I want to place a vent fan in my powder room bathroom (1st floor of colonial).
One wall outputs to the garage and another wall to the front porch.
Is outputting the vent fan to the garage the best placement?

Hi Sommerday...

I would run the duct work the same way that the joist bays run...

If that means going into the garage so that you don't have to drill 5" holes in your joists then you do that and then from the garage you run the vent and penetrate to the nearest outside wall.

If goes out to porch easiest that is fine as well.

Most important is that the exhaust from a bathroom fan get to the outside air... otherwise excess moisture can build up and cause problems for you down the road (depends on time of year, number of showers taken, etc... ).

Try not to penetrate the outside wall above or below windows if possible. Worst case, you can vent over windows, but under is usually not acceptable!

Let me know what you think...

MARK

Showers are not an issue in the powder bathroom.
My brother has his vented to his garage and does not like it and a contractor wanted to vent it through to the porch but I did not like that front porch placement.
Your idea of venting through the garage and then the outside is the best one and the one that I am going to use.
Thanks.