Re: Dryer Vent under Deck
Is it preferred to have it under the deck, no, however as long as there is air flow under there, then there won't be any problems. My dryer vent is also under a deck that is about 2 feet off the ground. There is no rot or problems associated with this set up. I have also had to install a dryer vent under a deck a few times for lack of any other option, again, with air space they have been no problem.
If your deck sits directly on the ground, then I would not recommend venting under it as this will only increase the moisture and potential for rot. Also, a significant amount of lint will be exhausted with the wet air, which will coat any surface that it's blow or deflected onto. When this happens, then the wood will always be wet and more prone to rot - regardless of whether it is pressure treated or not.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!