Condensation arghhhh

[Kpendy]

Ok guys I hate to do this but after searching for like 15 minutes I can't find anything that applies.

I have insulated the bananas out of my bus, r13 on top of original fiberglass on the walls all the way down under the windows, spray foam all the way down on the upper walls where windows were removed and on front and back, r25 on whole floor and even steps, and don't remember r value of rigid foam board on top of original fiberglass on ceiling.

So now that my bus stays nice and toasty I kick on my salamander heater for 3 minutes and I'm good for 30-45 minutes in 15 degree weather

When it gets warm in there now it condensates the windows all up and if I'm hearing in there for a whole day i will start to see it's bit on the ceiling ribs that the ceiling panels are screwed to.

Only thing I found about this was that houses do venting though the attic and we don't have an attic hahaha so how should I vent the ceiling?

I feel if I put a fan up there it will suck all of the heat out of the bus in the winter(because heat rises duh) but don't think that would be an issue for hot weather more of an advantage.

So I guess question is do I cut a couple holes spaced out on the roof to the interior and just put free flowing caps on them to stop water from getting in or should I put a fan in a hole in the ceiling? Either way not an issue I can do anything with it just wanna hear some advice from some ppl who have trial an error done this haha

Please and thank you thank you thank you

[Sundowner]

If it is on propane you will get lots of moisture

[Kpendy]

Well the salamander runs diesel but my permanent heating will be propane. I just need to know what the best option for venting is to keep it to a minimum.

[Sundowner]

I use a dehumidifier during the winter and that makes a big difference with the moisture problems

[family wagon]

Any kind of combustion yields water vapor; it doesn't matter whether the fuel is diesel, kerosene, propane, wood, etc.

Condensation happens when air comes into contact with a surface temperature below the dew point. Dew point and relative humidity are intimately connected.

Operation of an unvented heater inside the bus adds water vapor to the air, ie drives the relative humidity way up. That drives the dew point up. Condensation results. It'll even happen in the summer (think of a steamy shower) but it'll happen even faster in the winter.

It sounds like you may need a combination of humidity control (use a furnace-style heater or vent the combustion gases outside) and vapor barrier (keep vapor-laden air from passing through permeable insulation and condensing in or behind the insulation, wherever temperature and dew point cross).

[Versatile]

Leave a window open a bit.

[Kpendy]

I was thinking I'd have to do that, and honestly I like this option MUCHHHH more than cutting holes in anything lol plus I can skip wiring a fan up and just use an outlet for the dehumidifier.

Good thing is that thing is pretty darn airtight. I need to post some more pics

[DoubleO7]

I would never run a diesel fueled salamander heater in a confined space.
Carbon monoxide poisoning kills you.

[Kpendy]

Hahaha I leave the door open and a couple windows while it's runnin and close em a bit after I turn it off but diesels really not too bad it's like 1-10% emissions of gasoline depending on efficiency of the burn so a few minutes isn't guna kill ya but I hear ya for sure fumes in a closed space is not a good idea.

[Deezl Smoke]

Originally Posted by Kpendy

Ok guys I hate to do this but after searching for like 15 minutes I can't find anything that applies.

I have insulated the bananas out of my bus, r13 on top of original fiberglass on the walls all the way down under the windows, spray foam all the way down on the upper walls where windows were removed and on front and back, r25 on whole floor and even steps, and don't remember r value of rigid foam board on top of original fiberglass on ceiling.

So now that my bus stays nice and toasty I kick on my salamander heater for 3 minutes and I'm good for 30-45 minutes in 15 degree weather

When it gets warm in there now it condensates the windows all up and if I'm hearing in there for a whole day i will start to see it's bit on the ceiling ribs that the ceiling panels are screwed to.

Only thing I found about this was that houses do venting though the attic and we don't have an attic hahaha so how should I vent the ceiling?

I feel if I put a fan up there it will suck all of the heat out of the bus in the winter(because heat rises duh) but don't think that would be an issue for hot weather more of an advantage.

So I guess question is do I cut a couple holes spaced out on the roof to the interior and just put free flowing caps on them to stop water from getting in or should I put a fan in a hole in the ceiling? Either way not an issue I can do anything with it just wanna hear some advice from some ppl who have trial an error done this haha

Please and thank you thank you thank you

If it is cold outside, like below freezing, take a piece of heavy metal outside and let it get cold. Something like a lifting weight or equipment. Then take it into a warm room right away. What happens? Beads of water will collect on it and start running off until the metal warms back up enough.

This is what is happening to your bus. The windows are cold and the air inside is warm. There's a reason they call it "condensation". The warm air molecules "condense" or get smaller near the cold surfaces. As they condense and get smaller, they can not hold as much water in them. So the water is forced out.

[Kpendy]

Originally Posted by Deezl Smoke

If it is cold outside, like below freezing, take a piece of heavy metal outside and let it get cold. Something like a lifting weight or equipment. Then take it into a warm room right away. What happens? Beads of water will collect on it and start running off until the metal warms back up enough.

This is what is happening to your bus. The windows are cold and the air inside is warm. There's a reason they call it "condensation". The warm air molecules "condense" or get smaller near the cold surfaces. As they condense and get smaller, they can not hold as much water in them. So the water is forced out.

Ok lol I think we all understand WHY condensation happens now would be a good time to solve the HOW to get rid of it(which is what I asked) but thanks for the science lesson. lol I thought my question was pretty clear but just to clear up, I am looking for ANY SUGGESTIONS HOW TO COPE WITH/STOP THE CONDENSATION FROM HAPPENING. Any suggestions to this topic would be greatly appreciated.

[Iceni John]

You mention seeing condensation on the windows and ceiling ribs. Are the windows double-glazed? If not, the glass is just conducting the heat out and the cold in. It also seems like there are no thermal breaks in your roof - even if you insulated between the structural ribs, the ribs themselves are still a continuous conductor of heat or cold between the outer roof skin and the inner ceiling. Some folk use wood battens as a thermal break there. Heat moves only by conduction, convection or radiation - one or more of those three is happening in your bus, resulting in condensation. If there is snow on the bus roof, I would expect that it will melt first above the ribs.

John

[Deezl Smoke]

Originally Posted by Kpendy

Ok lol I think we all understand WHY condensation happens now would be a good time to solve the HOW to get rid of it(which is what I asked) but thanks for the science lesson. lol I thought my question was pretty clear but just to clear up, I am looking for ANY SUGGESTIONS HOW TO COPE WITH/STOP THE CONDENSATION FROM HAPPENING. Any suggestions to this topic would be greatly appreciated.

Interesting. So you know all about how condensation forms and dont need science lessons, yet you dont know how to stop it? You must have a phd.

I'd tell you, but that would require another science lesson, so I'll refrain.

[Rameses]

Originally Posted by Kpendy

ANY SUGGESTIONS HOW TO COPE WITH/STOP THE CONDENSATION FROM HAPPENING.

Easy.

Leave the heat turned off.

[Kpendy]

I still am not sure if you just don't understand my question or if you are legitimately slow, however if you have an answer to my original question that I have posted this thread for then I am more than happy to hear an answer, if not maybe comment in another thread that your response is appropriate for or where your "phd" is useful but I'd rather keep this thread to mature adults if that's ok with you.

[Carytowncat]

Do you have a carbon monoxide detector?
Please get one asap if you do not.
It is deadly, invisible, and odorless.
There are lots of stories of people opening lots of windows to let in fresh air, only to go to bed and die.

Once nice thing about wood stoves is the dry heat keeps the bus condensation free. In fact during cold nights i will often put a pot of water on the stove to moisten up the air.

Good luck!

[Tango]

Double pane windows will help.

[Kpendy]

I JUSTTTTT bought 2 indoor safe propane heaters like 3 days ago because I got them on sale for a price I couldn't pass up, really wanted to find a wood stove but I couldn't find one small enough new or used for a bus so I went with the heaters. And yea I need to get a monoxide detector probably my dog will be in there when it's finished and I don't want him gettin sick.

I'd love to get double pane windows but I really don't wanna replace the like 10 bus windows I left in. ��

[bansil]

Until you can control the moisture the heaters give off you can not stop the condensation, i also say get a couple carbon monoxide detectors, you do not have enough air exchange going on it sounds like.
I wouldn't worry about your dog getting sick?i would be more concerned with waking up dead.

[superdave]

the bad stuff your heater is putting out will build up from the floor up, it kills pets first then kids then you. dont run any unvented heater in your bus if you dont want water running down your ceiling and walls creating mold everywhere it goes.