Jmolan
Active member
I have wanted to do a write up for a while on the dreaded condensation we have all seen inside our vans. ( I am flat on my back recovering from pneumonia, so I have some time on my hands)
I will hit the basics of keeping dry, and have some stories to back it up. I apologize ahead to anyone who knows all this already. And don't hesitate to add or correct please.
OK basic concept. If you can keep this in your noggin, it will guide you as you beat the dripping.
Warm air: Think of warm air as a sponge, it can absorb a lot of water. You see warm moist air come in off the sea, climb the mountains where it is cooled, and it condenses into cloud or rain. Think of cold air as squeezing the sponge. Cold air releases moister.
In our vans, we warm them up inside by any number of methods. We also cook, have wet clothes, breath (You release a liter of water a night out your lungs) The warm inside air absorbs moister, but as soon as it comes in contact with cold metal window surrounds, pillars, uncovered windows, in condenses into water again. Think of a cold glass of lemonade or beer on a hot day, the out side is soaked. Same thing in the van.
We have all woke up in a tent with it raining on us from overhead, our vapor condensing on the colder tent surface. So how to beat this menace?
Most say "ventilate" and for many that is all that is needed. You have to give the warm water laden air a place to escape, so it does not settle on your colder surfaces.
What I learned, and found to be killer is, rather than use the air your are living in to heat up and try to vent vent (no positive pressure), set up a dynamic circulation system. If I bring cold dense dry outside air into my heater, and heat it up, I am adding a powerful force to soak up moister in the van. My heater is putting out dry warm air, that is like supercharged to absorb our vapors. Rather than warming wet air from inside the van. It is also a positive pressure inside the van. By simply cracking a vented window or just cracking the lid on my fantastic fan, the air flow scoops up the vapor and exits!
OK story time..... My boat in Bering Sea Alaska had a room about the size of a 40' container. It was bare painted steel, no insulation on the inside. It was used for gear storage, crew rain gear hooks, and a hang out spot for the crew to wait to hear what I had in mind next. Between waves slopping in to this room, the guys always came in to this room soaked and stripped off their gear and hung up there gloves etc. It had a big 220 volt industrial heater. Big fan, gong 24/7. But in the cold temps we had, the room was always wet.
It had a bare plywood floor that NEVER dyed out. The ceiling dripped like a rain forest. Everything was clammy, they called it the mushroom factory, warm as hell, but wet.
I finally had enough, I could never get them to leave the door open. I cut a 4" hole in the front of the room and plumbed a PVC pipe to the back of the big heater. I wrapped aluminum foil around the back to the heater to make sure only the air from the out side was going through the fan. I cut another 4" hole in the far end of the room near the cieling, made a gooseneck to keep out waves. My crew were very skeptical, like "oh boy there goes the Capt. again" I told them to keep the door shut. In 24 hours the plywood floor was bone dry! No more rain forest, gone. Now their gloves dryed out, and rain gear. They were pretty stoked.
So......Bring outside cold dry air into your heater, vent the warm moist air out, you will be styling.
These window vents are really valuable, and like $60. Not only to vent moister, but on a hot day I crack the window enough you cannot see it from the outside, I run the fantastic fan on suck, it moves a lot of air, keeping things cool. Hours of sitting and the van is livable when I return.
Also the window coverings my wife sewed up have been awesome in all seasons. Foil bubble
outside, ironing board material inside, suction cups to hold. Here is link if you want to try to sew your own. They are difficult to get right for my experienced seemstress wife, but so nice!
http://roadtreklife.blogspot.com/2013/03/diy-reflectix-window-insulation.html
[/ATTACH][/ATTACH]
I will hit the basics of keeping dry, and have some stories to back it up. I apologize ahead to anyone who knows all this already. And don't hesitate to add or correct please.
OK basic concept. If you can keep this in your noggin, it will guide you as you beat the dripping.
Warm air: Think of warm air as a sponge, it can absorb a lot of water. You see warm moist air come in off the sea, climb the mountains where it is cooled, and it condenses into cloud or rain. Think of cold air as squeezing the sponge. Cold air releases moister.
In our vans, we warm them up inside by any number of methods. We also cook, have wet clothes, breath (You release a liter of water a night out your lungs) The warm inside air absorbs moister, but as soon as it comes in contact with cold metal window surrounds, pillars, uncovered windows, in condenses into water again. Think of a cold glass of lemonade or beer on a hot day, the out side is soaked. Same thing in the van.
We have all woke up in a tent with it raining on us from overhead, our vapor condensing on the colder tent surface. So how to beat this menace?
Most say "ventilate" and for many that is all that is needed. You have to give the warm water laden air a place to escape, so it does not settle on your colder surfaces.
What I learned, and found to be killer is, rather than use the air your are living in to heat up and try to vent vent (no positive pressure), set up a dynamic circulation system. If I bring cold dense dry outside air into my heater, and heat it up, I am adding a powerful force to soak up moister in the van. My heater is putting out dry warm air, that is like supercharged to absorb our vapors. Rather than warming wet air from inside the van. It is also a positive pressure inside the van. By simply cracking a vented window or just cracking the lid on my fantastic fan, the air flow scoops up the vapor and exits!
OK story time..... My boat in Bering Sea Alaska had a room about the size of a 40' container. It was bare painted steel, no insulation on the inside. It was used for gear storage, crew rain gear hooks, and a hang out spot for the crew to wait to hear what I had in mind next. Between waves slopping in to this room, the guys always came in to this room soaked and stripped off their gear and hung up there gloves etc. It had a big 220 volt industrial heater. Big fan, gong 24/7. But in the cold temps we had, the room was always wet.
It had a bare plywood floor that NEVER dyed out. The ceiling dripped like a rain forest. Everything was clammy, they called it the mushroom factory, warm as hell, but wet.
I finally had enough, I could never get them to leave the door open. I cut a 4" hole in the front of the room and plumbed a PVC pipe to the back of the big heater. I wrapped aluminum foil around the back to the heater to make sure only the air from the out side was going through the fan. I cut another 4" hole in the far end of the room near the cieling, made a gooseneck to keep out waves. My crew were very skeptical, like "oh boy there goes the Capt. again" I told them to keep the door shut. In 24 hours the plywood floor was bone dry! No more rain forest, gone. Now their gloves dryed out, and rain gear. They were pretty stoked.
So......Bring outside cold dry air into your heater, vent the warm moist air out, you will be styling.
These window vents are really valuable, and like $60. Not only to vent moister, but on a hot day I crack the window enough you cannot see it from the outside, I run the fantastic fan on suck, it moves a lot of air, keeping things cool. Hours of sitting and the van is livable when I return.
Also the window coverings my wife sewed up have been awesome in all seasons. Foil bubble
outside, ironing board material inside, suction cups to hold. Here is link if you want to try to sew your own. They are difficult to get right for my experienced seemstress wife, but so nice!
http://roadtreklife.blogspot.com/2013/03/diy-reflectix-window-insulation.html
[/ATTACH][/ATTACH]
Attachments
Last edited:
vic
