Max fan open or closed for the winter

[Nelsonjald]

Good day everyone. I live on Vancouver Island. We get a little snow over the winter but a ton of rain. I have been covering my trailer for the past two winters which has kept the green mold and the black streaks to a minimum. I have a question in regards to ventilation.
I have two small heaters which run inside the trailer, under the cover. Last winter I closed all vents that would allow outside air into the trailer but I was thinking that maybe one should leave the Max Fan open slightly to allow this warmed air from the heaters to slowly vent out thus reducing the moisture level inside.
What do you think? Best to leave it completely sealed or leave a vent open. What are your experiences with this issue?
Thanks in advance for your opinions. Cheers.

[davescape]

Originally Posted by Nelsonjald

What do you think? Best to leave it completely sealed or leave a vent open. What are your experiences with this issue?

Opening the vent will let in as much moist area as it releases. Think of the trailer as a sealed plastic bag. If you dry out the inside of the bag on a nice sunny day and then seal it up there is little moisture inside. Take the bag into the shower (=wet coast weather) with you. If you open the bag, you will be letting in all the steam from the shower. Fresh winter air is very fresh, but its also very wet. If you leave the bag sealed, it will have the same amount of moisture inside before and after the shower.

Once you seal up your trailer, there will still be some moisture trapped inside. The heater will prevent the residual moisture from condensing. It doesn't have to be very warm for this to happen. If you open the vent, then the heater will have to run more often and you really haven't improved the moisture level inside. Its more like keeping a pot boiling on the stove and continually adding water.

You could also replace the heater with a dehumidifier. This could be electric or else some absorbent crystals like Dry-Z.

My process is:
1. winterize
2. open all the windows/vents on a clear day. I also open all the cabinet doors and fridge and leave them open all winter. I ensure there is ventilation space around the mattress and pile all the cushions on the table.
3. seal it all up after venting
3. put in a Dry-Z container (I put the Dry-Z device into an ice-cream bucket because its corrosive and I don't want any spills)
4. check container every month or so. I usually only get a few cups of water.

The results are: no mold, no smell, no pain.

I try to avoid going into the sealed trailer on wet days.

[cpaharley2008]

I close it up and use a Davis dehumidifier which is like leaving a 100 watt light on, there is some residual heat and no humidity. I place it on top of something metal as the bottom gets warm...they have a smaller 40 watt model which I place on the bamboo mat in the bathroom..

[gbaglo]

That isn't a dehumidifier. It's just a low wattage heater.

If it was a dehumidifier, there would be a container for the collected water.

[Ron in BC]

I don't agree with closing and sealing up anything in a wet and humid climate. For the last 40 years I've been using a light bulb in a tomato juice can to keep the interior of boats and trailers mold free.

For boats with multiple staterooms I put one in each area as the heat from one heater wouldn't be very effective. For the trailer I use the tall one placed under the cracked open vent.

You can debate the sealed up theory till the cows come home but all I know is that I leave bedding and cushions etc. in place and my interior is mold free.

Ron

[Donna D.]

You're very fortunate Ron for several reasons. Obviously you have electricity available to power a heater or your light bulb. I do not. Too, where I live the wind howls November to March. Any window or vent left open, even a bit, just drives moisture inside the trailer, home, shed, etc. It's even worse, if we should get snow or freezing rain.


Since 2002, when I bought my Scamp, I've used a passive dehumidifer, Dri-Z-Air classic in two tubs, everything buttoned up tightly and the cushions stored on the edges inside the trailer. I dump and refresh the crystals about every month to six weeks. Fortunately, I too have never had a hint of mold or mildew inside the trailer(s).

[Greg A]

Or you can just relocate to Arizona...

[Ron in BC]

Originally Posted by Greg A

Or you can just relocate to Arizona...

Gasp, you mean live in that heat factory full time. Are your flowers still out and your grass green? Oh wait, grass is that green stuff that we have in our yards rather than stones and cactus.

Donna, the O.P. did indicate that he had power. In that case I still go with open the vent a crack and keep a little heat on.

Without power, I agree, the Dri-Z-air is the way to go.

Ron

[AKCamper]

I agree with Donna, especially since we store our trailer without power. Big bucket of dri-z-air crystals inside a big bucket trailer closed up tight.

[davescape]

Originally Posted by Ron in BC

I don't agree with closing and sealing up anything in a wet and humid climate. For the last 40 years I've been using a light bulb in a tomato juice can to keep the interior of boats and trailers mold free.

For boats with multiple staterooms I put one in each area as the heat from one heater wouldn't be very effective. For the trailer I use the tall one placed under the cracked open vent.

You can debate the sealed up theory till the cows come home but all I know is that I leave bedding and cushions etc. in place and my interior is mold free.

Ron

Ron, the whole point of sealing it up is to change the climate inside the trailer. Once its sealed, no one cares what the outside is like. ...and I bet you seal up a lot of things like ýour tank of marine fuel or your box of flares. There's a science to it, just like that tomato juice can from 1978

[gbaglo]

On a cool, sunny day ( extremely rare in North Vancouver ), I will turn on an electric heater and open my Maxxfan to expel any moisture. Warm air holds more water than cool air and warm air rises, taking moisture with it as it exits through the fan. That's my theory, and I'm sticking to it, and using two Dri-Z-Air containers.

[Ron in BC]

Originally Posted by davescape

Ron, the whole point of sealing it up is to change the climate inside the trailer. Once its sealed, no one cares what the outside is like. ...and I bet you seal up a lot of things like ýour tank of marine fuel or your box of flares. There's a science to it, just like that tomato juice can from 1978

I think that the idea that closing the door and windows is equivalent to hermetically sealing the trailer and therefore locking in the "dry" air is a fallacy. The trailer is very porous to the infiltration of moisture laden air which increases the interior humidity. That's why products such as Dri-Z-air end up collecting moisture.

As Glenn says, warm air rises carrying with it moisture. My tomato can heater warms air and creates a small convection current up to the vent. Works for me.

Marine fuel tanks are never sealed, always vented.

Ron

[Fox hunt]

i close up my trailer and open cupboards fridge and bathroom door i then run an electric humidifier no condensation nice and dry all winter. i empty the dehumidifier weekly. Works for me I'm lucky to have electricity. I never got great results using heat to dry up the air and opening a window just brings in more moisture. I've tried the other methods this works the best for me. I also sometimes open it up on nice warm days for a few hours.

[ian&denis]

We’ve stored our trailer over 3 winters in mission BC. No power available. For winter storage we open the max fan vent, along with opening all cupboards, tilt the cushions o their sides. Stopped using dehumidifier several years ago. No mould issues at all. And it’s pretty soggy there.
Best practice? What ever you are comfortable with, however for us we have not had a lick of humidity problems for those past three years.

[Eggscape]

Your on the island so you don’t get much snow. Here in the interior of BC the snow can add up. I am going to keep the maxi close as I don’t want the snow load on the tarp to crush the opening mechanism of the fan. I will start with the bathroom fan open and see is the snow load closes that.