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

[Checkthisout]

A couple tweakers built this in a freeway median in less than a week. They were tired of getting wet in their tent.

 

[65NW]

A couple tweakers built this in a freeway median in less than a week. They were tired of getting wet in their tent.

View attachment 187226

Which HRV did they settle on to fix the condensation problem?
Don't want your window fogging up!

 

[Checkthisout]

Even the tweakers are smart enough to run an extension cord and steal power from the nearest lamp post or vacant business so they have power to run things.

 

[hugemoth]

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.

2.661 litres per 24 hrs is what mine uses on the lowest setting where it runs 99% of the time.

 

[RV8R]

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.

I’m trying to help you @Gueyog8a7

I have repaired millions of dollars worth of “Leaky Condos” in what you refer to as the PNW USA, but in Canada is just the “Pacific Coast”.

Did you read thru that thread I posted for you ?

Here is the Cole’s Notes;

The Van metal skin is a vapour barrier & it is on the wrong side of the “wall system”.

The Best System to deal with the Vapour Barrier issue is a properly installed “Spray Foam” product ,,, Why ?‍ ? ,,, Because it “effectively“ makes that van skin metal vapour barrier a continuous Vapour Barrier pushing the “Dew Point” to the inside face of the spray foam. Note The Best System - But Not Perfect

No air transfer to cold metal skin = no condensation on the inside face of the cood metal skin.

The above does not mean you won’t get condensation on the inside face if the spray foam ( which is a vapour barrier ) ,,, that is a function of your “RH” which you have to deal with regardless how you insulate. I already wrote you on how to deal with high interior “RH”.

Also, If you have leaks coming in from rain water, insulating your van is not the answer ,,, fixing the leaks is what you need.

Your Solution to This is;

1 Fix all exterior water leaks “Water Ingress”
2 Properly Insulate
3 Reduce Your Interior “RH”




Again, I am here to help You if You are willing to listen. If You are here to debate I can do that as well, but “free flowing air” that can condensate on the inside cold metal face of a van is a fools argument.

 

[RV8R]

Here is a website & Insulation Testing for Ya;

Insulation Testing – For Van Conversions – Build A Green RV

www.buildagreenrv.com

 

[65NW]

Did you read thru that thread I posted for you ?

Here is the Cole’s Notes;

The Van metal skin is a vapour barrier & it is on the wrong side of the “wall system”.

The Best System to deal with the Vapour Barrier issue is a properly installed “Spray Foam” product ,,, Why ?‍ ? ,,, Because it “effectively“ makes that van skin metal vapour barrier a continuous Vapour Barrier pushing the “Dew Point” to the inside face of the spray foam. Note The Best System - But Not Perfect

No air transfer to cold metal skin = no condensation on the inside face of the cood metal skin.

The above does not mean you won’t get condensation on the inside face if the spray foam ( which is a vapour barrier ) ,,, that is a function of your “RH” which you have to deal with regardless how you insulate. I already wrote you on how to deal with high interior “RH”.

Also, If you have leaks coming in from rain water, insulating your van is not the answer ,,, fixing the leaks is what you need.

Your Solution to This is;

1 Fix all exterior water leaks “Water Ingress”
2 Properly Insulate
3 Reduce Your Interior “RH”

This. Except 1. Even if there is no water from outside, exhaled breath overnight is enough to cause a fair amount of moisture to build up in a space that small.

My neighbor had his work van spray foamed with urethane, in a thin layer. Then it was coated in an egg shell bed liner that makes a hard and light reflective surface. Then clear coated. It looks pretty good (a bit lumpy) even if it wasn't cover but would be easy to put panels over. Quite warm and no condensation/frosting on the skin.

Edit. Photos

 

[Checkthisout]

On the cheap, just use the same stuff they insulate metal buildings with.

Fiberglass bonded to a vinyl vapor barrier. Could even attach it with the glue-on spike things.

 

[RV8R]

This. Except 1. Even if there is no water from outside, exhaled breath overnight is enough to cause a fair amount of moisture to build up in a space that small.

My neighbor had his work van spray foamed with urethane, in a thin layer. Then it was coated in an egg shell bed liner that makes a hard and light reflective surface. Then clear coated. It looks pretty good (a bit lumpy) even if it wasn't cover but would be easy to put panels over. Quite warm and no condensation/frosting on the skin.

Edit. Photos

Except 1 was covered in my post;



Your Neighbour & “space age” ”thin” urethane ?? ,,, Got a “Performance Spec” ??

I’m like “Joe Friday” ,,, Just the Facts !!

In this case, Just the Science

What’s the R Value ?

Come back with the manufactured performance specs & I will look at it.

”Lizard Skin” or “Snake Oil” ,,, No Thanks ,,, Just the Facts

 

[65NW]

Except 1 was covered in my post;

View attachment 187323

Your Neighbour & “space age” ”thin” urethane ?? ,,, Got a “Performance Spec” ??

I’m like “Joe Friday” ,,, Just the Facts !!

In this case, Just the Science

What’s the R Value ?

Come back with the manufactured performance specs & I will look at it.

”Lizard Skin” or “Snake Oil” ,,, No Thanks ,,, Just the Facts

Friday was yesterday, Joe. Youre not fooling me.

There will be moisture, if it doesn't come from outside it will come from what you exhale or from cooking. Not sure where we disagree.

Nothing space age about it. Polyisocyanurate foam has been around since the 70s though its less flammable now.

I have the same foam (filled to R25) in my cabin and have not had condensation on the foam even at -35f.

R7, data sheet attached.

Thickness is determined by the sprayer. Its a bit tricky because it continues to expand after application so takes some practice to get the fill thickness right. The local shop that did it tried to do a cavity fill once and it cost them a new van body.
Bond strength is about 50psi on a cleaned surface.

I was told by my shop it is fire retardant but had a pretty bad fire with the same stuff in a small enclosed space a few years ago. Its nasty when burnt.

 

[RV8R]

Friday was yesterday, Joe. Youre not fooling me.

There will be moisture, if it doesn't come from outside it will come from what you exhale or from cooking. Not sure where we disagree.

Nothing space age about it. Polyisocyanurate foam has been around since the 70s though its less flammable now.

I have the same foam (filled to R25) in my cabin and have not had condensation on the foam even at -35f.

R7, data sheet attached.

Thickness is determined by the sprayer. Its a bit tricky because it continues to expand after application so takes some practice to get the fill thickness right. The local shop that did it tried to do a cavity fill once and it cost them a new van body.
Bond strength is about 50psi on a cleaned surface.

I was told by my shop it is fire retardant but had a pretty bad fire with the same stuff in a small enclosed space a few years ago. Its nasty when burnt.

?

I don’t think we “disagree” ,,, You are saying he has to deal with interior “RH” & I am say the same thing ,,, & in a van with people breathing & cooking etc it has to be exhausted ,,, nothing quite like boiling water inside a van & keeping it inside.

Polyiso ? ,,, It is what I use. For some reason the photos you posted looked very thin not anywhere near 1” or more ,,, thus I thought you were promoting some “lizard skin product”.

in Canada the board Polyiso “foil faced” I use is “Enerfoil” R7 per inch

IKO Enerfoil® Sheathing - IKO Commercial Site 2024 Enerfoil - Foil Faced Rigid Insulation - Polyisocyanurate Board - IKO

Enerfoil is a non-permeable sheathing for cavity walls, stud walls or interior basements & can act as an all-in-one insulation or air & weather resistant barrier.

www.iko.com

Board Polyiso is “Factory Cured”


Here is some idea of what can go wrong “Field Curing” spray foam ,,, even by Commercial Applicators;

For a van, it can distort the thin sheet metal body “oil canning” effect if applied too aggressively. & can not field cure properly.. But it does fix the vapour barrier issue.


I have some spray foam in my own house & never had an issue ( It is a small area that begged for that application on a couple of sundecks that are roofs ).




Joe Saturday ?

 

[Gueyog8a7]

Would a heat duct and a fan pulling air from the roof down to the floor in the back of the van which seems to stay damp be effective?

I have the thermometer up in the headliner and it reads high temps 15-25c. So could I put the duct up there with a fan sucking and send the duct to the back of the van where the damp does not seem to shift? I am confused why it doesn't remove the damp back there. Given it is such a small van I would have expected the whole space to heat pretty quickly.

Anyway would the above suggestion produce be a good idea to circulate and recycle that warm air? I already bought the 100mm duct just didn't know what to do with it yet. Originally was going to put over the heater to direct it however since it is a stove not a normal diesel heater the heat exhaust is not a simple circle so would be quite a job to make an enclosed to capture that properly. I thought capturing from up high where it pools would be an easier way and pull it through with the spare fan I have.

 

[Reed Cole]

So it's something like this? The heat just comes off the cooktop? Definitely not as good as a regular heater that you mount on the floor, in terms of heating and forcing air movement.

Anything you can do to circulate the air will help.

 

[S Davis]

You are fighting a losing battle, you need to remove moisture. When you try and dry condensed moisture with air the air can’t already be saturated. By increasing temperature you make the air able to absorb more moisture but then you are going to have fully saturated air just at a higher temperature. This will also increase the condensation on cold surfaces. I do have some background in this area, I have 36 years in HVAC. This is one of the projects I handle humidity on.

 

[0truck0]

Would a heat duct and a fan pulling air from the roof down to the floor in the back of the van which seems to stay damp be effective?

I have the thermometer up in the headliner and it reads high temps 15-25c. So could I put the duct up there with a fan sucking and send the duct to the back of the van where the damp does not seem to shift? I am confused why it doesn't remove the damp back there. Given it is such a small van I would have expected the whole space to heat pretty quickly.

Anyway would the above suggestion produce be a good idea to circulate and recycle that warm air? I already bought the 100mm duct just didn't know what to do with it yet. Originally was going to put over the heater to direct it however since it is a stove not a normal diesel heater the heat exhaust is not a simple circle so would be quite a job to make an enclosed to capture that properly. I thought capturing from up high where it pools would be an easier way and pull it through with the spare fan I have.

If you have an area that seems to stay moist and needs ventilation then just a fan blowing on it, no heat needed, just the fresh aire should be enough. Fan can be very low speed, maybe even a computer fan.

 

[Checkthisout]

Would a heat duct and a fan pulling air from the roof down to the floor in the back of the van which seems to stay damp be effective?

No

I have the thermometer up in the headliner and it reads high temps 15-25c. So could I put the duct up there with a fan sucking and send the duct to the back of the van where the damp does not seem to shift? I am confused why it doesn't remove the damp back there. Given it is such a small van I would have expected the whole space to heat pretty quickly.

Imagine trying to dry out an evaporator coil of an a/c system by blowing air across it. The uninsulated steel of your van combined with 100% saturated air (its raining) is nothing more than blowing air onto an evaporator coil.

You need a dehumidifier or insulate.

Anyway would the above suggestion produce be a good idea to circulate and recycle that warm air? I already bought the 100mm duct just didn't know what to do with it yet. Originally was going to put over the heater to direct it however since it is a stove not a normal diesel heater the heat exhaust is not a simple circle so would be quite a job to make an enclosed to capture that properly. I thought capturing from up high where it pools would be an easier way and pull it through with the spare fan I have.

Circulating warm, wet air will do nothing to dry the space out.

 

[Gueyog8a7]

So it's something like this? The heat just comes off the cooktop? Definitely not as good as a regular heater that you mount on the floor, in terms of heating and forcing air movement.

Anything you can do to circulate the air will help.

Why "definitely not as good". The wattage is rated at the same and it does have a fan to force the air around. The only difference is it is not coming out of a cylindrical hole but rather a flat letterbox shaped aperture.

 

[Gueyog8a7]

If you have an area that seems to stay moist and needs ventilation then just a fan blowing on it, no heat needed, just the fresh aire should be enough. Fan can be very low speed, maybe even a computer fan.

No


Imagine trying to dry out an evaporator coil of an a/c system by blowing air across it. The uninsulated steel of your van combined with 100% saturated air (its raining) is nothing more than blowing air onto an evaporator coil.

You need a dehumidifier or insulate.



Circulating warm, wet air will do nothing to dry the space out.

Lol so many conflicting opinions.

 

[Checkthisout]

Lol so many conflicting opinions.

Insulate or get a dehumidifier or deal with the moisture until it stops raining.

The 5 stages of grief will lead you to these 3 conclusions.

 

[Reed Cole]

Why "definitely not as good". The wattage is rated at the same and it does have a fan to force the air around. The only difference is it is not coming out of a cylindrical hole but rather a flat letterbox shaped aperture.

Heat usually works better when it's coming from the floor, rather than counter height. Like it will actually heat the floor, you don't have to try to recirculate the air to heat the areas below your heater.