Greetings fellow Hunter owners from this 6 year Hunter owner. This is my first post. There are several reasons for adding (powered) fresh air to your boat:1. It decreases mildew. 2. If you have a furnace or heater it will diminish or eliminate condensation. 3. it can cool your hot cabin faster in those wind-less summer anchorages. 4. It makes the boat smell better! In my previous boat, a 35.5, I installed a Webasto air heater in the engine compartment. I got the cool air from 2 places: under the nav table, and from the cockpit lazerette (it's not sealed, it has rubber bumpers at the corners). I used 4 in. pvc pipe to duct the air down from the lazerette, a quick 90 degree turn thru the aft berth into the head and down under the sink to a Y with the nav duct. I replaced the towel rack above the toilet with 4 in. pvc and then (Voila!) I had a 4 in. towel rack that sent cold air and/or cabin air directly to the intake of the heater. Choice of exterior or recirculated air was made by using a cap to close off the exterior duct. Note: Recirculated air heats faster, outside air pressurizes the cabin eliminating both drafts and condensation. The recirculating vent was restricted so that if both were open, there would be more cold than recirculated air. Conversely, if the exterior duct were capped there would be only recirculated air. By adding a 4inch in-line "turbo" fan (Taylor)at the lazerette opening and a battery (AA) powered timer switch (Intermatic)at the nav station, I could power-blow outside air into the whole boat ducting system when the heater was off. By setting the timer to run for 15 mins. at mid-day in winter,(in concert with my trusty 110 volt cabin heater) the air in the boat was kept fresh with mildew and condensation kept at bay. An added benifit of this system is that if I closed all other vents in the system except the one in the head and opened a hatch in there as well, I could use the blower as an exaust fan for head odors! Third, When the outside air was cooler than the inside, I could open all vents and change the air inside the boat in just a few minutes! I now have a 40.5. It has 2 rear vents that enter thru the transom. I plan to add a fan and timer to the port duct for all of the purposes listed above except head odors. And since the new boat has a furnace I plan to duct the port vent to the intake for the aft zone radiator so that I can use the outside air and pressure features mentioned above. I hope that some of you find all of this to be helpful. I'm sure that a similar system could be fitted to any of our boats. I have great pride in the fact that it actually works! It has been (and will be) a great addition to our boat! Write back if you like.