Condensation

[m725amb]

This is the back of my m725. I am wanting to stop the condensation from happening. On the steel uprights on plan on injecting spray foam. I'm taking the insulation out and spray foaming the walls. Once all that is done putting tar paper on steel uprights before I screw plywood to it. Is this enough or should I do more

 

[southpier13]

rather than stopping, consider controlling. maybe a passive vent system via floor to roof or high wall conduits or chases which would evacuate moisture before it can settle in cold spots.

 

[alanymarce]

rather than stopping, consider controlling. maybe a passive vent system via floor to roof or high wall conduits or chases which would evacuate moisture before it can settle in cold spots.

Yes - you cannot prevent condensation; it happens because air containing water as vapour cools below dew point. Eliminating the water vapour is essentially impossible (unless you take the vehicle to the Atacama Desert and stay there), and avoiding temperature change is also more or less impossible (unless you keep the vehicle inside an airconditioned building at constant temperature and keep it there). So you need to find a way to circulate the air, which allows condensed water droplets (on surfaces below dew point) to evaporate into the air which is circulating. The air circulating needs to be at a temperature high enough to allow this.

 

[MTVR]

Ductless mini-split heat pump.

Pulls the moisture out of the air before it can condense, and dumps it outside via a drain tube.

 

[Alloy]

Research Type 1 - 2 - 3 vapor barriers

Also 1/2lb and 2lb spray (Urethane) foams.