I just want to point out one pitfall with lines to the outside that people don't seem to be aware of.
If you are pulling in air by force into your what will ultimately be your house, you create a positive pressure inside of your house. This will act as a back pressure to your inlet hose. If this positive pressure isn't relieved through some means like opening the door (which may not happen at night) then it will raise to equilibrium thereby nullifying the air inlet. The size of the air space in the house effects this also, so bigger airspaces take longer to pressurize. Another consequence is that a slower airflow can invite unwanted guests to take residence in your inlet. The may not be a consideration in some areas of the country but for me in TX, it is an issue.
Just wanted to throw that out there for people considering this idea.