worse in the back seats, especially in winter at altitude.

You will probably want a brush-style strip between the window and door. Thin rubber "b" or "D" shaped rubber strip works well at the top of the window. The front will need a bigger D-extrusion rubber strip. Same story for the rear doors. The rubber strips are best used at the top of the rear doors as they will keep it water-tight.

Air also leaks in around the bottom of the strut, and if you only have a single skin i.e. the boot cowl, then you are going to get more leaks around the landing gear leg attachments. Having a fabric interior does quite a nice job of sealing away those air leaks.

[rodsmith]

This is normal, you will need weather strips to make the cabin air and water tight. Otherwise the heater will not cope, and it is worse in the back seats, especially in winter at altitude.

You will probably want a brush-style strip between the window and door. Thin rubber "b" or "D" shaped rubber strip works well at the top of the window. The front will need a bigger D-extrusion rubber strip. Same story for the rear doors. The rubber strips are best used at the top of the rear doors as they will keep it water-tight.

Air also leaks in around the bottom of the strut, and if you only have a single skin i.e. the boot cowl, then you are going to get more leaks around the landing gear leg attachments. Having a fabric interior does quite a nice job of sealing away those air leaks.

I think you might be right about the gear leg attachments. My cutouts in the boot cowl for the front gear leg attachments are larger than necessary. They are covered by the gear leg fairings but they don't make a perfect seal. That probably is where I am getting the big air leaks, really the only place that makes sense. I don't have fabric cover ahead of the front door posts, just insulation blankets. Air from the gear leg opening is most likely blowing in behind them and exiting where they meet the door post. I have weather stripping ordered for the seaplane style doors which seem to have much less air intrusion.