It seems to me that there are two separate issues regarding condensation: one is eliminating or reducing the moisture that results from storing the trailer in a damp place like British Columbia rather than a dry place like southern Arizona; and the other is dealing with the condensation that is the consequence of normal use during winter or the rainy season.
Dri-Z-Air and other dehumidifiers will address the first issue, but won't deal with the kind of condensation that occurs in winter or rain.
A few years ago, we travelled full-time in our trailer from December through September. We spent the first 4 months skiing and had to find a way to deal with the condensation that resulted from our full-time occupation of the trailer, particularly in winter.
Here's what we learned during the first week:
Cooking with propane generated an
enormous amount of moisture. (Note that
propane furnaces are vented outside and do not add moisture to the interior.)
Boiling water, for tea, pasta, or vegetables added moisture to the air.
Our breathing during the night added huge amounts of moisture to the air.
The moisture given off by
our bodies during the night left the mattress damp.
The
temperature difference between our warm trailer and the -20 degrees celsius outside made the windows run with water, particularly on the windows when the blinds were down and the curtains drawn.
What we did:
1. We kept both roof vents as well as the bathroom vent open all the time (our trailer came with MaxiVent covers) to ensure air flow. This had little impact on warmth but major impact on condensation.
2. We stopped cooking with
propane completely during the winter and switched to a two-burner hot plate plus
microwave.
3. We improved airflow by:
- keeping all cupboard doors open an inch or two.
- cutting rectangular holes and fitting grilles (the kind you see over heating vents) along the areas below the seats and mattress, to improve airflow in the storage areas. We also put a grille between the bathroom and the bed area.
4. We installed two layers of storm-window film from Home Depot (attached with double-sided tape and shrunk to fit with a hair-dryer). This gave us triple-glazed windows.
5. We kept the mattress elevated, using two cooking pots, while we were gone during the day. It was bone dry when we got back.
6. We kept two ceramic heaters going during the day while we were gone, to help dry out the air.
The only condensation we experienced after taking these measures was moisture build-up on the trailer door, over which we hung insulating, foil-backed bubblepack during the night.
Cheers,
Elisabeth