Midnight Rain/condensation over bed

[Bus Busted]

   I have made a few runs down to TN from Indianapolis (very good trips for the most part). On one of the trips the temp dropped below the 40's and one night down to 28 Deg. We had a space heater running (portable oil filled fins) and the temp around 70 Deg. The day temp was in the 40's, but when the temp dropped overnight it started raining from everywhere. The next day we went to Lowe's and bought buckets to catch the drips, even using zip ties to hold them under the hatches. I am close to gutting the plastic and starting the wood panels for the conversion, but I need to find out about this before ruining good wood. There is not a lot of air movement with this style of heating, nor a flame to dry the air. What can I do to stop this? I would like to keep the hatches if I can.

The first picture shows the stock eagle trim dripping at the screw mount. The second Picture shows the dripping around the escape hatch. The third picture show how I have kept the heat inside the bus.

[Bill 340]

Our eagle did that when we were converting it, We opened the ceiling vent slightly at night and it stopped it,  But yes literaly Raining on your parade so to speak.

[gus]

You have a lot of humidity there or your bus is saturated with moisture, or both.

The easy way is to buy a $20 electric heater with fan and thermostat from WM, it will soon dry things out. The down side of these heaters is sometimes they dry the air too much but this is obviously not a problem in your case!

Since an oil filled heater has no fan or exposed heating elements it has no way to dry the air.

[Dave5Cs]

you just have to even out the inside and outside temps so condensation doesn't form. When you get insulation in there it won't do that anymore.

[Bob & Tracey]

Open a roof vent.

[scanzel]

Oil, propane and natural gas are a moist heat. Electric is a dry heat because the elements dry the air as heat passes over them. Big difference in a stove oven between electric and gas and the way baking comes out. The same in clothes dryers. Electric can bake you clothes if left in too long. Gas can too but would take longer. Either open an area for air or get a different heater.

[Scott & Heather]

Definitely do the electric space heater (or two) thing. As already said, they do a great job of dry heating. Propane will exacerbate the problem...so skip that. Once you insulate, this problem will go away. It did for us.

[Bus Busted]

Thanks for the good advice. I didn't know propane was a moist heat, so at that time I picked up a little propane heater thinking the flame would dry things out and it didn't. Now I know and will plan on insulating soon. Will pick up an electric space heater also. Thanks again, Jon

[Geoff]

I bought a portable house dehumidifer.  You would be surprised how fast the container fills with water.  Oh, and the dehumidifier also heats the air.

[buswarrior]

This post is playing fast and loose with the laws of physics when it comes to the moisture content in the air in a closed vehicle.

The moisture in the coach is the moisture in the coach.

The issue is how close the air in the coach is to saturation.

You can't reduce the moisture without a moisture removal system like a dehumidifier, or by exchanging the inside moist air with outside drier air. Most of our coaches are relatively leaky when it comes to air exchange, so we get a certain amount of "air exchange" whether we like it or not.

By changing the temperature inside the coach, you change the dew point for a given humidity inside, and can change when the condensation appears on windows and exposed structure.

Warm it up, less condensation, as warmer air can hold more moisture, and will shed less moisture as condensation.

Let it cool back off, conditions will return where the cooler air will shed moisture onto those cold surfaces again as condensation.

Then you can throw in the propane catalytic heater variable for some more moisture into the air...

happy coaching!
buswarrior

[robertglines1]

last winter I used a catlatic propane heater while insulating my coach. every metal rib would have moisture dripping. Now all are covered and the permanent hvac (mini-split) is installed and no more drips. Happy bussin   Bob

[qayqayt]

Be careful with the space heater.  Even with a thermostat, it might run a long time if it's cold enough outside.  At 1500 watts, they draw a lot of power and can be a fire hazard.  If you use an extension cord make sure it's heavy duty or it will overheat.  Consider a dehumidifier or for less than $100 you can get a space heater that will allow you to dial down the wattage to 600.  Set the thermostat at just above dew point so that you hardly feel the heat.

[gus]

The electric heaters I use have a Medium setting of 1000W which is all I ever use because the 1500W setting is really too hot.