ventilation

[Capt. M]

Ventilation check? Anyone with an O'Day 39 on a mooring? Do you have ventilation issues when boat is not in use? If not, what have you done? I'm excluding all the folks with slips, since if I had one, I would be plugged into shore power using my AC, which is what the prior owner did.My boat is vented as follows:>Thru deck solar vent in V-berth set to intake.>V-berth and head hatches on the venting setting (since I'm on a mooring, bow is usually into the wind). >replaced the main saloon hatch, changed it's orientation so it opens forward for intake as opposed to the rear.>Both aft cabins ports are left open.>Both aft cabins hatches are also left partially open>Added vents to entry door panel (for exhaust)With this configuration, when the boat in snot in use, I still get mold growth.Based on Sail magazine and others, most boast are under vented, I would hate to cut holes for dorade boxes and cowl vents to remedy my problem.My only thoughts are to add 2 more solar intake vents mounted on the V-berth and Head hatches.Any suggestions would be appreciated.

 

[james]

ventalation

I don't have a 39ft boat, but I would think that ventalation is the same on all boats. I would set all solar vents to exhaust the humidity from inside the boat. You need to have sufficient number to do the job. I would close all ports and hatches that allowed excess moisture ladden air inside. I would allow only one or two passive vents for some fresh air intake, but not enough to add moisture. For the most part, it takes little time to exchange the air in a boat when the hatches and ports are open. Spring and fall are the toughest of times when the differences in outside temperatures and inside temperatures create the perfect moisture condensation factor. Increasing insulation can decrease the condensation but difficult to do in the needed areas like head liners and exterior walls. I would close all the ports and hatches so that the moisture inside the boat will eventually be exhausted out by the solar vents. Over a time, the amount of moisture in the air will be low enough that it should not cause a problem. Good luck.

 

[John]

I have a 40. I am in a slip but have no a/c and use no shore power for ventilation. I have no issues other than it's pretty warm in there. I have a solar vent discharging thru the v berth hatch. I have the same two dorades as the 39. I keep it all closed up other than the solar vent. It is under vented and possibly the addition of more solar vents in the port and starboard hatches may help.