1974 911 Heat Tubes

[Porsche EV]

What function do the heat tubes inside the rocker panels perform? I'm debating installing period correct replacements or a high-quality high-temp air duct like the photo below which another user installed. I think I like the alternate using the high-temp air duct unless I would be missing an important function.

I'm sure there are many comments in the forum somewhere on this topic, just can't find them all.

[E Sully]

I believe the main function is to act as a muffler. I have read a thread on the technical forum concerning this. One member posted that he went with a method similar to what you propose and regretted it. It was too noisy.

Posts 65 and 69.
How to deal with "inherited" 1969 911E Targa?

[962porsche]

because of the work to replace the heater tubes don't be cheap ! the factory tubes are costly compared to the hose you are showing. the hose your showing will not last and as the air travels through the hose it will make noise.

[E Sully]

Prices vary from $140's to 240's each.
https://www.heritagepartscentre.com/us/91157202502-heater-hot-air-duct-in-rocker-panel.html
https://www.pelicanparts.com/More_Info/91157202502.htm?pn=911-572-025-02-OEM
https://dr911porscheparts.com/shop/heater-tube-356b-356c-912-930-912e-60-89/
https://parts.byersporsche.com/p/Porsche__911/AIR-DUCT-MUFFLER-Heated-air-tube/54485883/91157202502.html