I use a hood I built with 1x2s and foil backed insulation and 6" duct to a 400 cfm 6" in-line fan then to a 6" to 4" reducer, which is then connected to semi-rigid vent pipe that shares a exhaust point with the dryer.
I have a 20 GAL boil kettle and two 10GAL rubbermaid coolers that I use for a HLT and MLT with a single pump. I batch sparge. I get moisture and some condensation in the hood during the boil, but it's easy enough to wipe out with a paper towel. Other than that, it's pretty awesome to make the yard smell like a brewery instead of the house.
It's not the cheapest way to make beer, but I can make beer in any weather or temperature. It's pretty fool-proof and clean-up is easy enough. I just forget sometimes to keep valves closed when disconnecting hoses.