How do you ventilate and heat the van? Aren't the two at odds with one another?

[RV8R]

I thought that heating solves this. I know that whatever the wetness outside the van heater will always get rid of condensation so I guess the same must apply for whatever other heating as long as it is heating the space enough.

What have you guys done to cover your 'thermal bridges' where big blocks of insulation are no good like van frames and particularly the door frames. I guess I could be losing quite a lot through many exposed gaps here and there where I hadn't bothered completing the insulation. I know not the best but the priority moved to electronics and getting heating installed which was a big task.

I got a new pack of cork tiles now to cover the remaining exposed metal.

Hi @Gueyog8a7

I think I can help You. When in 2018 I first started researching what DIYers were doing to insulate their vans I was very surprised at how much bad information was out there.

I started this thread;

The Van Build Envelope - Design

www.promasterforum.com

I am a “Building Envelope Expert” on the “Wet Coast” in Canada. This is for buildings, not vans, but a lot of the Building Envelope Science transfers to vans

If You really want to understand HVAC & the process to dry out your van, read that long thread ( even join that Forum ), & learn.

In short You have to;

Stop any outside water leaks
dry out your van
insulate including what you can do to isolate air movement to the cold metal surface
Learn about “RH” & how to reduce it

It takes more energy to heat moist air than dry air. So in general, you heat up you moist air & then exhaust it outside, bring in fresh cold air, heat that air up & blow it outside, bring in cold outside air, repeat, repeat, repeat.



In order to help you, it would be good if you could post some photos. I would like to see your exhaust fans, your build, your heater, and other items that might create moisture like cooking facilities, shower, etc

 

[RV8R]

I have Private Pilot certificate. I understand dewpoint, rh etc.

The metal surfaces inside the van never change in temperature or maybe only slightly.

In cars without air conditioning, the defrost works by heating the surface where condensation might take place. Just letting in fresh air from the outside isn't enough.

On cars with a/c, you get better defrost performance because you both heat the surfaces where you don't want condensation as well as drying out the air.

This is how defroster grids that Heat the glass work.

Where Ya From @Checkthisout ?

You go to a party & walk into the room. How do you know who the Pilot is? Answer “You wait five minutes & he will walk up to you and say “Hi I’m a Pilot” ?

 

[Checkthisout]

Where Ya From @Checkthisout ?

You go to a party & walk into the room. How do you know who the Pilot is? Answer “You wait five minutes & he will walk up to you and say “Hi I’m a Pilot” ?

Gotta display my "street cred" on the topic of humidity.?

 

[RV8R]

Gotta display my "street cred" on the topic of humidity.?

I get it ?

Hard to contain the Love of Aviation, & Pilots of course know things & stuff like 29.92 & Adiabatic Lapse Rate & that IAS is a liar.

Ya wanna go “UP” pull back ,,, Ya wanna go ”DOWN” pull back HARDER ?.

 

[Gueyog8a7]

How much per day? It depends how cold it is. Sometimes I run it 24 hours per day.

I was talking to my mum yesterday and said I had used 10 litres in about 1 and a half weeks but closer to 2 probably. I this is only running and hour or two a day and the cost of that 10 litres was about 16 pounds at 1.62 pound per litre.

That we surmised would cost a fortune to run to keep the van dry running 24 hours a day! At that rate it would go through probably 10 litres a day!!!

I mainly, among some other reasons, started van life as a way to save money and this would have me hemorrhaging money.

Thinking about it doing the skin on the surfaces to avoid condensation buildup seems like the more cost effective option. Even though it may be an initial outlay of I estimate maybe 100 pounds (man I am missing my pound sign on this us keyboard) it would then not cost anything more.

I am fine heat wise even not running it at all except into minus figures so it is only for the van really and the heat way seems an extremely expensive way to solve the problem.

 

[Gueyog8a7]

Cork tiles are not closed cell, they will allow water vapour through and it will condense on the metal. The insulating effect is minimal.

Not my experience through testing both.

Plenty of arguments in vanlife about the "correct" way to do things particularly in the vapour barrier vs no vapour barrier debate.

We can agree to disagree.

I still take a lot from your many other posts .

 

[Gueyog8a7]

The OP is clearly cash-strapped. Suggesting he do a full RV build out while he's struggling probably isn't helpful.

I am not strapped for cash however I am saving up to buy land and so for all intents and purposes it is the same as I don't want to spend lavishly on the van as it is just a middle ground though will buy the odd more expensive item (like the diesel hob/heater) if it seems to make financial sense to do so. Also just ripping out 4 months of work I think is excessive.

I don't know why they suggest throw it all away and start again. There is no evidence it is rotted and cork is a fine insulator if people bother to look at the numbers. So no reason to just throw it away because it isn't what they are used to. The only problem is to stop moisture building behind it.

Sure there is some improvement to do but there is no need to throw the baby (existing insulation) out with the bathwater.

 

[Checkthisout]

I am not strapped for cash however I am saving up to buy land and so for all intents and purposes it is the same as I don't want to spend lavishly on the van as it is just a middle ground though will buy the odd more expensive item (like the diesel hob/heater) if it seems to make financial sense to do so. Also just ripping out 4 months of work I think is excessive.

Sure there is some improvement to do but there is no need to throw the baby (existing insulation) out with the bathwater.

Well, what about selling the van and getting a cheap Caravan? Can then transfer and use on new property for temp shelter?

I'm not giving solutions but you're in a different country so I'd like to know the pros and cons of an RV vs the van you're currently in.

 

[Checkthisout]

Also, it sounds like you're in a driveway. Do you have power availble to plug into?

 

[Gueyog8a7]

Well, what about selling the van and getting a cheap Caravan? Can then transfer and use on new property for temp shelter?

I'm not giving solutions but you're in a different country so I'd like to know the pros and cons of an RV vs the van you're currently in.

Why would I just give up the last 6 months of work for one small particular part I am having an issue with?

Vanlife is a thing. Hundreds of thousands of people are building their own. They have solved the issues I have brought up so why just give up at the first little hiccup? Vanlife is a learning experience in building a tiny home. It isn't about just doing the easiest option like buying a ready built motorhome.

Why do some people choose to build their own bricks and mortar houses vs just buying prebuilt? Because they can do everything how they want it. Is the former harder? Of course but not a reason to not do it.

Why do diysolar (what this forum is all about) when you can just pay for it off the grid?

 

[Gueyog8a7]

Also, it sounds like you're in a driveway. Do you have power availble to plug into?

Yes but the whole point is self sufficiency and living off grid. Not leeching electric on a driveway indefinitely. I am staying here temporarily while building the van.

Seems advice is veering far off the OP and going into general lifestyle advice . "Why not solve your issues by renting a central heated home".

 

[Gueyog8a7]

Hi @Gueyog8a7

I think I can help You. When in 2018 I first started researching what DIYers were doing to insulate their vans I was very surprised at how much bad information was out there.

I started this thread;

The Van Build Envelope - Design

www.promasterforum.com

View attachment 187185

I am a “Building Envelope Expert” on the “Wet Coast” in Canada. This is for buildings, not vans, but a lot of the Building Envelope Science transfers to vans

If You really want to understand HVAC & the process to dry out your van, read that long thread ( even join that Forum ), & learn.

In short You have to;

Stop any outside water leaks
dry out your van
insulate including what you can do to isolate air movement to the cold metal surface
Learn about “RH” & how to reduce it

It takes more energy to heat moist air than dry air. So in general, you heat up you moist air & then exhaust it outside, bring in fresh cold air, heat that air up & blow it outside, bring in cold outside air, repeat, repeat, repeat.



In order to help you, it would be good if you could post some photos. I would like to see your exhaust fans, your build, your heater, and other items that might create moisture like cooking facilities, shower, etc

The problem with UK weather though is it is mostly always going to be moist outside and inside isn't it. Uk I have been told is similar to pacific north west united states since I see your image is only US.

 

[Dave in AZ]

Yes but the whole point is self sufficiency and living off grid. Not leeching electric on a driveway indefinitely. I am staying here temporarily while building the van.

Seems advice is veering far off the OP and going into general lifestyle advice . "Why not solve your issues by renting a central heated home".

I think the driveway with electric question was a a good lean for you-- your issue is getting this thing dried out for now, without breaking the bank. You went through the heater cost being too much. However, electricity is like 1 pence vs 3 poi ds of diesel or something. So YES, just look at it as a temporary thing to let you dry the van out hey?

So, Get a cheap dehumidifier and plug it in. If you want to be "self sufficient" even while building out the van, then go pay the electrics owner 10 pounds for the month! Is your goal to solve the wetness problem as economically as possible, or make some kind of social justice martyr statement? Plug in an extension cord, power up a dehumidifier and maybe even a heater for a short bit while drying after, suck up the temporary loss of self sufficiency, and get 'er done.

After getting van dry and sealing any leaks, you can put up various moisture barriers to reduce moist air access to cold metal, thousands of threads on vanlife sites for that.
What do you think of the temporary use of cheap electricity to dry out?

Your struggle is interesting, I think it might apply to a lot of folks, including me with a pickup truck uninsulated metal camper shell.

 

[Gueyog8a7]

I am just reading this. Seems he goes into exhaustive detail. Had already watched some of his videos for electrical stuff on peoples recommendation. Condensation is indeed a hugely covered topic in vanlife so I guess nothing discussed here is new and just a case of researching the existing literature properly. Still doesn't stop the arguments on who/which theory is right .

THis is a good statement from the article taken from Boeing:

Because moist air will inevitably come in contact with cold structure, condensation cannot be eliminated. As a result, Boeing chose to evaluate potential moisture-control systems that can help […] minimize condensation, minimize dripping onto equipment and into the passenger cabin, maximize liquid drainage, optimize evaporative drying from wet surfaces and insulation blankets.

So even the best of them deal with it!

Oh that is good. Reading through the article they have come to pretty much the same conclusion as me. No vapour barrier and breathable insulation for most with some radiant on the bendy bits. Faroutride approved!

 

[Gueyog8a7]

I think the driveway with electric question was a a good lean for you-- your issue is getting this thing dried out for now, without breaking the bank. You went through the heater cost being too much. However, electricity is like 1 pence vs 3 poi ds of diesel or something. So YES, just look at it as a temporary thing to let you dry the van out hey?

So, Get a cheap dehumidifier and plug it in. If you want to be "self sufficient" even while building out the van, then go pay the electrics owner 10 pounds for the month! Is your goal to solve the wetness problem as economically as possible, or make some kind of social justice martyr statement? Plug in an extension cord, power up a dehumidifier and maybe even a heater for a short bit while drying after, suck up the temporary loss of self sufficiency, and get 'er done.

After getting van dry and sealing any leaks, you can put up various moisture barriers to reduce moist air access to cold metal, thousands of threads on vanlife sites for that.
What do you think of the temporary use of cheap electricity to dry out?

Your struggle is interesting, I think it might apply to a lot of folks, including me with a pickup truck uninsulated metal camper shell.

Sure I am planning to use the electric today to dry out the roof surfaces so I can apply more cork. No problem as a means to an end but I mean that the end goal is to get it under control to a point I wouldn't have to resort to using shore power.

I have been thinking that the roof is really the only problem area as the walls, while they do produce some condensation, will quickly dry out with a little heat. The majority is pooling at on the roof and not budging and forming the mold. So I can focus my attention on the roof as the walls can pretty much dry themselves out. The problem with the roof is it doesn't dry out due to the amount that accumulates and stays.

I applied some mould remover spray yesterday to the headliner where it had been growing. This is bad too because that is where I made an extended shelf for my clothes and so they are just sitting in a mold pit. Chucked them in a black bag for now and with the mold stuff having been doing its thing overnight plan to shove the 'leccy heater in there to dry her out then add a bunch of more insulation. There was one layer but was not enough. I know from smaller parts like ribs that two layers stopped the moisture from below. Trouble in those cases is. since they are ribs. it was forming from above and dripping down to soak the insulation!

It is just a case of experimentation.

 

[Dave in AZ]

I am just reading this. Seems he goes into exhaustive detail. Had already watched some of his videos for electrical stuff on peoples recommendation. Condensation is indeed a hugely covered topic in vanlife so I guess nothing discussed here is new and just a case of researching the existing literature properly. Still doesn't stop the arguments on who/which theory is right .

Great link there, I am enjoying it. The Boing article good too!

 

[Gueyog8a7]

I just realized that I was mostly using condensation on the windows as a gauge to the effect of my insulation which I see now was a poor choice as even the masters deal with that. Well the mould on the roof as well haha which certainly does want sorting.

 

[65NW]

Some mentioned an hrv. Most of these are large units but Lunos has a small hrv that uses bidirectional fans in a single tube with a ceramic core heat exchanger. It is not likely to be rv rated but if you installed it in a box with an external vent it would probably work fine. It needs a slight angle to drain to the exterior side when condensation builds up.

They had two models. One sold as a pair. When one pushes the other pulls, then they switch directions at the same time to keep equal air pressure in the room.
The other one has a split manifold with two fans in one unit. Does not move as much air but takes up less space.

 

[Checkthisout]

Yes but the whole point is self sufficiency and living off grid. Not leeching electric on a driveway indefinitely. I am staying here temporarily while building the van.

Seems advice is veering far off the OP and going into general lifestyle advice . "Why not solve your issues by renting a central heated home".

You gotta be kidding me.

If the first snag you hit and are unable to solve while pretend "roughing it" in your mom's driveway is the condensation on the steel inside your unfinished van then I'm sorry, self-subsistence isn't your thing.

Quit now before you succumb to the elements.

 

[Checkthisout]

Why would I just give up the last 6 months of work for one small particular part I am having an issue with?

If after 6 months, all you have is an uninsulated damp van interior then just quit. In less than 3 days, a meth head could have a dry space made up out of crap he found discarded behind businesses.

Vanlife is a thing. Hundreds of thousands of people are building their own. They have solved the issues I have brought up so why just give up at the first little hiccup? Vanlife is a learning experience in building a tiny home. It isn't about just doing the easiest option like buying a ready built motorhome.

You haven't solved the problem (you need to insulate the thing) because thats too hard. You're trying to get away with doing the easiest thing that takes the least amount of work and effort.

Why do some people choose to build their own bricks and mortar houses vs just buying prebuilt? Because they can do everything how they want it. Is the former harder? Of course but not a reason to not do it.

To save money but they don't do it by omitting things like insulation and hoping a space heater will keep the place warm and dry.

Why do diysolar (what this forum is all about) when you can just pay for it off the grid?

You would be money ahead selling your van and buying a used RV and living in that. Then again it might get a flat tire and you'll make a thread about the 6 month long journey you went on trying to get it fixed while doing everything except patching it and then airing it back up.