If you can't gather enough information from the mfrs. installation instructions to feel comfortable doing it yourself, call a licensed HVAC contractor.

Window exhaust can be an option in some cases, some locales prohibit this though. Do realize that you will need to inspect and clean the ductwork and if leaves were to collect in a window well it could pose a fire hazard.

Also, various birds/critters may find a way to enter through the hood so get a good quality unit with a damper door and do a visual inspection of it a few times a year.

When we first bought our house, the basement dryer was vented up through the wall to the outside. It was not getting the clothes dry so we had it vented straight out through the concrete block to the outside at the same level as the vent on the dryer. Our plumber said the higher you go with the venting, the less efficient it is. Our plumber did the work. It has made a world of difference. Now our clothes get dry the first time around instead of having to start the dry cycle a second or even third time! Good luck!