Alright- I respect your view but I'm still not sure if its right-
as I said above- the drum isn't airtight- I have a lot of doubt about how much air is actually pulled past the coil by the dryer blower at the other end of the exhaust vent- then there is also that HOLE at the top of the heating element duct-
below is a picture- not mine I got from another thread- but the configuration is exactly the same as mine- only my hole at the top of the heater duct on the right is not that large or round. I was sticking y finger in there when I'd first turn it on while rewiring to see if the coils were heating- I felt no particular strong airflow, nor excessive heat, and the hole itself would prevent a lot of vaccum effect past it- so I think the coil heat IS actually largely convection. I taped over the hole and will seal permanantly it just to not let insufficient heat escape there.
I was toying with an idea about turbo-charging the system by running some of the final vent back into the heating duct, and the nice round hole in this unit looks enticing to run a tube into,
plus it wouldn't pass the coil that way- but I nixed that with respect to it being MOIST air and needing some escape- the small 120 v heat blowing SO HARD out the back is still another matter.
Incidentally I ordered another heating coil, as this one proved not even labled to be the 5400 I thought- 3700 or something I think it said before I stuck it back in.
So, yes, I think your airflow concerns are more paramount in my concerns as well- but it just still seems an excessive vent with such little heat, and then there's the fact that the same blower and ducts are used in the 240 models. So in short I don't see the blower sucking air past the tumbling clothes. I see the tumbling clothes getting air by tumbling and through the heat duct opening and around the drum edges, but the air is only being vented out, not sucked through the heating duct.
I may take a pie plate cover the vent, worm clamp the wrap-
but cut the bottom third off- so lint can still escape
and try that- I MAY someday- just to experiment- better still as far as i'm concerned would be to reduce the fin volume- filing, grinding , breaking, but probably best drilled here and there, to reduce the blast out of the vent- if it didn't work, just put another in- Probabaly more viable than the duct cover, but harder and more exspense to reverse. May even take some strain off the old motor by not constantly pushing so much air.
You may be right about the lint and probably are- but an hour's worth of drying at very low heat didn't produce a healthy "peel" off the filters- I had to scrape the small amount-
so at this point I don't see it as much of a problem beyond routine maintenance, and if I reduce the airflow sometime in the future- I will at least get a good feel for what the norm is now- then I can more have a feel for what's what by trial and error and not speculation
