One of the main problems living aboard in the winter in a cold climate is condensation. There are different ways of battling it – some insulate the walls, others use a dehumidifier. I have chosen to go a slightly different route.
Condensation occurs when at least two conditions are present. One, a temperature differential between a surface and ambient air. And two, the presence of moisture in the air. We combat the difference in temps by wrapping boats in plastic which helps keep the outer surfaces from getting so cold. However, this wrap also tends to increase the relative humidity of the air inside the wrap. This increase in air moisture creates greater condensation when condensating does take place. What I have done to combat this is add a power vent to the wrap cover which constantly brings in cold dry air from the outside. This dry outside air basically scrubs the moisture out of the air inside the wrap and boat. I added two covered vents in the wrap at the bow of the boat and installed a power bathroom vent at the upper stern of the boat wrap. This system draws the air in at the bow and blows it out the vent at the stern.
One draw back of this venting system is that it brings cold air into the wrap. Sometimes when the air is really cold, I put a heater up at the front vents to heat the air as it enters the boat so that it does not cool the surface of the boat so much.
While I do not have any numbers to back this up, I believe this has made a major difference preventing moisture and condensation buildup inside the boat. Maybe others have done this as well, and can comment on the their success or failures.